[Federal Register Volume 64, Number 82 (Thursday, April 29, 1999)]
[Proposed Rules]
[Pages 23037-23039]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-10777]
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DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
[Docket No. NHTSA-98-4167; Notice 1]
Federal Motor Vehicle Safety Standards; Child Restraint Systems
AGENCY: National Highway Traffic Safety Administration (NHTSA), DOT.
ACTION: Denial of petition for rulemaking.
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SUMMARY: This document denies a petition for rulemaking requesting that
NHTSA amend Standard 213, ``Child Restraint Systems,'' to delete the
head excursion requirement for rear-facing convertible restraints.
Petitioners believe that infants should be rear-facing until at least 1
year of age, and that the head excursion limit in Standard 213 makes it
unnecessarily difficult for manufacturers to recommend their restraints
be used rear-facing for children of at least that age. NHTSA is denying
the petition because the head excursion limit serves a safety need and
there are unknown safety consequences to the petitioners' requested
action. Second, more and more manufacturers are able to meet the head
excursion requirement and certify rear-facing restraints for children
older than 1 year in age. Further, the petitioners did not provide--and
NHTSA has not identified--any data which indicate that injuries could
have been prevented by the requested amendment.
FOR FURTHER INFORMATION CONTACT: For nonlegal issues: Mike Huntley,
Office of Crashworthiness Standards, Special Vehicle and Systems
Division (telephone 202-366-0029).
For legal issues: Deirdre Fujita, Office of the Chief Counsel (202-
366-2992). Both can be reached at the National Highway Traffic Safety
Administration, 400 Seventh St., SW, Washington, DC 20590.
SUPPLEMENTARY INFORMATION:
I. Petitioners' Request
On March 1, 1997, Stephanie Trombello and Deborah Stewart,
Executive Director and Technical Consultant, respectively, of
SafetyBeltSafe U.S.A., Inglewood, California, petitioned NHTSA to amend
Federal Motor Vehicle Safety Standard No. 213, ``Child Restraint
Systems'' (49 CFR 571.213), concerning certain labeling and occupant
excursion requirements in the standard. Petitioners believe that
infants should be rear-facing until at least 1 year of age, and that
the head excursion limit in Standard 213 makes it unnecessarily
difficult for manufacturers of convertible 1 child restraint
systems to recommend that their restraints be used rear-facing until
the child is at least that age.
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\1\ A convertible restraint is used to restrain children from
birth to about 40 lb. When restraining an infant, the restraint is
positioned so that it faces the rear of a vehicle. When restraining
a toddler, the restraint is positioned so that it faces the front of
a vehicle.
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Standard 213 specifies performance requirements that a child
restraint must meet when tested with dummies representing the range of
children for which that child restraint is recommended. Under Standard
213's requirements, child restraints recommended for use by children
weighing over 22 lb are tested with a test dummy representing a 3-year-
old child. So tested, they must meet all performance requirements of
the standard, including limits on how far they allow the rear-facing
dummy's head to extend beyond and above the top of the child restraint
in a 30-mph dynamic test. (This document refers to these limits as the
head excursion limits.) The head excursion limits are set forth in
S5.1.3.2 of Standard 213, as follows:
S5.1.3.2. Rear-facing child restraint systems. In the case of
each rear-facing child restraint system, all portions of the test
dummy's torso shall be retained within the system and neither of the
target points on either side of the dummy's head and on the
transverse axis passing through the center of mass of the dummy's
head and perpendicular to the head's midsagittal plane, shall pass
through the transverse orthogonal planes whose intersection contains
the forward-most and top-most points on the child restraint system
surfaces.
The petitioners request that Standard 213 be amended to exclude
convertible child restraints from the head excursion limit when the
restraint is tested rear-facing with the 33 lb dummy. Petitioners state
that, but for the head excursion limit,
(S)ome currently available convertible safety seats have
performed well in crash tests with the 33-pound dummy in the rear-
facing position. (However, we) understand that the reason the
manufacturers have hesitated to change their instructions to
encourage rear-facing use for heavier babies is that the child's
head could ramp up and over the top edge of the car seat in a head-
on collision.
Petitioners believe that injuries will be prevented if NHTSA amends
the standard as they request. Twenty-two (22) lb is the weight of a
50th percentile 12-month-old. Petitioners state that many babies reach
22 lb at six months of age or even earlier. They believe that current
labeling on convertible child restraints results in parents of
``heavy'' infants turning the child forward when the child is less than
1 year.
Petitioners believe that the head excursion limit is unnecessary
because a heavy one-year-old is much shorter than the 33 lb (3-year-
old) dummy. They suggest that in lieu of the head excursion
requirement, parents can be instructed, by way of a label, to limit use
of the rear-facing child restraint based on the child's height. They
suggest a statement such as ``This safety seat may be used in the rear-
facing position until the child weighs 30 pounds if the child's head is
below the top edge (or within __ inches of the top edge) of the seat.''
II. Evaluation of Petition
NHTSA is denying the petition for the reasons set forth below.
