Residues of Quaternary Ammonium Compounds, N-Alkyl (C12-14, 40729-40736 [2010-17156]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 75, Number 134 (Wednesday, July 14, 2010)]
[Rules and Regulations]
[Pages 40729-40736]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-17156]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2008-0533; FRL-8833-2]


Residues of Quaternary Ammonium Compounds, N-Alkyl 
(C12-14) Dimethyl Ethylbenzyl Ammonium Chloride; Exemption 
from the Requirement of a Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation amends an existing exemption from the 
requirement of a tolerance for residues of n-alkyl (C12-14) 
dimethyl ethylbenzyl ammonium chloride on food contact surfaces when 
applied/used in public eating places, dairy processing equipment, and/
or food processing equipment and utensils. The regulation will exempt 
from the requirement of tolerance residues in food resulting from 
contact with surfaces treated with antimicrobial solutions where the 
end-use concentration of active quaternary compound does not exceed 400 
parts per million (ppm).

DATES: This regulation is effective July 14, 2010. Objections and 
requests for hearings must be received on or before September 13, 2010, 
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: EPA has established a docket for this action under docket 
identification (ID) number EPA-HQ-OPP-2008-0533. All documents in the 
docket are listed in the docket index available at https://www.regulations.gov. Although listed in the index, some information is 
not publicly available, e.g., Confidential Business Information (CBI) 
or other information whose disclosure is restricted by statute. Certain 
other material, such as copyrighted material, is not placed on the 
Internet and will be publicly available only in hard copy form. 
Publicly available docket materials are available in the electronic 
docket at https://www.regulations.gov, or, if only available in hard 
copy, at the OPP Regulatory Public Docket in Rm. S-4400, One Potomac 
Yard (South Bldg.), 2777 S. Crystal Dr., Arlington, VA. The Docket 
Facility is open from 8:30 a.m. to 4 p.m., Monday through Friday, 
excluding legal holidays. The Docket Facility telephone number is (703) 
305-5805.

FOR FURTHER INFORMATION CONTACT: Velma Noble, Antimicrobials Division 
(7510P), Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460-0001; telephone number: (703) 308-6233; e-mail 
address: noble.velma@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

    You may be potentially affected by this action if you are dairy 
cattle milk producer, food manufacturer, or beverage manufacturer. 
Potentially affected entities may include, but are not limited to:
     Dairy cattle milk production (NAICS code 11212).
     Food manufacturing (NAICS code 311).
     Beverage manufacturing (NAICS code 3121).
    This listing is not intended to be exhaustive, but rather provides 
a guide for readers regarding entities likely to be affected by this 
action. Other types of entities not listed in this unit could also be 
affected. The North American Industrial Classification System (NAICS) 
codes have been provided to assist you and others in determining 
whether this action might apply to certain entities. If you have any 
questions regarding the applicability of this action to a particular 
entity, consult the person listed under FOR FURTHER INFORMATION 
CONTACT.

 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 https://www.gpoaccess.gov/ecfr.

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-2008-0533 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 
September 13, 2010. 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 that does not contain any 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 a copy of 
your non-CBI objection or hearing request, identified by docket ID 
number EPA-HQ-OPP-2008-0533, by one of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov. 
Follow the on-line instructions for submitting comments.
     Mail: Office of Pesticide Programs (OPP) Regulatory Public 
Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania 
Ave., NW., Washington, DC 20460-0001.
     Delivery: OPP Regulatory Public Docket (7502P), 
Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South 
Bldg.), 2777 S. Crystal Dr., Arlington, VA. Deliveries are only 
accepted during the Docket Facility 's normal hours of operation (8:30 
a.m. to 4 p.m., Monday through Friday, excluding legal holidays). 
Special arrangements should be made for deliveries of boxed 
information. The Docket Facility telephone number is (703) 305-5805.

II. Summary of Petitioned-For Exemption

    In the Federal Register of November 28, 2007 (72 FR 67299) (FRL-
8141-1), EPA issued a notice pursuant to section 408(d)(3) of FFDCA, 21 
U.S.C. 346a(d)(3), announcing the filing of a pesticide tolerance 
petition (PP 8F7323) by Stepan Company, 22 West Frontage Rd., 
Northfield, IL 60093. The petition requested that 40 CFR 180.940(a) be 
amended by increasing concentration limits for n-alkyl 
(C12-14) dimethyl ethylbenzyl ammonium chloride in end-use 
solutions eligible for tolerance exemption. That notice referenced a 
summary of the petition prepared by Stepan Company, the registrant, 
which is available in the docket, https://www.regulations.gov.

