[Federal Register Volume 81, Number 70 (Tuesday, April 12, 2016)]
[Rules and Regulations]
[Pages 21472-21478]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-08282]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2014-0449; FRL-9944-11]


1,2-Propanediol, 3-[3-[1, 3, 3, 3-tetramethyl-1-
[(trimethylsilyl)oxy]-1-disiloxanyl] propoxy]-; Exemption From the 
Requirement of a Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes an exemption from the requirement 
of a tolerance for residues of 1,2-propanediol, 3-[3-[1, 3, 3, 3-
tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]- (CAS Reg. 
No. 70280-68-1) when used as an inert ingredient (antifoaming agent) in 
pesticide formulations applied to growing crops at a maximum 
concentration not to exceed 5% by weight. Exponent, on behalf of ISK 
Biosciences submitted a petition to EPA under the Federal Food, Drug, 
and Cosmetic Act (FFDCA), requesting establishment of an exemption from 
the requirement of a tolerance. This regulation eliminates the need to 
establish a maximum permissible level for residues of 1,2-propanediol, 
3-[3-[1, 3, 3, 3-tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxyanyl] 
propoxy]-.

DATES: This regulation is effective April 12, 2016. Objections and 
requests for hearings must be received on or before June 13, 2016, and 
must be filed in accordance with the instructions provided in 40 CFR 
part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).

ADDRESSES: The docket for this action, identified by docket 
identification (ID) number EPA-HQ-OPP-2014-0449, is available at http://www.regulations.gov or at the Office of Pesticide Programs Regulatory 
Public Docket (OPP Docket) in the Environmental Protection Agency 
Docket Center (EPA/DC), West William Jefferson Clinton Bldg., Rm. 3334, 
1301 Constitution Ave. NW., Washington, DC 20460-0001. The Public 
Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through 
Friday, excluding legal holidays. The telephone number for the Public 
Reading Room is (202) 566-1744, and the telephone number for the OPP 
Docket is (703) 305-5805. Please review the visitor instructions and 
additional information about the docket available at http://www.epa.gov/dockets.

FOR FURTHER INFORMATION CONTACT: Susan Lewis, Registration Division 
(7505P), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave. NW., Washington, DC 20460-0001; main telephone 
number: (703) 305-7090; email address: [email protected].

SUPPLEMENTARY INFORMATION: 

I. General Information

A. Does this action apply to me?

    You may be potentially affected by this action if you are an 
agricultural producer, food manufacturer, or pesticide manufacturer. 
The following list of North American Industrial Classification System 
(NAICS) codes is not intended to be exhaustive, but rather provides a 
guide to help readers determine whether this document applies to them. 
Potentially affected entities may include:
     Crop production (NAICS code 111).
     Animal production (NAICS code 112).
     Food manufacturing (NAICS code 311).
     Pesticide manufacturing (NAICS code 32532).

[[Page 21473]]

B. How can I get electronic access to other related information?

    You may access a frequently updated electronic version of 40 CFR 
part 180 through the Government Printing Office's e-CFR site at http://www.ecfr.gov/cgi-bin/text-idx?&c=ecfr&tpl=/ecfrbrowse/Title40/40tab_02.tpl. To access the OCSPP test guidelines referenced in this 
document electronically, please go to http://www.epa.gov/ocspp and 
select ``Test Methods and Guidelines.''

C. How can I file an objection or hearing request?

    Under FFDCA section 408(g), 21 U.S.C. 346a, any person may file an 
objection to any aspect of this regulation and may also request a 
hearing on those objections. You must file your objection or request a 
hearing on this regulation in accordance with the instructions provided 
in 40 CFR part 178. To ensure proper receipt by EPA, you must identify 
docket ID number EPA-HQ-OPP-2014-0449 in the subject line on the first 
page of your submission. All objections and requests for a hearing must 
be in writing, and must be received by the Hearing Clerk on or before 
June 13, 2016. Addresses for mail and hand delivery of objections and 
hearing requests are provided in 40 CFR 178.25(b).
    In addition to filing an objection or hearing request with the 
Hearing Clerk as described in 40 CFR part 178, please submit a copy of 
the filing (excluding any Confidential Business Information (CBI)) for 
inclusion in the public docket. Information not marked confidential 
pursuant to 40 CFR part 2 may be disclosed publicly by EPA without 
prior notice. Submit the non-CBI copy of your objection or hearing 
request, identified by docket ID number EPA-HQ-OPP-2014-0449, by one of 
the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov. 
Follow the online instructions for submitting comments. Do not submit 
electronically any information you consider to be CBI or other 
information whose disclosure is restricted by statute.
     Mail: OPP Docket, Environmental Protection Agency Docket 
Center (EPA/DC), (28221T), 1200 Pennsylvania Ave. NW., Washington, DC 
20460-0001.
     Hand Delivery: To make special arrangements for hand 
delivery or delivery of boxed information, please follow the 
instructions at http://www.epa.gov/dockets/contacts.html.
    Additional instructions on commenting or visiting the docket, along 
with more information about dockets generally, is available at http://www.epa.gov/dockets.

