[Federal Register Volume 62, Number 228 (Wednesday, November 26, 1997)]
[Rules and Regulations]
[Pages 63228-63235]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-30947]
[[Page 63227]]
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Part IV
Environmental Protection Agency
_______________________________________________________________________
40 CFR Part 180
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Cypermethrin and Zeta-Cypermethrin; Pesticide Tolerance; Final Rules
Federal Register / Vol. 62, No. 228 / Wednesday, November 26, 1997 /
Rules and Regulations
[[Page 63228]]
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-300583; FRL-5755-3]
RIN 2070-AB78
Cypermethrin; Pesticide Tolerance
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes permanent tolerances for residues
of cypermethrin ()alpha-cyano-(3-
phenoxyphenyl)methyl()cis,trans-3(2,2-dichloroethyenyl)-
2,2-dimethylcyclopropane carboxylate in or on the commodities brassica,
head and stem at 2.0 parts per million (ppm); brassica, leafy at 14.0
ppm; cattle, fat at 0.05 ppm; cattle, meat at 0.05 ppm; cattle, meat
byproducts (mbyp) at 0.05 ppm; cottonseed at 0.5 ppm; goats, fat at
0.05 ppm; goats, meat at 0.05 ppm; goats, mbyp at 0.05 ppm; hogs, fat
at 0.05 ppm; hogs, meat at 0.05 ppm; hogs, mbyp at 0.05 ppm; horses,
fat at 0.05 ppm; horses, meat at 0.05 ppm; horses, mbyp at 0.05 ppm;
lettuce, head at 10.0 ppm; milk at 0.05 ppm; onions, bulb at 0.10 ppm;
pecans 0.05 ppm; sheep, fat at 0.05; sheep, meat at 0.05 ppm; and
sheep, mbyp at 0.05 ppm. It also removes the time limitations for
tolerances for cypermethrin on the same commodities expires on November
15, 1997. FMC Corporation requested these tolerances under the Federal
Food, Drug, and Cosmetic Act, as amended by the Food Quality Protection
Act of 1996.
DATES: This regulation is effective November 26, 1997. Objections and
requests for hearings must be received by EPA on or before January 26,
1998.
ADDRESSES: Written objections and hearing requests, identified by the
docket control number, OPP-300583, must be submitted to: Hearing Clerk
(1900), Environmental Protection Agency, Rm. M3708, 401 M St., SW.,
Washington, DC 20460. Fees accompanying objections and hearing requests
shall be labeled ``Tolerance Petition Fees'' and forwarded to: EPA
Headquarters Accounting Operations Branch, OPP (Tolerance Fees), P.O.
Box 360277M, Pittsburgh, PA 15251. A copy of any objections and hearing
requests filed with the Hearing Clerk, identified by the docket control
number, OPP-300583, must also be submitted to: Public Information and
Records Integrity Branch, Information Resources and Services Division
(7502C), Office of Pesticide Programs, Environmental Protection Agency,
401 M St., SW., Washington, DC 20460. In person, bring a copy of
objections and hearing requests to Rm. 1132, Crystal Mall #2, 1921
Jefferson Davis Hwy., Arlington, VA.
A copy of objections and hearing requests filed with the Hearing
Clerk may also be submitted electronically by sending electronic mail
(e-mail) to: [email protected]. Follow the instructions in
Unit VI. of this preamble. No Confidential Business Information (CBI)
should be submitted through e-mail.
FOR FURTHER INFORMATION CONTACT: By mail: George T. Larocca, Product
Manager (PM-13), Registration Division (7505C), Office of Pesticide
Programs, Environmental Protection Agency, 401 M St., SW., Washington,
DC 20460. Office location, telephone number, and e-mail address:
Crystal Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA, (703) 305-
6100, e-mail: [email protected].
SUPPLEMENTARY INFORMATION: In the Federal Register of June 15, 1984 (49
FR 24864), EPA established time-limited tolerances under section 408
and 409 of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C.
346 a(d) and 348 for residues of cypermethrin. These tolerances expire
on November 15, 1997. On September 15, 1997, FMC Corporation requested
that the time limitation for tolerances established for residues of the
insecticide cypermethrin in these commodities be removed based on
environmental effects data that they had submitted as a condition of
the registration. FMC Corporation also submitted a summary of its
petitions as required under the FFDCA, as amended by the Food Quality
Protection Act (FQPA) of 1996 (Pub. L. 104-170).
In the Federal Register of September 25, 1997, (62 FR 50337) (FRL-
5748-2), EPA issued a notice pursuant to section 408 of the FFDCA, 21
U.S.C. 346a(e) announcing the filing of pesticide petitions (PP 2F2623,
4F2986, 4F2986, 3F2824, 7F3498, 4F3011, and 4F4291) for tolerances by
the FMC Corporation, 1735 Market St., Philadelphia, PA 19103. This
notice included a summary of the petitions prepared by the FMC
Corporation. There were no comments received in response to the notice
of filing. The petitions requested that 40 CFR 180.418 be amended by
removing the time limitations for tolerances of the insecticide
cypermethrin (()alpha-cyano-(3-
phenoxyphenyl)methyl()cis,trans-3(2,2-dichloroethyenyl)-
2,2-dimethylcyclopropane carboxylate) in or on the commodities
brassica, head and stem at 2.0 ppm; brassica, leafy at 14.0 ppm;
cattle, fat at 0.05 ppm; cattle, meat at 0.05 ppm; cattle, mbyp at 0.05
ppm; cottonseed at 0.5 ppm; goats, fat at 0.05 ppm; goats, meat at 0.05
ppm; goats, mbyp at 0.05 ppm; hogs, fat at 0.05 ppm; hogs, meat at 0.05
ppm; hogs, mbyp at 0.05 ppm; horses, fat at 0.05 ppm; horses, meat at
0.05 ppm; horses, mbyp at 0.05 ppm; lettuce, head at 10.0 ppm; milk at
0.05 ppm; onions, bulb at 0.10 ppm; pecans 0.05 ppm; sheep, fat at
0.05; sheep, meat at 0.05 ppm; and sheep, mbyp at 0.05 ppm. Tolerances
for livestock commodities were inadvertently not listed in the notice
of filing, although the tolerance petition, PP2F2623 previously
establishing these tolerances was listed. The livestock commodity
tolerances were considered by EPA for risk assessment purposes.
