[Federal Register Volume 89, Number 150 (Monday, August 5, 2024)]
[Notices]
[Pages 63473-63490]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-17251]


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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

[Docket No. NHTSA-2023-0038]


Supplemental Initial Decision That Certain Frontal Driver and 
Passenger Air Bag Inflators Manufactured by ARC Automotive Inc. and 
Delphi Automotive Systems LLC, and Vehicles in Which Those Inflators 
Were Installed, Contain a Safety Defect

AGENCY: National Highway Traffic Safety Administration (NHTSA), 
Department of Transportation (DOT).

ACTION: Notice of supplemental initial decision; request for public 
comments.

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SUMMARY: NHTSA is confirming its initial decision that certain frontal 
driver and passenger air bag inflators manufactured by ARC Automotive 
Inc. and Delphi Automotive Systems LLC, and vehicles in which those 
inflators were installed, contain a defect related to motor vehicle 
safety. NHTSA is issuing this supplemental initial decision to address 
in greater detail the basis for the agency's initial decision and to 
ensure that all vehicles and manufacturers that would be impacted by 
any recall order are included within the scope of the initial decision.

DATES: Comments must be received on or before September 4, 2024.

ADDRESSES: You may submit written submissions to the docket number 
identified in the heading of this document by any of the following 
methods:
     Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the online instructions for submitting 
comments.
     Mail: Docket Management Facility: U.S. Department of 
Transportation, 1200 New Jersey Avenue SE, West Building Ground Floor, 
Room W12-140, Washington, DC 20590-0001.
     Hand Delivery or Courier: 1200 New Jersey Avenue SE, West 
Building Ground Floor, Room W12-140, between 9 a.m. and 5 p.m. ET, 
Monday through Friday, except Federal holidays.
     Fax: (202) 493-2251.
    Instructions: All submissions must include the agency name and 
docket number. Note that all written submissions received will be 
posted without change to https://www.regulations.gov, including any 
personal information provided. Please see the Privacy Act discussion 
below. We will consider all written submissions received before the 
close of business on September 4, 2024.
    Docket: For access to the docket to read background documents or 
written submissions received, go to https://www.regulations.gov at any 
time or to 1200 New Jersey Avenue SE, West Building Ground Floor, Room 
W12-140, Washington, DC 20590, between 9 a.m. and 5 p.m., Monday 
through Friday, except Federal holidays. Telephone 202-366-9826.
    Privacy Act: In accordance with 49 U.S.C. 30118(b)(1), NHTSA will 
make a final decision only after providing an opportunity for 
manufacturers and any interested person to present information, views, 
and arguments. DOT posts written submissions submitted by manufacturers 
and

[[Page 63474]]

interested persons, without edit, including any personal information 
the submitter provides, to www.regulations.gov, as described in the 
system of records notice (DOT/ALL-14 Federal Docket Management System 
(FDMS)), which can be reviewed at www.transportation.gov/privacy.
    Confidential Business Information: If you wish to submit any 
information under a claim of confidentiality, you must submit your 
request directly to NHTSA's Office of the Chief Counsel. Requests for 
confidentiality are governed by 49 CFR part 512. NHTSA is currently 
treating electronic submission as an acceptable method for submitting 
confidential business information (CBI) to the agency under part 512. 
If you would like to submit a request for confidential treatment, you 
may email your submission to Allison Hendrickson in the Office of the 
Chief Counsel at [email protected] or you may contact her for 
a secure file transfer link. At this time, you should not send a 
duplicate hardcopy of your electronic CBI submissions to DOT 
headquarters. If you claim that any of the information or documents 
provided to the agency constitute confidential business information 
within the meaning of 5 U.S.C. 552(b)(4) or are protected from 
disclosure pursuant to 18 U.S.C. 1905, you must submit supporting 
information together with the materials that are the subject of the 
confidentiality request, in accordance with part 512, to the Office of 
the Chief Counsel. Your request must include a cover letter setting 
forth the information specified in NHTSA's confidential business 
information regulation (49 CFR 512.8) and a certificate, pursuant to 
Sec.  512.4(b) and part 512, appendix A. In addition, you should submit 
a copy, from which you have redacted the claimed confidential business 
information, to the Docket at the address given above.

FOR FURTHER INFORMATION CONTACT: Allison Hendrickson, Office of the 
Chief Counsel, National Highway Traffic Safety Administration, 1200 New 
Jersey Avenue SE, Washington, DC 20590; (202) 366-2992.
    The publicly available information on which this supplemental 
initial decision is based is available on the agency's website at 
https://www.nhtsa.gov/recalls?nhtsaId=EA16003, https://www.nhtsa.gov/recalls?nhtsaId=PE15027, and on the public docket under Docket No. 
NHTSA-2023-0038.
    The information in the investigative file for which confidential 
treatment has been requested was shared with the manufacturers that 
would be affected in the event of a recall order, as required under 49 
U.S.C. 30118(a) and 49 CFR 554.10(b). That information was shared with 
the manufacturers under a protective agreement. The information subject 
to confidentiality requests remains unredacted in this document 
pursuant to 49 U.S.C. 30167(b). File-path citations to the 
investigative file have been shared with the manufacturers in a 
confidential appendix to this decision.

SUPPLEMENTARY INFORMATION: Pursuant to 49 U.S.C. 30118(a) and 49 CFR 
554.10, NHTSA confirms its initial decision that certain frontal driver 
and passenger air bag inflators manufactured by ARC Automotive Inc. 
(ARC) and Delphi Automotive Systems LLC (Delphi), and vehicles in which 
those inflators were installed, contain a defect related to motor 
vehicle safety.
    NHTSA previously issued an initial decision on September 5, 
2023.\1\ After additional consideration of the totality of the 
evidence, including comments previously submitted in this proceeding, 
NHTSA is issuing this supplemental initial decision to address in 
greater detail the basis for the agency's initial decision and to 
ensure that all vehicles and vehicle manufacturers that would be 
impacted by any recall order are included within the scope of the 
initial decision. This action allows for additional transparency and 
additional comment from any interested persons.\2\
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    \1\ 88 FR 62140 (Sept. 8, 2023).
    \2\ NHTSA is addressing certain comments in this supplemental 
initial decision to describe the basis of its initial decision more 
fully and, in certain instances, to update certain information, 
including its calculation of predicted future ruptures. NHTSA 
reviewed and considered all written and oral comments previously 
submitted in this proceeding. NHTSA intends to further and more 
fully address all comments it ultimately receives if and when it 
issues a final decision in this proceeding.
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    The additional information provided in this notice confirms the 
agency's initial decision that certain frontal driver- and passenger-
side hybrid toroidal air bag inflators manufactured by ARC and Delphi 
from 2000 through the full implementation of the automated borescope 
(the subject inflators) contain a defect related to motor vehicle 
safety. The implementation of the borescope, beginning in August of 
2017, was fully completed in June of 2018. The latter date is a 
correction from the January 2018 completion date identified in the 
September 5, 2023 initial decision.\3\
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    \3\ ARC completed implementation of the automated borescope 
process on lines producing PH7 inflators (which are passenger-side 
inflators) in January 2018, and then completed implementation on the 
remaining lines producing toroidal inflators in June 2018.
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    Based on available information, approximately 51 million subject 
inflators were manufactured and installed in approximately 49 million 
vehicles in the United States.\4\ The subject inflators were 
incorporated into air bag modules manufactured by five air bag module 
suppliers and ultimately used in vehicles manufactured by 13 vehicle 
manufacturers: BMW of North America, LLC (BMW), FCA US LLC (FCA), Ford 
Motor Company (Ford), General Motors LLC (GM), Hyundai Motor America, 
Inc. (Hyundai), Jaguar Land Rover North America (JLR), LLC, Kia 
America, Inc. (Kia), Maserati North America, Inc., Mercedes-Benz USA 
LLC, Porsche Cars North America, Inc. (Porsche), Tesla Inc., Toyota 
Motor North America, Inc. (Toyota), and Volkswagen Group of America, 
Inc. (Volkswagen).\5\ Although JLR was not included in the September 
2023 initial decision, the agency has confirmed that it has vehicles in 
the U.S. with the subject inflators.
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    \4\ While the correction to June 2018 increases the number of 
subject inflators, based on best available information, the agency 
is adjusting its estimate to approximately 51 million inflators. The 
exact number of recalled inflators and vehicles would be confirmed 
by the manufacturers as part of any recall filings that may result.
    \5\ In the event of a recall order, BMW would be responsible for 
recalling vehicles manufactured by Rolls Royce Motor Cars, General 
Motors would be responsible for recalling vehicles manufactured by 
Isuzu Motors Limited, and Volkswagen would be responsible for 
recalling vehicles manufactured by Audi AG.
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    These air bag inflators are at risk of rupturing when the vehicle's 
air bag is commanded to deploy, causing metal debris to be forcefully 
ejected into the occupant compartment of the vehicle. A rupturing air 
bag inflator poses an unreasonable risk of serious injury or death to 
vehicle occupants. At least seven people have been injured and one 
person has been killed by these rupturing air bag inflators within the 
United States. NHTSA has identified evidence during its investigation 
that connects these ruptures to the friction welding process, which has 
created, in some instances, blockage material, including excessive weld 
flash, and, in others, insufficient friction weld bonds. Upon air bag 
deployment, any loose debris in the center support, including weld 
flash, can block the exit orifice, causing over-pressurization and 
rupture. Additionally, friction welds with insufficient bonds have also 
led to inflator ruptures. The same friction welding process was used 
across ARC and Delphi's various manufacturing plants and lines to 
produce the subject inflators. When an inflator ruptures, shrapnel or 
metal fragments from the

[[Page 63475]]

inflator are forcefully propelled through the air bag cushion and into 
the occupant compartment. Additional inflator ruptures are expected to 
occur in the future, risking more serious injuries and deaths, if they 
are not recalled and replaced.

I. Investigation and Proceeding Background

    On July 13, 2015, NHTSA's Office of Defects Investigation (ODI) 
opened a Preliminary Evaluation (PE) defect investigation, designated 
PE15-027, to investigate an alleged safety defect in hybrid toroidal 
inflators designed by ARC and manufactured by ARC and Delphi for use in 
vehicles sold or leased in the United States. NHTSA opened the 
investigation after receiving reports of ruptures in vehicles (field 
ruptures). Specifically, driver-side air bag inflators in a model year 
(MY) 2002 Chrysler Town & Country and a MY 2004 Kia Optima ruptured 
upon air bag deployment during crashes.
    In the early stages of the investigation, NHTSA collected 
information from ARC regarding the design and manufacturing process for 
frontal driver- and passenger-side hybrid toroidal inflators. Frontal 
driver-side and passenger-side inflators are used to inflate air bags 
immediately in front of vehicle occupants in those seats. A hybrid 
inflator uses stored gas that is excited by propellant to fill the air 
bag cushion, and toroidal inflators are round, non-cylindrical 
inflators. NHTSA's investigation involved both single-stage and dual-
stage inflators. Single-stage inflators deploy at a preset speed and at 
full force. Dual-stage inflators deploy at two different stages 
depending on the size of the occupant as measured by the load sensor in 
the front seat and the severity of the impact.\6\ ARC licensed its 
design and manufacturing specifications to Delphi, which manufactured 
approximately 11 million of the approximate 51 million subject 
inflators using the same friction welding process at issue.\7\ ARC 
manufactured the other subject inflators at several different 
manufacturing facilities.
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    \6\ The two inflation stages can deploy sequentially or 
simultaneously. Typically, the first stage is approximately 80% of 
the full force of the air bag, and the second stage is approximately 
20% of the full force of the air bag. The second stage can deploy 
simultaneously with the first stage should the severity of the 
impact warrant dual deployment. The second stage can deploy 
subsequent to the deployment of the first stage for lower severity 
impacts.
    \7\ Delphi stopped manufacturing the inflators in 2004. The 
Delphi entity that manufactured these inflators no longer exists. 
NHTSA indicated in its April 27, 2023 recall request letter that the 
entity was acquired by Autoliv ASP, Inc. (``Autoliv''). Autoliv has 
since provided NHTSA with some information indicating that it may 
not have legal liability for the Delphi-manufactured inflators. At 
this time, NHTSA has not verified the entity that has legal 
responsibility under 49 U.S.C. chapter 301 for those inflators. 
However, regardless of that responsibility, the vehicle 
manufacturers that used the inflators as original equipment would be 
responsible for carrying out any recalls.
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    NHTSA learned that, based on ARC's inflator design, part of the 
manufacturing process for these inflators involves a welding method 
known as friction welding. Through this method, once certain pieces of 
the inflator are ready to be joined together, they are aligned. One 
piece is held stationary while the other is rotated at a high velocity 
and simultaneously pressed together with the stationary piece. The 
friction generated by the high-velocity rotation creates heat, which 
melts the metal. Once the proper temperature has been reached, the 
rotation is stopped, and the pressure is increased to weld the parts 
together. Each inflator undergoes three friction welds at two points in 
the manufacturing process.\8\ Friction welding produces a byproduct 
called ``weld flash'' or ``weld slag'' that accumulates along the weld 
seam. In an attempt to prevent weld flash from blocking the gas flow 
during deployment, a pin, known as a flash-dam pin, is inserted through 
the exit orifice during the friction welding process between the center 
support and upper half of the inflator housing. The flash-dam pin is 
removed after the weld is complete. This friction welding process was 
used in all five ARC plants where the subject inflators were made--
located in Knoxville, Tennessee; Reynosa, Mexico; Xi'an, China; Ningbo, 
China; and Skopje, Macedonia--and on all manufacturing lines that 
produced the subject inflators. It was also used by Delphi when it 
produced subject inflators under a license agreement.
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    \8\ See ARC Presentation on CADH Inflator Design; ARC 
Presentation on PH7 Inflator Process Details.
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    During a crash that triggers an air bag deployment, a signal is 
sent to the inflator. When it receives this signal, the inflator's 
initiator ignites the propellant that is stored inside the inflator.\9\ 
The propellant burns and excites pressurized gas stored in the 
inflator.\10\ To fill the air bag cushion, the gas flows through the 
inflator's hollow center support and exits through the exit orifice at 
the top of the center support.\11\ The inflator's exit orifice is the 
single path for the gas to exit the inflator and fill the air bag 
cushion. If the exit orifice is blocked during deployment such that the 
gas cannot escape, the inflator will likely over-pressurize and 
rupture. In this event, the center support typically elongates, splits 
into two pieces, and ejects from the inflator housing. These 
characteristics indicate that a rupture was caused by over-
pressurization of the inflator.\12\ In some instances, the blockage can 
still be seen in the upper half of the center support after the 
rupture. In others, the blockage may become knocked loose by the force 
of the rupture but can leave small indentations on the edge of the exit 
orifice, which are known as ``witness marks.'' \13\
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    \9\ See ARC Response to Request 1 of NHTSA Aug. 25, 2015 IR 
Letter at p. 16.
    \10\ See id.
    \11\ See id.
    \12\ See ARC Presentation dated Mar. 1, 2016 on MY 2004 Kia 
Optima Rupture at pp. 5, 22; ARC Presentation dated Aug. 25, 2017 on 
SGO 2016-01/2017-01 Report 39 at pp. 6, 11, 37; ARC Response to 
Request 1 of NHTSA Aug. 25, 2015 IR Letter at p. 72.
    \13\ See ARC Presentation dated Apr. 1, 2017 on SGO 2016-01/
2017-01 Report 80 at pp. 8-11; ARC Presentation dated Nov. 10, 2017 
on SGO 2016-01/2017-01 Report 120 at p. 7; ARC Presentation dated 
Apr. 5, 2017 on SGO 2016-01/2017-01 Report 130 at pp. 8-11; ARC 
Presentation dated Nov. 8, 2017 on SGO 2016-01/2017-01 Report 178 at 
pp. 13-14.
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    During the PE phase of the investigation, NHTSA collected a list of 
air bag module (or Tier 1) manufacturers to which ARC sold the 
inflators from 2000 through 2004, which covered the timeframe between 
when ARC had begun manufacturing hybrid toroidal inflators and the 
manufacture dates of the two inflators that ruptured in vehicles. NHTSA 
then obtained information from the air bag module manufacturers to 
identify the vehicle manufacturers that had purchased those air bag 
modules and incorporated them into their vehicles. In addition, NHTSA 
ordered vehicle and inflator manufacturers, including ARC, to report 
any alleged or suspected inflator field rupture under Standing General 
Orders (SGO) 2015-01 and 2015-02.\14\ Manufacturers subject to these 
orders must submit an initial report upon notification of an alleged 
field rupture incident, as well as ongoing supplemental reports as the 
investigation into the incident progresses and until it is complete.
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    \14\ Those orders were not limited to ARC or the vehicle 
manufacturers that used ARC inflators. They were intended to help 
NHTSA learn of any alleged inflator ruptures, including inflators 
not designed or manufactured by ARC. Since their original issuance, 
these orders have been updated and superseded by SGO 2015-01A and 
SGO 2015-02A. https://static.nhtsa.gov/odi/inv/2015/INLM-EA15001-62640.pdf; https://static.nhtsa.gov/odi/inv/2015/INLM-EA15001-62642.pdf.
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    On July 11, 2016, an ARC-manufactured inflator in a MY 2009 Hyundai 
Elantra ruptured in Canada. The driver was killed. ARC confirmed that 
this inflator was manufactured using the same manufacturing processes