[[Page 40730]]

III. 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 exemption is ``safe.'' Section 408(c)(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. Pursuant to section 408(c)(2)(B) of FFDCA, in 
establishing or maintaining in effect an exemption from the requirement 
of a tolerance, EPA must take into account the factors set forth in 
section 408(b)(2)(C) of FFDCA, which 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.''
    Consistent with section 408(c)(2)(A) of FFDCA, and the factors 
specified in section 408(c)(2)(B) of FFDCA, 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 residues of n-alkyl 
(C12-14) dimethyl ethylbenzyl ammonium chloride on food 
contact surfaces when applied/used in public eating places, dairy 
processing equipment, and/or food processing equipment and utensils. 
EPA's assessment of exposures and risks associated with amending the 
exemption from the requirement for a tolerance follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its 
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 n-alkyl (C12-14) dimethyl 
ethylbenzyl ammonium chloride 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.
    The alkyl dimethyl benzyl ammonium chlorides (ADBAC) chemical case 
is comprised of 24 compounds that are structurally similar and are a 
subgroup of the class of chemicals known as quaternary ammonium 
compounds. Quaternary ammonium compounds are a class of salts derived 
from ammonium in which nitrogen atom is attached to four organic 
groups. ADBAC is characterized by having a positively charged nitrogen 
atom covalently bonded to three alkyl group substituents (two methyls 
and R component) and a benzyl substituent. The R component represents 
the different number of hydrocarbon carbon moieties delineated by 
different percentages (e.g., Alkyl (50% C14, 40% 
C12, 10% C16) dimethyl benzyl ammonium chloride). 
In finished form, these quaternary ammonium compounds are salts with 
the positively charged nitrogen (cation) balanced by a negatively 
charged anion. The most common anion for the quaternary ammonium 
compounds in this cluster is chloride. However, other anions, such as 
saccharide and bromide are also used. The Agency clustered these 
chemicals together because variance in the length and conformation of 
alkyl carbon chains between 12 and 18 does not appear to significantly 
affect the toxicity or fate of the ADBAC compound. In all ADBACs, it is 
the positive entity (quaternized nitrogen) that is of relevance from 
toxicology and exposure perspectives. The negative part of ADBAC 
(counter ion) is a relatively non-toxic entity (chloride). Alkyl (50% 
C14, 40% C12, 10% C16) dimethyl benzyl 
ammonium chloride (PC code 069105) was chosen by the Agency as the 
representative chemical for the ADBAC subgroup of quaternary ammonium 
compounds, and the toxicology database for alkyl (50% C14, 
40% C12, 10% C16) dimethyl benzyl ammonium 
chloride is considered representative of the hazard for the ADBAC 
subgroup. The individual exposure scenarios in the ADBAC assessments 
(as well as the aggregate assessment in the RED) were developed by 
assuming that an ADBAC compound was used on 100% of the surfaces 
authorized on the label that could result in human exposure and summing 
the percent active ingredients on the labels for all of the ADBAC 
compounds when used in combination.
    Quaternary ammonium compounds are corrosive on contact with the 
skin and eyes. They typically cause highly-irritating localized effects 
which occur at the portals of entry. On the other hand, ADBACs are only 
moderately toxic systemically by oral, dermal, and inhalation routes of 
exposure. Systemic toxicity occurs after absorption and distribution of 
the chemical to tissues in the body. Such toxicity is dependent on 
physiological factors within the tissue/organ, and also how the body 
eliminates the chemical (Kinetics). These chemicals are classified as 
``not likely'' to be human carcinogens based on negative 
carcinogenicity studies in both rats and mice. There is no evidence of 
these chemicals being associated with increased susceptibility to 
developmental toxicity or reproductive toxicity based on two 
developmental toxicity studies and a 2-generation reproductive study. 
Lastly, they are negative for mutagenicity and neurotoxicity. Specific 
information on the studies received and the nature of the toxic effects 
caused by ADBAC, can be found at https://www.regulations.gov. Docket ID 
Number EPA-HQ-OPP-2005-0339, Alkyl dimethyl benzyl ammonium chloride 
(ADBAC)- Report of Antimicrobials Division Toxicity Endpoint Committee 
(ADTC) and the Hazard Identification Assessment Review Committee 
(HIARC).