The basis for time-limited tolerances that expire November 15,
1997, was given in the October 20, 1993, Federal Register (58 FR
54094). These time-limited tolerances were predicated on the expiration
of pesticide product registrations that were made conditional due to
lack of certain ecological and environmental effects data. The
rationale for using time-limited tolerances was to encourage pesticide
manufacturers to comply with the conditions of registration in a timely
manner. There is no regulatory requirement to make tolerances time-
limited due to the conditional status of a product registration under
the Federal Insecticide, Fungicide, Rodenticide Act (FIFRA), as
amended. It is current EPA policy to no longer establish time
limitations on tolerances with expiration dates if none of the
conditions of registration have any bearing on human dietary risk. The
current petition actions meet that condition and thus the expiration
dates associated with specific crop tolerances are being deleted.
I. Risk Assessment and Statutory Findings
New section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a
tolerance (the legal limit for a pesticide chemical residue in or on a
food) only if EPA determines that the tolerance is ``safe.'' Section
408(b)(2)(A)(ii) of the FFDCA defines ``safe'' to mean that ``there is
a reasonable certainty that no harm will result from aggregate exposure
to the pesticide chemical residue, including all anticipated dietary
exposures and all other exposures for which there is reliable
information.'' This includes exposure through drinking water and in
residential settings, but does not include occupational exposure.
Section
[[Page 63229]]
408(b)(2)(C) of the FFDCA requires EPA to give special consideration to
exposure of infants and children to the pesticide chemical residue in
establishing a tolerance and to ``ensure that there is a reasonable
certainty that no harm will result to infants and children from
aggregate exposure to the pesticide chemical residue....''
EPA performs a number of analyses to determine the risks from
aggregate exposure to pesticide residues. First, EPA determines the
toxicity of pesticides based primarily on toxicological studies using
laboratory animals. These studies address many adverse health effects,
including (but not limited to) reproductive effects, developmental
toxicity, toxicity to the nervous system, and carcinogenicity. Second,
EPA examines exposure to the pesticide through the diet (e.g., food and
drinking water) and through exposures that occur as a result of
pesticide use in residential settings.
A. Toxicity
1. Threshold and non-threshold effects. For many animal studies, a
dose response relationship can be determined, which provides a dose
that causes adverse effects (threshold effects) and doses causing no-
observed effects (the ``no-observed effect level'' or ``NOEL'').
Once a study has been evaluated and the observed effects have been
determined to be threshold effects, EPA generally divides the NOEL from
the study with the lowest NOEL by an uncertainty factor (usually 100 or
more) to determine the Reference Dose (RfD). The RfD is a level at or
below which daily aggregate exposure over a lifetime will not pose
appreciable risks to human health. An uncertainty factor (sometimes
called a ``safety factor'') of 100 is commonly used since it is assumed
that people may be up to 10 times more sensitive to pesticides than the
test animals, and that one person or subgroup of the population (such
as infants and children) could be up to 10 times more sensitive to a
pesticide than another. In addition, EPA assesses the potential risks
to infants and children based on the weight of the evidence of the
toxicology studies and determines whether an additional uncertainty
factor is warranted. Thus, an aggregate daily exposure to a pesticide
residue at or below the RfD (expressed as 100% or less of the RfD) is
generally considered acceptable by EPA. EPA generally uses the RfD to
evaluate the chronic risks posed by pesticide exposure. For shorter
term risks, EPA calculates a margin of exposure (MOE) by dividing the
estimated human exposure into the NOEL from the appropriate animal
study. Commonly, EPA finds MOEs lower than 100 to be unacceptable. This
100-fold MOE is based on the same rationale as the 100-fold uncertainty
factor.
Lifetime feeding studies in two species of laboratory animals are
conducted to screen pesticides for cancer effects. When evidence of
increased cancer is noted in these studies, the Agency conducts a
weight of the evidence review of all relevant toxicological data
including short-term and mutagenicity studies and structure activity
relationship. Once a pesticide has been classified as a potential human
carcinogen, different types of risk assessments (e.g., linear low-dose
extrapolations or MOE calculation based on the appropriate NOEL) will
be carried out based on the nature of the carcinogenic response and the
Agency's knowledge of its mode of action.
2. Differences in toxic effect due to exposure duration. The
toxicological effects of a pesticide can vary with different exposure
durations. EPA considers the entire toxicity data base, and based on
the effects seen for different durations and routes of exposure,
determines which risk assessments should be done to assure that the
public is adequately protected from any pesticide exposure scenario.
Both short and long durations of exposure are always considered.
Typically, risk assessments include ``acute,'' ``short-term,''
``intermediate-term,'' and ``chronic'' risks. These assessments are
defined by the Agency as follows.
Acute risk, by the Agency's definition, results from 1-day
consumption of food and water, and reflects toxicity which could be
expressed following a single-oral exposure to the pesticide residues.
High-end exposure to food and water residues are typically assumed.
Short-term risk results from exposure to the pesticide for a period
of 1-7 days, and therefore overlaps with the acute risk assessment.
Historically, this risk assessment was intended to address primarily
dermal and inhalation exposure which could result, for example, from
residential pesticide applications. However, since enaction of FQPA,
this assessment has been expanded to include both dietary and non-
dietary sources of exposure, and will typically consider exposure from
food, water, and residential uses when reliable data are available. In
this assessment, risks from average food and water exposure, and high-
end residential exposure, are aggregated. High-end exposures from all
three sources are not typically added because of the very low
probability of this occurring in most cases, and because the other
conservative assumptions built into the assessment assure adequate
protection of public health. However, for cases in which high-end
exposure can reasonably be expected from multiple sources (e.g.
frequent and widespread homeowner use in a specific geographical area),
multiple high-end risks will be aggregated and presented as part of the
comprehensive risk assessment/characterization. Since the toxicological
endpoint considered in this assessment reflects exposure over a period
of at least 7 days, an additional degree of conservatism is built into
the assessment; i.e., the risk assessment nominally covers 1-7 days
exposure, and the toxicological endpoint/NOEL is selected to be
adequate for at least 7 days of exposure. (Toxicity results at lower
levels when the dosing duration is increased.)