[[Page 63476]]

described above in this section. ODI upgraded the investigation to an 
Engineering Analysis, designated EA16-003, on August 4, 2016. During 
this phase of the investigation, ODI issued information request letters 
to ARC, Delphi, air bag module manufacturers, and vehicle manufacturers 
in 2016, 2020, 2021, and 2022. These letters requested information for 
an expanded timeframe on the production volume of the subject 
inflators, air bag modules with the subject inflators and vehicles with 
the subject inflators, testing procedures and results, complaints, and 
air bag deployments.
    Also during this phase of the investigation, NHTSA issued Standing 
General Order 2016-01. Standing General Order 2016-01 required ARC to 
notify the agency of non-field ruptures of inflators. It was superseded 
by SGO 2017-01, which revised the reportable rupture incidents to 
include only those occurring during lot acceptance tests. Lot 
acceptance tests (also referred to as ``LATs'') are random tests of 
completed air bag inflators produced for use in consumer vehicles.\15\ 
If an inflator ruptures or fails in some way during a lot acceptance 
test, the entire lot of inflators is quarantined. Under these SGOs, ARC 
reported thirty-four ruptures of frontal driver- and passenger-side 
hybrid toroidal inflators during lot acceptance testing.\16\
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    \15\ A lot acceptance test is conducted at the beginning, 
middle, and end of a manufacturing shift, or at any time the 
assembly line is shifted to production of a different part. The term 
``lot'' refers to the inflators that were manufactured in an 
identified manufacturing plant on a specific assembly line for a 
specific shift.
    \16\ Two vehicle manufacturers have conducted small inflator 
recalls associated with lot acceptance testing. First, BMW recalled 
thirty-six vehicles after learning that the production lot in which 
there had been a rupture was not fully contained, and some inflators 
from the lot were shipped by ARC to a module supplier and ultimately 
were incorporated into vehicles. NHTSA Recall Nos. 17V-189 
(describing the safety risk as ``impaired gas flow could create 
excessive internal pressure, which could result in the body of the 
inflator rupturing upon deployment''). Second, Ford recalled 650 
vehicles after its air bag module supplier notified Ford of ``an 
abnormal deployment'' of an inflator during a lot acceptance test at 
the supplier's engineering facility. NHTSA Recall Nos. 17V-529 
(``Preliminary analysis indicates that weld flash from the inflator 
canister welding process at the Tier 2 inflator supplier may 
obstruct the gas exhaust port.'').
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    ARC's lot acceptance testing process evidenced a problem, but the 
problem was not addressed by actions limited to specific lots. Since 
NHTSA issued SGOs 2015-01 and 2015-02, manufacturers have reported to 
the agency and confirmed five ruptures in vehicles in the United States 
of ARC-manufactured frontal driver- and passenger-side hybrid toroidal 
inflators, for a total of seven confirmed field ruptures in the United 
States, plus the fatal rupture in Canada. In response to some of the 
field ruptures, the relevant vehicle manufacturer issued a small recall 
targeted at the production lot of the ruptured inflator.\17\ Such 
recalls, like the quarantine process for lot acceptance test ruptures, 
are premised on the idea that there is some sort of manufacturing 
problem limited to that short period of production at that particular 
facility. As detailed below, however, the evidence collected in NHTSA's 
investigation shows that ruptures have occurred in inflators 
manufactured across different time periods, plants, and manufacturing 
lines, thus warranting a broader recall.
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    \17\ See NHTSA Recall Nos. 19V-019 (recalling 1,145 vehicles), 
21V-782 (recalling 555 vehicles), 22E-040 (recalling 74 replacement 
air bag modules), 22V-246 (recalling 2,687 vehicles), and 22V-543 
(recalling 1,216 vehicles). Following the most recent rupture, GM 
also expanded on its earlier lot recalls by recalling four model 
years of three vehicle makes. NHTSA Recall No 23V-334.
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    In a recall request letter sent to ARC on April 27, 2023, the 
agency tentatively concluded that the subject inflators present a 
defect related to motor vehicle safety.\18\ NHTSA explained that a 
defect resulting in metal fragments being projected toward vehicle 
occupants creates an unreasonable risk of death and injury.\19\ The 
agency, therefore, demanded that ARC file a recall identifying the 
subject inflators as defective.\20\ In its response on May 11, 2023, 
ARC described the seven U.S. field ruptures as ``random `one-off' 
manufacturing anomalies'' that had been properly addressed by the lot 
recalls.\21\ ARC refused to acknowledge the safety defect or file a 
recall.\22\
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    \18\ See NHTSA Recall Request Letter to ARC, https://static.nhtsa.gov/odi/inv/2016/INRM-EA16003-90615.pdf.
    \19\ See id.
    \20\ See id.
    \21\ See ARC Response to NHTSA Recall Request Letter, https://static.nhtsa.gov/odi/inv/2016/INRR-EA16003-90616.pdf at p. 2.
    \22\ See id. at p. 1.
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    When a safety defect exists in original equipment used by more than 
one vehicle manufacturer, as in this case, the equipment supplier and 
each vehicle manufacturer must notify the agency by filing a recall 
report. 49 CFR 573.3(f). A defect in original equipment (meaning 
equipment originally installed in or on a vehicle) is considered a 
defect in the vehicle. 49 U.S.C. 30102(b)(1)(C), (F). Therefore, 
vehicle manufacturers are generally responsible for carrying out 
recalls of their vehicles containing defective parts, such as air bag 
inflators, by notifying vehicle owners and providing a free remedy. See 
id. sections 30118-20. An equipment manufacturer is also responsible 
under the Safety Act for recalling its replacement equipment. See id. 
30118. Replacement equipment is ``motor vehicle equipment . . . that is 
not original equipment.'' Id. section 30102(b)(1)(D).
    The National Traffic and Motor Vehicle Safety Act (Safety Act) 
imposes an affirmative obligation on a manufacturer to initiate a 
recall if it ``learns the vehicle or equipment contains a defect and 
decides in good faith that the defect is related to motor vehicle 
safety.'' Id. section 30118(c)(1). To date, the manufacturers of the 
subject inflators, and the manufacturers of the vehicles containing the 
subject inflators, have not commenced broader recalls addressing the 
full scope of the problem. Thus, NHTSA is using its authority under the 
Safety Act to consider ordering a recall.
    The Safety Act authorizes NHTSA to order a recall when the 
Administrator \23\ determines that a vehicle or replacement equipment 
``contains a defect related to motor vehicle safety.'' Id. section 
30118(b). The Safety Act defines a ``defect'' as ``any defect in 
performance, construction, a component, or material of a motor vehicle 
or motor vehicle equipment.'' Id. section 30102(a)(3). A defect is 
related to motor vehicle safety if it presents an unreasonable risk of 
an accident or of death or serious injury in an accident. Id. section 
30102(a)(9).
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    \23\ As authorized by statute, the Secretary has delegated the 
authority in the Safety Act to the NHTSA Administrator. 49 U.S.C. 
105(d); 49 CFR 1.95(a). In the absence of an Administrator, the 
Deputy Administrator performs the functions and duties of the 
Administrator. 49 CFR 501.4(a), 501.5(a).
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    Before it can order a recall, the agency first issues an initial 
decision finding a defect in a vehicle or replacement equipment, 
notifies the manufacturer of the decision and provides it with the 
information on which the decision was based, and publishes notice of 
the decision in the Federal Register. Id. section 30118(a); 49 CFR 
554.10. The manufacturer and the public are afforded an opportunity to 
present information, views, and arguments at a public meeting, in 
written comments, or both. 49 CFR 554.10. After considering the 
available information, the Administrator may make a final decision 
finding a safety defect and ordering a recall. 49 U.S.C. 30118(b); 49 
CFR 554.11.
    In the instant proceeding, NHTSA issued an initial decision of a 
safety defect on September 5, 2023 regarding frontal driver- and 
passenger-side hybrid toroidal inflators manufactured

[[Page 63477]]

by ARC and Delphi from 2000 through January 2018. 88 FR 62140 (Sept. 8, 
2023). NHTSA held a public meeting on October 5, 2023, during which the 
agency presented information about its investigation and initial 
decision, and manufacturers and members of the public were invited to 
make their own statements.\24\ ARC and certain other members of the 
public, including the son of the person killed by a subject inflator 
rupture, made statements at the public meeting.\25\ NHTSA also provided 
manufacturers and the public the opportunity to submit written comments 
in response to the initial decision,\26\ which were due December 18, 
2023.\27\
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    \24\ See Public Meeting Transcript and Addenda, Docket No. 
NHTSA-2023-0038, https://www.regulations.gov/document/NHTSA-2023-0038-0003.
    \25\ Id.
    \26\ Public versions of all written comments are posted on the 
public docket at https://www.regulations.gov/docket/NHTSA-2023-0038/comments.
    \27\ See Second Extension of Deadline for Written Submissions, 
https://www.regulations.gov/document/NHTSA-2023-0038-0005.
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II. Initial Determination of Defect Related to Motor Vehicle Safety

    After further consideration of all available information, including 
from its investigation and this proceeding, NHTSA is confirming its 
initial determination that the subject inflators contain a defect and 
that the defect is related to motor vehicle safety. The subject 
inflators may rupture upon deployment and project shrapnel into the 
occupant compartment, which is likely to cause and has caused serious 
injury and death to vehicle occupants.

A. The Subject Inflators Are Defective

    Air bag inflators that have an established risk of rupturing when 
commanded to deploy are defective within the meaning of the Safety Act. 
The Safety Act defines ``defect'' as including ``any defect in 
performance, construction, a component, or material of a motor vehicle 
or motor vehicle equipment.'' 49 U.S.C. 30102(a)(3). ``Defect'' must be 
understood by its plain meaning: a flaw, shortcoming, or 
abnormality.\28\ An inflator that is at risk of rupturing when 
commanded to deploy is flawed. It turns a lifesaving device into one 
that can do great harm, including causing death or serious injury.
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    \28\ https://www.merriam-webster.com/dictionary/defect.
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    Air bags and related components can be defective in multiple ways. 
Among other things, the air bag may fail to deploy when appropriate, 
deploy when it should not, or only partially deploy. All of these 
defects are issues that the agency takes seriously and that have 
resulted in recalls.\29\ An air bag inflator that has a risk of 
rupturing when commanded to deploy--sending shrapnel into the occupant 
compartment--presents a particularly dangerous type of defect. This is 
why the industry standard calls for tests to confirm that ``an inflator 
shall not eject any components or fragments.'' \30\ In other words, an 
inflator rupture is not an industry-accepted failure mode.
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    \29\ See, e.g., NHTSA Recall 24V-064 (recall issued by Honda 
addressing air bags that may deploy in a crash when they should have 
been suppressed); NHTSA Recall 23V-865 (recall issued by Toyota 
addressing air bags that may not deploy in a crash when intended); 
NHTSA Recall No. 12V-055 (recall issued by Nissan for vehicles 
equipped with curtain air bags with incorrect propellant mixture, 
possibly resulting in partial deployment); NHTSA Recall No. 01V-318 
(recall issued by Ford for vehicles with replacement inflators 
having insufficient welds, possibly preventing proper inflation of 
the air bag).
    \30\ See USCAR Inflator Technical Requirements and Validation, 
p. 7 ] 3.2.2 (SAE Int'l, 2023). See also USCAR Inflator Technical 
Requirements and Validation, p. 10 ] 3.2.2 (SAE Int'l, 2013).
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    The subject inflators exhibit this especially dangerous defect, 
which warrants NHTSA's taking the significant step of proposing to 
order a recall. To date, there have been seven confirmed field ruptures 
of the subject inflators in vehicles in the United States, each of 
which presented evidence of over-pressurization or weld insufficiency 
as a likely cause of the failure. In addition, there have been twenty-
three reported ruptures during lot acceptance testing that share over-
pressurization or weld insufficiency commonalities with the seven field 
ruptures. Moreover, at least an additional four inflators have ruptured 
in vehicles outside the United States, killing at least one person.
    To be sure, the overwhelming majority of the subject inflators will 
not rupture upon deployment. However, based on the evidence linking 
past ruptures to the same friction welding process, all of the subject 
inflators are at risk of rupturing. The unpredictable nature of this 
defect has played out with some inflators passing lot acceptance 
testing but later rupturing in a vehicle and causing injury or death. 
The only way to know which of the subject inflators remaining in 
vehicles will rupture is for them to deploy. The Safety Act does not 
allow such a defect to go unaddressed.
    In recognition of the commonsense understanding that an inflator 
that may rupture is defective, some vehicle manufacturers have already 
issued limited recalls following field ruptures.\31\ This approach is 
insufficient to address the defect. The evidence shows that the risk of 
rupture pervades the entire subject inflator population and, as such, a 
recall for all subject inflators is needed. Ruptures have continued to 
occur outside the scope of these lot-based recalls and in lots that 
passed lot acceptance testing. There is no reasonable basis to conclude 
that the recalls issued to this point have captured the full scope of 
the defect. Instead, NHTSA has preliminarily concluded, based on the 
available evidence, that all the subject inflators are defective.
---------------------------------------------------------------------------

    \31\ After the most recent rupture, GM apparently recognized 
that a lot-based recall was no longer sufficient. However, the 
ensuing recall was limited to specific model years and models of 
vehicles and fails to address the full population of GM vehicles 
containing the subject inflators. See Recall No. 23V-334 (recalling 
2014-2017 Buick Enclave, Chevrolet Traverse, and GMC Acadia 
vehicles).
---------------------------------------------------------------------------

    Whether there is a ``defect'' depends on the specific facts and 
circumstances of each case, including the nature of the component 
involved and its importance to the safe operation of the vehicle, the 
circumstances in which failures occurred, and the number of failures 
experienced. U.S. v. General Motors Corp., 518 F.2d 420, 427, 438 n.84 
(D.C. Cir. 1975) (``Wheels''). Considering all of the available 
information, NHTSA finds that there is sufficient evidence that the 
total population of subject inflators is defective within the meaning 
of the Safety Act.
1. An Air Bag Is Critical to the Safe Operation of a Vehicle
    Factors to be considered in determining whether a defect exists 
include the relationship between the component and safe vehicle 
operation and the circumstances of the failures involved. An air bag is 
vital to the safe operation of a vehicle. It is a required safety 
device.\32\ In the event of a crash where the air bag is commanded to 
deploy, which can include a minor crash, the air bag helps protect the 
occupant's upper body and head from impact with hard objects such as 
the windows, dashboard, and steering wheel. NHTSA estimates that air 
bags saved more than fifty thousand lives between 1987 and 2017. The 
defect in this case turns this life-saving purpose on its head, instead 
introducing a risk of serious injury or death from flying metal 
fragments ejected into the occupant compartment. As described below in 
section II.A.3, rupturing inflators have caused severe injuries, the 
most common of which are injuries to

[[Page 63478]]

the face, head, jaw, and neck. In three instances, a piece of the 
inflator became lodged in the driver's neck or arm and had to be 
surgically removed.\33\ In another, the shrapnel caused permanent 
muscle and nerve damage to the driver.\34\ In two instances, the driver 
died after being struck by a piece of the inflator. By forcefully 
propelling metal shrapnel into the occupant compartment, often aimed 
directly at an occupants' face, the rupturing inflator creates a high 
risk of severe injury or death, potentially converting a minor crash 
into a life-threatening event.
---------------------------------------------------------------------------

    \32\ Federal Motor Vehicle Safety Standard 208 sets requirements 
for occupant crash protection, including air bags. 49 CFR 571.208.
    \33\ See Email dated Apr. 5, 2023 to NHTSA from Hurley Medical 
Center; Photos attached to email dated Apr. 5, 2023 to NHTSA from 
Hurley Medical Center; Medical Discharge Summaries, Report ID 
****8352 at p. 3; Information package provided by the Saudi Ministry 
of Commerce and Industry; Hyundai Report submitted for MY 2011 
Hyundai Elantra Rupture.
    \34\ See VOQ dated Dec. 20, 2014.
---------------------------------------------------------------------------