B. Toxicological Points of Departure/Levels of Concern

    For hazards that have a threshold below which there is no 
appreciable risk, a toxicological point of departure (POD) is 
identified as the basis for derivation of reference values for risk 
assessment. The POD may be defined as the highest dose at which no 
adverse effects are observed (the NOAEL) in the toxicology study 
identified as appropriate for use in risk assessment. However, if a 
NOAEL cannot be determined, the lowest dose at which adverse effects of 
concern are identified (the LOAEL) or a Benchmark Dose (BMD) approach 
is sometimes used for risk assessment. Uncertainty/safety factors (UFs) 
are used in conjunction with the POD to take into account uncertainties 
inherent in the extrapolation from laboratory animal data to humans and 
in the variations in sensitivity among members of the human population 
as well as other unknowns. The Level of Concern (LOC) is a reference 
value expressed as either a reference dose/population adjusted dose 
(RfD/PAD) or margin of exposure (MOE). Safety is assessed for acute and 
chronic dietary risks by comparing aggregate food and water exposure to 
the pesticide to the acute population adjusted dose (aPAD) and chronic 
population adjusted dose (cPAD). The aPAD and cPAD are calculated by

[[Page 40731]]

dividing the POD by all applicable uncertainty/safety factors. 
Aggregate short-, intermediate-, and chronic-term risks are evaluated 
by comparing food, water, and residential exposure to the POD to ensure 
that the MOE called for by the product of all applicable UFs is not 
exceeded. For non-threshold risks, the Agency assumes that any amount 
of exposure will lead to some degree of risk and estimates risk in 
terms of the probability of a cancer occurrence greater than that 
expected in a lifetime. Generally, cancer risks are considered non-
threshold. For more information on the general principles EPA uses in 
risk characterization and a complete description of the risk assessment 
process, see https://www.epa.gov/pesticides/factsheets/riskassess.htm.
    A summary of the toxicological endpoints for ADBAC used for human 
risk assessment is shown in Table 1 of this unit.

      Table 1.--Summary of Toxicological Doses and Endpoints for ADBAC Use in Human Health Risk Assessment
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                                        Point of Departure and
          Exposure/Scenario               Uncertainty/Safety     RfD, PAD, LOC for Risk  Study and Toxicological
                                               Factors                 Assessment                Effects
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Acute dietary (general population,     An acute dietary
 females 13+, infants and children)     endpoint was not
                                        identified in the
                                        database.
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Chronic dietary (all populations)      NOAEL = 44 mg/kg/day     Chronic RfD = 0.44 mg/   Chronic toxicity/
                                       UFA = 10x..............   kg/day                   carcinogencity-rat
                                       UFH = 10x..............  cPAD = 0.44 mg/kg/day..   MRID 41947501
                                       FQPA SF = 1x...........                           LOAEL = 88 mg/kg/day
                                                                                          based on decreased
                                                                                          body weight and weight
                                                                                          gain
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Incidental oral short-term (1 to 30    NOAEL = 10 mg/kg/day     LOC for MOE = 100        Developmental Toxicity-
 days)                                 UFA = 10x..............                            Rat MRID 42351501
                                       UFH = 10x..............                           LOAEL = 30 mg/kg/day
                                       FQPA SF = 1x...........                            based on clinical
                                                                                          signs and decrease
                                                                                          body weight gain
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Incidental oral intermediate-term (1   NOAEL = 10 mg/kg/day     LOC for MOE = 100        Developmental Toxicity-
 to 6 months)                          UFA = 10x..............                            Rat MRID 42351501
                                       UFH = 10 x.............                           LOAEL = 30 mg/kg/day
                                       FQPA SF = 1x...........                            based on clinical
                                                                                          signs and decrease
                                                                                          body weight gain
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Dermal short-term (1 to 30 days)       Dermal study NOAEL = 20  LOC for MOE = 10d        21-day dermal toxicity-
 (Formulated product (4% ai.))          mg/kg/day (333 ug/                                guinea pigs MRID
                                        cm2)b                                             41105801
                                       UFA = 3x...............                           LOAEL = 40 mg/kg/day
                                       UFH = 3x...............                            based on denuded non-
                                       FQPA SF = 1x...........                            vascularized epidermal
                                                                                          layer
----------------------------------------------------------------------------------------------------------------
Dermal intermediate-term (technical    Dermal study NOAEL= 20   LOC for MOE = 10d        90-day dermal in rats
 grade a.i.) (1 to 6 months)            mg/kg/day (80 ug/cm2)c                            MRID 41499601
                                       UFA = 3x...............                           LOAEL = 20 mg/kg/day
                                       UFH = 3x...............                            based on highest doest
                                       FQPA SF = 1x...........                            tested before
                                                                                          irritation became
                                                                                          significant.
                                                                                          Irritation not
                                                                                          observed until day 43
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Dermal Short-term (technical grade     No endpoint identified
 a.i)                                   from the available
                                        data on dermal
                                        irritation. Dermal
                                        irritation in the 90-
                                        day dermal toxicity
                                        study was not evident
                                        until day 43 (MRID
                                        41499601)d
----------------------------------------------------------------------------------------------------------------
Long-term Dermal (technical grade      No appropriate endpoint
 a.i.)                                  identified. No
                                        systemic effects
                                        observed up to 20 mg/
                                        kg/day, highest dose
                                        of technical that
                                        could be tested
                                        without irritation
                                        effects.d
----------------------------------------------------------------------------------------------------------------
Inhalation (all exposures)             Oral study NOAEL = 3 mg/ LOC for MOE = 1000       Developmental Toxicity-
                                        kg/day 100%                                       rabbit MRID 42392801
                                       UFA = 10x..............                           LOAEL = 9 mg/kg/day
                                       UFH = 10x..............                            based on clinical
                                       FQPA SF = 10x..........                            signs of toxicity in
                                       (UFdb)a................                            maternal animals
----------------------------------------------------------------------------------------------------------------
UFA = extrapolation from animal to human (interspecies).
UFH = potential variation in sensitivity among members of the human population (intraspecies).
FQPA SF = FQPA Safety Factor.
PAD = population adjusted dose (a = acute, c = chronic).
RfD = reference dose.
MOE = margin of exposure.