Intermediate-term risk results from exposure for 7 days to several
months. This assessment is handled in a manner similar to the short-
term risk assessment.
Chronic risk assessment describes risk which could result from
several months to a lifetime of exposure. For this assessment, risks
are aggregated considering average exposure from all sources for
representative population subgroups including infants and children.
B. Aggregate Exposure
In examining aggregate exposure, section 408 of the FFDCA requires
that EPA take into account available and reliable information
concerning exposure from the pesticide residue in the food in question,
residues in other foods for which there are tolerances, residues in
ground water or surface water that is consumed as drinking water, and
other non-occupational exposures through pesticide use in gardens,
lawns, or buildings (residential and other indoor uses). Dietary
exposure to residues of a pesticide in a food commodity are estimated
by multiplying the average daily consumption of the food forms of that
commodity by the tolerance level or the anticipated pesticide residue
level. The Theoretical Maximum Residue Contribution (TMRC) is an
estimate of the level of residues consumed daily if each food item
contained pesticide residues equal to the tolerance. In evaluating food
exposures, EPA takes into account varying consumption patterns of major
identifiable subgroups of consumers, including infants and children.
The TMRC is a ``worst case'' estimate since it is based on the
[[Page 63230]]
assumptions that food contains pesticide residues at the tolerance
level and that 100% of the crop is treated by pesticides that have
established tolerances. If the TMRC exceeds the RfD or poses a lifetime
cancer risk that is greater than approximately one in a million, EPA
attempts to derive a more accurate exposure estimate for the pesticide
by evaluating additional types of information (anticipated residue data
and/or percent of crop treated data) which show, generally, that
pesticide residues in most foods when they are eaten are well below
established tolerances.
II. Aggregate Risk Assessment and Determination of Safety
Consistent with section 408(b)(2)(D) of the 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
cypermethrin and to make a determination on aggregate exposure,
consistent with section 408(b)(2) of the FFDCA, for tolerances for
residues of cypermethrin in or on the commodities brassica, head and
stem at 2.0 ppm; brassica, leafy at 14.0 ppm; cattle, fat at 0.05 ppm;
cattle, meat at 0.05 ppm; cattle, mbyp at 0.05 ppm; cottonseed at 0.5
ppm; goats, fat at 0.05 ppm; goats, meat at 0.05 ppm; goats, mbyp at
0.05 ppm; hogs, fat at 0.05 ppm; hogs, meat at 0.05 ppm; hogs, mbyp at
0.05 ppm; horses, fat at 0.05 ppm; horses, meat at 0.05 ppm; horses,
mbyp at 0.05 ppm; lettuce, head at 10.0 ppm; milk at 0.05 ppm; onions,
bulb at 0.10 ppm; pecans 0.05 ppm; sheep, fat at 0.05; sheep, meat at
0.05 ppm; and sheep, mbyp at 0.05 ppm. EPA's assessment of the dietary
exposures and risks associated with establishing the 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. The nature of the toxic effects caused by cypermethrin are
discussed in this unit.
1. Acute toxicity. The required battery of acute toxicity studies
has been submitted and found adequate. The findings were as follows:
oral toxicity, LD50 > 263 milligram/kilogram (mg/kg); dermal
toxicity, LD50 > 2,460 mg/kg; inhalation toxicity
LC50, 2.5 mg/liter (L); primary eye irritation--Toxicity
Category III; primary dermal irritation --Toxicity Category IV.
Cypermethrin is considered to be a dermal sensitizer.
2. Mutagenicity. The Agency has reviewed several mutagenicity
studies. Types include an Ames mutagenicity assay; a dominant lethal
study, a mouse lymphoma mutagenicity assay, a Chinese hamster ovary/
hypoxanthine quanine phosphoribose transferase (CHO/HGPRT) assay, and a
bone marrow cytogenic study. The data base for mutagenicity is
considered to be adequate. Based on the available mutagenicity studies,
there are no concerns for mutagenicity at this time.
3. Reproductive and developmental toxicity--i. Developmental
toxicity study in the rat. Cypermethrin was administered by gavage to
rats at dose levels of 0, 17.5, 35, or 70 mg/kg/day on days 6-15 of
gestation. The maternal lowest-observed effect level (LOEL) is 35 mg/
kg/day, based on bodyweight. The maternal NOEL is 17.5 mg/kg/day. The
developmental LOEL was > 70 mg/kg/day. The developmental NOEL is > 70
mg/kg/day. The developmental toxicity study in the rat was classified
acceptable.
ii. Developmental toxicity study in the rabbit. Cypermethrin was
administered to rabbits by gelatin capsule at dose levels of 0, 3, 10,
or 30 mg/kg/day on days 6 to 18 inclusive of gestation. There were no
effects on the does of any kind reported. The maternal LOEL was > 30
mg/kg/day. The maternal NOEL is > 30 mg/kg/day. There were no treatment
related effects on either the skeletal or visceral structures reported.
The developmental LOEL is > 30 mg/kg/day. The developmental NOEL was >
30 mg/kg/day. The developmental toxicity study in the rabbit is
classified supplementary and does not satisfy the guideline requirement
for a developmental toxicity study in the rabbit. The study was not
considered upgradeable because the dose levels selected are too low.
iii. Developmental toxicity study in the rabbit. Cypermethrin was
administered to 20 New Zealand White rabbits per dose group by gavage
at dose levels of 0, 100, 450, or 700 mg/kg/day from days 7 through 19
of gestation. The does were sacrificed on day 29 of gestation. The
maternal LOEL was 450 mg/kg/day, based on bodyweight gain. The maternal
NOEL was 100 mg/kg/day. There were no indications of developmental
toxicity. The NOEL and LOEL for developmental toxicity was > 700 mg/kg/
day. This study in the rabbit was classified acceptable.
iv. Three-generation reproduction study in rats. Cypermethrin was
administered to rats at dose levels of 0, 50, 150, or 1,000/750 ppm
(reduced to 750 ppm after 12 weeks because of severe neurological
symptoms). These dose levels correspond to 2.5, 7.5, or 50/37.5 mg/kg/
day. Three successive generations were produced, each consisting of two
separate breedings to produce six sets of litters. The LOEL is 150 ppm
(7.5 mg/kg/day) based on consistent decreased bodyweight gain in both
sexes. The NOEL was 50 ppm (2.5 mg/kg/day). The study was classified
acceptable.