    The circumstances in which these failures occur are also severe. 
The ruptures occur with no warning to the driver or other vehicle 
occupants.\35\ A vehicle owner can neither prevent this failure from 
occurring nor take action to mitigate the severity of its outcome, 
given the rapid pace of an air bag deployment and the already 
vulnerable position of the occupants in the midst of a collision. A 
vehicle's air bags can deploy even in minor crashes, meaning this 
defect can turn an incident from which the occupants could have walked 
away unscathed into one that will likely cause serious injury or death. 
There is no way for a vehicle owner, or anyone else, to know that a 
particular subject inflator will rupture until it is too late. The 
safety of vehicle occupants is significantly compromised by the rupture 
of the subject inflators--a considerable factor in the agency's 
determination that the subject inflators are defective under the Safety 
Act.
---------------------------------------------------------------------------

    \35\ Severity, frequency, and detectability are factors that 
NHTSA and manufacturers consider when deciding whether there is a 
safety defect requiring a recall. See Risk-Based Process for Safety 
Defect Analysis and Management of Recalls, DOT HS 812 984 (Nov. 
2020), https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/14895_odi_defectsrecallspubdoc_110520-v6a-tag.pdf. These factors are 
interrelated so high severity and non-detectible failures warrant a 
recall with a lower frequency of occurrence. See id.
---------------------------------------------------------------------------

2. Problems That Lead to Over-Pressurization and Weld Failure May Be 
Present Throughout the Entire Population of Inflators
    While the actual occurrence of ruptures is rare, the subject 
inflators' risk of rupture nevertheless constitutes a defect, 
especially when considering the nature and purpose of an inflator and 
the severity of the risk to vehicle occupants. For a component that is 
designed to function without replacement, courts have found that a 
defect may be established by showing that a significant--or non-de 
minimis--number of failures occurred in normal operation. E.g., Wheels, 
518 F.2d at 427, 438 n.84. As mentioned in the section above, the 
number of failures is one of the factors among the various facts and 
circumstances that assists in the agency's determination of whether 
there is a defect related to motor vehicle safety, requiring a recall. 
Indeed, ``[t]he purpose of the Safety Act . . . is not to protect 
individuals from the risks associated with defective vehicles only 
after serious injuries have already occurred; it is to prevent serious 
injuries stemming from established defects before they occur.'' United 
States v. General Motors Corp., 565 F.2d 754, 759 (D.C. Cir. 1977) 
(``Carburetors'').
    Air bags are not subjected to wear and do not require maintenance. 
As such, they are not replaced unless and until they deploy. The 
subject inflators are hermetically sealed, protecting the interior from 
elements that may cause propellant degradation.\36\ Nevertheless, 
ruptures have continued to occur despite manufacturers' assertions that 
narrower recalls have addressed the safety defect. NHTSA's 
investigation and analysis of the ruptures supports its preliminary 
determination that all subject inflators are at risk of rupturing and, 
therefore, contain a defect.
---------------------------------------------------------------------------

    \36\ See USCAR Inflator Technical Requirements and Validation at 
] 3.2.11 (SAE Int'l, 2023).
---------------------------------------------------------------------------

    During its investigation, NHTSA obtained evidence of issues in the 
friction welding process of the subject inflators that resulted in 
either over-pressurization or weld failure when the inflators were 
commanded to deploy. This propensity for over-pressurization or weld 
failure, based on one or more variables, can cause and has caused 
repeated ruptures of the subject inflators. All seven known field 
ruptures in vehicles in the United States, along with at least twenty-
three lot acceptance testing ruptures, were caused by over-
pressurization or weld failure. Thus, the evidence demonstrates that 
the same friction welding process used to manufacture all of the 
subject inflators creates a risk of rupture. Stated more plainly, any 
of the subject inflators is subject to over-pressurization or weld 
failure leading to rupture when commanded to deploy. There is no 
evidence-based means to predict which specific subject inflators will 
rupture when commanded to deploy. Limited-scope recalls initiated in 
response to some of the ruptures were reactionary and narrowly focused 
and did not proactively address the propensity of the larger population 
of subject inflators to rupture. As a result, ruptures continued to 
occur.
    The ruptures that have already occurred in vehicles have 
demonstrated the unpredictable nature of the defect. As detailed below, 
these ruptures have involved inflators manufactured at different times 
and in different manufacturing facilities, both single-stage and dual-
stage air bag inflators, driver-side and passenger-side inflators, 
inflators incorporated into air bag modules by different module 
suppliers, and inflators used in different vehicle manufacturers' 
vehicles. The inflators that ruptured due to over-pressurization or 
weld failure in lot acceptance testing likewise had been manufactured 
at different times in different manufacturing facilities, included both 
single-stage and dual-stage air bag inflators, driver-side and 
passenger-side inflators, and were intended to be sold to different air 
bag module suppliers. The critical element that the subject inflators 
have in common is the friction welding process--significant evidence 
indicates that this process has led to ruptures caused by over-
pressurization and weld failure.
3. The Inflators Have Ruptured in the Field Seven Times
    The defect in the subject inflators has manifested in seven 
confirmed ruptures in vehicles in the United States, injuring at least 
seven people and killing another.
First Field Rupture--January 2009, Ohio
    The first known field rupture of a subject inflator in the United 
States occurred on January 29, 2009 in Ohio. The driver of a MY 2002 
Chrysler Town & Country was turning into a driveway and collided with 
another vehicle. The crash triggered air bag deployment, and the 
driver-side, dual-stage air bag inflator--manufactured in ARC's 
Knoxville, Tennessee plant--ruptured, sending pieces of metal through 
the air bag cushion and into the occupant compartment. The driver 
sustained severe injuries to the face, neck, shoulder, and jaw, causing 
permanent muscle and nerve damage.\37\
---------------------------------------------------------------------------

    \37\ See VOQ dated Dec. 20, 2014.
---------------------------------------------------------------------------

    During an inspection of the vehicle, ARC took photographs of the 
pieces of the ruptured inflator, including the center support. When the 
inflator in the MY 2002 Chrysler Town & Country ruptured, the center 
support elongated, split into two pieces, and ejected from

[[Page 63479]]

the inflator housing.\38\ These characteristics indicate that a rupture 
was caused by over-pressurization of the inflator.\39\ The photos of 
the upper portion of the center support show a blockage in the exit 
orifice.\40\ NHTSA and ARC agree that because this blockage prevented 
the gas from escaping through the exit orifice, the pressure inside the 
inflator built and exceeded the inflator's strength limit and, 
ultimately, the inflator over-pressurized and broke apart (i.e., 
ruptured). ARC posited that the blockage was caused by a piece of the 
flash-dam pin, a tool that is inserted through the exit orifice during 
the friction welding process in an attempt to prevent weld flash from 
blocking the gas flow. The flash-dam pin is normally removed after 
completion of the weld, but based on visual inspection of the 
photographs, ARC suggested that a piece of this pin broke off during 
the manufacturing process and, during deployment, blocked the 
inflator's exit orifice.\41\ No metallurgical testing was done to 
determine the composition of the blockage material.
---------------------------------------------------------------------------

    \38\ See Photos of air bag parts from MY 2002 Chrysler Town & 
Country Rupture at pp. 6-9.
    \39\ See ARC Presentation dated Mar. 1, 2016 on MY 2004 Kia 
Optima Rupture at pp. 5, 22; ARC Presentation dated Aug. 25, 2017 on 
SGO 2016-01/2017-01 Report 39 at pp. 6, 11, 37; ARC Response to 
Request 1 of NHTSA Aug. 25, 2015 IR Letter at p. 72.
    \40\ See Photos of air bag parts from MY 2002 Chrysler Town & 
Country Rupture at pp. 6-9.
    \41\ See Written Response of ARC Automotive, Inc. to the 
September 5, 2023, Initial Decision Docket No. NHTSA-2023-0038 at p. 
32, https://www.regulations.gov/comment/NHTSA-2023-0038-0027.
---------------------------------------------------------------------------

    The vehicle manufacturer, FCA,\42\ has not advanced any contrasting 
potential explanation for this field rupture.
---------------------------------------------------------------------------

    \42\ Then known as Chrysler.
---------------------------------------------------------------------------

Second Field Rupture--April 2014, New Mexico
    The second known field rupture of a subject inflator occurred on 
April 8, 2014 in New Mexico. The driver of a MY 2004 Kia Optima 
collided with a roadside barrier, triggering air bag deployment. The 
driver-side, single stage air bag inflator--manufactured in ARC's 
Knoxville, Tennessee plant--ruptured, and fragments were propelled 
through the air bag cushion and into the occupant compartment. At the 
hospital, a piece of the shrapnel was removed from the driver's 
neck.\43\ The driver was also treated for head trauma, a jaw fracture, 
and lacerations to the lip, neck, and cheek.\44\
---------------------------------------------------------------------------

    \43\ See Medical Discharge Summaries, Report ID ****8352 at p. 
3.
    \44\ See id.
---------------------------------------------------------------------------

    ARC conducted a visual, on-site inspection of the vehicle and 
inflator parts and took photographs of the vehicle and inflator pieces. 
As with the MY 2002 Chrysler Town & Country rupture, the center support 
of the inflator elongated, broke into two pieces, and ejected from the 
inflator housing.\45\ ARC concluded that the inflator ruptured due to 
over-pressurization,\46\ a conclusion with which NHTSA agrees. ARC's 
analysis identified exit orifice blockage as the most likely cause of 
the over-pressurization and rupture.\47\ The photographs of the center 
support taken after the rupture occurred do not show that a blockage 
remained in the exit orifice.\48\ ARC surmised that an internal 
blockage of the exit orifice was unlikely based on this observation and 
three additional indicators: (1) during manufacturing, the inflator had 
been filled with the stored, internal gas through the exit orifice, (2) 
the lot acceptance test data for the associated lot of inflators was 
compliant, and (3) the exit orifice diameter was an acceptable 
size.\49\ ARC hypothesized, instead, that the over-pressurization was 
caused by an external blockage of the exit orifice and conducted tests 
to mimic this condition.\50\
---------------------------------------------------------------------------

    \45\ See ARC Presentation dated Mar. 1, 2016 on MY 2004 Kia 
Optima Rupture at pp. 5, 22.
    \46\ See id.
    \47\ See id. at pp. 5, 7, 32.
    \48\ See id. at pp. 8-9.
    \49\ See id. at p. 68.
    \50\ See id. at pp. 70-71, 74.
---------------------------------------------------------------------------

    The photos of the center support in this instance do not show exit 
orifice blockage; however, the blockage could have been knocked out of 
the exit orifice when the inflator ruptured, as likely happened in 
several of the lot acceptance test ruptures believed to have been 
caused by internal exit orifice blockage.\51\ Debris found inside the 
air bag cushion after this rupture was of a sufficient size to block 
the exit orifice.\52\ Therefore, the evidence does not undermine 
internal blockage as the underlying reason for the over-pressurization 
in this incident. The three additional indicators listed above and 
cited by ARC are present for each of the U.S. field ruptures and do 
not, separately or combined, refute internal blockage of the exit 
orifice as the cause of over-pressurization.
---------------------------------------------------------------------------

    \51\ See ARC Presentation dated Apr. 1, 2017 on SGO 2016-01/
2017-01 Report 80 at pp. 8-11; ARC Presentation dated Nov. 10, 2017 
on SGO 2016-01/2017-01 Report 120 at p. 7; ARC Presentation dated 
Apr. 5, 2017 on SGO 2016-01/2017-01 Report 130 at pp. 8-11; ARC 
Presentation dated Nov. 8, 2017 on SGO 2016-01/2017-01 Report 178 at 
pp. 13-14.
    \52\ See Photo 25 from inspection of MY 2004 Kia Optima rupture; 
Photo 27 from inspection of MY 2004 Kia Optima rupture; Photo 29 
from inspection of MY 2004 Kia Optima rupture; Photo 31 from 
inspection of MY 2004 Kia Optima rupture; Photo 33 from inspection 
of MY 2004 Kia Optima rupture; Photo 34 from inspection of MY 2004 
Kia Optima rupture.
---------------------------------------------------------------------------

    In comments, Kia disputed that the rupture may have been caused by 
weld slag blocking the inflator orifice and noted a number of 
observations. However, in attempting to explain the rupture, Kia could 
only conclude that it was ``an isolated case of unknown cause.''
Third Field Rupture--September 2017, Pennsylvania
    The third known field rupture occurred on September 22, 2017 in 
Pennsylvania. The driver of a MY 2011 Chevrolet Malibu rear-ended 
another vehicle, triggering air bag deployment. The driver-side, dual 
stage air bag inflator--manufactured in ARC's Reynosa, Mexico plant 
\53\--ruptured. Pieces of the inflator shot through the air bag cushion 
and into the occupant compartment. The shrapnel caused multiple 
fractures to the driver's face, nose, and jaw as well as other trauma, 
lacerations, and nerve damage to the face.\54\
---------------------------------------------------------------------------

    \53\ In the September 5, 2023 Initial Decision, the description 
of this field rupture incorrectly stated that the vehicle was a MY 
2010 Chevrolet Malibu and that the inflator had been manufactured in 
Xi'an China.
    \54\ See Complaint filed in lawsuit arising from the crash on 
Sept. 22, 2017 at pp. 11-12.
---------------------------------------------------------------------------

    General Motors (GM) took photographs of the vehicle and inflator 
during an on-site inspection. A visual inspection of photos of the 
inflator shows that the center support did not elongate, split in two, 
or eject from the inflator.\55\ These characteristics are unique to 
this field rupture. Based on observations made during physical 
inspections on December 13, 2018 and January 22, 2019, GM noted the 
lack of center support elongation as an indication that the exit 
orifice was not blocked in this rupture.\56\ Neither GM nor ARC nor 
NHTSA were able to conduct destructive testing on the inflator, so all 
conclusions and hypotheses were based on visual inspection of the 
photographs.
---------------------------------------------------------------------------

    \55\ See Photos from inspection of MY 2011 Chevrolet Malibu 
rupture at p. 65; GM Presentation dated Jan. 29, 2019 on MY 2011 
Chevrolet Malibu rupture at pp. 4-6.
    \56\ See GM Presentation dated Jan. 29, 2019 on MY 2011 
Chevrolet Malibu rupture at pp. 1, 3.
---------------------------------------------------------------------------

    Based on information available to it, ARC proffered a potential 
explanation that partially attributed the rupture to issues with 
Operation 50 of the inflator manufacturing process.\57\ Similarly, GM

[[Page 63480]]

noted that the inflator ruptured specifically at the Operation 50 weld, 
along with another weld.\58\ For driver-side subject inflators, 
Operation 50 is the point in the manufacturing process at which two 
friction welds occur: The center support is friction welded to the 
inside of the lower half of the inflator housing, and, at the same 
time, the lower and upper halves of the inflator housing are friction 
welded together.\59\ In their analyses of this field rupture, ARC and 
GM identified issues with this particular friction weld and posited 
those issues as potential causes of the rupture. These descriptions are 
repeated in ARC's analyses of certain ruptures that occurred during lot 
acceptance testing where deficiencies in this same friction weld were 
identified as having contributed to each failure.\60\
---------------------------------------------------------------------------

    \57\ See ARC Presentation dated Mar. 21, 2019 on MY 2011 
Chevrolet Malibu rupture at p. 4.
    \58\ See GM Presentation dated Jan. 29, 2019 on MY 2011 
Chevrolet Malibu rupture at p. 3.
    \59\ See ARC Presentation on CADH Inflator Design at slide 12.
    \60\ See ARC Presentation dated Oct. 17, 2016 on SGO 2016-01/
2017-01 Report 3 at pp. 14-16; ARC Report dated Nov. 4, 2016 under 
SGO 2016-01/2017-01 Report 5 at p. 2; ARC Report dated Nov. 4, 2016 
under SGO 2016-01/2017-01 Report 5 at p. 2; ARC Presentation dated 
Nov. 7, 2016 on SGO 2016-01/2017-01 Report 12 at slides 39-40; ARC 
Report dated Dec. 12, 2016 under SGO 2016-01/2017-01 Report 13; ARC 
Report dated Dec. 12, 2016 under SGO 2016-01/2017-01 Report 18; ARC 
Presentation dated Feb. 8, 2017 on A9/ZB Model Inflators at pp. 2-3; 
ARC Presentation dated May 14, 2017 on SGO 2016-01/2017-01 Report 20 
at slides 27-30; ARC Report dated Dec. 14, 2016 under SGO 2016-01/
2017-01 Report 22 at p. 2.
---------------------------------------------------------------------------