II. Petition for Exemption

    In the Federal Register of April 6, 2015 (80 FR 18327) (FRL-9924-
00), EPA issued a document pursuant to FFDCA section 408, 21 U.S.C. 
346a, announcing the filing of a pesticide petition (PP IN-10699) by 
Exponent, on behalf of ISK Biosciences, 7470 Auburn Road, Suite A, 
Concord, OH 44077. The petition requested that 40 CFR 180.920 be 
amended by establishing an exemption from the requirement of a 
tolerance for residues of 1,2-propanediol, 3-[3-[1, 3, 3, 3-
tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]- (CAS Reg. 
No. 70280-68-1) when used as an inert ingredient (antifoaming agent) in 
pesticide formulations applied to growing crops at a maximum 
concentration not to exceed 10% in formulation. That document 
referenced a summary of the petition prepared by Exponent, the 
petitioner, which is available in the docket, http://www.regulations.gov. There were no comments received in response to the 
notice of filing.
    Based upon review of the data supporting the petition, EPA has 
modified the limitation on the maximum concentration in the pesticide 
formulation from 10% to 5%. This limitation is based on the Agency's 
risk assessment which can be found at http://www.regulations.gov in 
document, ``1,2-Propanediol, 3-[3-[1,3,3,3,3-tetramethyl-1-
[(trimethylsilyl)oxy]-1-disiloxanyl]propoxy]-; Human health Risk 
Assessment and Ecological Effects Assessment to Support Proposed 
Exemption from the Requirement of a Tolerance When Used as an Inert 
Ingredient in Pre-harvest Pesticide Products Under 40 CFR 180.920'' in 
docket ID number EPA-HQ-OPP-2014-0449.

III. Inert Ingredient Definition

    Inert ingredients are all ingredients that are not active 
ingredients as defined in 40 CFR 153.125 and include, but are not 
limited to, the following types of ingredients (except when they have a 
pesticidal efficacy of their own): Solvents such as alcohols and 
hydrocarbons; surfactants such as polyoxyethylene polymers and fatty 
acids; carriers such as clay and diatomaceous earth; thickeners such as 
carrageenan and modified cellulose; wetting, spreading, and dispersing 
agents; propellants in aerosol dispensers; microencapsulating agents; 
and emulsifiers. The term ``inert'' is not intended to imply 
nontoxicity; the ingredient may or may not be chemically active. 
Generally, EPA has exempted inert ingredients from the requirement of a 
tolerance based on the low toxicity of the individual inert 
ingredients.

IV. Aggregate Risk Assessment and Determination of Safety

    Section 408(c)(2)(A)(i) of FFDCA allows EPA to establish an 
exemption from the requirement for a tolerance (the legal limit for a 
pesticide chemical residue in or on a food) only if EPA determines that 
the tolerance is ``safe.'' Section 408(b)(2)(A)(ii) of FFDCA defines 
``safe'' to mean that ``there is a reasonable certainty that no harm 
will result from aggregate exposure to the pesticide chemical residue, 
including all anticipated dietary exposures and all other exposures for 
which there is reliable information.'' This includes exposure through 
drinking water and in residential settings, but does not include 
occupational exposure. Section 408(b)(2)(C) of FFDCA requires EPA to 
give special consideration to exposure of infants and children to the 
pesticide chemical residue in establishing a tolerance and to ``ensure 
that there is a reasonable certainty that no harm will result to 
infants and children from aggregate exposure to the pesticide chemical 
residue. . .''
    EPA establishes exemptions from the requirement of a tolerance only 
in those cases where it can be clearly demonstrated that the risks from 
aggregate exposure to pesticide chemical residues under reasonably 
foreseeable circumstances will pose no appreciable risks to human 
health. In order to determine the risks from aggregate exposure to 
pesticide inert ingredients, the Agency considers the toxicity of the 
inert in conjunction with possible exposure to residues of the inert 
ingredient through food, drinking water, and through other exposures 
that occur as a result of pesticide use in residential settings. If EPA 
is able to determine that a finite tolerance is not necessary to ensure 
that there is a reasonable certainty that no harm will result from 
aggregate exposure to the inert ingredient, an exemption from the 
requirement of a tolerance may be established.
    Consistent with FFDCA section 408(c)(2)(A), and the factors 
specified in FFDCA section 408(c)(2)(B), EPA has reviewed the available 
scientific data and other relevant information in support of this 
action. EPA has sufficient data to assess the hazards of and to make a 
determination on aggregate exposure for 1,2-propanediol, 3-[3-[1, 3, 3, 
3-tetramethyl-1-

[[Page 21474]]