4. Subchronic toxicity. The data base for subchronic toxicity is
considered to be complete except for a series 82-4 subchronic
inhalation toxicity study of 90-days duration. This study is required
if inhalation exposure is for periods greater than 21-days.
i. Subchronic oral study in the rat. Cypermethrin was administered
to rats at dose levels of 0, 75, 150, or 1,500 ppm (corresponding to 0,
3.75, 7.5, or 75 mg/kg/day) for 90 days. The LOEL is 1,500 ppm (75 mg/
kg/day) based on bodyweight. The NOEL was 150 ppm (7.5 mg/kg/day). This
study did not satisfy the guideline requirement for a subchronic oral
study (82-1) in rats, but did not require upgrading because an
acceptable chronic feeding study with rats was available.
ii. Subchronic oral study in the dog. Cypermethrin was administered
to beagle dogs at dose levels of 0, 5, 50, 500, or 1,500 ppm
(corresponding to 0.125, 1.25, 12.5, and 37.5 mg/kg/day) for 13 weeks.
The NOEL is 500 ppm (12.5 mg/kg/day). This subchronic toxicity study
was classified supplementary.
iii. 21-Day dermal study in the rabbit. Cypermethrin was applied at
dose levels of control, 2, 20, or 200 mg/kg/day applied in 20% weight/
weight (w/w) basis PEG 300 with daily applications for 3 weeks for a
total of 15 applications. The LOEL is 200 mg/kg/day based on liver
effects. The NOEL is 20 mg/kg/day. This subchronic dermal toxicity
study was classified acceptable and satisfies the guideline requirement
for a subchronic dermal study (82-2) in rabbit.
iv. 21-Day inhalation study in the rat. Cypermethrin was
administered to rats by nose only exposure at concentrations of 0,
0.01, 0.05, or 0.25 mg/L for 6 hours per day, 5 days per week for a
total of 15 exposures. The LOEL was 0.05 mg/L based mainly on
bodyweight decrease. The NOEL was 0.01 mg/L. This study was classified
acceptable.
5. Chronic toxicity/carcinogenicity--i. Chronic oral study in the
dog. Cypermethrin was administered to beagle dogs at dose levels of 0,
1, 5, or 15 mg/kg/day for 52 weeks. The LOEL
[[Page 63231]]
was 5 mg/kg/day based on gastrointestinal effects. The NOEL is 1 mg/kg/
day. This chronic toxicity study was classified acceptable.
ii. Carcinogenicity study in the mouse. Cypermethrin was
administered to mice at dose levels of control-1, control-2, 100, 400,
and 1,600 ppm (corresponding to 0, 0, 14, 57, or 229 mg/kg/day) for 97
weeks for males and 101 weeks for females. The LOEL was 400 ppm (57 mg/
kg/day) based on liver weight. The NOEL was 100 ppm (14 mg/kg/day).
This study was determined to be positive for induction of benign
alveologenic neoplasms. This carcinogenicity study was classified
acceptable and satisfies the guideline requirement for a
carcinogenicity study (83-2) in mice.
iii. Chronic feeding/oncogenicity study in the rat. Cypermethrin
was administered to rats at dose levels of control-1, control-2, 20,
150, or 1500 ppm (corresponding to 0, 0, 1, 7.5, or 75 mg/kg/day) for 2
years. The LOEL is 1,500 ppm (75 mg/kg/day) based on bodyweight. The
NOEL was 150 ppm (7.5 mg/kg/day). Cypermethrin was not considered to be
oncogenic in this study. A possible association with increased
testicular interstitial tumors was not considered definite. This
chronic toxicity/carcinogenicity study was classified as acceptable and
satisfies the guideline requirement for a chronic oral feeding/
carcinogenicity study (83-5) in rats.
6. Metabolism. Studies in rats, dogs, and mice are available to
support the requirement of metabolism in mammals. Studies show that
cypermethrin is readily absorbed from the gastrointestinal tract and
extensively metabolized. It is mostly excreted in the urine. Studies
submitted to the Agency were acceptable. No additional data are
required.
7. Neurotoxicity. Additional data considered by the Agency included
an acute delayed type neurotoxicity in hens, an acute neurotoxicity
screening study in rats with a NOEL of 30 mg/kg and a LOEL of 100 mg/
kg, and a subchronic neurotoxicity screening study in rats with a NOEL
of 31 mg/kg/day and a LOEL of 77 mg/kg/day. Additional data will be
required under a special Data Call-In (DCI) letter pursuant to section
3(c)(2)(B) of FIFRA. Although these data are lacking EPA has a
sufficient toxicity data base to support these tolerances and these
additional studies are not expected to significantly change its risk
assessment.
B. Toxicological Endpoints
1. Acute toxicity. To assess risk from acute dietary exposure, the
Agency used a NOEL of 1.0 mg/kg/day based on increased incidence of
passage of liquid stools at 5 mg/kg/day and above starting the first
weeks of dosing in a the chronic-dog study.
2. Short- and intermediate-term toxicity.To assess risk from (non-
food) short- and intermediate-term dermal exposure, the Agency used a
NOEL of 5 mg/kg/day from the chronic-dog study, incorporating 25%
dermal absorption. A dermal absorption rate of 25% was derived based on
the weight-of-evidence available for structurally related pyrethroids.
For exposure via inhalation, the Agency used a NOEL of 0.01 mg/L from
the 21-day inhalation study in rats.
3. Chronic toxicity. EPA has established the RfD for cypermethrin
at 0.01 mg/kg/day. This RfD is based on a NOEL of 1.0 mg/kg/day from
the chronic-dog study with an uncertainty factor of 100.