    While NHTSA acknowledges that characteristics of this field rupture 
differ from those seen in the other U.S. field ruptures, they do not 
undermine the agency's defect determination. These characteristics are 
not anomalous or isolated; they also appear in several lot acceptance 
test ruptures. After studying each such rupture, ARC attributed all of 
these ruptures partially to friction weld failures.\61\ Moreover, 
manufacturers attributed other field and lot acceptance test ruptures 
to additional issues related to the friction welding process, including 
excessive weld flash--created by friction welding--that blocked the 
exit orifice, and a broken piece of the flash-dam pin--a tool used to 
try to prevent weld flash blockage--that blocked the exit orifice. In 
fact, the extent to which the MY 2011 Chevrolet Malibu rupture differs 
from other field ruptures serves as evidence that there are variations 
in the friction welding process, intentional or unintentional, that can 
lead and have led to ruptures.
---------------------------------------------------------------------------

    \61\ See id.
---------------------------------------------------------------------------

    Appearing to recognize these variations, several commenters 
suggested that more testing and analysis of the variables in the 
subject inflators' design and manufacturing process is needed to 
support NHTSA's initial decision. However, in the many years since the 
first ruptures occurred and the investigation opened, the agency and 
the manufacturers have conducted extensive analyses. To the extent some 
commenters point to a lack of confirmed root cause for every incident, 
the agency notes that a root cause determination is not required to 
determine that a defect exists, as discussed further below in section 
II.A.6. The agency also does not believe that additional analysis is 
likely to shed meaningful light on issues that remain unsettled at this 
point. In light of the severe safety risk, the Safety Act warrants a 
recall based on the already clear evidence of a defect.
Fourth Field Rupture--August 2021, Michigan
    The fourth known field rupture occurred on August 15, 2021. In 
Michigan, the driver of a MY 2015 Chevrolet Traverse vehicle, returning 
from a family outing with her children,\62\ was turning onto a highway 
and was struck by another vehicle. The air bags deployed, and the 
driver-side, dual stage air bag inflator--manufactured in ARC's 
Reynosa, Mexico plant--ruptured, sending fragments of metal through the 
air bag cushion and into the occupant compartment. The pieces of the 
center support struck the driver in the neck, and the driver died from 
the injury.
---------------------------------------------------------------------------

    \62\ Public Meeting Transcript and Addenda at pp. 73-74, Docket 
No. NHTSA-2023-0038, https://www.regulations.gov/document/NHTSA-2023-0038-0003.
---------------------------------------------------------------------------

    One of the driver's children traveled from Michigan to Washington, 
DC to speak at the public meeting on October 5, 2023 in support of 
NHTSA's initial determination that the subject inflators are defective 
and should be recalled. During the meeting, he described in detail his 
presence at the crash scene and how the air bag, rather than protecting 
his mother from injury, exploded, sent metal shrapnel into her face and 
neck, and ultimately killed her.\63\
---------------------------------------------------------------------------

    \63\ Id.
---------------------------------------------------------------------------

    Photos taken by Michigan State Police personnel after the crash 
show that the center support elongated, split in two, and ejected from 
the inflator,\64\ demonstrating that over-pressurization caused the 
rupture. The Michigan State Police also performed X-rays of the 
inflator pieces and provided the images to GM.\65\ The X-rays do not 
show any obstruction in the exit orifice.\66\ NHTSA does not believe 
the X-ray images negate the possibility of exit orifice blockage. The 
force of the rupture could have knocked any blockage material loose, as 
the evidence suggests happened in lot acceptance test ruptures. \67\ 
Moreover, an X-ray image is not always detailed enough to identify 
witness marks caused by debris in the exit orifice.
---------------------------------------------------------------------------

    \64\ See Photos from inspection of MY 2015 Chevrolet Traverse 
rupture in Michigan at pp. 188-229.
    \65\ See GM Presentation dated Oct. 6, 2021 on MY 2015 Chevrolet 
Traverse rupture in Michigan at p. 10.
    \66\ See id.
    \67\ See ARC Presentation dated Apr. 1, 2017 on SGO 2016-01/
2017-01 Report 80 at pp. 8-11; ARC Presentation dated Nov. 10, 2017 
on SGO 2016-01/2017-01 Report 120 at p. 7; ARC Presentation dated 
Apr. 5, 2017 on SGO 2016-01/2017-01 Report 130 at pp. 8-11; ARC 
Presentation dated Nov. 8, 2017 on SGO 2016-01/2017-01 Report 178 at 
pp. 13-14.
---------------------------------------------------------------------------

    GM noted that the X-ray images for this field rupture did not show 
material in the exit orifice and that CT scans of inflators retrieved 
from the same lot did not show exit orifice blockage.\68\ As explained 
above, X-ray images cannot rule out exit orifice blockage as the cause 
of over-pressurization, and, furthermore, lot-based comparisons are not 
broad enough to guarantee that the risk is contained. GM studied this 
rupture in tandem with the subsequent fifth field rupture (discussed in 
more detail below) and a lot acceptance test rupture.\69\ The remainder 
of GM's analysis related to propellant was not specifically applicable 
to this field rupture.\70\ ARC likewise has not offered any potential 
explanations for this fatal field rupture incident, though it is 
undisputed that over-pressurization ultimately caused the rupture.
---------------------------------------------------------------------------

    \68\ See GM Presentation dated Jun. 15, 2022 on DAB ARC Inflator 
Ruptures at p. 2.
    \69\ See id. at p. 1.
    \70\ GM enlisted the help of an independent research firm to 
study propellant-related issues more broadly. The group studied 329 
driver-side subject inflators manufactured between 2013 and 2021. 
While the study identified ``[m]any areas of manufacturing 
variability,'' it concluded that ``moisture migration into the 
propellant,'' which is the cause of propellant degradation, ``is not 
a concern in this inflators design.'' See Northrop Grumman 
Presentation dated May 5, 2023 on GM ARC Inflator Investigation at 
p. 48. GM did not identify a specific explanation for the inflator 
ruptures but proposed that too much propellant, low propellant 
density, and ``possible other unknown factors'' may be considered as 
contributors. See GM Presentation dated Jun. 15, 2022 on DAB ARC 
Inflator Ruptures at p. 1.
---------------------------------------------------------------------------

Fifth Field Rupture--October 2021, Kentucky
    The fifth known field rupture occurred on October 20, 2021. In 
Kentucky, the driver of a MY 2015 Chevrolet Traverse vehicle collided 
with another vehicle at an intersection, which triggered the air bags 
to deploy.

[[Page 63481]]

The driver-side, dual stage air bag inflator--manufactured in ARC's 
Reynosa, Mexico plant--ruptured, and fragments of the metal inflator 
were projected through the air bag cushion and into the occupant 
compartment. The driver sustained injuries to the face.
    Photographs were taken of the vehicle as well as the ruptured 
inflator pieces. The photos show that the center support elongated, 
split in two, and ejected from the inflator,\71\ demonstrating that 
over-pressurization caused the rupture. The upper portion of the broken 
center support shot through the air bag cushion and into the driver-
seat head rest.\72\ The photos of this piece of the center support show 
material blocking the exit orifice.\73\ GM suggests the material may be 
fabric from the head rest,\74\ however, a determination of the blockage 
material has not been confirmed as the manufacturers were not able to 
perform an analysis of the material to identify its makeup.
---------------------------------------------------------------------------

    \71\ See GM Presentation dated Apr. 6, 2022 on MY 2015 Chevrolet 
Traverse rupture in Kentucky at p. 3.
    \72\ See id. at p. 4.
    \73\ See id. at p. 3.
    \74\ See id.
---------------------------------------------------------------------------

    GM assessed this field rupture in tandem with the previous field 
rupture and a lot acceptance test rupture, as explained above in 
discussing the fourth rupture (2021 Michigan). As GM stated in that 
analysis, no parts from the same lot as the inflator in this field 
rupture were available for analysis,\75\ so the conclusions in its 
report are not particularly relevant. GM did not perform a separate 
analysis for this field rupture. Similarly, ARC has not provided a 
potential explanation for this rupture.
---------------------------------------------------------------------------

    \75\ See GM Presentation dated Jun. 15, 2022 on DAB ARC Inflator 
Ruptures at p. 2.
---------------------------------------------------------------------------

Sixth Field Rupture--December 2021, California
    The sixth known field rupture occurred on December 18, 2021 in 
California. The driver of a MY 2016 Audi A3 e-Tron collided with 
another vehicle. The air bags deployed, and the passenger-side, dual 
stage inflator--manufactured in ARC's Reynosa, Mexico plant--ruptured, 
with some of the fragments projecting through the air bag cushion and 
into the occupant compartment. The passenger suffered serious injuries 
to the face and ear.\76\ The pieces of the inflator also struck the 
driver, causing lacerations to the right hand and right shin.\77\
---------------------------------------------------------------------------

    \76\ See Complaint filed in lawsuit arising from the crash on 
Dec. 18, 2021 at p. 2.
    \77\ See State of California Crash Report dated Dec. 18, 2021 at 
p. 3.
---------------------------------------------------------------------------

    Photos from the vehicle inspection indicate that the center support 
split in two and ejected from the inflator,\78\ demonstrating that 
over-pressurization caused the rupture. The upper portion of the center 
support ultimately ejected through the windshield and the lower portion 
became lodged in the instrument panel.\79\ The upper portion of the 
center support was never recovered and, therefore, never analyzed for 
blockage. Neither ARC nor Volkswagen has offered potential explanations 
for this rupture.
---------------------------------------------------------------------------

    \78\ See Photos from inspection of MY 2016 Audi A3 e-Tron 
rupture.
    \79\ See id.
---------------------------------------------------------------------------

Seventh Field Rupture--March 2023, Michigan
    The seventh, and most recent, known field rupture occurred on March 
22, 2023 in Michigan. The driver of a MY 2017 Chevrolet Traverse 
vehicle collided with a tree, causing the air bags to deploy. The 
driver-side, dual stage inflator--manufactured in ARC's Reynosa, Mexico 
plant--ruptured, sending fragments through the air bag cushion and into 
the occupant compartment. The driver suffered injuries to the face, 
teeth, and neck. A child in the back seat also suffered lacerations to 
the face, potentially caused by shrapnel from the inflator rupture or 
other debris from the crash. The upper portion of the center support 
struck the driver in the neck and had to be surgically removed from the 
driver's airway.\80\
---------------------------------------------------------------------------

    \80\ See Email dated Apr. 5, 2023 to NHTSA from Hurley Medical 
Center; Photos attached to email dated Apr. 5, 2023 to NHTSA from 
Hurley Medical Center.
---------------------------------------------------------------------------

    Photos taken of the vehicle and pieces of the inflator show that 
the center support elongated, split in two, and ejected from the 
inflator,\81\ once again demonstrating that over-pressurization caused 
the rupture. Photos of the removed upper center support show that the 
exit orifice was completely blocked.\82\ No further explanation for 
this rupture has been advanced by ARC or GM.
---------------------------------------------------------------------------

    \81\ See Photo 10 from inspection of MY 2017 Chevrolet Traverse 
rupture; Photo 35 from inspection of MY 2017 Chevrolet Traverse 
rupture; Photo 38 from inspection of MY 2017 Chevrolet Traverse 
rupture; Photo 17 from inspection of MY 2017 Chevrolet Traverse 
rupture.
    \82\ See Photos attached to email dated Apr. 5, 2023 to NHTSA 
from Hurley Medical Center; Photo 38 from inspection of MY 2017 
Chevrolet Traverse rupture; Photo 36 from inspection of MY 2017 
Chevrolet Traverse rupture; Photo 48 from inspection of MY 2017 
Chevrolet Traverse rupture; Photo 45 from inspection of MY 2017 
Chevrolet Traverse rupture.
---------------------------------------------------------------------------

Foreign Field Ruptures
    In addition to the seven confirmed field ruptures in the U.S., 
there are four confirmed ruptures of frontal driver- and passenger-side 
hybrid toroidal ARC inflators that occurred in other countries. In July 
of 2016, a driver-side hybrid toroidal ARC inflator manufactured in 
ARC's Xi'an, China plant ruptured in a MY 2009 Hyundai Elantra in 
Canada.\83\ The center support split into two pieces and ejected, a 
piece of which struck and killed the driver.\84\ In October of 2017, a 
passenger-side hybrid toroidal ARC inflator manufactured in ARC's 
Knoxville, Tennessee plant ruptured in a MY 2015 Volkswagen Golf in 
Turkey.\85\ The center support split in two and ejected from the 
inflator housing, and Volkswagen hypothesized that weld flash blockage 
of the exit orifice caused the rupture.\86\ Fortunately, there was no 
passenger in the vehicle, and no one was injured.\87\ In March of 2020, 
a passenger-side hybrid toroidal ARC inflator manufactured in ARC's 
Xi'an, China plant ruptured in a 2009 Hyundai Elantra in Saudi Arabia, 
sending fragments of metal into the occupant compartment.\88\ The 
driver sustained injuries in the incident.\89\ In October of 2021, a 
driver-side hybrid toroidal ARC inflator manufactured in ARC's Xi'an, 
China plant ruptured in a MY 2011 Hyundai Elantra Touring in Saudi 
Arabia.\90\ The center support broke into two pieces and ejected from 
the inflator housing.\91\ The driver was seriously injured when a piece 
of the center support struck the driver's arm and had to be surgically 
removed.\92\
---------------------------------------------------------------------------

    \83\ See Hyundai Report dated Jul. 20, 2016 under SGO 2015-01/
2015-02; Hyundai Letter to NHTSA dated Apr. 15, 2020 at p. 2.
    \84\ See Hyundai Report dated Jul. 20, 2016 under SGO 2015-01/
2015-02; Hyundai Letter to NHTSA dated Apr. 15, 2020 at p. 2; Photo 
1 from inspection of MY 2009 Hyundai Elantra rupture; Photo 2 from 
inspection of MY 2009 Hyundai Elantra rupture; Photo 375 from 
inspection of MY 2009 Hyundai Elantra rupture.
    \85\ See Key Safety Systems Report dated Dec. 1, 2017 under SGO 
2015-01/2015-02.
    \86\ See Photos from inspection of MY 2015 Volkswagen Golf 
rupture; Volkswagen Presentation on MY 2015 Volkswagen Golf rupture.
    \87\ See Key Safety Systems Report dated Dec. 1, 2017 under SGO 
2015-01/2015-02.
    \88\ See Hyundai Letter to NHTSA dated Apr. 15, 2020 at p. 2.
    \89\ See Hyundai Report dated Mar. 30, 2020 under SGO 2015-01/
2015-02.
    \90\ See Hyundai Report dated Apr. 7, 2023 under SGO 2015-01/
2015-02; Hyundai Report dated May 26, 2023 on Canada Safety Recall 
R0239 ARC Inflator.
    \91\ See Information package provided by the Saudi Ministry of 
Commerce and Industry.
    \92\ See id.