[[Page 40732]]

 
a An additional uncertainity factor of 10x is applied for use of an oral endpoint for route-to-route
  extrapolation in the absence of an inhalation toxicity study.
b Formulated-based dermal endpoint = (20 mg/kg guinea pig x 0.43 kg guinea pig x 1,000 ug/mg)/25.8cm2 area of
  guinea pig dosed = 33 ug/cm2.
c TGAI-based dermal endpoint = (20 mg/kg rat x 0.2 kg rat x 1000 ug/mg)/ 50 cm2 area of rate dosed = 80 ug/cm2.
d For dermal exposures, irritation as the effect was selected for the short-term endpoint and a reduced margin
  of exposure (MOE) was used to characterize the risk. The use of irritation as a toxic endpoint for assessment
  of dermal risk is appropriate in this case, as dermal exposure that results in primarily an irritation
  response is considered a self-limiting type of exposure that is not expected to last for any length of time,
  and variability in the response is not expected to be as great as systemic toxic responses. For ADBAC, the MOE
  for short-term dermal risk is reduced to a total factor of 10x (3x for interspecies extrapolation, 3x for
  intraspecies variation.)

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. In evaluating dietary 
exposure to n-alkyl (C12-14) dimethyl ethylbenzyl ammonium 
chloride, EPA considered exposure under the petitioned-for exemption as 
well as all existing ADBAC exemptions or tolerances in 40 CFR 
180.940(a), and (c). EPA assessed dietary exposures from ADBAC in food 
as follows:
    ADBACs are to be used as a sanitizer on counter tops, utensils, 
appliances, tables, refrigerators, food packaging, and beverage 
bottling. The use of these actives in antimicrobial products for use on 
food or feed contact surfaces, agricultural commodities, and 
application to food-grade eggs may result in pesticide residues in 
human food. Residues from treated surfaces, such as utensils, 
countertops, equipment, and appliances can migrate to food coming into 
contact with the treated and rinsed surfaces and can be ingested by 
humans.
    The Agency assessed chronic dietary exposures from the use of ADBAC 
as a disinfectant and food contact sanitizer on utensils, countertops, 
and in food/beverage processing facilities. The assessment calculated 
the Daily Dietary Dose (DDD) and the Estimated Daily Intake (EDI) using 
modified Food and Drug Administration (FDA) methodologies for utensils 
and Indirect Dietary Residential Exposure Model software (IDREAM) for 
countertops. IDREAM incorporates consumption data from U.S. Department 
of Agriculture (USDA) Continuing Surface of Food Intakes by Individuals 
(CSFII) for 1994-1996, and 1998. The 1994-1996, and 1998 data are based 
on the reported consumption of more than 20,000 individuals over 2 non-
consecutive survey days.
    The Estimated Daily Intake (EDI) calculations presented in this 
assessment for treated indirect dietary exposures resulting from 
sanitizing utensils assumed that food would contact 4,000 
cm2 (which represents contact with treated silverware, 
china, and glass used by an individual who regularly eats three meals 
per day at an institutional or public facility) and that the residual 
solution remaining on the surface or pesticide migration fraction is 1 
mg per square centimeter of treated area. The body weights used for 
this assessment were 70 kilogram (kg) for an adult male, 60 kg for an 
adult woman, and 10 kg for an infant. Based on data provided in a new 
residue study, Transferability Equivalence among Quats and Measured 
Food Surrogate Transfer Efficiency (MRID 46870703), a conservative 
transfer rate of 43% was used to estimate the amount of residues on the 
surface that will be transferred to food and subsequently ingested. The 
maximum application rate for ADBAC on utensils is 0.0033 lbs a.i per 