4. Carcinogenicity. Using its Guidelines for Carcinogen Risk
Assessment published September 24, 1986 (51 FR 33992) the
Carcinogenicity Peer Review Committee (CPRC) has classified
cypermethrin as a Group C chemical, possible human carcinogen, based on
increased incidence of lung adenomas in female mice, but did not
recommend assignment of a cancer potency factor (Q*1) for a linear
quantitative cancer risk assessment. Instead, the CPRC recommended the
RfD approach. Based on the CPRC's recommendation that the RfD approach
be used to assess dietary cancer risk, a quantitative linear dietary
cancer risk assessment was not performed. Human health risk concerns
due to long-term consumption of cypermethrin residues are adequately
addressed by the dietary risk evaluation chronic exposure analysis
using the RfD.
C. Exposures and Risks
1. From food and feed uses. Tolerances have been established (40
CFR 180.418) for the residues of cypermethrin. For the purposes of
dietary risk assessment, residue data generated from residue field
trials conducted at maximum application rates and minimum preharvest
intervals were used. To assess secondary exposure from edible animal
commodities, animal dietary burdens were calculated using mean field
trial residue, adjusted for percent crop treated and applying
appropriate processing factors for all feed items. Risk assessments
were conducted by EPA to assess dietary exposures and risks from
cypermethrin as follows:
i. Acute exposure and risk. Acute dietary risk assessments are
performed for a food-use pesticide if a toxicological study has
indicated the possibility of an effect of concern occurring as a result
of a 1-day or single exposure. The acute dietary exposure assessment
used Monte Carlo modeling (in accordance with Tier 3 of EPA June 1996
``Acute Dietary Exposure Assessment'' guidance document) incorporating
anticipated residues and percent crop treated refinement. The acute
exposure via dietary intake for the U.S. Population is estimated at
0.004438 mg/kg/day. The acute dietary risk estimated by as MOE at the
99.9th percentile for the U.S. population is 225. The acute dietary
exposure for children is 0.005465 mg/kg/day with a resulting MOE of
183. EPA concludes that there is a reasonable certainty of no harm for
MOEs of 100 or greater.
ii. Chronic exposure and risk. The chronic dietary exposure
assessment incorporated anticipated residues, tolerance values, FDA and
PDP monitoring data, and percent crop treated information. The RfD used
was 0.01 mg/kg/day. For the U.S. population, the exposure was estimated
at 0.000025 mg/kg/day. The risk assessment resulted in use of 0.3% of
the RfD. For children 0.000042 mg/kg/day, which uses 0.4% of the RfD.
Section 408(b)(2)(E) of the FFDCA authorizes EPA to consider
available data and information on the anticipated residue levels of
pesticides residues in food and the actual levels of pesticide
chemicals that have been measured in food. If EPA relies on such
information, EPA must require that data be provided 5 years after the
tolerance is established, modified, or left in effect, demonstrating
that the levels in food are not above the levels anticipated. Following
the initial data submission, EPA is authorized to require similar use
data on the actual percent of crop treated when establishing a
tolerance only where the Agency can make the following findings:
a. That the data used are reliable and provide a valid basis for
showing the percentage of food derived from a crop that is likely to
contain residues.
b. That the exposure estimate does not underestimate the exposure
for any significant subpopulation.
c. Where data on regional pesticide use and food consumption are
available, that the exposure estimate does not understate exposure for
any regional population.
In addition, the Agency must provide for periodic evaluation of any
estimates used.
The percent of crop treated estimates for cypermethrin were derived
from Federal and market basket survey data.
[[Page 63232]]
EPA considers these data reliable. A range of estimates supplied by
this data and upper end of this range was used for the exposure
assessment. By using this upper end estimate of percent crop treated,
the Agency is reasonably certain that exposure is not underestimated
for any significant subpopulation. Further, regional consumption
information is taken into account through EPA's computer based model
for evaluating exposure of significant subpopulations including several
regional groups. Review of this regional data allows the Agency to be
reasonably certain that no regional population is exposed to residue
levels higher than those estimated by the Agency. To meet the
requirement for data on anticipated residues, EPA will issue a Data
Call-In (DCI) notice pursuant to section 408(f) of the FFDCA requiring
submission of data on anticipated residues in conjunction with approval
of the registration under FIFRA.
2. From drinking water. Studies show that cypermethrin is immobile
in soil and does not leach into ground water. Drinking water residue
levels were estimated using the PRZM1/EXAMS computer models in 1993 for
comparative ecological risk assessment.
i. Acute exposure and risk. For the U.S. population, acute exposure
is estimated at 0.000126 mg/kg/day (MOE = 7,965). For non-nursing
infants < 1 year old, exposure is estimated at 0.000242 mg/kg/day (MOE
= 4,138).
ii. Chronic exposure and risk. For the U.S. population, chronic
exposure is estimated at 0.000005 mg/kg/day, or essentially 0% of the
RfD. For non-nursing infants < 1 year old, exposure is estimated at
0.000021 mg/kg/day, or 0.2% of the RfD.
3. From non-dietary exposure. i. Cypermethrin is currently
registered for use on lawns and carpets. Non-occupational exposure to
cypermethrin may occur as a result of inhalation or contact from indoor
residential, indoor commercial, and outdoor residential uses. Using
surrogate data and conservative exposure scenarios, the Agency has
estimated combined inhalation, dermal, and oral non-dietary exposure.
ii. Short- and intermediate-term exposure and risk. For the U.S.
population, exposure is estimated at 0.0000515 mg/kg/day. For infants
less than 1 year old, the exposure is estimated at 0.00259 mg/kg/day.
4. Cumulative exposure to substances with common mechanism of
toxicity. Section 408(b)(2)(D)(v) of the 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.'' The Agency believes that
``available information'' in this context might include not only
toxicity, chemistry, and exposure data, but also scientific policies
and methodologies for understanding common mechanisms of toxicity and
conducting cumulative risk assessments. For most pesticides, although
the Agency has some information in its files that may turn out to be
helpful in eventually determining whether a pesticide shares a common
mechanism of toxicity with any other substances, EPA does not at this
time have the methodologies to resolve the complex scientific issues
concerning common mechanism of toxicity in a meaningful way. EPA has
begun a pilot process to study this issue further through the
examination of particular classes of pesticides. The Agency hopes that
the results of this pilot process will increase the Agency's scientific
understanding of this question such that EPA will be able to develop
and apply scientific principles for better determining which chemicals
have a common mechanism of toxicity and evaluating the cumulative
effects of such chemicals. The Agency anticipates, however, that even
as its understanding of the science of common mechanisms increases,
decisions on specific classes of chemicals will be heavily dependent on
chemical specific data, much of which may not be presently available.