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[[Page 63482]]

4. A Comparison to Peer Inflators Supports a Defect Determination
    While the overall incidence of rupture is rare, these failures can 
result and have resulted in severe injury or death. As such, and 
considering the evidence of problems in the friction welding process, 
the subject inflators present a defect. Moreover, the number of field 
ruptures in the United States described here stands in stark contrast 
to the near absence of such occurrences from other manufacturers of 
frontal air bag inflators. In assessing a defect, courts have 
considered how the number of failures compares to the number seen from 
other manufacturers particularly in situations where--unlike here--the 
circumstances of failure do not reveal an obvious defect. See, e.g., 
Wheels, 518 F.2d at 438 n.84. Such a comparison further bolsters the 
conclusion that the subject inflators are defective.
    As previously discussed in section I, SGOs 2015-01A and 2015-02A 
require all manufacturers to report alleged inflator field ruptures to 
NHTSA. Out of all of the field ruptures reflected in reports received 
as of July 2024,\93\ NHTSA identified only one comparable U.S. field 
rupture of a non-ARC air bag inflator, which has resulted in three 
recalls.\94\ The agency recognizes that the predecessor SGOs, 2015-01 
and 2015-02 (with similar reporting requirements), were first issued on 
July 27, 2015. NHTSA believes it likely, however, that if other alleged 
ruptures had occurred before the SGOs' issuance, the agency would have 
been made aware of them through various channels. For example, the 
first Takata inflator ruptures occurred in 2007-2008,\95\ and the first 
Takata recall was initiated in 2008, so it is likely that, due to the 
publicity, any inflator ruptures after that time would have been 
reported to NHTSA through a complaint, which is how NHTSA learned of 
the subject inflator rupture in the MY 2002 Chrysler Town & 
Country.\96\
---------------------------------------------------------------------------

    \93\ This does not include field ruptures--based on the agency's 
review of these reports and field incidents--that involved inflators 
manufactured by Takata, many of which have long been under recall. 
As one commenter asserted (albeit in the context of discussing how 
to define the defective population) it is difficult to make ``direct 
rate comparisons'' between the inflators here and those in the 
Takata recalls, and the Takata recalls ``have limited comparative 
value'' given, among other things, the apparent failure mechanisms 
and the number of reported deaths and injuries associated with 
Takata air bag inflators. Comments of Jay Logel at p. 7 (Dec. 18, 
2023).
    \94\ NHTSA Recall Nos. 20V-681, 21V-766, and 21V-800.
    \95\ Approximately 67 million non-desiccated Takata PSAN air bag 
inflators, across nineteen vehicle manufacturers, are under recall 
because they may rupture when deployed, causing serious injury or 
even death. Certain other types of Takata inflators are also under 
recall. For more information about the Takata air bag inflator 
recalls, see Takata Recall Spotlight (NHTSA), https://www.nhtsa.gov/vehicle-safety/takata-recall-spotlight.
    \96\ In addition, since 2002, manufacturers have been required 
under NHTSA's early warning reporting regulations to report on 
incidents involving injury or death. See 49 CFR part 579, subpart C.
---------------------------------------------------------------------------

    A collection of all SGO reports involving confirmed ruptures of 
frontal driver and passenger air bag inflators thus yielded a total of 
eighteen potentially relevant reports involving non-ARC inflators. Of 
these eighteen, ten of the reported ruptures occurred outside of the 
United States. Relative to the U.S. market, the agency does not have 
the requisite depth of information (e.g., the total inflator population 
manufactured for each additional relevant foreign market) to enable an 
effective peer comparison that would encompass inflators manufactured 
for the various foreign markets. In addition, the considerations 
relevant to determining whether a defect exists under U.S. law may not 
be the same in other countries. The foreign ruptures are, therefore, 
not included in a comparison with seven U.S. subject inflator field 
ruptures.\97\
---------------------------------------------------------------------------

    \97\ To the extent any of the foreign field ruptures evidence a 
pattern, the agency is taking a closer look to ensure such trends do 
not implicate vehicles or equipment in the U.S.
---------------------------------------------------------------------------

    Of the remaining eight ruptures in the collection of reports, six 
inflators appear to be substandard or imitation products not designed 
or manufactured to meet U.S. safety standards or based on the same 
industry standards as legitimate inflators. For this reason, they 
should not be used as peer comparators. Of the remaining two ruptures, 
one involved reported damage--scratching--on the inflator housing that 
appeared to have been caused by a tool and not by deployment or 
rupture. Further, while the reporting inflator manufacturer confirmed a 
rupture, the reporting vehicle manufacturer did not.\98\ Given that 
none of the seven ruptures involving the subject inflators contained 
similar evidence, it is inappropriate to use this event in a 
comparison.
---------------------------------------------------------------------------

    \98\ Compare Air Bag Inflator Rupture Incident Report (Initial & 
Final), Autoliv (Dec. 2, 2016) (confirming rupture but noting that 
``scratching'' on areas of the inflator are ``not consistent with 
Autoliv's quality requirements and the inflator exhibits damage/
scratches inconsistent with normal deployment or a rupture'') with 
Air Bag Inflator Rupture Incident Report (Final), Nissan (Dec. 20, 
2016) (``There is damage on the outside of the housing which appears 
to be caused by an external tool, as evidenced by the multiple 
witness marks surrounding the hole in the inflator. Nissan does not 
believe that a rupture occurred in this incident.'').
---------------------------------------------------------------------------

    Appropriately filtering the list of confirmed ruptures of frontal 
driver- and passenger-side air bag inflators to include true peer 
incidents, there is only a single field rupture from all other inflator 
manufacturers to compare to the seven subject inflator field ruptures. 
As noted above, that rupture already resulted in three recalls, and the 
scope of vehicles under these recalls is broader than just a particular 
lot. NHTSA is not aware of further ruptures of that type of inflator, 
which is distinguishable from the repeated ruptures of the subject 
inflators. After each lot recall of subject inflators, another inflator 
outside the scope of the recall eventually ruptured in a vehicle, 
supporting the need for a more comprehensive recall to address the full 
defective population.
5. ARC's Addition of an Automated Borescope Examination Process 
Recognizes and Mitigates the Risk of a Field Rupture Due to Exit 
Orifice Blockage
    In August of 2017, ARC began adding an automated borescope to the 
manufacturing process.\99\ After the last friction weld is complete, 
the borescope inspects the inside of the center support to detect any 
debris, including weld flash.\100\ By June of 2018, ARC had fully 
implemented this process by installing these automated borescopes on 
all assembly lines used to manufacture the subject inflators. ARC 
rejects any inflator for which the borescope detects material or debris 
in excess of the specified parameters,\101\ and, from the first 
borescope installation to March 2023, ARC rejected 195,166 inflators 
based on the borescope's inspection.\102\
---------------------------------------------------------------------------

    \99\ See ARC Presentation dated Oct. 2017 on Automated 
Borescope.
    \100\ See id.
    \101\ See id.
    \102\ See ARC Response to Request 8 of NHTSA May 31, 2023 
Special Order.
---------------------------------------------------------------------------

    The automated borescope examination process, which detects 
excessive weld flash or other debris in the inflator center support, 
recognizes and mitigates the risk of a field rupture due to exit 
orifice blockage. The agency is unaware of a field rupture of a 
frontal, driver- or passenger-side hybrid toroidal inflator 
manufactured using the borescope examination process. Thus, the subject 
inflators subject to this initial determination are the inflators 
manufactured before the full implementation of this process change.
    The borescope process provides additional evidence of the 
likelihood that problematic levels of debris are present in the subject 
inflator population. Inflators built after the

[[Page 63483]]

borescope process was introduced continued to otherwise undergo the 
same friction welding process as before the borescope inspection began. 
This means that the rejection rates from the borescope inspections 
provide insight into the extent of debris present in the subject 
inflators, which were produced under similar manufacturing procedures. 
Before implementation of the borescope process, there was no analogous 
mechanism in place for detecting--and removing from the manufacturing 
line--inflators with excessive and dangerous levels of debris.
    Moreover, ARC's representations during this investigation suggest 
that the number of inflators with excessive debris before 2017 was 
potentially even higher than the extent of debris present in inflators 
manufactured after borescope implementation. By 2017, ARC claims that 
it had already taken numerous other steps to update the manufacturing 
process for the inflators, such as upgrading the welding equipment on 
several production lines and refining welding tolerances in response to 
field and testing ruptures.\103\ In this investigation, ARC has claimed 
that the manufacturing procedures and equipment in place by 2017 were 
improvements on the procedures and equipment in place in the preceding 
years of inflator production. If so, the rate of unacceptable inflators 
due to debris as revealed by the borescope inspections likely would 
have been even higher for inflators built during the years in which the 
manufacturing processes were less stringent. At the very least, the 
nearly 200,000 inflators rejected between the start of the borescope 
implementation process and March 2023 corroborate the other evidence 
from analyses of the field ruptures and lot acceptance testing ruptures 
that suggests a large number of inflators in the subject population 
contain unacceptable levels of debris, posing a risk of rupture.
---------------------------------------------------------------------------

    \103\ See, e.g., ARC Working Group Meeting Minutes dated Dec. 5, 
2017.
---------------------------------------------------------------------------

6. The Field and LAT Ruptures Show a Defect Common to All of the 
Subject Inflators
    The evidence demonstrates that the friction welding process is 
responsible for debris and weld insufficiencies, which have led to 
over-pressurization and weld failures, causing ruptures. The seven 
confirmed ruptures of the subject inflators in vehicles in the United 
States each presented evidence of over-pressurization or weld 
insufficiency as a likely cause of the rupture. In addition, at least 
twenty-three of the reported lot acceptance test ruptures share over-
pressurization or weld insufficiency commonalities with the seven field 
ruptures. These instances of over-pressurization and weld insufficiency 
are linked to the friction welding process.
    As described in section II.A.3, ARC and GM identified problems with 
one of the friction welds in their analyses of the rupture of the MY 
2011 Chevrolet Malibu inflator, attributing the rupture as most likely 
caused by a failure of the friction weld.\104\ ARC reiterated the cause 
of the rupture as a ``welding issue'' in its response to the agency's 
September 2023 initial decision.\105\ In six of the subject inflator 
ruptures that occurred during lot acceptance tests, ARC identified 
similar issues related to the same friction weld, again noting that 
friction weld failure as a potential causes of the ruptures.\106\ In 
addition, the investigative file contains significant evidence that the 
friction welding process has led to exit orifice blockage, causing 
over-pressurization and rupture. Information gathered in three of the 
U.S. field incidents includes evidence of material in the exit orifice: 
photos of the upper portion of the center support in the MY 2002 
Chrysler Town & Country show an unmistakable blockage in the exit 
orifice; \107\ photos of the upper piece of the center support in the 
MY 2015 Chevrolet Traverse in Kentucky show material blocking the exit 
orifice; \108\ and photos of the upper portion of the center support in 
the MY 2017 Chevrolet Traverse show that the exit orifice was 
completely blocked.\109\ Exit orifice blockage remains a possible cause 
based on the evidence for three other incidents--the MY 2004 Kia 
Optima, the MY 2015 Chevrolet Traverse in Michigan, and the MY 2016 
Audi A3 e-Tron. In addition, Volkswagen attributed weld flash blockage 
leading to over pressurization as a potential cause for the inflator 
rupture in the MY 2015 Volkswagen Golf in Turkey.
---------------------------------------------------------------------------

    \104\ See ARC Presentation dated Mar. 21, 2019 on MY 2011 
Chevrolet Malibu rupture at p. 4; GM Presentation dated Jan. 29, 
2019 on MY 2011 Chevrolet Malibu rupture at p. 3.
    \105\ See Written Response of ARC Automotive, Inc. to the 
September 5, 2023, Initial Decision Docket No. NHTSA-2023-0038 at p. 
32, https://www.regulations.gov/comment/NHTSA-2023-0038-0027 at n. 
31.
    \106\ See ARC Presentation dated Oct. 17, 2016 on SGO 2016-01/
2017-01 Report 3 at pp. 14-16; ARC Report dated Nov. 4, 2016 under 
SGO 2016-01/2017-01 Report 5 pdf at p. 2; ARC Report dated Nov. 9, 
2016 under SGO 2016-01/2017-01 Report 8 at p. 2; ARC Presentation 
dated Nov. 7, 2016 on SGO 2016-01/2017-01 Report 12 at slides 39-40; 
ARC Report dated Dec. 12, 2016 under SGO 2016-01/2017-01 Report 13; 
ARC Report dated Dec. 12, 2016 under SGO 2016-01/2017-01 Report 18; 
ARC Presentation dated Feb. 8, 2017 on A9/ZB Model Inflators at pp. 
2-3; ARC Presentation dated May 14, 2017 on SGO 2016-01/2017-01 
Report 20 at slides 27-30; ARC Report dated Dec. 14, 2016 under SGO 
2016-01/2017-01 Report 22 at p. 2.
    \107\ See id.
    \108\ See id. at p. 3.
    \109\ See Photos attached to email dated Apr. 5, 2023 to NHTSA 
from Hurley Medical Center; Photo 38 from inspection of MY 2017 
Chevrolet Traverse rupture; Photo 36 from inspection of MY 2017 
Chevrolet Traverse rupture; Photo 48 from inspection of MY 2017 
Chevrolet Traverse rupture; Photo 45 from inspection of MY 2017 
Chevrolet Traverse rupture.
---------------------------------------------------------------------------

    Other data support exit orifice blockage as a common factor in 
these ruptures. In May of 2017, a group of manufacturers involved in 
the investigation that has been described as the ``Collaboration 
Group'' joined together to study the subject inflators. The 
Collaboration Group analyzed fourteen reports submitted pursuant to 
SGOs 2016-01 and 2017-01 of passenger-side hybrid toroidal inflator 
ruptures during lot acceptance test deployments and conducted related 
testing. The Collaboration Group concluded that all fourteen ruptures 
were caused by over-pressurization; in all fourteen incidents, the 
center support elongated, split in two, and ejected from the inflator 
housing; and, in all fourteen incidents, the upper portion of the 
center support had material in the exit orifice, witness marks around 
the exit orifice (indicating debris was forced into the exit orifice 
upon deployment but was subsequently knocked loose), or other evidence 
of exit orifice blockage or obstruction.\110\ ARC has acknowledged the 
exit orifice blockage issue by implementing changes in its Failure Mode 
and Effects Analysis (FMEA) \111\ and manufacturing process

[[Page 63484]]

to mitigate it.\112\ In fact, ARC implemented the automated borescope 
to identify excessive weld flash and other debris inside the inflator 
on all of its toroidal air bag inflator manufacturing lines as a direct 
response to the Collaboration Group's findings.\113\ The borescope 
inspection process has identified unacceptable levels of debris in 
inflators produced on all ARC production lines using friction welding 
to manufacture hybrid toroidal inflators, which include 20 different 
production lines across five different ARC manufacturing plants. This 
extensive range illustrates that problems with excessive debris apply 
broadly across the subject inflators.
---------------------------------------------------------------------------

    \110\ See ARC Presentation dated Feb. 8, 2017 on SGO 2016-01/
2017-01 Report 4; ARC Presentation dated Dec. 8, 2016 on Inflator 
Incidents Update at p. 17; ARC Presentation dated Jan. 10, 2017 on 
SGO 2016-01/2017-01 Report 39; ARC Presentation dated Mar. 9, 2017 
on ZC Anomaly; ARC Presentation dated Apr. 1, 2017 on SGO 2016-01/
2017-01 Report 80; ARC Presentation dated Apr. 1, 2017 on SGO 2016-
01/2017-01 Report 94; ARC Presentation dated Apr. 5, 2017 on SGO 
2016-01/2017-01 Report 95; ARC Presentation dated Nov. 10, 2017 on 
SGO 2016-01/2017-01 Report 120; ARC Presentation dated Apr. 5, 2017 
on SGO 2016-01/2017-01 Report 130; ARC Presentation dated Nov. 10, 
2017 on SGO 2016-01/2017-01 Report 158; ARC Presentation dated Nov. 
10 2017 on SGO 2016-01/2017-01 Report 176; ARC Presentation dated 
Nov. 8, 2017 on SGO 2016-01/2017-01 Report 178; ARC Presentation 
dated Nov. 10 2017 on SGO 2016-01/2017-01 Report 184; ARC 
Presentation dated Nov. 10 2017 on SGO 2016-01/2017-01 Report 186; 
ARC Presentation dated Nov. 10 2017 on SGO 2016-01/2017-01 Report 
192.
    \111\ In general, a Failure Mode and Effects Analysis is a 
qualitative tool associated with the design and manufacturing 
process that businesses use to identify and analyze potential 
failures in processes, such as those involving equipment, systems, 
and personnel. The goal of this analysis is to prevent failures, 
improve processes, and reduce the likelihood of failure causes and 
effects.
    \112\ See ARC Presentation dated Apr. 5, 2017 on SGO 2016-01/
2017-01 Report 95 at p. 86.
    \113\ See ARC Working Group 8D Technical Closure Statement at p. 
1.
---------------------------------------------------------------------------

    Some commenters suggested that the results of a field recovery 
program conducted by certain manufacturers during NHTSA's investigation 
show there is no defect in the subject inflator population. This 
program was initiated in the early stages of the investigation during 
the Preliminary Evaluation. During the field recovery program, 918 
inflators from a subpopulation of the total subject inflator population 
were collected from salvage yards and deployed, with none of the 
inflators rupturing. Given the fact that this testing program was 
developed after just the first two U.S. field ruptures (the MY 2002 
Chrysler Town & Country and the MY 2004 Kia Optima), the inflators 
tested represent a limited portion of the total subject population. 
They were selected based on (1) production date, with the vast majority 
being manufactured between 2001 and 2004, and (2) the vehicles into 
which the inflators were incorporated, which were Chrysler, Kia, and GM 
vehicles.\114\ As such, the overall number of inflators recovered and 
deployed under the field recovery program was low compared to what 
ultimately became the total number of inflators in the subject 
population. While there were no ruptures under the field recovery 
program, ruptures in the field continued: after the program's 
initiation, there were five additional U.S. ruptures of the subject 
inflators.
---------------------------------------------------------------------------

