Cyromazine; Pesticide Tolerance

Note: EPA no longer updates this information, but it may be useful as a reference or resource.

[Federal Register: September 24, 2003 (Volume 68, Number 185)]
[Rules and Regulations]
[Page 55261-55269]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr24se03-1]

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Rules and Regulations
Federal Register
________________________________________________________________________

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having general applicability and legal effect, most of which are keyed
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-2003-0269; FRL-7326-5]

Cyromazine; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This regulation establishes tolerances for residues of
cyromazine in or on leek; onion, green; onion, potato; onion, tree;
onion, welsh; shallot, fresh leaves; garlic, bulb; garlic, great-
headed, bulb; onion, dry bulb; rakkyo, bulb; shallot, bulb; vegetable,
brassica, leafy, group 5, except broccoli; broccoli; turnip, greens;
cabbage, abyssinian; cabbage, seakale; hanover salad, leaves; kidney of
cattle, goat, hog, horse, and sheep; and meat byproducts, except
kidney, of cattle, goat, hog, horse, and sheep. The petitioner has
requested that existing tolerances for residues of cyromazine in/on dry
bulb onion at 2.0 ppm, green onion at 0.1 ppm, and mustard greens and
cabbage, Chinese at 3.0 ppm be deleted. Interregional Research Project
Number 4 (IR-4) requested these tolerances under the Federal Food,
Drug, and Cosmetic Act (FFDCA), as amended by the Food Quality
Protection Act of 1996 (FQPA).

DATES: This regulation is effective September 24, 2003. Objections and
requests for hearings, identified by docket ID number OPP-2003-0269,
must be received on or before November 24, 2003.

ADDRESSES: Written objections and hearing requests may be submitted
electronically, by mail, or through hand delivery/courier. Follow the
detailed instructions as provided in Unit VI. of the SUPPLEMENTARY
INFORMATION.

FOR FURTHER INFORMATION CONTACT: Shaja R. Brothers, Registration
Division (7505C), Office of Pesticide Programs, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW.,Washington, DC 20460-
0001; telephone number: (703) 308-3194; e-mail address:
brothers.shaja@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

You may be potentially affected by this action if you an are
agricultural producer, food manufacturer, and pesticide manufacturer.
Potentially affected entities may include, but are not limited to:
? Industry (NAICS 111), e.g., Crop production.
? Industry (NAICS 112), e.g., Animal production.
? Industry (NAICS 311), e.g., Food manufacturing.
? Industry (NAICS 32532), e.g., Pesticide manufacturing.
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 Copies of this Document and Other Related Information?

1. Docket. EPA has established an official public docket for this
action under docket identification (ID) number OPP-2003-0269. The
official public docket consists of the documents specifically
referenced in this action, any public comments received, and other
information related to this action. Although a part of the official
docket, the public docket does not include Confidential Business
Information (CBI) or other information whose disclosure is restricted
by statute. The official public docket is the collection of materials
that is available for public viewing at the Public Information and
Records Integrity Branch (PIRIB), Rm. 119, Crystal Mall #2,
1921 Jefferson Davis Hwy., Arlington, VA. This docket facility is open
from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal
holidays. The docket telephone number is (703) 305-5805.
2. Electronic access. You may access this Federal Register document
electronically through the EPA Internet under the ``Federal Register''
listings at http://www.epa.gov/fedrgstr/. A frequently updated
electronic version of 40 CFR part 180 is available at http://www.access.
gpo.gov/nara/cfr/cfrhtml_00/Title_40/40cfr180_00.html,
a beta site currently under development. To access the OPPTS Harmonized
Guidelines referenced in this document, go directly to the guidelines
at http://www.epa.gov/opptsfrs/home/guidelin.htm.
An electronic version of the public docket is available through
EPA's electronic public docket and comment system, EPA Dockets. You may
use EPA Dockets at http://www.regulations.gov/ to submit or view public
comments, access the index listing of the contents of the official
public docket, and to access those documents in the public docket that
are available electronically. Although not all docket materials may be
available electronically, you may still access any of the publicly
available docket materials through the docket facility identified in
Unit I.B.1. Once in the system, select ``search,'' then key in the
appropriate docket ID number.