Four members of the insecticide class pyrethroids produce a common
metabolite known as DCVA (3-(2,2-dichloroethenyl)-2,2-
dimethylcyclopropane carboxylic acid). These insecticides are
cyfluthrin, cypermethrin, zeta-cypermethrin and permethrin. Although
the residues of DCVA can be estimated, no toxicology data on the
compound per se are available to directly conduct a hazard evaluation
and thereby establish an appropriate endpoint for use in a joint risk
assessment. To date, for the purpose of assessing the risk of the
parent compound the toxicity of DCVA has been assumed to be equivalent
to the parent compound. However, due to the different toxicological
profiles of cyfluthrin, cypermethrin, permethrin, and zeta-
cypermethrin, EPA does not believe that it would be appropriate to
cumulate DCVA for these pesticides, or DCVA residues from one of these
pesticides with the parent of another of these pesticides, in
conducting the risk assessment for these pesticides.
Accordingly, EPA does not have, at this time, available data to
determine whether cypermethrin has a common mechanism of toxicity with
other substances or how to include this pesticide in a cumulative risk
assessment. For the purposes of this tolerance action, therefore, EPA
has not assumed that cypermethrin has a common mechanism of toxicity
with other substances.
D. Aggregate Risks and Determination of Safety for U.S. Population
The Agency has determined that an aggregate systemic oral and
dermal exposure risk assessment is not appropriate due to difference in
the toxicity endpoints observed between the oral (neurotoxicity) and
dermal (hepatotoxicity) routes. An aggregate oral and inhalation risk
assessment is appropriate due to the similarity of toxicity
(neurotoxicity) observed in rats via these routes.
1. Acute risk. Aggregate acute risk represents the sum of acute
food and acute drinking water exposure. For cypermethrin, the aggregate
acute exposure is estimated at 0.004564 mg/kg/day, with a resulting MOE
of 219 for the adult U.S. population.
2. Chronic risk. Aggregate chronic exposure is the sum of chronic
exposure from food and chronic water. Using the exposure assumptions
described above, EPA has concluded that aggregate exposure to
cypermethrin from food and water will utilize 0.3% of the RfD for the
U.S. population. EPA generally has no concern for exposures below 100%
of the RfD because the RfD represents the level at or below which daily
aggregate dietary exposure over a lifetime will not pose appreciable
risks to human health. EPA concludes that there is a reasonable
certainty that no harm will result from aggregate exposure to
cypermethrin residues.
3. Short- and intermediate-term risk. Short- and intermediate-term
aggregate exposure takes into account chronic dietary food and water
(considered to be a background exposure level) plus short-term and
intermediate-term residential exposure. For cypermethrin, exposure is
estimated at 0.000082 mg/kg/day, with a resulting MOE of 61,000 for the
U.S. population.
E. Aggregate Cancer Risk for U.S. Population
Cypermethrin is classified as a weak Group C carcinogen based on
the increased incidence of lung adenomas in female mice. An RfD
approach was recommended for human risk assessment purposes. Therefore,
a quantitative dietary cancer risk
[[Page 63233]]
assessment was not performed. Dietary risk concerns due to long-term
consumption of cypermethrin are adequately addressed in the chronic
exposure analysis. For the U.S. population, less than 1% of the RfD is
occupied by aggregate chronic food and water exposure.
F. Aggregate Risks and Determination of Safety for Infants and Children
1. Safety factor for infants and children--i. In general. In
assessing the potential for additional sensitivity of infants and
children to residues of cypermethrin, EPA considered data from
developmental toxicity studies in the rat and rabbit and a three-
generation reproduction study in the rat. The developmental toxicity
studies are designed to evaluate adverse effects on the developing
organism resulting from pesticide exposure during prenatal development
to one or both parents. Reproduction studies provide information
relating to effects from exposure to the pesticide on the reproductive
capability of mating animals and data on systemic toxicity.
Section 408 of the FFDCA provides that EPA shall apply an
additional 10-fold margin of safety for infants and children in the
case of threshold effects to account for pre- and post-natal toxicity
and the completeness of the data base unless EPA determines that a
different margin of safety will be safe for infants and children.
Margins of safety are incorporated into EPA risk assessments either
directly through use of a MOE analysis or through using uncertainty
(safety) factors in calculating a dose level that poses no appreciable
risk to humans. EPA believes that reliable data support using the
standard MOE and uncertainty factor (usually 100 for combined inter-
and intra-species variability) and not the additional 10-fold MOE/
uncertainty factor when EPA has a complete data base under existing
guidelines and when the severity of the effect in infants or children
or the potency or unusual toxic properties of a compound do not raise
concerns regarding the adequacy of the standard MOE/safety factor.
ii. Developmental toxicity studies. In the prenatal developmental
toxicity studies in rats and rabbits, there was no evidence of
developmental toxicity at the highest dose tested (70 mg/kg/day in rats
and 700 mg/kg/day in rabbits).
iii. Reproductive toxicity study. An acceptable three-generation
reproduction study in rats has been submitted. Offspring toxicity was
observed only at the highest dietary level tested, (700/1,000 ppm; 50/
37.5 mg/kg/day), while toxicity in parental animals was observed at the
lower treatment levels. The parental systemic NOEL was 50 ppm (2.5 mg/
kg/day) and the parental systemic LOEL was 150 ppm (7.5 mg/kg/day).
iv. Pre- and post-natal sensitivity. The developmental and
reproductive toxicity data demonstrated no indications of increased
pre- and post-natal sensitivity.
v. Based on the above, EPA concludes that reliable data support the
use of the standard 100-fold uncertainty factor, and that an additional
uncertainty factor is not needed to protect the safety of infants and
children.