gallon of treatment solution.
    There are two levels of refinement for assessing dietary exposure 
to antimicrobial products used on countertops. The Tier 2 approach, a 
refined exposure estimate in comparison to the Tier 1, was utilized for 
this assessment. This conservative approach uses food consumption and 
preparation patterns as well as data and assumptions that are not 
chemical-specific. Food ingredients are separated into nine categories 
based on food preparation, food physical properties, and potential, or 
likelihood of contact with treated countertops. The nine food 
categories are liquids, fruit, bread, cheese, vegetable, meat, purees 
(e.g., pudding, oatmeal), pieces (foods normally consumed in small 
pieces), and powders (foods normally used in powder/granular forms). 
Assumed countertop residues are converted to estimated residues 
contacting the countertops using a translation factor for each food 
category, and default residue transfer efficiency for a representative 
food. Therefore, IDREAM combines the estimated countertop residues for 
surface treatment products, CSFII consumption data, food-specific 
conversion factors that relate the surface area contacting a countertop 
with corresponding weight of the food item, and the transfer efficiency 
of residues from countertops to food. Conservative assumptions for 
these analyses include: All disinfectants registered to disinfect 
kitchen countertops are included; all foods are prepared on treated 
countertops; all prepared foods will come in contact with treated 
countertops at the maximum active ingredient (a.i.) residues; these 
residues will not diminish over time (i.e., residue reduction will not 
occur from cooking or preparation processes); there is a 100% 
likelihood of contact to account for both commercial and residential 
scenarios; all commercial facilities and households use the same 
disinfectant product; all foods are prepared and consumed.
    When assessing the food bottling/packaging use, EPA assumed a 100% 
transfer rate because the food is potentially in contact with the 
treated surfaces for very long periods of time. The maximum application 
rate for ADBAC for bottling/packing of food is 0.0103 lbs a.i per 
gallon of treatment solution. EDI values were calculated using an 
approach similar to that used for treated food utensils. Exposure was 
assumed to occur through the ingestion of three food products that 
might be packaged in treated material: milk, egg products, and 
beverages (alcoholic and non-alcoholic). A calorie intake modification 
factor of 0.64 was applied to the EDI for a child to account for the 
differences between intake values among children and adults.
    2. Dietary exposure from drinking water. ADBAC is applied to 
nursery ornamentals and turf as an bactericide and fungicide. The Tier 
1 surface water and groundwater model was used to assess Estimated 
Drinking Water Concentrations (EDWCs). EPA modeled the ornamental plant 
use because this use has the highest application rate of all labeled 
uses -- 302 lbs. a.i/Acre, and a maximum of 3 applications per year. 
The EDWCs determined for the nursery ornamental use are also protective 
of all other uses with lower application rates. The EDWC for surface 
water is 331 ug/L and groundwater is 5.4 ug/L. There were no major 
degradates of ADBAC in the laboratory studies.
    ADBAC is also used for mosquito control and as an algaecide in 
decorative ponds and pools. Because the mosquito control and algaecide 
uses are both periodic in nature and are restricted to a limited use 
area, EPA expects drinking water exposures from these uses to be 
minimal in comparison to the ornamental plant exposure estimate for 
drinking water using the Tier 1 surface and ground water model.

[[Page 40733]]