    \114\ See Field Recovery Program Data Sheet dated May 10, 2018.
---------------------------------------------------------------------------

    The field recovery program confirmed, however, that some inflators 
in the field contain large amounts of debris. Prior to their 
deployment, the recovered inflators underwent X-ray imaging and, in 
some cases, CT scanning to determine whether debris intruded upon the 
exit orifice opening.\115\ Seven of the recovered inflators were 
identified as containing such debris, including from weld flash.\116\ 
All of those inflators deployed normally, which is consistent with the 
large number of complex variables that may factor into whether debris 
in the inflator leads to over-pressurization. The existence of this 
debris around the exit orifice of inflators in the field demonstrates 
the prevalence of this issue in the subject inflator population.
---------------------------------------------------------------------------

    \115\ See ARC Inspection Procedure and Evaluation dated Feb. 28, 
2017.
    \116\ See Field Recovery Program Deployment Data Sheet; ARC 
Presentation dated Aug. 1, 2017 on Field Recovery Program.
---------------------------------------------------------------------------

    ARC's own failure analysis throughout the investigation has also 
indicated that, even if the company has been unable to identify the 
full universe of variables that can lead to a rupture, the 
commonalities in the failures are sufficient to reveal the nature of 
the problem--including the failure mode and the aspects of the inflator 
design and welding process most likely to contribute to it. In 2016, 
ARC was even able to conduct testing that replicated four ruptures out 
of 50 deployments.\117\ In doing so, ARC identified five manufacturing 
variables in the assembly process that, when out of limits, appeared to 
contribute to the likelihood of a rupture.\118\ ARC's fault trees and 
failure mode effects analyses similarly isolate the specific steps in 
the manufacturing process most likely relevant to the ruptures. The 
existence of factual differences or different variables that led to the 
ruptures does not establish that the ruptures lacked a common defect.
---------------------------------------------------------------------------

    \117\ See ARC Presentation on Design of Experiment #5.
    \118\ Id. Additional efforts in 2017 to replicate the failure 
mode in a more precise manner were unsuccessful, further indicating 
that different variables may combine to contribute to the risk of 
rupture. See ARC Working Group Meeting Minutes dated Feb. 13, 2018.
---------------------------------------------------------------------------

    Outside of this investigation, ARC has openly acknowledged the 
problems with its friction welding process that have led to the defect 
NHTSA seeks to remedy. For instance, in representations to the United 
States government outside of this investigation, ARC has acknowledged 
that the ``problematic'' characteristics of the subject inflators are 
not limited to isolated production lots. Specifically, in a patent 
application filed with the United States Patent and Trademark Office in 
2020, ARC requested a patent on an improved air bag inflator design. 
When explaining the background of existing designs that prompted the 
need for an improved design, ARC's application represented that 
``[s]ome existing inflator assemblies utilize a center support 
structure that requires two simultaneous welds, which is problematic in 
respect of manufacturing and also increases the potential for weld 
particles to exit the inflator upon deployment. Existing designs have 
also been configured to fragment during deployment as a consequence, in 
the event of excessive pressure increase within the inflator due to 
some failure or external condition or the like, these existing inflator 
designs can be potentially hazardous for vehicle occupants.'' \119\
---------------------------------------------------------------------------

    \119\ U.S. Pat. App. Pub. No. 2022/0185224 A1 to Rose et al., at 
]] 0005-06.
---------------------------------------------------------------------------

    The claimed improvements to mitigate these problems with prior 
inflators focused on the precise aspects of the inflator that are at 
issue in NHTSA's proceeding. Specifically, ARC intentionally redesigned 
its inflator in a way that would avoid the friction welding process 
that caused problems for the subject inflator, such as the step of 
simultaneously friction welding the top and bottom of the inflator 
housing to the center support.\120\ As ARC explained in the patent 
application, ``[t]he described inflator also eliminates the requirement 
for simultaneous welds, which facilitates manufacturing and reduces 
potential weld particles.'' \121\ In addition, the redesigned inflator 
included a pressure relief valve to create a failure mode that would 
avoid rupture if over pressurization occurred.\122\ These 
representations and redesign efforts demonstrate that, at the same time 
ARC was insisting in the NHTSA investigation that the subject inflators 
were neither defective nor inappropriate in their performance, the 
company was actively trying to correct the problems with its inflators 
and conceding the existence of those problems to another agency in the 
United States government.
---------------------------------------------------------------------------

    \120\ For the subject inflators, ARC refers to this step of the 
manufacturing process as Operation 50 for the driver-side inflator 
and Operation 42 for the passenger-side inflator. See, e.g., ARC 
Presentation on CADH Inflator Design.
    \121\ U.S. Pat. App. Pub. No. 2022/0185224 A1 to Rose et al., at 
] 0047.
    \122\ ``The inflator also advantageously includes a pressure 
relief in the event of an elevated system internal pressure without 
any rupture of the inflator.'' Id.
---------------------------------------------------------------------------

    Ignoring the evidence of a common defect attributable to the 
friction welding process, certain commenters have nevertheless argued 
that there is, as of yet, no definitive, established ``root cause.'' 
\123\ While comments from two

[[Page 63485]]

individuals supported NHTSA's identification of weld-flash evidence 
\124\ common to several of the ruptures, other commenters incorrectly 
suggested that, to establish a defect here, NHTSA must identify a more 
specific cause that is identical in each of the failures. Some of these 
comments hinge, at least in part, on the notion that a specific root 
cause of the defect in the Takata air bag inflators had been 
identified.\125\ For example, Hyundai asserted that the agency's 
September 2023 initial decision was ``entirely inconsistent with its 
decision-making in the Takata case,'' citing in part a consensus root 
cause at the time of the Takata recall request letter.\126\ Whether a 
particular recall had an identified cause before or at the time it was 
filed does not establish that such a particularized root cause is a 
requirement for a recall. It is not.\127\A `` `defect' includes any 
defect in performance, construction, component, or material of a motor 
vehicle or motor vehicle equipment.'' 49 U.S.C. 30102(a)(3) (emphasis 
added). Accordingly, ``a determination of `defect' does not require any 
predicate of a finding identifying engineering, metallurgical, or 
manufacturing failures. A determination of `defect' may be based 
exclusively on the performance record of the vehicle or component.'' 
Wheels, 518 F.2d at 432 (emphasis added); see also United States v. 
General Motors Corp., 841 F.2d 400, 413 (D.C. Cir. 1988) (explaining 
that a defect can be established by the performance record alone and 
does not require an engineering explanation).\128\ A non-defective 
inflator does not rupture when it is commanded to deploy, absent some 
extraordinary circumstance such as tampering.\129\ The repeated 
ruptures of the subject inflators would not have occurred absent a 
defect.\130\
---------------------------------------------------------------------------

    \123\ See, e.g., Comments of Kia America Inc. at pp. 1-2; 
Written Comments of General Motors LLC at p. 13; Comments from 
Hyundai Motor America at pp. 2, 20; Public Comment Submitted by 
Jacqueline Glassman at p. 10 (stating that while the root cause 
``may not necessarily be a prerequisite to understanding that there 
is a safety related defect,'' there must ``be some meaningful 
relationship in order to infer that the underlying problem is a 
`class-wide' problem.'').
    This is despite the years of analysis the industry has 
undertaken during the agency's investigation. The agency does not 
believe that it is either necessary or appropriate to allow for 
additional time for such analysis.
    \124\ See John Keller P.E., Comments on NHTSA's Initial decision 
to Declare ARC Automotive Toroidal Airbag Inflators Defective (Dec. 
6, 2023) at p. 1; Jerry W. Cox, Esq., Comments in Support of the 
National Highway Traffic Safety Administration's Initial Decision to 
Declare 52 Million ARC Automotive Airbag Inflators Defective at p. 
2.
    \125\ Commenters appear to overstate NHTSA's reliance on the 
Takata recalls as a basis for the initial decision here. Takata was 
discussed essentially twice in the initial decision: in a section 
providing general background on air bags and in another providing 
background on the agency's past practices regarding recall request 
letters. NHTSA's references to Takata in the initial decision were 
made to provide context on recalls involving inflator ruptures and 
not as a particularized substantive argument.
    \126\ In fact, NHTSA's recall request letter to Takata makes 
clear that the agency believed that multiple variables could result 
in propellant degradation, which caused ruptures. Letter from F. 
Borris, NHTSA, to K. Higuchi, TK Holdings Inc. (Nov. 26, 2014), 
https://static.nhtsa.gov/odi/inv/2014/INRM-PE14016-60978.pdf 
(describing high absolute humidity as one variable, but explaining 
that other ruptures occurred outside areas of high absolute 
humidity). That is also the case here, where the evidence points to 
multiple variables that may result in over pressurization, causing 
rupture.
    \127\ Pointing to the specific facts in the Takata recalls as 
precedent for necessary elements to order a recall, among other 
things, ignores that each recall is fact specific--and suggests, 
incorrectly, that the agency must match the bases for the Takata 
recalls to order a recall here.
    \128\ It is well established that a safety defect determination 
does not require an engineering explanation or root cause. See NHTSA 
Enforcement Guidance Bulletin 2016-02: Safety-Related Defects and 
Automated Safety Technologies, 81 FR 65705, 65708 (Sept. 23, 2016).
    \129\ See NHTSA, Special Crash Investigations: On-Site Air Bag 
Inflator Rupture Crash Investigation; Vehicle: 2009 Honda Civic; 
Location: Maryland; Crash Date: September 2017 (June 2020), https://crashstats.nhtsa.dot.gov/Api/Public/Publication/812972 (explaining, 
in investigation into ruptured inflator, that ``[t]he wiring harness 
for the driver's frontal air bag inflator had been tampered with 
since the vehicle's date of manufacture'').
    \130\ In much of the prior litigation under Safety Act the issue 
of whether there was a defect was not in question, in part due to 
the obvious nature of the defect. See, e.g., United States v. 
General Motors Corp., 561 F.2d 923, 924 (D.C. Cir. 1977) (``Pitman 
Arms''); United States v. Ford Motor Co., 453 F. Supp. 1240, 1249 
(D.D.C. 1978).
---------------------------------------------------------------------------

    Manufacturers' arguments related to a ``root cause'' finding are 
inconsistent with their legal obligations and actions they have taken 
pursuant to those obligations. Under the Safety Act, a manufacturer is 
required to initiate a recall once it ``learns the vehicle or equipment 
contains a defect and decides in good faith that the defect is related 
to motor vehicle safety.'' 49 U.S.C. 30118(c)(1). It is common for the 
industry to recognize obvious defects without identifying a specific 
cause when, based on the performance record, they present a severe risk 
to safety.\131\ Related to air bags in particular, manufacturers have 
recalled inflators susceptible to rupture without identifying the type 
of particularized cause demanded by the commenters.\132\ In fact, ARC 
and other manufacturers have done so here. For example, BMW, GM, and 
Volkswagen initiated recalls without identifying a cause based on the 
severity of the risk as shown by one rupture.\133\ ARC acknowledged 
that it has ``supported targeted recalls by vehicle manufacturers 
related to field ruptures and production lots with an identified 
potential risk of defect.'' \134\ These actions are consistent with a 
manufacturer's obligations under the Safety Act to recall vehicles when 
it decides a defect related to motor vehicle safety exists. The Safety 
Act does not allow a manufacturer to evade or delay a recall because it 
has not identified a specific ``root cause.'' NHTSA routinely takes 
enforcement actions against manufacturers for failure to timely make 
recall determinations, including where the lack of an identified root 
cause contributed to the delay.\135\
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    \131\ See Defect Notices, NHTSA Recall Nos. 23V-867 (In 
describing the cause of the defect that ``may lead to thermal 
overload, possibly resulting in smoke or a fire,'' Volkswagen stated 
that ``[t]he root cause is still under investigation, but the risk 
is associated with the battery modules exhibiting the potentially 
critical self-discharge behavior.''); 23V-840 (In its description of 
the cause of a defect that ``can lead to thermal events and in some 
cases fires,'' Porsche states that ``[t]he root cause is still under 
investigation.''); 23V-369 (JLR provides ``NR,'' commonly understood 
to mean `no response,' to describe the cause of a ``thermal 
overload'' condition that ``may show as smoke or fire'' and ``can 
result in increased risk of occupant injury.''); 23V-626 (In 
determining a defect exists that can ``result in a loss of motive 
power,'' Ford identified one contributing factor but stated that ``a 
second factor must be present or induced,'' and that ``[t]his factor 
is still unknown and under investigation.''); 24V-099 (For a defect 
affecting seatbelt function that ``may result in injury in the event 
of a crash,'' Ford attributed the issue to corrosion ``caused by an 
undefined supplier manufacturing issue.''); and 24V-418 (For a 
defect resulting in seatbelts becoming ``unavailable as an occupant 
restraint'' and resulting in ``an increased risk of injury if the 
vehicle is involved in a crash,'' GM describes the cause as ``[t]wo 
internal components'' that ``may be slightly our of dimensional 
specifications'' but does not explain how the components came to be 
out of specifications.)
    \132\ See Defect Notice, NHTSA Recall No. 16V-045 (``The cause 
is yet not determined. Takata and Volkswagen are still under 
investigation of the root cause.'').
    \133\ See Defect Notices, NHTSA Recall Nos. 17V-189 (``The root 
cause has not yet been determined and is still under 
investigation.''); 19V-019 (providing no response (``NR'') as to the 
description of the cause); 21V-782 (providing no response (``NR'') 
as to the description of the cause); 22E-040 (``GM's investigation 
has not identified the specific root cause of the LAT rupture''); 
22V-246 (providing no response (``NR'') as to the description of the 
cause); 22V-543 (``The root cause is currently unknown . . . .''). 
Even in GM's most recent ARC-related recall, which it no longer 
sought to limit to a specific production lot, it indicated as to 
cause that ``GM is continuing its investigation into this 
incident.'' See Defect Notice, NHTSA Recall No. 23V-334.
    \134\ See Written Response of ARC Automotive, Inc. to the 
September 5, 2023, Initial Decision Docket No. NHTSA-2023-0038 at p. 
20, https://www.regulations.gov/comment/NHTSA-2023-0038-0027.
    \135\ See, e.g., Consent Order between NHTSA and Daimler Trucks 
North America, LLC, In re: AQ18-002 ] 29 (Dec. 29, 2020), https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/aq18-002_consent_order_executed.pdf (``DTNA acknowledges that the failure 
to identify a specific root cause, develop an adequate repair or 
remedy, or confirm the affected population of vehicles are not bases 
for delaying the identification of a defect or noncompliance, the 
determination of whether a defect related to motor vehicle safety, 
or the timely reporting a defect or noncompliance to NHTSA.''); 
Consent Order between NHTSA and General Motors Company, In re: TQ14-
001 ] 24 (May 16, 2014), https://www.nhtsa.gov/sites/nhtsa.gov/files/2021-11/TQ14-001-General-Motors-Consent-Order-5-6-2014-tag.pdf 
(``GM shall not delay holding any meeting . . . to decide whether or 
not to recommend or. conduct a safety recall because GM has not yet 
identified the precise cause of a defect, a remedy for the defect, 
or prepared a plan for remedying the defect.'').