2. Acute risk. For children 1 to 6 years old, (most highly exposed
subgroup), the aggregate acute exposure is estimated at 0.005572 mg/kg/
day, with a resulting MOE of 179. EPA generally has no concern for MOEs
over 100.
3. Chronic risk. Using conservative exposure assumptions, EPA has
concluded that aggregate chronic exposure to cypermethrin from food and
water is estimated at 0.000044 mg/kg/day for children 1 to 6 years old
(most highly exposed subgroup) will utilize 0.4% of the RfD.
4. Short- or intermediate-term risk. Short- and intermediate-term
aggregate exposure takes into account chronic dietary food and water
(considered to be a background exposure level) plus short-term and
intermediate-term residential exposure. The MOE for non-nursing infants
< 1 year old (most highly exposed subgroup) is estimated at 1,900.
Therefore, it may be concluded that there is reasonable certainty
that no harm will result to infants and children from aggregate
exposure to cypermethrin residues.
5. Special docket. The complete acute and chronic exposure analyses
(including dietary, non-dietary, drinking water, and residential
exposure, and analysis of exposure to infants and children) used for
risk assessment purposes can be found in the Special Docket for the
FQPA under the title ``Risk Assessment for Extension of Tolerances for
Synthetic Pyrethroids.'' Further explanation regarding EPA's decision
regarding the additional safety factor can also be found in the Special
Docket.
G. Endocrine Disrupter Effects
EPA is required to develop a screening program to determine whether
certain substances (including all pesticides and inerts ) ``may have an
effect in humans that is similar to an effect produced by a naturally
occurring estrogen, or such other endocrine effect....'' The Agency is
currently working with interested stakeholders, including other
government agencies, public interest groups, industry, and research
scientists in developing a screening and testing program and a priority
setting scheme to implement the program. Congress has allowed 3 years
from passage of FQPA (August 3, 1999) to implement this program. At
that time, EPA may require further testing of this active ingredient
and end use products for endocrine disruption effects.
III. Other Considerations
A. Metabolism in Plants and Animals
The metabolism of cypermethrin in plants and animals is adequately
understood. Studies have been conducted to delineate the metabolism of
radiolabelled cypermethrin in various crops all showing similar
results. The residue of concern is cypermethrin parent.
B. Analytical Enforcement Methodology
Adequate enforcement methodology Gas Chromatography with Electron
Capture Detection (GC/ECD) is available in PAM II for enforcement of
the tolerances.
C. Magnitude of Residues
Crop field trial residue data and animal feeding data from studies
conducted at the maximum label rates for brassica, head and stem;
brassica, leafy; cotton; lettuce, head; onions, bulb; and pecans show
that the established cypermethrin tolerances on brassica, head and stem
at 2.0 ppm; brassica, leafy at 14.0 ppm; cattle, fat at 0.05 ppm,
cattle, meat at 0.05 ppm, cattle, mbyp at 0.05 ppm; cottonseed of 0.5
ppm; hogs, fat at 0.05 ppm, hogs, meat at 0.05 ppm, hogs, mbyp at 0.05
ppm; horses, fat at 0.05 ppm, horses, meat at 0.05 ppm, horses, mbyp at
0.05 ppm; lettuce, head at 10.0 ppm; milk at 0.05 ppm; onions, bulb at
0.10 ppm; pecans 0.05 ppm; sheep, fat at 0.05 ppm, sheep, meat at 0.05
ppm; and sheep, mbyp at 0.05 ppm will not be exceeded when the
cypermethrin products labeled for these uses are used as directed.
D. International Residue Limits
The Codex tolerances for cypermethrin are: Brassica vegetables, 1
ppm; lettuce, 2 ppm; milk, 0.05 ppm; onions, bulb, 0.1 ppm; meat, fat
basis, 0.2 ppm; mammalian edible mby, 0.05 ppm. Mexico has established
a tolerance for cottonseed at 0.5 ppm. There are no Canadian tolerances
established for cypermethrin. As indicated in Unit II. of this
preamble, there are differences between the FFDCA section 408
tolerances and the Codex Maximum Residue Limits (MRLs) value for
specific
[[Page 63234]]
commdities. These differences could be caused by differences in methods
to establish tolerances, calculation of animal feed dietary exposure,
and as a result of different agricultural practices. EPA will
specifically address these differences when the pesticides are
reregistered and the tolerances made permanent.
IV. Conclusion
Therefore, permanent tolerances are established for residues of
cypermethrin in or on the commodities brassica, head and stem at 2.0
ppm; brassica, leafy at 14.0 ppm; cattle, fat at 0.05 ppm; cattle, meat
at 0.05 ppm; cattle, mbyp at 0.05 ppm; cottonseed at 0.5 ppm; goats,
fat at 0.05 ppm; goats, meat at 0.05 ppm; goats, mbyp at 0.05 ppm;
hogs, fat at 0.05 ppm; hogs, meat at 0.05 ppm; hogs, mbyp at 0.05 ppm;
horses, fat at 0.05 ppm; horses, meat at 0.05 ppm; horses, mbyp at 0.05
ppm; lettuce, head at 10.0 ppm; milk at 0.05 ppm; onions, bulb at 0.10
ppm; pecans 0.05 ppm; sheep, fat at 0.05; sheep, meat at 0.05 ppm; and
sheep, mbyp at 0.05 ppm.
V. Objections and Hearing Requests
New section 408(g) of the FFDCA provides essentially the same
process for persons to ``object'' to a tolerance regulation issued by
EPA under new section 408(e) and (l)(6) of the FFDCA as was provided in
the old section 408 and in section 409 of FFDCA. However, the period
for filing objections is 60 days, rather than 30 days. EPA currently
has procedural regulations which govern the submission of objections
and hearing requests. These regulations will require some modification
to reflect the new law. However, until those modifications can be made,
EPA will continue to use those procedural regulations with appropriate
adjustments to reflect the new law.