Additionally, antisapstain and cooling water tower uses for ADBAC are 
potential exposures to drinking water. These uses are also expected to 
result in minimal exposure in comparison to the modeled EDWCs for the 
ornamental use taking into account that the Tier 1 model assumed that 
ADBAC was applied at 302 lbs./Acre across the entire watershed.
    Specific information on the dietary and drinking water exposure 
assessments for ADBAC can be found at https://www.regulations.gov. 
Docket ID Number EPA-HQ-OPP-2006-0339, Dietary Risk Assessment on ADBAC 
and Tier 1 Drinking Water Assessment for Alkyl Dimethyl Benzyl Ammonium 
Chloride (ADBAC) & Didecyl Dimethyl Ammonium Chloride (DDAC).
    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).
    ADBAC is currently registered for the following residential non-
dietary sites: Homes, swimming pools, humidifiers. EPA assessed 
residential exposure using the following assumptions: Residential 
exposure may occur during the application as well as post application 
of ADBAC to indoor hard surfaces (e.g., mopping, wiping, trigger pump 
sprays), carpets, swimming pools, wood as a preservative, textiles 
(e.g., diaper treated during washing and clothes treated with fabric 
spray), and humidifiers. The residential handler scenarios were 
assessed to determine dermal and inhalation exposures. Residential post 
application scenarios such as children exposure to treated toys and 
floors were also assessed to determine dermal and incidental oral 
exposures. Surrogate dermal and inhalation unit exposure values were 
estimated using Pesticide Handler Exposure Database (PHED) data and the 
Chemical Manufactures Association Antimicrobial Exposure Assessment 
Study (USEPA, 1999), and the SWIMODEL 3.0 was utilized to conduct 
exposure assessments of pesticides found in swimming pools and spas 
(Versar, 2003). Note that for this assessment, EPA assumed that 
residential users complete all elements of an application (mix/load/
apply) without the use of personal protective equipment.
    The duration for most residential exposures is believed to be best 
represented by the short-term duration (1 to 30 days). The short-term 
duration was chosen for this assessment because the residential handler 
and post-application scenarios are assumed to be performed on an 
episodic, not daily basis.
    Specific information on the residential exposure assessment for 
ADBAC Quaternaries can be found at https://www.regulations.gov. Docket 
ID Number EPA-HQ-OPP-2006-0339 Alkyl Dimethyl Benzyl Ammonium Chloride 
(ADBAC) Occupational and Residential Exposure Assessment.
     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's risk assessment for any individual ADBAC is based on an 
assessment of the cumulative exposure to all ADBACs. The individual 
exposure scenarios in the ADBAC assessments (as well as the aggregate 
assessment in the RED) were developed by assuming that an ADBAC 
compound was used on 100% of the surfaces authorized on the label that 
could result in human exposure and summing the percent active 
ingredients on the labels for all of the ADBACs when used in 
combination. Thus, because the risk assessment for ADBAC accounts for 
exposures to all of the ADBACs, there is no need for a separate 
cumulative risk assessment for those compounds. The Agency has not 
identified any other substances as sharing a common mode of toxicity 
with ADBAC. For information regarding EPA's efforts to determine which 
chemicals have a common mechanism of toxicity and to evaluate the 
cumulative effects of such chemical, see EPA's website at https://www.epa.gov/pesticides/cumulative.

D. Safety Factor for Infants and Children

    1. In general. Section 408 of FFDCA provides that EPA shall apply 
an additional (10X) tenfold 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 FQPA Safety Factor (SF). In 
applying this provision, EPA either retains the default value of 10X 
when reliable data do not support the choice of a different factor, or, 
if reliable data are available, EPA uses a different additional FQPA SF 
value based on the use of traditional UFs and/or FQPA SFs, as 
appropriate.
    2. Prenatal and postnatal sensitivity. There is no evidence that 
ADBAC result in increased susceptibility in in utero rats or rabbits in 
the prenatal developmental studies or in young rats in the 2-generation 
reproduction study.
    3. Conclusion. EPA has determined that reliable data show that it 
would be safe for infants and children to reduce the FQPA SF to 1X. 
That decision is based on the following findings:
    i. The toxicity database for ADBAC is complete.
    ii. There is no indication that ADBAC is a neurotoxic chemical and 
there is no need for a developmental neurotoxicity study or additional 
UFs to account for neurotoxicity.
    iii. There is no evidence that ADBAC results in increased 
susceptibility in in utero rats or rabbits in the prenatal 
developmental studies or in young rats in the 2-generation reproduction 
study.
    iv. There are no residual uncertainties identified in the exposure 
databases. Conservative ground and surface water modeling estimates 
were used. Similarly conservative residential standard operating 
procedures (SOPs) were used 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 
ADBAC.

E. Aggregate Risks and Determination of Safety

    The chronic dietary aggregate risk assessment includes direct and 
indirect food contact uses as well as drinking water exposures. Based 
on the results of the chronic aggregate assessment, the estimated 
chronic risks for adults and children are 8.4% and 40.9% of the cPAD. 
Therefore, the chronic dietary aggregate risks are not of concern 
(i.e., less than 100% of cPAD).
    Short-term and intermediate-term aggregate risks were calculated 
using the total MOE approach. Only the short-term aggregate is 
presented here because the endpoints for incidental oral as well as 
inhalation are identical for the short- and intermediate-term 
durations. The aggregate risks are not of concern for adults for any of 
the three routes of exposure. The aggregate adult MOEs are 1,200 for 
oral, 480 for dermal, and 2,000 for inhalation, which are greater than 
the target MOE of 100 for the oral, 1,000 for inhalation, and 10 for 
dermal. For children, the aggregate risk estimate for each of the 
routes of exposure are also above the target MOEs of 100 for the oral, 
1,000 for inhalation, and 10 for dermal (MOE=140 for the oral route,