[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]- including exposure 
resulting from the exemption established by this action. EPA's 
assessment of exposures and risks associated with 1,2-propanediol, 3-
[3-[1, 3, 3, 3-tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxyanyl] 
propoxy]- follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered their 
validity, completeness, and reliability as well as the relationship of 
the results of the studies to human risk. EPA has also considered 
available information concerning the variability of the sensitivities 
of major identifiable subgroups of consumers, including infants and 
children. Specific information on the studies received and the nature 
of the adverse effects caused by 1,2-propanediol, 3-[3-[1, 3, 3, 3-
tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]- as well 
as the no-observed-adverse-effect-level (NOAEL) and the lowest-
observed-adverse-effect-level (LOAEL) from the toxicity studies are 
discussed in this unit.
    There is currently limited data available for 1,2-propanediol, 3-
[3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]-1-
disiloxanyl]propoxy]-. The Agency received three studies specifically 
testing 1,2-propanediol, 3-[3-[1,3,3,3-tetramethyl-1-
[(trimethylsilyl)oxy]-1-disiloxanyl]propoxy]-: acute oral toxicity, 
acute dermal toxicity, and an Ames assay. Those studies showed that 
1,2-propanediol, 3-[3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]-1-
disiloxanyl]propoxy]- was non-toxic via acute oral and acute dermal 
exposures and was negative for mutagenicity. To assess the remaining 
potential toxicity of 1,2-propanediol, 3-[3-[1,3,3,3-tetramethyl-1-
[(trimethylsilyl)oxy]-1-disiloxanyl]propoxy]-, the Agency relied on 
data for a suitable cluster of structurally related linear short chain 
siloxane (Si-2 to Si-5) compounds. Based on the similar structures and 
physicochemical properties of these compounds to 1,2-propanediol, 3-[3-
[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxanyl]propoxy]-, 
which primarily differ only in the number of siloxane units, the Agency 
has determined that the toxicological properties of these compounds is 
representative of the toxicity of 3-[3-[1,3,3,3-tetramethyl-1-
[(trimethylsilyl)oxy]-1-disiloxanyl]propoxy]-. The Agency has also 
determined that these data adequately address the physicochemical, 
mammalian metabolism, mammalian toxicological, and environmental fate 
endpoints of 1,2-propanediol,3-[3-[1,3,3,3-tetramethyl-1-
[(trimethylsilyl)oxy]-1-disiloxanyl]propoxy]-.
    Oral repeat dose toxicity studies are available for structurally 
similar linear short chain siloxane chemicals, for durations ranging 
from 28 days up to one year in rats, rabbits, and dogs. The lowest 
NOAELs were in the 25 milligram/kilogram/day (mg/kg/day) range for two 
28-day oral repeat dose rat studies and a 90-day dog study. LOAELs for 
these studies were based mainly on liver effects which were present in 
all of these studies.
    Dermal repeated dose toxicity studies are available for two of the 
structurally similar linear short chain siloxane compounds. A 28-day 
dermal toxicity study in rats and rabbits showed no adverse effects up 
to limit dose of 1,000 mg/kg/day. The NOAEL was 1,000 mg/kg/day; the 
highest dose tested in both studies.
    Inhalation repeated dose toxicity studies are available for three 
of the structurally similar linear short chain siloxane compounds. Both 
28-day and 90-day rat inhalation studies are available as well as a 
one-year chronic inhalation study. The lowest inhalation NOAEL was 3.9 
milligrams per Liter (mg/L) in a 90-day study, equivalent to a dose of 
greater than 1,000 mg/kg/day, a limit dose value.
    A carcinogenicity study is available on one structurally-related 
short chain siloxane compound. An increase incidence of Leydig cell 
tumors (LCTs) in males was observed at all doses. However, due to the 
high background incidence of LCTs in Fischer 344 rats, this effect has 
been determined to not be treatment-related. Renal tubular adenomas and 
carcinomas were also observed in the study but are attributable to male 
rat specific alpha-2[mu]-globulin mediated nephrotoxicity and therefore 
not relevant to cancer risk concerns in humans. Genotoxicity studies on 
1,2-propanediol,3-[3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]-1-
disiloxanyl]propoxy]- and structurally-related compounds were negative 
for genotoxic effects. A DEREK (structure-activity modeling) analysis 
was conducted and identified no structural alerts for possible 
carcinogenicity among the linear short chain siloxane compounds. 
Therefore, based on the lack of human-relevant carcinogenicity in the 
available study, and the results of the genotoxicity studies and DEREK 
analysis, 1,2-propanediol,3-[3-[1,3,3,3-tetramethyl-1-
[(trimethylsilyl)oxy]-1-disiloxanyl]propoxy]- is not expected to be 
carcinogenic.
    Reproductive and developmental toxicity studies with linear short 
chain siloxane compounds demonstrated no adverse effects at doses at or 
below limit dose levels. No evidence of immunotoxicity or neuro 
toxicity at doses below the limit dose was observed in the available 
studies for the structurally related linear short chain siloxane (Si-2 
to Si-5) compounds at up to limit dose levels.
    There are currently no publically-available metabolism studies for 
1,2-propanediol,3-[3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]-1-
disiloxanyl]propoxy]-, however, the expected mammalian metabolic 
pathways which may be involved in the degradation of 1,2-propanediol,3-
[3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxanyl]propoxy]- 
include a combination of ether hydrolysis followed by [szlig]-oxidation 
of the carbon chain followed by methyl oxidation of the silyl methyl 
groups. Methyl oxidation would result in the formation of a mixture of 
primary and alcohol metabolites. The more polar primary alcohol 
functionalities can both be conjugated and excreted directly or further 
oxidized to form a mixture of more polar carboxylic acid metabolites 
that are readily conjugated and excreted.
    Specific information on the studies received and the nature of the 
adverse effects caused by 1,2-propanediol,3-[3-[1,3,3,3-tetramethyl-1-
[(trimethylsilyl)oxy]-1-disiloxanyl]propoxy]- as well as the NOAEL and 
the LOAEL from the toxicity studies can be found at http://www.regulations.gov in document, ``1,2-Propanediol,3-[3-[1,3,3,3-
tetraamethyl-1-[(trimethylsilyl)oxy]-1-disiloxanyl]propoxy]-; Human 
Health Risk Assessment and Ecological Effects Assessment to Support 
Proposed Exemption from the Requirement of a Tolerance When Used as an 
Inert Ingredient in Pre-harvest Pesticide Products Under 40 CFR 
180.920'' in docket ID number EPA-HQ-OPP-2014-0449.