II. Background and Statutory Findings

In the Federal Register of August 6, 2003 (68 FR 46616) (FRL-7319-
3), EPA issued a notice pursuant to section 408 of FFDCA, 21 U.S.C.
346a, as amended by FQPA (Public Law 104-170), announcing the filing of
pesticide petitions (PP 2E6507 and 2E6510) by IR-4, 681 US Highway
#1 South, New Brunswick, NJ 08902-3390. That notice included a
summary of the petitions prepared by Syngenta Crop Protection
Incorporated, the registrant.
The petitions requested that 40 CFR 180.414 be amended by
establishing tolerances for residues of the insecticide, cyromazine,
(N-cyclopropyl-1,3,5-triazine-2,4,6-triamine), in or on the following
commodities: leek; onion, green; onion, potato; onion, tree; onion,
welsh; and shallot, fresh leaves at 3.0 parts per million (ppm)
(2E6507), garlic, bulb; garlic, great-headed, bulb; onion, dry bulb;
rakkyo, bulb; and shallot, bulb at 0.2 ppm (2E6507), vegetable,
brassica,

[[Page 55262]]

leafy, group 5, except broccoli at 10.0 ppm (2E6510), broccoli at 1.0
ppm, turnip, greens; cabbage, abyssinian; cabbage, seakale; and hanover
salad, leaves at 10.0 ppm, and kidney of cattle, goat, hog, horse, and
sheep at 0.2 ppm, and meat byproducts, except kidney, of cattle, goat,
hog, horse, and sheep at 0.05 ppm (2E6510).
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 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. For further discussion of the
regulatory requirements of section 408 of the FFDCA and a complete
description of the risk assessment process, see the final rule on
Bifenthrin Pesticide Tolerances (62 FR 62961, November 26, 1997) (FRL-
5754-7).

III. 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 and to
make a determination on aggregate exposure, consistent with section
408(b)(2) of the FFDCA, for tolerances for residues of cyromazine on
leek; onion, green; onion, potato; onion, tree; onion, welsh; and
shallot, fresh leaves at 3.0 ppm, garlic, bulb; garlic, great-headed,
bulb; onion, dry bulb; rakkyo, bulb; and shallot, bulb at 0.2 ppm,
vegetable, brassica, leafy, group 5, except broccoli at 10.0 ppm,
broccoli at 1.0 ppm, turnip, greens; cabbage, abyssinian; cabbage,
seakale; and hanover salad, leaves at 10.0 ppm, and kidney of cattle,
goat, hog, horse, and sheep at 0.2 ppm, and meat byproducts, except
kidney, of cattle, goat, hog, horse, and sheepat 0.05 ppm. EPA's
assessment of exposures and risks associated with establishing the
tolerances follow.

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 cyromazine are
discussed in Table 1 of this unit as well as the no-observed-adverse-
effect-level (NOAEL) and the lowest-observed-adverse-effect-level
(LOAEL) from the toxicity studies reviewed.

Table 1.--Subchronic, Chronic, and Other Toxicity
----------------------------------------------------------------------------------------------------------------
Guideline No. Study Type Results
----------------------------------------------------------------------------------------------------------------
870.3100 Subchronic oral-Dog The systemic toxicity LOAEL is 1,000 ppm
(25 mg/kg/day) based on alteration in
liver weight in males.
The systemic toxicity NOAEL is 300 ppm (7.5
mg/kg/day).
----------------------------------------------------------------------------------------------------------------
870.3100 Subchronic oral-Rat The systemic toxicity LOAEL is 300 ppm (30
mg/kg/day), based on alteration in the
liver weight changes in males.
The systemic toxicity NOAEL is 30 ppm (3 mg/
kg/day).
----------------------------------------------------------------------------------------------------------------
870.3200 21-day dermal toxicity- No treatment related systemic toxicity was
Rabbit noted. The systemic toxicity NOAEL > 2,000
mg/kg/day.
The systemic toxicity LOAEL > 2,000 mg/kg/
day.
No dermal irritation was noted. The dermal
toxicity NOAEL > 2,000 mg/kg/day.
The dermal toxicity LOAEL > 2,000 mg/kg/
day.
----------------------------------------------------------------------------------------------------------------
870.3200 21-day dermal toxicity- No treatment related systemic toxicity was
Rabbit noted. The systemic toxicity NOAEL > 2,010
mg/kg/day.
The systemic toxicity LOAEL > 2,010 mg/kg/
day.
No dermal irritation was noted. The dermal
toxicity NOAEL > 2,010 mg/kg/day.
The dermal toxicity LOAEL > 2,010 mg/kg/
day.
----------------------------------------------------------------------------------------------------------------
870.4100 Chronic oral (6-months)- The systemic toxicity LOAEL is 3,000 ppm
Dog (75 mg/kg/day) based on alteration in
hematological parameters (hemoglobin, and
hematocrit).
The systemic toxicity NOAEL is 300 ppm (7.5
mg/kg/day).
----------------------------------------------------------------------------------------------------------------
870.4300 Combine Chronic/ The systemic toxicity LOAEL is 300 ppm (15
Carcinogenicity-Rat mg/kg/day) based on decreased body weight.
The systemic toxicity NOAEL is 30 ppm. (1.5
mg/kg/day). There is no evidence of
carcinogenicity.
----------------------------------------------------------------------------------------------------------------
870.4200 Carcinogenicity-Mouse The systemic toxicity LOAEL is 1,000 ppm
(150 mg/kg/day) based on decreased body
weight.
The systemic toxicity NOAEL is 50 ppm. (7.5
mg/kg/day). There is no evidence of
carcinogenicity.
----------------------------------------------------------------------------------------------------------------