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[[Page 63486]]

    Commenters' arguments regarding root cause also ignore the evidence 
of a common defect collected during NHTSA's investigation and described 
above in this section and II.A.2-3 & 5. The evidence indicates that 
problems related to friction welding can lead to both over-
pressurization due to exit orifice blockage and insufficient friction 
welds. All of the field ruptures and a majority of the lot acceptance 
test ruptures share these commonalities.
    The evidence collected in NHTSA's investigation establishes that 
the subject inflators have an unacceptable risk of rupturing. 
Therefore, the entire subject inflator population is defective and must 
be recalled. As demonstrated by past ruptures, the occurrence of a 
rupture is unpredictable. Ruptures have occurred outside of narrower 
inflator populations previously identified by the manufacturers to be 
the defective population. There is substantial evidence tying the 
defect to the friction welding process, and this process was used 
across all manufacturing lines and plants that produced the subject 
inflators. After multiple years of thorough investigation and analysis, 
the evidence does not identify another element linking the ruptures. As 
such, the subject inflator population identified in this decision is 
the narrowest defective population supported by the evidence.
    ARC claims the subject inflator population is too broad due to 
variations in design and manufacturing of the subject inflators. 
Similarly, other commenters have pointed out these variations and 
assert that certain subpopulations of the subject inflators should be 
excluded from the scope of a recall, e.g., passenger-side subject 
inflators and subject inflators installed in certain makes and models. 
Despite years of comprehensive analysis, NHTSA has found no design or 
manufacturing evidence that shows these subpopulations are less 
susceptible to rupture. In addition to the field rupture of a 
passenger-side inflator, passenger-side inflators also ruptured in 
fourteen lot acceptance tests. While NHTSA recognizes there may be 
practical and logistical challenges to implementing a recall for the 
full defective population, these concerns do not warrant a narrower 
scope. Under the Safety Act, unreasonable risks cannot be countenanced 
simply because of logistical challenges that may be involved in 
remedying them.
    None of the manufacturers have provided compelling technical 
evidence that connects any of these variations to the defect or to a 
particular subset of inflators that rebuts the need to recall the 
subject inflators, ``[a]nd there is justice in this allocation to the 
manufacturer[s] of the burden of compiling significant data on the 
causes and consequences of mishaps in [their] cars.'' United States v. 
General Motors Corp., 561 F.2d 923, 931 (D.C. Cir. 1977) (``Pitman 
Arms''). And contrary to Hyundai's comment that there is ``little 
downside'' for the agency to ``complete the necessary investigation and 
make a rational judgment as to whether'' and to what extent a recall is 
needed, there is already sufficient evidence that the full population 
of subject inflators is defective. There is significant ``downside'' at 
this point to further investigation in lieu of a recall.\136\ Absent a 
recall, vehicle owners are not notified of the defect or entitled to 
have it addressed when a remedy is available. NHTSA has, accordingly, 
initially determined that the full population of subject inflators is 
defective.
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    \136\ Hyundai also noted that ``no other country with a similar 
safety recall legal framework'' has required a recall for the 
subject inflators. There are seven confirmed U.S. ruptures of the 
subject inflators, and over 20 million fewer ARC inflators were 
distributed globally (across all countries) than to the U.S. In any 
case, NHTSA's action is based on U.S. law. NHTSA is not bound by 
other jurisdictions and their respective authorities and is making 
this decision based on the facts before it (all of which may, or may 
not, be available to other jurisdictions).
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B. The Defect Is Related to Motor Vehicle Safety

    NHTSA has also preliminarily concluded based on the available 
evidence that the defect in the subject inflators (as described in 
section II.A) is related to motor vehicle safety because a risk of 
inflator rupture presents an unreasonable risk of death or injury in 
the event of an accident. It is undisputed that rupturing inflators 
have forcefully propelled pieces of metal at occupants, resulting in 
grave, permanent injuries and death. Future rupture events likely would 
have similar outcomes. An air bag's life-saving purpose also has 
bearing on the unreasonableness of this defect.
    The Safety Act defines ``motor vehicle safety'' as ``the 
performance of a motor vehicle or motor vehicle equipment in a way that 
protects the public against unreasonable risk of accidents occurring 
because of the design, construction, or performance of a motor vehicle, 
and against unreasonable risk of death or injury in an accident and 
includes nonoperational safety of a motor vehicle.'' 49 U.S.C. 
30102(a)(9). The statute does not further define what constitutes an 
``unreasonable risk.'' Based on the ordinary meaning of that term, the 
high severity of an inflator rupture coupled with the inability of a 
vehicle owner or occupant to detect that the rupture will occur or 
otherwise mitigate the risk warrants a finding that the risk is 
unreasonable despite the low probability that a rupture will occur when 
the inflator is commanded to deploy.
    In considering this issue, courts have found that an assessment of 
whether a risk is unreasonable requires a `` `commonsense' approach.'' 
Carburetors, 565 F.2d at 757. The most obvious, or ``commonsense,'' 
consideration in this assessment is, of course, the safety risk itself. 
A defect that ``leads to failures in a vital component . . . is prima 
facie an `unreasonable risk.' '' Pitman Arms, 561 F.2d at 929. In other 
words, there is ``no question'' that a risk of an ``extremely 
dangerous'' situation ``should be considered an unreasonable risk to 
safety.'' Carburetors at 757. If the risk is sufficiently severe, even 
an ``exceedingly small'' or ``negligible'' number of expected incidents 
is ``unreasonably large.'' Id. at 759.\137\ This is so regardless of 
whether any injuries have already occurred, or whether the projected 
number of failures or injuries in the future is trending down. See id.
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    \137\ Commenters asserted that NHTSA did not use or follow risk 
matrices used by NHTSA's Office of Defects Investigation (ODI). 
NHTSA's risk matrices are not recall-determination tools. Rather, 
the matrices are used ``[t]o assist in objectively evaluating 
whether a potential defect issue should be advanced to the next 
stage for an investigation. . . . ODI uses these matrices as 
deliberative tools to assist in evaluating the risk posed by a 
potential defect and identifying issues that should be elevated to 
an investigation.'' Risk-Based Process for Safety Defect Analysis 
and Management of Recalls, DOT HS 812 984 (Nov. 2020), https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/14895_odi_defectsrecallspubdoc_110520-v6a-tag.pdf. NHTSA decided 
back in 2015 that this issue warranted investigation under its risk-
based processes. Further, ODI's risk matrices and their application 
are not binding on NHTSA or any outside entity, and they are not 
``guidance''; they are a tool for ODI personnel.
---------------------------------------------------------------------------

    Courts have also considered certain particularly severe defects to 
be ``per se'' safety-related defects regardless of how many injuries or 
accidents are likely to occur in the future. These decisions have 
involved defects that cause the failure of a critical component, a 
vehicle fire, a loss of vehicle control, and a

[[Page 63487]]

defect that suddenly moves the driver away from the steering wheel, 
accelerator, and brake controls. See Carburetors, 565 F.2d 754 (engine 
fires); Pitman Arms, 561 F.2d 923 (loss of control); United States v. 
Ford Motor Co., 453 F. Supp. 1240 (D.D.C. 1978) (``Wipers'') (loss of 
visibility); United States v. Ford Motor Co., 421 F. Supp. 1239, 1243-
44 (D.D.C. 1976) (``Seatbacks'') (loss of control); see also NHTSA, 
Motor Vehicle Safety Defects and Recalls: What Every Vehicle Owner 
Should Know, available at https://www.nhtsa.gov/sites/nhtsa.gov//documents/14218-mvsdefectsandrecalls_041619-v2-tag.pdf (providing 
examples of safety-related defects, including ``[a]ir bags that deploy 
under conditions for which they are not intended to deploy'' and 
``[c]ritical vehicle components that break, fall apart, or separate 
from the vehicle, causing potential loss of vehicle control or injury 
to people inside or outside the vehicle'').
1. The Risk Posed by an Inflator Rupture Is Severe
    Here, there is no question that an inflator rupture presents an 
extreme danger. As already described, a rupture turns a component with 
the sole purpose of preventing serious injury and death into a device 
that can cause serious injury or death; the defect simultaneously 
undermines the component's life-saving purpose and introduces a life-
threatening danger. To reiterate, the consequences of these ruptures 
thus far include lacerations to the legs, harm to the jaw and ear, 
severe injuries to the face, neck, head, shoulder, and arm, injury to 
the airway requiring a tracheostomy, and death. Commonsense dictates 
that the defect here poses an unreasonable risk. See Carburetors, 565 
F.2d at 757-59.
    Even if a vehicle occupant is fortunate enough not to be struck by 
the metal fragments ejected out of the inflator upon a rupture, the 
rupture also undermines the intended effectiveness of the air bag in 
protecting an occupant in a crash. An air bag is designed to deploy in 
a precise manner under very strict timeframes. Over the course of 
milliseconds, numerous vehicle systems working in tandem must perform a 
multitude of functions in a particular order to ensure that the airbag 
protects the occupant.\138\ An air bag inflator is a critically 
important component in this sequence as it is responsible for ensuring 
that an air bag inflates a precise amount at a precise time in order to 
be in the right position when it meets the vehicle's occupant. When an 
inflator ruptures, the pressure accumulating in the inflator to is 
suddenly released, resulting in a complete disruption of the tightly 
controlled gas flow intended for the inflator.\139\ This disrupts the 
air bag inflation timing, undermining the air bag's ability to perform 
its intended safety function. Thus, even apart from a rupture's 
dangerous explosion of metal fragments towards a vehicle occupant, the 
rupture deprives a vehicle occupant of the benefit of an air bag.\140\ 
Manufacturers have issued recalls to address the increased safety risk 
to vehicle occupants when air bags do not properly inflate.\141\
---------------------------------------------------------------------------

    \138\ Such functions include but are not limited to detecting an 
impact, classifying the impact as severe enough to warrant an air 
bag deployment, understanding the likely positioning of the vehicle 
occupant based on the occupant's seating position and seatbelt 
status, commanding deployment of the air bag at a specified 
inflation rate to match the occupant's expected position, and 
reaching a level of air bag inflation necessary for the cushion of 
the air bag to reduce the expected crash forces. This is a very 
complex dynamic in which numerous life-critical systems are 
interdependent and all components must perform exactly as intended 
to protect the vehicle occupants.
    \139\ This release causes the gas flow rate into the air bag to 
suddenly spike before dramatically dropping as the inflator's 
pressure equalizes with the ambient air.
    \140\ During the investigation, both ARC and at least one 
vehicle manufacturer acknowledged that the rupture of one of the 
subject inflators could cause an air bag to underinflate. See ARC 
Presentation dated Mar. 1, 2016 on MY 2004 Kia Optima Rupture; 
Hyundai Letter to NHTSA dated Apr. 15, 2020.
    \141\ See NHTSA Recall Nos. 12V-055 and 01V-318.
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    Hundreds of recalls are issued each year for safety-related 
defects. In 2023 alone, there were nearly 800 such vehicle recalls. The 
vast majority of these recalls were uninfluenced by a NHTSA 
investigation.\142\ The nature of the defects and potential 
consequences ranged widely. While some involved fire risks or loss of 
vehicle control (and certain such recalls were accompanied by a ``do 
not drive'' advisory), others involved a variety of components and 
other potential consequences: sun visors that may detach (may distract 
or obstruct view); aluminum siding that may detach from a trailer; 
incorrectly assembled door latches that may allow the door to open 
unexpectedly during operation; incorrectly installed headlights 
(reducing visibility); and detached rearview mirror lenses (reducing 
visibility).\143\ When viewed broadly against the backdrop of the 
hundreds of recalls issued each year for various types of components 
and attendant consequences, the severity of an inflator rupture--where 
the consequence of the defect is the projection of shrapnel into the 
occupant compartment--is extreme. The latent nature of the defect 
further exacerbates its severity. This defect cannot be discerned by a 
diligent vehicle owner or even as the result of an inspection. The 
defect only becomes apparent upon a deployment but, by then, the danger 
has already manifested. As a result, this defect provides no 
opportunity for a driver to take any mitigating actions absent a 
recall--either ahead of manifestation of the defect, or when the defect 
manifests.
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    \142\ NHTSA 2023 Annual Report: Safety Recalls (Mar. 2024), 
available at https://www.nhtsa.gov/sites/nhtsa.gov/files/2024-03/NHTSA-2023-Annual-Recalls-Report_0.pdf. ``Uninfluenced'' recalls are 
recalls issued by a manufacturer not influenced by NHTSA 
investigation into the issue.
    \143\ See NHTSA Recall Dashboard, https://datahub.transportation.gov/Automobiles/NHTSA-Recalls-by-Manufacturer/mu99-t4jn; Recall Nos. 23V-781, 23V-612, 23V-373, 23V-
650, 23V-856. The recall dashboard is a user-friendly platform that 
can be used to sort, filter, visualize, and export recall data.
---------------------------------------------------------------------------

    The air bag inflator industry itself has long recognized the 
severity of the risk posed by an inflator rupture and the importance of 
preventing it. The United States Council for Automotive Research 
(USCAR) has published specifications establishing performance and 
validation requirements for air bag inflators. These requirements 
include assurance against certain behaviors in the event of an inflator 
rupture, which USCAR refers to as a burst. The specifications provide a 
testing procedure to confirm the structural integrity of an inflator, 
instructing the tester to block any exit orifices and increase the 
pressure until the inflator ruptures.\144\ This test is to ensure that 
``[a]n Inflator shall not eject any components or fragments during any 
portion of [design validation] and [production validation] testing.'' 
\145\ In the event of a rupture, any separation must be ductile and 
``the inflator shall not fragment or eject any part of the structural 
components.'' \146\
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    \144\ USCAR Inflator Technical Requirements and Validation at p. 
30 ] 5.2.3.1 (SAE Int'l, 2023).
    \145\ Id. at p. 7 ] 3.2.2.
    \146\ Id at p. 7 ] 3.2.2.1.
---------------------------------------------------------------------------

    ARC's own design practices similarly recognize that inflator 
ruptures present an unacceptable level of risk. Similar to the USCAR 
specifications described above, ARC's own internal mistake proofing 
protocol acknowledged that it was critical during the Operation 50 step 
of the manufacturing process to ensure that ``no vent orifice or weld 
flash blockage'' occurred.\147\ This is because ARC recognized that if 
those conditions exist, ``[t]he inflator can ``over pressurize and 
result in parts

[[Page 63488]]

ejecting.'' \148\ ARC assigned this type of over pressurization and 
rupture an FMEA severity number of 10 out of 10--the highest level of 
severity of all risks in ARC's FMEA. Any inflators in which such 
blockage occurred were to be ``manually scrapped'' and prompt a 
supervisor notification. As these materials illustrate, at the design 
and manufacturing planning stages, ARC expected a strict lack of 
tolerance for conditions that created a risk of ruptures, out of 
concern for the precise dangers at issue in this proceeding.
---------------------------------------------------------------------------

    \147\ See ARC Response to Requests 2 & 3 of NHTSA Aug. 25, 2015 
IR Letter at p. 40.
    \148\ Id.
---------------------------------------------------------------------------