B. Toxicological Points of Departure/Levels of Concern

    Once a pesticide's toxicological profile is determined, EPA 
identifies toxicological points of departure (POD) and levels of 
concern to use in evaluating the risk posed by human exposure to the 
pesticide. For hazards that have a threshold below which there is no 
appreciable risk, the toxicological POD is used as the basis for 
derivation of reference values for risk assessment. PODs are developed 
based on a careful analysis of the doses in each

[[Page 21475]]

toxicological study to determine the dose at which the NOAEL and the 
LOAEL are identified. Uncertainty/safety factors are used in 
conjunction with the POD to calculate a safe exposure level--generally 
referred to as a population-adjusted dose (PAD) or a reference dose 
(RfD)--and a safe margin of exposure (MOE). For non-threshold risks, 
the Agency assumes that any amount of exposure will lead to some degree 
of risk. Thus, the Agency estimates risk in terms of the probability of 
an occurrence of the adverse effect expected in a lifetime. For more 
information on the general principles EPA uses in risk characterization 
and a complete description of the risk assessment process, see http://www.epa.gov/pesticides/factsheets/riskassess.htm.
    A summary of the toxicological endpoints for 1,2-propanediol, 3-[3-
[1, 3, 3, 3-tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxyanyl] 
propoxy]- used for human risk assessment is shown in Table 1 of this 
unit.
    The 28-day studies in rats the NOAEL was 25 mg/kg/day with a LOAEL 
of 250 mg/kg/day based on based on increases in absolute liver weights, 
hepatocellular hypertrophy and protoporphyrin accumulation with 
associated bile duct proliferation and periportal chronic inflammation. 
A 90-day dog study had a NOAEL of 24 mg/kg/day with a LOAEL of 77 mg/
kg/day based on increased relative liver weight in females and lower 
relative testes weight in males with slight testicular atrophy or 
hypoplasia in males. A NOAEL of 25 mg/kg/day was selected for use as 
the endpoint for dietary exposure in this risk assessment. An 
additional uncertainty factor of 3X was applied for the use of shorter 
term study for a chronic risk assessment.
    Dermal and inhalation exposure endpoints were not selected as there 
were no adverse effects observed up to limit dose levels in both rat 
and rabbit dermal and inhalation toxicity studies.

   Table 1--Summary of Toxicological Doses and Endpoints for 1,2-propanediol, 3-[3-[1, 3, 3, 3-tetramethyl-1-
                [(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]- for Use in Human Risk Assessment
----------------------------------------------------------------------------------------------------------------
                                        Point of departure and
          Exposure/scenario               uncertainty/safety     RfD, PAD, LOC for risk  Study and toxicological
                                               factors                 assessment                 effects
----------------------------------------------------------------------------------------------------------------
Acute dietary (All populations)......  An acute effect was not found in the database therefore an acute dietary
                                        assessment is not necessary.
----------------------------------------------------------------------------------------------------------------
Chronic dietary (All populations)....  NOAEL= 25 mg/kg/day....  Chronic RfD = 0.08 mg/   28-Day oral toxicity
                                       UFA = 10x..............   kg/day.                  study-rat LOAEL = 250
                                       UFH = 10x..............  cPAD = 0.08 mg/kg/day..   mg/kg/day based on
                                       FQPA SF = 3x...........                            protoporphyrin
                                                                                          accumulation in the
                                                                                          liver.
Incidental oral short-term (1 to 30    NOAEL= 25 mg/kg/day....  LOC for MOE = 300......  28-Day oral toxicity
 days).                                UFA = 10x..............                            study-rat LOAEL = 250
                                       UFH = 10x..............                            mg/kg/day based on
                                       FQPA SF = 3x...........                            protoporphyrin
                                                                                          accumulation in the
                                                                                          liver.
Incidental oral intermediate-term (1   NOAEL= 25 mg/kg/day....  LOC for MOE = 300......  28-Day oral toxicity
 to 6 months).                         UFA = 10x..............                            study-rat LOAEL = 250
                                       UFH = 10x..............                            mg/kg/day based on
                                       FQPA SF = 3x...........                            protoporphyrin
                                                                                          accumulation in the
                                                                                          liver.
                                      --------------------------------------------------------------------------
Cancer (Oral, dermal, inhalation)....  Not likely to be carcinogenic to humans based on the lack of increased
                                        incidence of tumor formation compared to controls in the 1-year
                                        carcinogenicity study, lack of mutagenicity, and no structural alerts
                                        for genotoxicity or carcinogenicity identified in a qualitative
                                        structure activity relationship (SAR) database, DEREK.
----------------------------------------------------------------------------------------------------------------
FQPA SF = Food Quality Protection Act Safety Factor. LOAEL = lowest-observed-adverse-effect-level. LOC = level
  of concern. mg/kg/day = milligram/kilogram/day. MOE = margin of exposure. NOAEL = no-observed-adverse-effect-
  level. PAD = population adjusted dose (a = acute, c = chronic). RfD = reference dose. UF = uncertainty factor.
  UFA = extrapolation from animal to human (interspecies). UFH = potential variation in sensitivity among
  members of the human population (intraspecies). UFS = use of a short-term study for long-term risk assessment.

