[Federal Register Volume 75, Number 134 (Wednesday, July 14, 2010)]
[Rules and Regulations]
[Pages 40729-40736]
From the Federal Register Online via the Government Publishing 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 http://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 http://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: [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 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 http://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: http://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, http://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 http://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 http://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
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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
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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
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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
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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 http://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 http://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 http://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,
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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