[[Page 40734]]

1,200 for the dermal route, and are thus not of concern). There were no 
inhalation risks identified.
    Based on the toxicological and exposure data discussed in this 
preamble, EPA concludes that will not pose a risk under reasonably 
foreseeable circumstances. Accordingly, EPA finds that there is a 
reasonable certainty of no harm will result to the general population, 
or to infants and children from aggregate exposure to ADBAC residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    An analytical method for food is not needed. Food contact 
sanitizers are typically regulated by the State health departments to 
ensure that the food industry is using products in compliance with the 
regulations in 40 CFR 180.940. The end-use solution that is applied to 
the food contact surface is analyzed not food items that may come into 
contact with treated surface. An analytical method is available to 
analyze the use dilution that is applied to food contact surfaces. A 
titration method is used to determine the total amount of quaternary 
compound. If the use solution is a mixture of ADBAC and didecyl 
dimethyl ammonium chloride (DDAC), then High Pressure Liquid 
Chromatogram-Ultraviolet Visible (HPLC-UV) is used to determine the 
amount of ADBAC. The amount of DDAC is determined by calculating the 
difference between the total amount of quaternary compounds and ADBAC.

B. International Residue Limits

    In making its tolerance decisions, EPA seeks to harmonize U.S. 
tolerances with international standards whenever possible, consistent 
with U.S. food safety standards and agricultural practices. EPA 
considers the international maximum residue limits (MRLs) established 
by the Codex Alimentarius Commission (Codex), as required by FFDCA 
section 408(b)(4). The Codex Alimentarius is a joint U.N. Food and 
Agriculture Organization/World Health Organization food standards 
program, and it is recognized as an international food safety 
standards-setting organization in trade agreements to which the United 
States is a party. EPA may establish a tolerance that is different from 
a Codex MRL; however, FFDCA section 408(b)(4) requires that EPA explain 
the reasons for departing from the Codex level.
     The Codex has not established a MRL for n-alkyl 
(C12-14) dimethyl ethylbenzyl ammonium chloride.

C. Response to Comments

    EPA received no comments in response to the notice of filing for 
the petition to amend the tolerance exemption for the ADBAC compound 
addressed in this rulemaking, n-alkyl (C12-14) dimethyl 
ethylbenzyl ammonium chloride. However, in October, 2008, EPA received 
comments on a final rule amending the tolerance exemption for a similar 
ADBAC compound, n-alkyl (C12-18) dimethyl benzyl ammonium 
chloride. (73 FR 49101) (August 20, 2008). The commenter mistakenly 
assumed that this final rule was a ``proposed EPA action'' and urged 
that EPA require submission of new data on ADBAC, review studies that 
have recently become available on ADBAC, and conduct a revised risk 
assessment for the chemical. Because the petition for the current 
action was pending at the time that the comments on the related final 
rule were received, EPA considered those comments in ruling on the 
petition addressed in this action.
    The commenter raised several concerns with regard to the earlier 
tolerance action as to an ADBAC compound: (1) ADBAC and other 
quaternary ammonium compounds may be reproductive and genetic 
toxicants; (2) quaternary ammonium compounds are linked with increased 
occupational asthma and immune system sensitization; and (3) quaternary 
ammonium compounds are persistent in the environment. The commenter 
also raised various environmental concerns with the quaternary ammonium 
compounds but these concerns are relevant only to EPA's decision to 
register ADBAC under the Federal Insecticide, Fungicide, and 
Rodenticide Act (``FIFRA''), 7 U.S.C. 136 et seq., and not tolerance 
actions under section 408 of the FFDCA. EPA has prepared a detailed 
response to each of the commenter's arguments and included that 
document in the record for this action. EPA's response as to the FFDCA-
related comments is summarized below.
    EPA does not believe that ADBAC poses unacceptable reproductive 
risks. In the ADBAC risk assessment, the Agency relied on available, 
reliable, quantitative animal data to characterize hazards associated 
with uses of ADBAC including reproductive function and effects on the 
developing mammalian fetus. In the developmental studies with rats 
(range-finding MRID 42645101 and main study MRID 42351501) and rabbits 
(range-finding MRID 42734401 and main study MRID 42392801), there was 
no increased sensitivity of developing fetuses to ADBAC compared to 
adult animals. In a 2-generation reproductive toxicity study (MRID 
41385001), effects on rat pups were observed in the absence of 
statistically significant maternal toxicity, but only at the highest 
dose (160 mg/kg/day). The effects observed were considered to be 
nonspecific (decreased pup body weight and weight gain during 
lactation) and there were no effects of ADBAC on reproductive indices. 
It is important to note that the endpoints selected from the rat oral 
developmental toxicity study (NOAEL = 10 mg/kg/day) or the 21-day 
dermal toxicity studies (NOAEL = 20 mg/kg/day) are well below the dose 
causing these nonspecific effects. Therefore, the endpoints used in 
risk assessment are protective of infants and children. The commenter 
relied on a scientific literature article in which a researcher 
speculated that a severe decline in the fertility of the researcher's 
laboratory mouse population was due to exposure to quaternary ammonium 
compounds. EPA concludes that the results of the specific studies 
designed to examine the reproductive effects of pesticides outweigh the 
speculative article.
    EPA does not believe ADBAC is a genetic toxicant. In evaluating 
ADBAC's potential mutagenicity, EPA relied on testing results in a 
battery of mutagenicity studies, including an HGPRT/CHO forward 
mutation assay (MRID 42290801, reformat of MRID 41012701), an in vivo 
bone marrow chromosomal aberration assay (MRID 40311101, supplement 
MRID 43037701), and an unscheduled DNA synthesis (UDS) assay (MRID 
42290802, reformat of 41012601), all of which demonstrated that ADBAC 
did not induce mutagenic effects. Further support for this conclusion 
is provided by carcinogenicity testing in long-term studies using both 
rats (MRID 41947501) and mice (MRID 41765201). In both studies, ADBAC 
was tested at adequate dose levels and found to be negative for 
induction of tumors. In contrast, the commenter relies on the result in 
an in vitro mutagenicity test. The weight of the evidence clearly 
supports EPA's conclusion. In vivo mutagenicity testing (as does 
carcinogenicity testing in rodents) carries far greater weight than in 
vitro testing because in vivo testing is much more likely to simulate 
the detoxifying effects present in the living animal.
    Finally, although EPA would agree that the chemical properties of 
ADBAC indicate that it will only degrade slowly in the environment, 
these properties were taken into account in estimating exposure to 
humans to ADBAC in drinking water in assessing ADBAC