1. Rear-Facing Restraints Certified Above 22 Lb
Infants should be transported rear-facing until the child's
skeletal and muscular structure can develop to where they can more
safely withstand crash forces in a forward-facing position, which
typically occurs at around age 1. Transporting infants rear-facing
spreads crash forces evenly across the infant's back and shoulders, the
strongest part of the child's body.
[[Page 23038]]
Further, the infant's head will be supported by the seating surface in
a crash, which helps reduce the likelihood of severe neck injuries in a
crash. To better enable child restraint manufacturers to produce rear-
facing child restraints for children up to age 1, Standard 213
specifies that child restraints will not be tested with the 3-year-old
child test dummy unless the restraint is recommended for use by a child
weighing more than the 50th percentile 12-month-old (which weighs 22
lb) (see July 6, 1995 final rule, 60 FR 50477).2
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\2\ The interrelationship of weight, height, and age as they
relate to positioning an infant rear facing in a child restraint
system was discussed at length in the development of this rule,
which amended FMVSS No. 213 to add a greater array of sizes and
weights of test dummies for use in the standard's compliance tests.
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While positioning an infant rear-facing is generally preferable to
facing the child forward, that may not be the case if the child
restraint system is unable to adequately limit the head excursion of
the child, or otherwise meet the performance requirements of Standard
213. If the head excursion limit were deleted, that would negate the
agency's ability to evaluate the restraint's ability to limit the
upwards ramping of a child's head in a crash and would hamper the
evaluation of the restraint's ability to prevent the partial or full
ejection of the dummy.
Petitioners state that a ``heavy'' 1-year-old is much shorter than
the 33 lb dummy, but do not provide any values quantifying the height
difference. Available data indicate only a 3.5 centimeter (cm)
difference in height. NHTSA evaluated data in a 1975 report by the
University of Michigan, ``Physical Characteristics of Children as
Related to Death and Injury for Consumer Product Safety Design,'' May
1975 (UM-HSRI-BI-75-5, HS 017743), to determine the difference in
sitting heights between a 95th percentile 1-year-old and a 50th
percentile 3-year-old child. The sitting height (crown-rump) of the
95th percentile 1-year-old (combined sexes) is approximately 50 cm,
while that of the 50th percentile 3-year-old (combined sexes) is 53.5
cm.3 The agency believes that the 3.5 cm height difference
is not of a magnitude to render the 3-year-old dummy inappropriate as a
test device for evaluating the restraint's ability to limit the head
excursion of a 95th percentile 12-month-old child. To the contrary, the
difference between the two may be unsubstantial.
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\3\ The agency's 3-year-old dummy represents a 50th percentile
male child. Data on the sitting height of a 50th percentile male are
not available.
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Petitioners have also not provided data showing that a ``heavy'' 1-
year-old would have adequate head support in a crash without a head
excursion limit in the standard. They believe that a child whose head
is ``below the top edge (or within __ inches of the top edge) of the
seat'' will be adequately protected, but do not specify what value
should be specified in the blank. They also do not provide data
supporting their belief that a child restraint will adequately support
a child's head which is ``below the top edge'' or below that
unspecified location on the child restraint. NHTSA is concerned that
not enough is known about the safety consequences of reducing the
stringency of the head excursion requirement for rear-facing child
restraints.
In addition to the above consideration, the current requirement is
practicable. Some manufacturers have been able to develop convertible
child restraints that they have certified as meeting Standard 213 when
tested rear-facing with the 33 lb dummy. NHTSA is aware of at least
three manufacturers who currently market convertible child restraints
that are certified for children weighing more than 22 lb, in the rear-
facing position. Century, Evenflo and Britax have all developed
products which they certify meet all requirements of Standard 213 when
tested in the rear-facing position with the 33 lb dummy. Thus, NHTSA
believes that rear-facing restraints are available to families with
``heavy'' infants that exceed 22 lb prior to 1 year of age.
In summary, petitioners state that ``although the 3-year-old dummy
may be too tall for full head support in the rear-facing position, a
heavy 1-year-old is much shorter,'' but did not provide any technical
rationale to support eliminating the excursion requirements of the
standard when testing convertible restraints in the rear facing
position with the 3-year-old dummy. Petitioners did not explain why the
head excursion limit should be relaxed given the insubstantial sitting
height difference between an average 3-year-old child and a ``heavy''
1-year-old child, nor did they explain the extent to which the head
excursion limit could be relaxed given that height difference. These
factors, in conjunction with the knowledge that various manufacturers
have developed convertible restraints that meet the current
requirements of the standard while tested rear-facing with the 33 lb,
3-year-old dummy, lead the agency to believe that the current excursion
requirement does not impose an unreasonable impediment to restraint
manufacturers in the design of rear-facing restraints for children over
22 lb.