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. In evaluating dietary 
exposure to 1,2-propanediol, 3-[3-[1, 3, 3, 3-tetramethyl-1-
[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]-, EPA considered 
exposure under the proposed exemption from the requirement of a 
tolerance. EPA assessed dietary exposures from 1,2-propanediol, 3-[3-
[1, 3, 3, 3-tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxyanyl] 
propoxy]- in food as follows:
    i. Acute Exposure. Quantitative acute dietary exposure and risk 
assessments are performed for a food-use pesticide chemical, if a 
toxicological study has indicated the possibility of an effect of 
concern occurring as a result of a 1-day or single exposure. No such 
effects were identified in the toxicological studies for 1,2-
propanediol, 3-[3-[1, 3, 3, 3-tetramethyl-1-[(trimethylsilyl)oxy]-1-
disiloxyanyl] propoxy]-; therefore, a quantitative acute dietary 
exposure assessment is unnecessary.
    ii. Chronic exposure. The chronic dietary exposure assessment for 
this inert ingredient utilizes the Dietary Exposure Evaluation Model 
Food Commodity Intake Database (DEEM-FCID), Version 3.16, EPA, which 
includes food consumption information from the U.S. Department of 
Agriculture's National Health and Nutrition Examination Survey, ``What 
We Eat In America'', (NHANES/WWEIA). This dietary survey was conducted 
from 2003 to 2008. In the absence of actual residue data, the inert 
ingredient evaluation is based on a highly conservative model which 
assumes that the residue level of the inert ingredient would be no 
higher than the highest established tolerance for an active ingredient 
on a given commodity. Implicit in this assumption is that there would 
be similar rates of degradation between the active and inert ingredient 
(if any) and that the concentration of inert ingredient in the 
scenarios leading to these highest of tolerances would be no higher 
than the concentration of the active ingredient. The model assumes 100 
percent crop treated (PCT) for all crops and that every food eaten by a 
person each day has tolerance-level residues. A complete description of 
the general approach taken to assess inert ingredient risks in the 
absence of residue data is contained in the memorandum entitled ``Alkyl 
Amines Polyalkoxylates (Cluster 4):

[[Page 21476]]

Acute and Chronic Aggregate (Food and Drinking Water) Dietary Exposure 
and Risk Assessments for the Inerts,'' (D361707, S. Piper, 2/25/09) and 
can be found at http://www.regulations.gov in docket ID number EPA-HQ-
OPP-2008-0738.
    iii. Cancer. Based on the data summarized in Unit III.A., EPA has 
concluded that 1,2-propanediol, 3-[3-[1, 3, 3, 3-tetramethyl-1-
[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]- does not pose a cancer 
risk to humans. Therefore, a dietary exposure assessment for the 
purpose of assessing cancer risk is unnecessary.
    2. Dietary exposure from drinking water. For the purpose of the 
screening level dietary risk assessment to support this request for an 
exemption from the requirement of a tolerance for 1,2-propanediol, 3-
[3-[1, 3, 3, 3-tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxyanyl] 
propoxy]-, a conservative drinking water concentration value of 100 
parts per billion (ppb) based on screening level modeling was used to 
assess the contribution to drinking water for the chronic dietary risk 
assessments for parent compound. These values were directly entered 
into the dietary exposure model.
    3. From non-dietary exposure. The term ``residential exposure'' is 
used in this document to refer to non-occupational, non-dietary 
exposure (e.g., textiles (clothing and diapers), carpets, swimming 
pools, and hard surface disinfection on walls, floors, tables).
    Residential use patterns are possible for pesticide products 
containing 1,2-propanediol, 3-[3-[1, 3, 3, 3-tetramethyl-1-
[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]-. Residential exposure 
could occur via the dermal and inhalation routes of exposure. However, 
there are no concerns for dermal or inhalation exposure because no 
effects were seen in dermal or inhalation toxicity studies up to the 
limit dose. Incidental oral exposure for children is possible either by 
hand-to-mouth or object-to-mouth ingestion resulting from contact with 
treated surfaces.
    4. Cumulative effects from substances with a common mechanism of 
toxicity. Section 408(b)(2)(D)(v) of FFDCA requires that, when 
considering whether to establish, modify, or revoke a tolerance, the 
Agency consider ``available information'' concerning the cumulative 
effects of a particular pesticide's residues and ``other substances 
that have a common mechanism of toxicity.''
    EPA has not found 1,2-propanediol, 3-[3-[1, 3, 3, 3-tetramethyl-1-
[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]- to share a common 
mechanism of toxicity with any other substances, and 1,2-propanediol, 
3-[3-[1, 3, 3, 3-tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxyanyl] 
propoxy]- does not appear to produce a toxic metabolite produced by 
other substances. For the purposes of this tolerance action, therefore, 
EPA has assumed that 1,2-propanediol, 3-[3-[1, 3, 3, 3-tetramethyl-1-
[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]- does not have a common 
mechanism of toxicity with other substances. For information regarding 
EPA's efforts to determine which chemicals have a common mechanism of 
toxicity and to evaluate the cumulative effects of such chemicals, see 
EPA's Web site at http://www.epa.gov/pesticides/cumulative.