[[Page 55263]]

870.3700 Developmental toxicity- The maternal toxicity LOAEL is 30 mg/kg/
Rabbit day, based on reduced body weight gain and
food consumption.
The maternal toxicity NOAEL is 10 mg/kg/
day.
The developmental toxicity LOAEL was not
established.
The developmental toxicity NOAEL > 60 mg/kg/
day (HDT).
----------------------------------------------------------------------------------------------------------------
870.3700 Developmental toxicity-Rat The maternal toxicity LOAEL is 300 mg/kg/
day, based on clinical signs (red or clear
nasal discharge) and decreased body
weights.
The maternal toxicity NOAEL = 100 mg/kg/
day.
The developmental toxicity LOAEL is 600 mg/
kg/day (HDT), based on increased incidence
of minor skeletal variations.
The developmental toxicity NOAEL is 300 mg/
kg/day.
----------------------------------------------------------------------------------------------------------------
870.3800 Two-generation The parental systemic toxicity LOAEL is
reproduction-Rat 3,000 ppm (150 mg/kg/day) based on
decreased body weights that were
associated with decreased food efficiency.
The parental systemic toxicity NOAEL is
1,000 ppm (50 mg/kg/day).
The offspring systemic/developmental
toxicity LOAEL is 3,000 ppm (150 mg/kg/
day), based on decreased body weights at
birth and through weaning.
The systemic/developmental toxicity NOAEL
is 1,000 ppm (50 mg/kg/day).
No effects were noted on reproductive
parameters and no reproductive toxicity
LOAEL was determined.
The reproductive toxicity NOAEL is >= 3,000
ppm (150 mg/kg/day).
----------------------------------------------------------------------------------------------------------------
870.7485 Metabolism-Rat Cyromazine was well absorbed after oral
administration. Excretion was rapid at the
dose (3 mg/kg), but an apparent delay in
excretion occurred at the high dose (300
mg/kg). Fecal elimination was equivalent
among dose groups except the high dose
males, where a greater percentage was
eliminated by this route. The origin of
fecal radioactivity was via biliary
elimination. Residual radioactivity in
tissues was minimal in all dose groups.
Urinary and fecal metabolites of \14\C-
cyromazine were isolated and identified by
TLC, HPLC, and GC/MS. The major compounds
were the N-dealkylated product melamine,
hydroxycyromazine, and unmetabolized
cyromazine identified.
----------------------------------------------------------------------------------------------------------------
870.7600 Dermal Absorption-Rat Absorption at 10 hrs = 13 %. Cyromazine
apparently rapidly absorbed into the skin
in an inverse dose related manner. The
absorption into the skin is followed by a
slower release into the body. The main
route of excretion is apparently by the
urine. There is no evidence that the
compound is sequestered in the skin.
Mean absorption based on blood, urinary/
fecal excretion, and carcass, ranged from
0.6 to 7% for animals sacrificed at the
end of the exposure periods. For animals
exposed for 10 and 24 hours and followed
for 48 hours post-exposure, mean
absorption ranged from 8 to 14.5%. Total
radioactivity absorbed generally decreased
as dose increased indicating saturation of
absorption with increasing dose. Amounts
remaining in/on the skin at termination
ranged from 4.5% (10 mg dose/2 h exposure)
to 24% ( 0.1 mg dose/24 hour exposure).
The majority of the absorbed radioactivity
was found in the urine and carcass. Most
of the unabsorbed radioactivity was found
in the skin washes from each dose/
duration.
----------------------------------------------------------------------------------------------------------------
870.7600 Dermal Absorption-Rat Absorption at 10 hrs = 10%. Mean total
recoveries of applied radioactivity from
all dose groups ranged from 85 to 101%.
Mean absorption based on blood, urinary/
fecal excretion, and carcass, ranged from
2% to 11%. Total radioactivity absorbed
generally increased with increasing
exposure time but decreased with
increasing dose indicating saturation of
penetration with increasing dose. The
majority of the absorbed radioactivity was
found in the urine and carcass. Most of
the unabsorbed radioactivity was found in
the skin washes from each dose/duration
(35-90%). However, based on measurements
of skin absorption, a significant amount
of radioactive dose was also found in the
skin itself (9-40%). Mean absorption with
inclusion of radioactivity in dissolved
skin ranged from 10 to 45%. The ratio of
the amount of radioactive dose in the skin
wash to the radioactivity in the skin
itself decreased with time indicating
penetration into the subsurface of the
skin with time after treatment.
----------------------------------------------------------------------------------------------------------------
870.5395 Gene mutation in Hamster Negative mutagen.
(Chinese)-Mutagenic-
Nucleus Anomaly
----------------------------------------------------------------------------------------------------------------
870.5100 Mutagenic-Point Mutation Negative results for point mutations in
Salmonella typhimurium TA1537, TA1537, TA98, and TA100 with and
without activation.
----------------------------------------------------------------------------------------------------------------
870.5450 Mutagenic-Dominant lethal Negative mutagen.
test species: Mouse
----------------------------------------------------------------------------------------------------------------