2. Excursion Requirements; Total Height Considerations
Petitioners also recommend that Standard 213's labeling
requirements should be amended such that ``references to the total
height of the child should be deleted, since the only significant
measurements are the child's weight and the length of the torso.'' (The
standard currently requires that manufacturers label their child
restraints with information on both the height and weight of children
for whom the restraint is recommended.) The agency discussed at length
the relevancy of height as a significant criterion in the development,
evaluation, and certification of child restraints in a 1995 rulemaking
to incorporate the new set of test dummies into Standard 213 for
compliance testing.
In the notice of proposed rulemaking (NPRM) for that regulation,
NHTSA had proposed that Standard 213 should require that manufacturers
base their height recommendations on the sitting height of the child
(51 FR 12225, March 16, 1994). In response to the NPRM, commenters
generally agreed that the height of a child is an important factor in
the certification and proper use of child restraint systems. While some
supported the use of a sitting height criterion as had been proposed by
the agency in the NPRM, others objected to its use because of concerns
regarding the complexity and potential misinterpretation of information
by users of these child restraint systems. Those who opposed adoption
of a sitting height criterion proposed incorporation of a sitting
height limit which references a readily identifiable body landmark
(such as the top of the ears or top of the head) in relation to the top
of the head restraint in conjunction with modified labeling
requirements to convey information about the proper use of the child
restraint to the consumer to prevent whiplash-type injuries.
In the final rule (July 6, 1995, 60 FR 35127), the agency
reconfirmed that information about the suitability of a restraint for
children of certain heights serves a useful purpose in that it helps
ensure the proper fit of a restraint to the child. At the same time,
the agency acknowledged that consumers may not know the sitting height
of their child as well as they know standing height. The latter is
routinely measured by pediatricians and provided to parents during the
child's medical examinations. Because standing height is more familiar
to parents, the final rule specified recommended standing height,
[[Page 23039]]
rather than sitting height, to be on the label.
Since the existing Standard 213 required manufacturers to label
each child restraint with recommendations for the maximum height of
children who can safely occupy the system, and because NHTSA was
unconvinced of a need to change to sitting height, the final rule
maintained the status quo. Petitioners have not provided any
information supporting their request to change to sitting height and
the agency is unaware of any reason to amend the standard as they
suggest. Accordingly, the agency is denying this request.
3. Crash Data
Underlying the petition is the implication that infants weighing
over 22 lb are being injured because parents position them forward-
facing in a vehicle before the infants are 1 year of age. Petitioners
did not provide any data or statistics indicating a greater incidence
of neck and spinal cord injuries for this segment of the population.
NHTSA examined the agency's National Automotive Sampling System (NASS)
General Estimates System (GES) 4 records for the years 1988-
1996 for those crashes (1) involving an infant under 1 year of age, and
(2) where both the child's weight and the child restraint orientation
(rear or forward facing) were known. In 328 total cases investigated by
NASS , there were no reported incidences of serious spine or other
neck-related injuries. Seventeen (17) percent of the 328 cases (55 of
328) involved infants weighing between 23 and 30 lb who were positioned
forward facing in his/her child restraint at the time of the crash, but
in only one case did the child receive a serious (AIS level 3 or
greater) injury. Injuries to heavy infants placed forward-facing in
vehicles have not occurred with any frequency.5
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\4\ Data for the General Estimates System (GES) come from a
nationally representative sample of police reported motor vehicle
crashes of all types, from minor to fatal. The system began
operation in 1988, and was created to identify traffic safety
problem areas, provide a basis for regulatory and consumer
initiatives, and form the basis for cost and benefit analyses of
traffic safety initiatives. The information is used to estimate how
many motor vehicle crashes of different kinds take place, and what
happens when they occur. Although various sources suggest that about
half the motor vehicle crashes in the country are not reported to
the police, the majority of these unreported crashes involve only
minor property damage and no significant personal injury. By
restricting attention to police-reported crashes, the GES
concentrates on those crashes of greatest concern to the highway
safety community and the general public.
\5\ The vast majority (273 of 328, or 83 percent) of reported
cases involved infants weighing 22 lb or less. Nearly one half (47
percent) of these infants were positioned forward-facing in their
child restraints. This clearly suggests that nearly one half of the
adults placing the infants in the child restraints either: (1) Were
unaware that infants are safest rear-facing in child restraints, or
(2) chose to ignore the manufacturer's recommendations and placed
their child forward-facing in the restraint. This suggests a need to
better inform parents about the need to properly position infants
weighing less than 22 lb in vehicles.
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In accordance with 49 CFR part 552, this completes the agency's
review of the petition. For the aforementioned reasons, the agency has
decided not to amend Standard 213 at this time to afford child
restraint manufacturers greater latitude in certifying rear-facing
convertible restraints. NHTSA has concluded that there is no reasonable
possibility that the amendment requested by the petitioners would be
issued at the conclusion of the rulemaking proceeding. Accordingly, the
petition is denied.
Authority: 49 U.S.C. 322, 30111, 30115, 30117 and 30166;
delegation of authority at 49 CFR 1.50
Issued on April 20, 1999.
L. Robert Shelton,
Associate Administrator for Safety Performance Standards.
[FR Doc. 99-10777 Filed 4-28-99; 8:45 am]
BILLING CODE 4910-59-P