Any person may, by January 26, 1998 file written objections to any
aspect of this regulation and may also request a hearing on those
objections. Objections and hearing requests must be filed with the
Hearing Clerk, at the address given above (40 CFR 178.20). A copy of
the objections and/or hearing requests filed with the Hearing Clerk
should be submitted to the OPP Docket for this rulemaking. The
objections submitted must specify the provisions of the regulation
deemed objectionable and the grounds for the objections (40 CFR
178.25). Each objection must be accompanied by the fee prescribed by 40
CFR 180.33(i). If a hearing is requested, the objections must include a
statement of the factual issues on which a hearing is requested, the
requestor's contentions on such issues, and a summary of any evidence
relied upon by the requestor (40 CFR 178.27). A request for a hearing
will be granted if the Administrator determines that the material
submitted shows the following: There is genuine and substantial issue
of fact; there is a reasonable possibility that available evidence
identified by the requestor would, if established, resolve one or more
of such issues in favor of the requestor, taking into account
uncontested claims or facts to the contrary; and resolution of the
factual issues in the manner sought by the requestor would be adequate
to justify the action requested (40 CFR 178.32). Information submitted
in connection with an objection or hearing request may be claimed
confidential by marking any part or all of that information as CBI.
Information so marked will not be disclosed except in accordance with
procedures set forth in 40 CFR part 2. A copy of the information that
does not contain CBI must be submitted for inclusion in the public
record. Information not marked confidential may be disclosed publicly
by EPA without prior notice.
VI. Public Record and Electronic Submissions
The official record for this rulemaking, as well as the public
version, has been established for this rulemaking under docket control
number OPP-300583 (including comments and data submitted electronically
as described below). A public version of this record, including
printed, paper versions of electronic comments, which does not include
any information claimed as CBI, is available for inspection from 8:30
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The
official rulemaking record is the paper record maintained at the
Virginia address in ``ADDRESSES'' at the beginning of this document.
Electronic comments may be sent directly to EPA at:
[email protected].
Electronic objections and hearing requests must be submitted as an
ASCII file avoiding the use of special characters and any form of
encryption. Objections and hearing requests will also be accepted on
disks in WordPerfect 5.1/6.1 or ASCII file format. All copies of
objections and hearing requests in electronic form must be identified
by the docket control number, OPP-300583. No CBI should be submitted
through e-mail. Electronic copies of objections and hearing requests on
this rule may be filed online at many Federal Depository Libraries.
VII. Regulatory Assessment Requirements
This final rule establishes tolerances under FFDCA section 408(d)
in response to a petition submitted to the Agency. The Office of
Management and Budget (OMB) has exempted these types of actions from
review under Executive Order 12866, entitled Regulatory Planning and
Review (58 FR 51735, October 4, 1993). 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., or impose any enforceable
duty or contain any unfunded mandate as described under Title II of the
Unfunded Mandates Reform Act of 1995 (UMRA) (Pub. L. 104-4). Nor does
it require any prior consultation as specified by Executive Order
12875, entitled Enhancing the Intergovernmental Partnership (58 FR
58093, October 28, 1993), or special considerations as required by
Executive Order 12898, entitled Federal Actions to Address
Environmental Justice in Minority Populations and Low-Income
Populations (59 FR 7629, February 16, 1994), or require OMB review in
accordance with Executive Order 13045, entitled Protection of Children
from Environmental Health Risks and Safety Risks (62 FR 19885, April
23, 1997).
In addition, since these tolerances and exemptions that are
established on the basis of a petition under FFDCA section 408(d), such
as the tolerances 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. Nevertheless, the Agency has
previously assessed whether establishing tolerances, exemptions from
tolerances, raising tolerance levels or expanding exemptions might
adversely impact small entities and concluded, as a generic matter,
that there is no adverse economic impact. The factual basis for the
Agency's generic certification for tolerance actions published on May
4, 1981 (46 FR 24950) and was provided to the Chief Counsel for
Advocacy of the Small Business Administration.
VIII. Submission to Congress and the General Accounting Office
Under 5 U.S.C. 801(a)(1)(A), as added by the Small Business
Regulatory Enforcement Fairness Act of 1996, the Agency has submitted 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 General Accounting Office prior to publication of this rule in
today's Federal Register.
[[Page 63235]]
This 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: November 14, 1997.
James Jones,
Acting Director, Registration Division, Office of Pesticide Programs.
Therefore, 40 CFR chapter I is amended as follows:
PART 180--[AMENDED]
1. The authority citation for part 180 continues to read as
follows:
Authority: 21 U.S.C. 346a and 371.
2. Section 180.418 is revised to read as follows:
Sec. 180.418 Cypermethrin and an isomer zeta-cypermethrin; tolerances
for residues.
(a) General. (1) Tolerances are established for residues of the
insecticide cypermethrin ()alpha cyano-(3-
phenoxyphenyl)methyl()cis,trans-3(2,2-dichloroethenyl-2,2-
dimethylcyclopropanecarboxylate in or on the following commodities:
------------------------------------------------------------------------
Parts per
Commodity million
------------------------------------------------------------------------
Brassica, head and stem.................................... 2.0
Brassica, leafy............................................ 14.0
Cattle, fat................................................ 0.05
Cattle, mbyp............................................... 0.05
Cattle, meat............................................... 0.05
Cottonseed................................................. 0.5
Goats, fat................................................. 0.05
Goats, mbyp................................................ 0.05
Goats, meat................................................ 0.05
Hogs, fat.................................................. 0.05
Hogs, mbyp................................................. 0.05
Hogs, meat................................................. 0.05
Horses, fat................................................ 0.05
Horses, mbyp............................................... 0.05
Horses, meat............................................... 0.05
Lettuce, head.............................................. 10.0
Milk....................................................... 0.05
Onions, bulb............................................... 0.10
Pecans..................................................... 0.05
Sheep, fat................................................. 0.05
Sheep, mbyp................................................ 0.05
Sheep, meat................................................ 0.05
------------------------------------------------------------------------
(2) [Reserved]
(b) Section 18 emergency exemptions. [Reserved]
(c) Tolerances with regional registrations. [Reserved]
(d) Indirect or inadvertent residues. [Reserved]
[FR Doc. 97-30947 Filed 11-25-97; 8:45 am]
BILLING CODE 6560-50-F