D. Safety Factor for Infants and Children

    1. In general. Section 408(b)(2)(C) of FFDCA provides that EPA 
shall apply an additional tenfold (10X) margin of safety for infants 
and children in the case of threshold effects to account for prenatal 
and postnatal toxicity and the completeness of the database on toxicity 
and exposure unless EPA determines based on reliable data that a 
different margin of safety will be safe for infants and children. This 
additional margin of safety is commonly referred to as the Food Quality 
Protection Act Safety Factor (FQPA SF). In applying this provision, EPA 
either retains the default value of 10X, or uses a different additional 
safety factor when reliable data available to EPA support the choice of 
a different factor.
    2. Prenatal and postnatal sensitivity. Although some adverse 
reproductive effects were observed in the inhalation developmental/
reproductive toxicity studies, these effects were at dose levels far in 
excess of the clear NOAEL established in the oral reproductive and 
developmental screening study and the regulatory doses used in the risk 
assessment were selected to be protective of these effects.
    3. Conclusion. EPA has determined that reliable data show the 
safety of infants and children would be adequately protected if the 
FQPA SF were reduced to 3x to account for the use of a subchronic study 
to derive a chronic reference dose. That decision is also based on the 
following findings:
    i. Although only limited data on 1,2-propanediol, 3-[3-[1, 3, 3, 3-
tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]- is 
available, the Agency has reliable data based on the structurally 
related linear short chain siloxane (Si-2 to Si-5) compounds to 
adequately characterize the toxicity and assess the risk from dietary 
exposure to 1,2-propanediol, 3-[3-[1, 3, 3, 3-tetramethyl-1-
[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]-.
    ii. There is no indication that 1,2-propanediol, 3-[3-[1, 3, 3, 3-
tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]- is a 
neurotoxic chemical at doses below the limit dose and there is no need 
for a developmental neurotoxicity study or additional uncertainty 
factors (UFs) to account for neurotoxicity.
    iii. There is no indication that 1,2-propanediol, 3-[3-[1, 3, 3, 3-
tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]- is a 
immunotoxic chemical and there is no need for a immunotoxicity study or 
additional UFs to account for immunotoxicity.
    iv. As discussed in Unit IV.D.2., there is no need to retain the 
FQPA 10x to address any concern for potential increased susceptibility 
in infants and children from prenatal or postnatal exposure to 1,2-
propanediol, 3-[3-[1, 3, 3, 3-tetramethyl-1-[(trimethylsilyl)oxy]-1-
disiloxyanyl] propoxy]-.
    v. There are no residual uncertainties identified in the exposure 
databases. The dietary food exposure assessments were performed based 
on a highly conservative model that assumes 100 percent crop treated 
(PCT) for all crops and that every food eaten by a person each day has 
residues of inert ingredient equivalent to the residue level of the 
highest established tolerance for an active ingredient on a given 
commodity. EPA made conservative (protective) assumptions in the ground 
and surface water modeling used to assess exposure to 1,2-propanediol, 
3-[3-[1, 3, 3, 3-tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxyanyl] 
propoxy]- in drinking water. EPA used similarly conservative 
assumptions to assess post-application exposure of children as well as 
incidental oral exposure of toddlers. These assessments will not 
underestimate the exposure and risks posed by 1,2-propanediol, 3-[3-[1, 
3, 3, 3-tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]-.