    As previously discussed in section II.A.6, manufacturers in the 
instant case have also recognized the severity of the defective 
inflators in several ways. A single rupture was enough to prompt BMW, 
GM, and Volkswagen to issue recalls.\149\ Some manufacturers engaged 
private research firms to try to better understand the defect.\150\ In 
an effort to eliminate this severe risk from future inflators with the 
same design as the subject inflators, ARC implemented the automated 
borescope on all of its toroidal air bag inflator manufacturing 
lines.\151\ Going a step further, ARC has taken steps to remove the 
potential for this defect and the associated risk by considering other 
inflator designs.\152\ All of these actions underscore the commonsense 
recognition that a piece of equipment intended to protect people from 
injury and save lives that, instead, explodes and propels metal toward 
vehicle occupants presents an unreasonable risk to motor vehicle 
safety.
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    \149\ See Defect Notices, NHTSA Recall Nos. 17V-189, https://static.bnhtsa.gov/odi/rcl/2017/RCLRPT-17V189-8204.PDF (``The root 
cause has not yet been determined and is still under 
investigation.''); 19V-019, https://static.nhtsa.gov/odi/rcl/2019/RCLRPT-19V019-2023.PDF (providing no response (``NR'') as to the 
description of the cause); 21V-782, https://static.bnhtsa.gov/odi/rcl/2021/RCLRPT-21V782-3621.PDF (providing no response (``NR'') as 
to the description of the cause); 22E-040, https://static.nhtsa.gov/odi/rcl/2022/RCLRPT-22E040-9723.PDF (``GM's investigation has not 
identified the specific root cause of the LAT rupture''); 22V-246, 
https://static.bnhtsa.gov/odi/rcl/2022/RCLRPT-22V246-3538.PDF 
(providing no response (``NR'') as to the description of the cause); 
22V-543, https://static.nhtsa.gov/odi/rcl/2022/RCLRPT-22V543-3225.pdf (``The root cause is currently unknown . . . .''). Even in 
GM's most recent ARC-related recall, which it no longer sought to 
limit to a specific production lot, it indicated as to cause that 
``GM is continuing its investigation into this incident.'' See 
https://static.bnhtsa.gov/odi/rcl/2023/RCLRPT-23V334-3445.PDF.
    \150\ See Northrop Grumman Presentation dated May 5, 2023 on GM 
ARC Inflator Investigation; Memorandum--Meeting with HMA with 
Enclosure, Docket No. NHTSA-2023-0038, https://www.regulations.gov/document/NHTSA-2023-0038-0029.
    \151\ See ARC Working Group 8D Technical Closure Statement at p. 
1.
    \152\ See U.S. Pat. App. Pub. No. 2022/0185224 A1 to Rose et 
al., at ]] 0005-06.
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    Some commenters contended that the ``commonsense'' approach to the 
assessment of unreasonable risk requires a cost consideration, and that 
NHTSA did not consider costs in issuing its decision. This contention 
is essentially based on language in Wheels, in which the U.S. Court of 
Appeals for the D.C. Circuit discussed an approach to safety in the 
context of defects--specifically, a `` 'commonsense' balancing of 
safety benefits and economic cost'' that recognizes that 
``manufacturers are not required to design vehicles or components that 
never fail.'' The court stated that ``[i]t would appear economically, 
if not technologically, infeasible for manufacturers to use tires that 
do not wear out, lights that never burn out, and brakes that do not 
need adjusting or relining. Such parts cannot reasonably be termed 
defective if they fail because of age and wear.'' Wheels, 518 F.2d at 
435-36.
    The subject air bag inflators are not the type of ``wear and tear'' 
component to which the cost consideration described in Wheels would be 
apposite. Similar to the defective component in Carburetors, ``[h]ere 
we do not deal with a part which is subject to failure because of age 
and wear, or a part which drivers reasonably expect to have to check 
and replace because of the particular problem involved.'' Carburetors, 
565 F.2d at 759-60. The inflator industry already designs inflators 
never to rupture. In any case, by requiring a recall of the subject 
inflators, the agency is not requiring manufacturers to produce 
``perfect, accident-free vehicles at any expense.'' See Carburetors, 
565 F.2d at 760. Rather, it is requiring the notification of owners 
about these inflators ``which did not, from the beginning, meet the 
manufacturer's own standards.'' See id. at 760.
2. Future Inflator Ruptures Are Expected
    As the agency observed in its September 2023 initial decision, new 
ruptures have occurred outside of the sub-populations of vehicles 
previously recalled, and it is expected that additional ruptures will 
occur in the future. See Carburetors, 565 F.2d at 758 (``[W]here a 
defect--a term used in the sense of an `error or mistake'--has been 
established in a motor vehicle, and where this defect results in 
hazards as potentially dangerous as a sudden engine fire, and where 
there is no dispute that at least some such hazards, in this case 
fires, can definitely be expected to occur in the future, then the 
defect must be viewed as one `related to motor vehicle safety.' '') 
(footnotes omitted). However, just as the agency (and manufacturers) 
could not have predicted the vehicles in which ruptures have already 
occurred, nor can it predict the vehicles in which ruptures will occur 
for vehicles that remain equipped with subject inflators. Each of those 
inflators remains at risk. What is predictable is that the consequences 
of a rupture will be severe and possibly deadly. Thus, even though the 
risk of any individual inflator rupturing is low, it is nevertheless 
unreasonable. ``The purpose of the Safety Act . . . is not to protect 
individuals from risks associated with defective vehicles only after 
serious injuries have already occurred; it is to prevent serious 
injuries stemming from established defects before they occur.'' Id. at 
759.
    NHTSA is supplementing its statistical evaluation of the rupture 
risk of the subject inflators as a result of several adjustments made 
since the initial decision and partially as informed by the comments 
received.\153\ Upon additional analysis, NHTSA finds that the subject 
inflators have a higher risk of rupture than initially believed, based 
on a lowered estimate of the number of subject inflators that have 
previously deployed in the field. NHTSA's estimate is based on 
38,480,407 vehicles that have subject inflators in the driver-side air 
bag only, 8,992,543 vehicles that have subject inflators in the 
passenger-side air bag only, and 1,873,066 vehicles that have subject 
inflators in both driver- and passenger-side air bags, totaling 
approximately 49 million vehicles. NHTSA now estimates that 1,349,802 
of the subject air bag inflators (combined driver-side and passenger-
side) deployed in vehicles between 2000 and 2023.\154\ Based on the 
known field ruptures, the rupture rate of the subject inflators is 
therefore 7 out of 1,349,802. In other words, the risk of any subject 
inflator rupturing when commanded to deploy was and is 1 in 
192,829.\155\ NHTSA is adding to the docket a report more fully 
explaining its statistical considerations and findings. See NHTSA, 
Estimating the Rupture Rate and Projecting Future Ruptures for

[[Page 63489]]

Subject Inflators in NHTSA's Proceeding Related to EA16-003.
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    \153\ Changes include applying different deployment rates to 
driver- and passenger-side inflators based on historical crash data, 
refining the classification of vehicles for purposes of accounting 
for attrition, and accounting for vehicles being driven fewer miles 
as they age. These changes address a number of comments directed at 
this analysis.
    \154\ NHTSA previously estimated that approximately 2,600,000 of 
the subject air bag inflators had deployed in the field.
    \155\ This is an increase from the prior estimate of 7 in 2.6 
million (or 1 in 371,429).
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    NHTSA does not conduct statistical analyses as a matter of course 
in every defect investigation. Nor was a statistical analysis strictly 
necessary here--particularly given that the unreasonable risk here is 
self-evident and one of ``common sense.'' The analysis was initiated in 
response to a statement by ARC. In its response to the agency's recall 
request letter, ARC asserted that seven ruptures as compared to the 
total subject inflator population was insufficient to determine that a 
defect exists in the subject inflator population.\156\ However, a 
rupture only occurs if the air bag deploys. As such, it is more 
appropriate and accurate to compare the number of past field ruptures 
to the number of past field deployments to determine the rate at which 
the subject inflators have ruptured. Determining an estimated number of 
past field deployments required statistical calculations, which yielded 
the initial analysis. NHTSA disagrees with General Motors' 
characterization of NHTSA's reliance on that statistical analysis as 
``heavy.'' Indeed, the analysis was previously addressed in just a few 
sentences of NHTSA's September 2023 initial decision.\157\ The 
statistical analysis, now updated, is not a prediction of the future. 
It is, rather, additional information that supplements the agency's 
ordinary consideration of what constitutes an unreasonable risk, 
including engineering and investigative evidence. Although it supports 
NHTSA's conclusion, the statistical analysis was not necessary to 
NHTSA's September 2023 initial decision. That remains the case here as 
well.\158\
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    \156\ ARC's May 11, 2023 Response to NHTSA's Recall Request 
Letter, p. 2, https://static.nhtsa.gov/odi/inv/2016/INRR-EA16003-90616.pdf.
    \157\ A NHTSA statistician also further explained her work, in 
the interest of transparency, at the October 2023 public meeting.
    \158\ GM asserted that NHTSA's statistical analysis is 
inconsistent with the agency's previous rejection of an earlier, 
separate statistical analysis (which GM characterizes as a ``much 
more sophisticated predictive model'') in a previously submitted 
petition for inconsequentiality. See 85 FR 76159 (Nov. 27, 2020) 
(decision on petition). The statistical analysis that GM provided in 
its previous inconsequentiality petition was submitted to support 
the argument that the defect in an air bag inflator (i.e., an air 
bag inflator in which a defect had already been determined to exist) 
was, nonetheless, inconsequential to motor vehicle safety as 
installed in GM vehicles.
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    While NHTSA's updated statistical analysis confirms the commonsense 
understanding that inflator ruptures will continue to be rare, the 
severity of rupture renders that risk unacceptable under the Safety 
Act. Unsurprisingly, the manufacturers who have continued to dispute 
the need for a broader recall disagree that the risk is unreasonable. A 
number of commenters challenged the persuasiveness of the future 
rupture risk, asserting that the estimated number of future ruptures is 
too low to present an unreasonable risk to motor vehicle safety. 
Comments emphasizing the low number of expected future ruptures are 
unconvincing. Up to this point, the subject inflators have ruptured 
rarely, and yet they have still injured or killed at least eight people 
in the United States. The evidence is sufficient for the agency to find 
that the rare, though expected, occurrence of future rupture is 
unreasonable given the severity. Under the plain language of the Safety 
Act, such a severe, undetectable, and unpredictable risk of an inflator 
rupturing and sending shrapnel at high speed into the occupant 
compartment of a vehicle is ``unreasonable.'' Even a ``negligible'' 
number of future ruptures is unreasonable given that a foreseeable 
outcome is severe injury or death. See Carburetors, 565 F.2d 754 at 
759; Pitman Arms, 561 F.2d at 924.
    While an inflator rupture occurs if the inflator has been commanded 
to deploy in a crash, several commenters nevertheless asserted that the 
relevant population of inflators from which to derive a rupture rate 
should be the entire subject inflator population (51 million, rather 
than the number of inflators estimated to have actually deployed). The 
reasons were varied, including that all inflators have the same 
potential to undergo deployment and rupture in a crash, that use of the 
entire population best accounts for both the risk of a deployment and 
the risk of a rupture and, as commented by ARC, ``permits a more 
accurate comparison to peer inflator data and more appropriately 
compares the risk to comparable peer populations.'' \159\
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    \159\ Written Response of ARC Automotive, Inc. to the September 
5, 2023, Initial Decision (Dec. 18, 2023 (Corrected--February 12, 
2024), at p. 23. ARC also asserted that such an approach would be 
based on two directly observable inputs (number of inflators and 
known field events) instead of one (number of field events) with a 
separate estimated input (deployments). See id. at p. 22. Whether an 
input is ``directly observable'' has little import in determining 
appropriate variables to use as a statistical matter in developing 
risk assessments. While the total inflator population may be more 
accurately estimated, that does not render it the more appropriate 
metric.
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    NHTSA agrees that, in the event of a deployment, each of the 
subject inflators is equally at risk of rupture. None can be eliminated 
as not at risk, and it is not possible to know whether a particular 
inflator will rupture unless a deployment occurs. But a deployment is a 
necessary condition for a failure, and the vast majority of inflators 
have not deployed. Including the entire population of manufactured 
inflators in deriving a rupture rate--knowing that the overwhelming 
majority have not deployed--vastly understates the prevalence of the 
defect by ignoring the necessary condition for a failure. This would 
lead to a vast understatement of the true rupture rate and predicted 
future ruptures. For this reason, it is wholly appropriate to ground 
the predicted future rupture rate with reference to ruptures 
experienced in past deployments, and not to the total number of 
manufactured inflators.\160\
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    \160\ General Motors refers to a previous investigation 
regarding Mini Cooper S exhaust pipe tips in which the total 
population was used to refer to a failure rate. The product at issue 
there, however, did not involve a necessary condition like a 
deployment of the subject air bags for the defect to manifest. And 
notably, in previously evaluating certain statistical analyses in a 
General Motors inconsequentiality petition regarding Takata air bag 
inflators, NHTSA described the risk at issue in terms consistent 
with that here. See 85 FR 76159 (Nov. 27, 2020) (describing the 
fleet-level risk as ``the probability that at least one air bag will 
rupture among the thousands of air bag deployments expected to occur 
in the nearly 5.9 million affected GMT900 vehicles over the coming 
years'').
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    The notion that the total population of inflators allows for better 
peer comparison is also unconvincing. As explained above in II.A.4, 
there has been only one U.S. rupture of a non-Takata air bag inflator 
(other than an ARC air bag inflator), and any reference to the 
comparative rupture rates is of limited import, because that inflator 
was recalled after the first rupture. Therefore, it is unknown whether 
ruptures would have continued to occur in the absence of a recall. As 
is the case here, NHTSA believed the risk was unreasonable and a recall 
was warranted. The severity of inflator ruptures was also evident 
there, as the rupture resulted in a fatality. In that case, however, 
the manufacturer agreed to broad recalls of entire models (all model 
years) of vehicles that used the same type of inflator without the need 
for the agency to exercise its statutory authority to order a 
recall.\161\
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    \161\ See NHTSA Recall Nos. 20V-681, 21V-766, and 21V-800.
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    Some commenters asserted that NHTSA improperly assumed that 
manufacturing variables in different variants of the subject inflators 
have no impact on the rupture rate. However, there is no evidence-based 
justification for treating any subpopulation of the subject inflators 
as presenting more or less risk. FCA stated that certain field ruptures 
should not be included in the analysis--the ruptures in the MY 2002 
Chrysler Town & Country and the MY

[[Page 63490]]

2011 Chevrolet Malibu--because of these incidents did not have an 
underlying cause or failure mode in common with the other 
ruptures.\162\ NHTSA does not agree that these incidents lack 
sufficient commonality to be considered, as described in section II.A. 
Additionally, as previously explained, root cause is not necessary for 
a defect determination. It is not appropriate to eliminate any of the 
ruptures in vehicles--the very incidents where people have already been 
harmed--from its evaluation of whether there is an unreasonable risk.
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    \162\ See Comments of FCA US LLC Regarding Initial Decision at 
pp. 5-6.
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    Consumer safety ``would be most ill served by extending [a] delay 
based on new predictions that the number of injuries caused by the 
defect will diminish.'' Carburetors, 565 F.2d at 759. The agency also 
does not believe that logistical and cost-related concerns raised by 
commenters about a recall of the subject inflators warrants leaving the 
unreasonable risk unaddressed by a recall. NHTSA acknowledges the 
potential ramifications of a recall of this magnitude and does not take 
its decision lightly. However, the crux of this issue is not a variety 
of potential (or even attenuated or largely hypothetical) 
reverberations stemming from a recall--it is that there is defect in 
the subject inflators that presents an unreasonable risk of death or 
injury in the event of a crash, and that defect must be addressed.
    Every subject inflator that deploys is at risk of rupture, and 
rupture events are unpredictable and dangerous. Three of the seven 
field ruptures in the United States occurred between 2009 and 2017, and 
three more field ruptures occurred in the span of just over four months 
in 2021. The last field rupture occurred very recently, in 2023. While 
it is impossible to predict when the next rupture will occur, each 
inflator that deploys is at risk. NHTSA's statistical evaluation of the 
future rupture risk, while not imperative to its decision here, 
reinforces that field ruptures are expected to occur in the future, and 
any hopes premised simply on the relatively low odds of an inflator 
rupturing are insufficient to warrant inaction. Cf. Carburetors, 565 
F.2d at 759 (``[T]he fact that in past reported cases good luck and 
swift reactions have prevented many serious injuries does not mean that 
luck will continue to work in favor of passengers of burning cars. As a 
matter of statistics their chances may well . . . appear quite 
favorable. The purpose of the Safety Act, however, is not to protect 
individuals from the risks associated with defective vehicles only 
after serious injuries have already occurred; it is to prevent serious 
injuries stemming from established defects before they occur.''). With 
each subject inflator that deploys, the vehicle occupants are at risk 
of severe injury or death from a rupture. That risk is plainly 
unreasonable under the Safety Act.

III. Conclusion

    Every field rupture of the subject inflators in the United States 
has resulted in at least one vehicle occupant being injured, several 
have resulted in severe injury, and one has resulted in death. Seven of 
the subject inflators have already ruptured in vehicles the United 
States. The facts and circumstances surrounding these U.S. field 
ruptures, the four foreign field ruptures, and the twenty-three lot 
acceptance test ruptures underscore the severe impact of the defect on 
motor vehicle safety. Based on its comprehensive analysis, NHTSA has 
concluded that the evidence shows that the causes of these ruptures 
stem from use of a friction welding process without adequate inspection 
safeguards in place and that all of the subject inflators were produced 
using this same process. As such, all of the subject inflators have a 
risk of rupture and are defective. The pattern and evidence of these 
ruptures confirms that the reactionary, limited-scope recalls are 
insufficient to address the safety risk and that a recall for the full 
subject inflator population is necessary. Given the severity of a 
rupture and the known ruptures there is ample evidence of a defect in 
the subject inflators. Common sense demands acknowledging that metal 
shrapnel projecting at high speeds and causing injury or death presents 
an unreasonable risk to safety, and the Safety Act does not allow for 
such a risk to remain unaddressed.
    Pursuant to the Safety Act, NHTSA may make a final decision ``only 
after giving the manufacturer[s] an opportunity to present information, 
views, and arguments showing that there is no defect or noncompliance 
or that the defect does not affect motor vehicle safety. Any interested 
person also shall be given an opportunity to present information, 
views, and arguments.'' 49 U.S.C. 30118(b)(1). Given the more extensive 
detail and discussion of the technical issues in this notice, and to 
ensure opportunity for additional public feedback, NHTSA is providing 
an additional 30-day comment period. No additional public meeting will 
be held.
    If NHTSA makes a final decision that the subject inflators contain 
a safety defect, NHTSA will order ARC to comply with the obligation to 
file notice of the safety defect with the agency and will order the 
vehicle manufacturers to carry out recalls by providing notice and a 
free remedy. See id. section 30118(b)(2).
    Authority: 49 U.S.C. 30118(a), (b); 49 CFR 554.10; delegations of 
authority at 49 CFR 1.50(a) and 49 CFR 501.8.

Eileen Sullivan,
Associate Administrator for Enforcement.
[FR Doc. 2024-17251 Filed 8-2-24; 8:45 am]
BILLING CODE 4910-59-P