[[Page 40735]]

risks. Accordingly, ADBAC's persistence does not render it unsafe.

V. Conclusion

    Therefore, the exemption from the requirement of a tolerance in 40 
CFR 180.940(a) for Quaternary Ammonium Compounds: n-alkyl (C 
12-14) dimethyl ethylbenzyl ammonium chloride (CAS Reg. No. 
85409-23-0) is amended to increase from 200 ppm to 400 ppm the level of 
the end-use concentration of all quaternary chemicals that may be 
present in solution when the solution is ready for use.

VI. Statutory and Executive Order Reviews

    This final rule establishes a tolerance under section 408(d) of 
FFDCA 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 final rule has been 
exempted from review under Executive Order 12866, this final rule 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 final rule does not contain any 
information collections 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 section 408(d) of FFDCA, such as the tolerance 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 final rule 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 section 408(n)(4) of FFDCA. 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 final rule. In addition, 
this final rule does not impose any enforceable duty or contain any 
unfunded mandate as described under Title II of the Unfunded Mandates 
Reform Act of 1995 (UMRA) (Public Law 104-4).
    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 of 1995 (NTTAA), Public Law 104-113, section 12(d) (15 U.S.C. 272 
note).

VII. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report to each House of the Congress and to 
the Comptroller General of the United States. 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 this final rule in the Federal 
Register. This final rule 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: July 8, 2010.
Joan Harrigan-Farrelly,
Director, Antimicrobials Division, Office of Pesticide Programs.

0
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. Section 180.940 is amended by revising the following entry in the 
table in paragraph (a) to read as follows:


Sec.  180.940  Tolerance exemptions for active and inert ingredients 
for use in antimicrobial formulations (Food-contact surface sanitizing 
solutions).

* * * * *
    (a) * * *

------------------------------------------------------------------------
       Pesticide Chemical            CAS Reg. No.           Limits
------------------------------------------------------------------------
                                * * * * *
Quaternary Ammonium Compounds: n- 85409-23-0          When ready for
 alkyl (C 12-14) dimethyl                              use, the end-use
 ethylbenzyl ammonium chloride,                        concentration of
 average molecular weight (in                          all quaternary
 amu), 377 to 384.                                     chemicals in
                                                       solution is not
                                                       to exceed 400 ppm
                                                       of active
                                                       quaternary
                                                       compound.
                                * * * * *
------------------------------------------------------------------------


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[FR Doc. 2010-17156 Filed 7-13-10; 8:45 am]
BILLING CODE 6560-50-S