E. Aggregate Risks and Determination of Safety

    EPA determines whether acute and chronic dietary pesticide 
exposures are safe by comparing aggregate exposure estimates to the 
acute PAD (aPAD) and chronic PAD (cPAD). For linear cancer risks, EPA 
calculates the lifetime probability of acquiring cancer given the 
estimated aggregate exposure. Short-, intermediate-, and chronic-term 
risks are evaluated by comparing the estimated aggregate food, water, 
and residential exposure to the appropriate

[[Page 21477]]

PODs to ensure that an adequate MOE exists.
    1. Acute risk. An acute aggregate risk assessment takes into 
account acute exposure estimates from dietary consumption of food and 
drinking water. No adverse effect resulting from a single oral exposure 
was identified and no acute dietary endpoint was selected. Therefore, 
1,2-propanediol, 3-[3-[1, 3, 3, 3-tetramethyl-1-[(trimethylsilyl)oxy]-
1-disiloxyanyl] propoxy]- is not expected to pose an acute risk.
    2. Chronic risk. Using the exposure assumptions described in this 
unit for chronic exposure, EPA has concluded that chronic exposure to 
1,2-propanediol, 3-[3-[1, 3, 3, 3-tetramethyl-1-[(trimethylsilyl)oxy]-
1-disiloxyanyl] propoxy]- from food and water will utilize 88.3% of the 
cPAD for children 1-2 years old, the population group receiving the 
greatest exposure. Based on the explanation in this unit regarding 
residential use patterns, chronic residential exposure to residues of 
1,2-propanediol, 3-[3-[1, 3, 3, 3-tetramethyl-1-[(trimethylsilyl)oxy]-
1-disiloxyanyl] propoxy]- is not expected.
    3. Short-term risk. Short-term aggregate exposure takes into 
account short-term residential exposure plus chronic exposure to food 
and water (considered to be a background exposure level).
    1,2-Propanediol, 3-[3-[1, 3, 3, 3-tetramethyl-1-
[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]- may be used as an inert 
ingredient in pesticide products that would result in short-term 
residential exposure. Short-term risk is assessed based on short-term 
residential exposure plus chronic dietary exposure. Although short-term 
residential exposure is possible, there was no endpoint of concern 
identified in both dermal and inhalation toxicity studies. However the 
Agency has determined that it is appropriate to aggregate chronic 
exposure through food and water with short-term residential exposures 
for children. EPA has concluded the combined short-term aggregated 
food, water, and residential exposures results in an aggregate MOE of 
334 for children. Children's aggregate MOE combines average food and 
water exposure from the chronic dietary exposure with residential 
exposure associated with contact with treated lawns (hand-to-mouth + 
object-to-mouth). As the level of concern is for MOEs that are lower 
than 300, these MOEs are not of concern.
    4. Intermediate-term risk. Intermediate-term aggregate exposure 
takes into account intermediate-term residential exposure plus chronic 
exposure to food and water (considered to be a background exposure 
level).
    1,2-Propanediol, 3-[3-[1, 3, 3, 3-tetramethyl-1-
[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]- may be used as an inert 
ingredient in pesticide products that would result in intermediate-term 
residential exposure. Intermediate-term risk is assessed based on 
intermediate-term residential exposure plus chronic dietary exposure. 
Although intermediate-term residential exposure is possible, there was 
no endpoint of concern identified in both dermal and inhalation 
toxicity. However the Agency has determined that it is appropriate to 
aggregate chronic exposure through food and water with intermediate-
term residential exposures for children. EPA has concluded the combined 
intermediate-term aggregated food, water, and residential exposures 
results in an aggregate MOE of 342 for children. Children's aggregate 
MOE combines average food and water exposure from the chronic dietary 
exposure with residential exposure associated with contact with treated 
lawns (hand-to-mouth + object-to-mouth). As the level of concern is for 
MOEs that are lower than 300, these MOEs are not of concern.
    5. Aggregate cancer risk for U.S. population. As discussed in Unit 
IV.A., EPA does not expect 1,2-propanediol, 3-[3-[1, 3, 3, 3-
tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]- to pose a 
cancer risk to humans.
    6. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
to the general population, or to infants and children from aggregate 
exposure to 1,2-propanediol, 3-[3-[1, 3, 3, 3-tetramethyl-1-
[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]- residues.

V. Other Considerations

A. Analytical Enforcement Methodology

    Although EPA is establishing a limitation on the amount of 1,2-
propanediol, 3-[3-[1, 3, 3, 3-tetramethyl-1-[(trimethylsilyl)oxy]-1-
disiloxyanyl] propoxy]- that may be used in pesticide formulations, an 
analytical enforcement methodology is not necessary for this exemption 
from the requirement of tolerance. The limitation will be enforced 
through the pesticide registration process under the Federal 
Insecticide, Fungicide, and Rodenticide Act (FIFRA), 7 U.S.C. 136 et 
seq. EPA will not register any pesticide for sale or distribution for 
use on growing crops with concentrations of 1,2-propanediol, 3-[3-[1, 
3, 3, 3-tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]- 
exceeding 5% by weight of the formulation.

B. Revisions to Petitioned-For Tolerances

    Based upon an evaluation of the data included in the petition, EPA 
is establishing an exemption from the requirement of a tolerance for 
residues of 1,2-propanediol 3-[3-[1, 3, 3, 3-tetramethyl-1-
[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]- when used in pesticide 
formulations as an inert ingredient (antifoaming agent), not to exceed 
5% by weight of the formulation, instead of the 10% limit requested. 
The basis for this revision can be found at http://www.regulations.gov 
in document, ``1,2-Propanediol,3-[3-[1,3,3,3-tetraamethyl-1-
[(trimethylsilyl)oxy]-1-disiloxanyl]propoxy]-; Human Health Risk 
Assessment and Ecological Effects Assessment to Support Proposed 
Exemption from the Requirement of a Tolerance When Used as an Inert 
Ingredient in Pre-harvest Pesticide Products Under 40 CFR 180.920'' in 
docket ID number EPA-HQ-OPP-2014-0449.

VI. Conclusions

    Therefore, an exemption from the requirement of a tolerance is 
established under 40 CFR 180.920 for 1,2-propanediol, 3-[3-[1, 3, 3, 3-
tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxyanyl] propoxy]- (CAS Reg. 
No. 70280-68-1) when used as an inert ingredient (antifoaming agent) in 
pesticide formulations applied to growing crops at a maximum 
concentration not to exceed 5% by weight in formulation.

VII. Statutory and Executive Order Reviews

    This action establishes an exemption from the requirement of a 
tolerance under FFDCA section 408(d) in response to a petition 
submitted to the Agency. The Office of Management and Budget (OMB) has 
exempted these types of actions from review under Executive Order 
12866, entitled ``Regulatory Planning and Review'' (58 FR 51735, 
October 4, 1993). Because this action has been exempted from review 
under Executive Order 12866, this action is not subject to Executive 
Order 13211, entitled ``Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use'' (66 FR 
28355, May 22, 2001) or Executive Order 13045, entitled ``Protection of 
Children from Environmental Health Risks and Safety Risks'' (62 FR 
19885, April 23, 1997). This action does not contain any information 
collections

[[Page 21478]]

subject to OMB approval under the Paperwork Reduction Act (PRA) (44 
U.S.C. 3501 et seq.), nor does it require any special considerations 
under Executive Order 12898, entitled ``Federal Actions to Address 
Environmental Justice in Minority Populations and Low-Income 
Populations'' (59 FR 7629, February 16, 1994).
    Since tolerances and exemptions that are established on the basis 
of a petition under FFDCA section 408(d), such as the exemption in this 
final rule, do not require the issuance of a proposed rule, the 
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et 
seq.), do not apply.
    This action directly regulates growers, food processors, food 
handlers, and food retailers, not States or tribes, nor does this 
action alter the relationships or distribution of power and 
responsibilities established by Congress in the preemption provisions 
of FFDCA section 408(n)(4). As such, the Agency has determined that 
this action will not have a substantial direct effect on States or 
tribal governments, on the relationship between the national government 
and the States or tribal governments, or on the distribution of power 
and responsibilities among the various levels of government or between 
the Federal Government and Indian tribes. Thus, the Agency has 
determined that Executive Order 13132, entitled ``Federalism'' (64 FR 
43255, August 10, 1999) and Executive Order 13175, entitled 
``Consultation and Coordination with Indian Tribal Governments'' (65 FR 
67249, November 9, 2000) do not apply to this action. In addition, this 
action does not impose any enforceable duty or contain any unfunded 
mandate as described under Title II of the Unfunded Mandates Reform Act 
(UMRA) (2 U.S.C. 1501 et seq.).
    This action does not involve any technical standards that would 
require Agency consideration of voluntary consensus standards pursuant 
to section 12(d) of the National Technology Transfer and Advancement 
Act (NTTAA) (15 U.S.C. 272 note).

VIII. Congressional Review Act

    Pursuant to the Congressional Review Act (5 U.S.C. 801 et seq.), 
EPA will submit a report containing this rule and other required 
information to the U.S. Senate, the U.S. House of Representatives, and 
the Comptroller General of the United States prior to publication of 
the rule in the Federal Register. This action is not a ``major rule'' 
as defined by 5 U.S.C. 804(2).

List of Subjects in 40 CFR Part 180

    Environmental protection, Administrative practice and procedure, 
Agricultural commodities, Pesticides and pests, Reporting and 
recordkeeping requirements.

    Dated: March 31, 2016.
G. Jeffrey Herndon,
Director, Registration Division, Office of Pesticide Programs.

    Therefore, 40 CFR chapter I is amended as follows:

PART 180--[AMENDED]

0
1. The authority citation for part 180 continues to read as follows:

    Authority: 21 U.S.C. 321(q), 346a and 371.


0
2. In Sec.  180.920, add alphabetically the inert ingredient to the 
table to read as follows:


Sec.  180.920  Inert ingredients used pre-harvest; exemptions from the 
requirement of a tolerance.

* * * * *

----------------------------------------------------------------------------------------------------------------
            Inert ingredients                         Limits                               Uses
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
1,2-Propanediol, 3-[3-[1, 3, 3, 3-         Not to exceed 5% by weight    Antifoaming agent.
 tetramethyl-1-[(trimethylsilyl)oxy]-1-     of pesticide formulation.
 disiloxyanyl] propoxy]- (CAS Reg. No.
 70280-68-1).
 
                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------

[FR Doc. 2016-08282 Filed 4-11-16; 8:45 am]
BILLING CODE 6560-50-P