[[Page 55264]]

B. Toxicological Endpoints

The dose at which no adverse effects are observed (the NOAEL) from
the toxicology study identified as appropriate for use in risk
assessment is used to estimate the toxicological level of concern
(LOC). However, the lowest dose at which adverse effects of concern are
identified (the LOAEL) is sometimes used for risk assessment if no
NOAEL was achieved in the toxicology study selected. An uncertainty
factor (UF) is applied to reflect 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. An UF of 100 is routinely used, 10X to account for
interspecies differences and 10X for intra species differences.
For dietary risk assessment (other than cancer) the Agency uses the
UF to calculate an acute or chronic reference dose (acute RfD or
chronic RfD) where the RfD is equal to the NOAEL divided by the
appropriate UF (RfD = NOAEL/UF). Where an additional safety factors
(SF) is retained due to concerns unique to the FQPA, this additional
factor is applied to the RfD by dividing the RfD by such additional
factor. The acute or chronic Population Adjusted Dose (aPAD or cPAD) is
a modification of the RfD to accommodate this type of FQPA SF.
For non-dietary risk assessments (other than cancer) the UF is used
to determine the LOC. For example, when 100 is the appropriate UF (10X
to account for interspecies differences and 10X for intraspecies
differences) the LOC is 100. To estimate risk, a ratio of the NOAEL to
exposures (margin of exposure (MOE) = NOAEL/exposure) is calculated and
compared to the LOC.
The linear default risk methodology (Q*) is the primary method
currently used by the Agency to quantify carcinogenic risk. The Q*
approach assumes that any amount of exposure will lead to some degree
of cancer risk. A Q* is calculated and used to estimate risk which
represents a probability of occurrence of additional cancer cases
(e.g., risk is expressed as 1 x 10-\6\ or one in a million).
Under certain specific circumstances, MOE calculations will be used for
the carcinogenic risk assessment. In this non-linear approach, a
``point of departure'' is identified below which carcinogenic effects
are not expected. The point of departure is typically a NOAEL based on
an endpoint related to cancer effects though it may be a different
value derived from the dose response curve. To estimate risk, a ratio
of the point of departure to exposure (MOE_cancer = point of
departure/exposures) is calculated. A summary of the toxicological
endpoints for cyromazine used for human risk assessment is shown is
shown in Table 2 of this unit:

Table 2.--Summary of Toxicological Dose and Endpoints for Cyromazine for Use in Human Risk Assessment
----------------------------------------------------------------------------------------------------------------
Special FQPA SF and
Exposure Scenario Dose Used in Risk Level of Concern for Study and Toxicological
Assessment, UF Risk Assessment Effects
----------------------------------------------------------------------------------------------------------------
Acute Dietary (All populations) NA NA An appropriate endpoint
attributable to a
single dose (exposure)
of cyromazine was not
observed in oral
toxicity studies.
Thus, an acute dietary
endpoint was not
chosen.
-----------------------------------------------------------------------------------------
Chronic Dietary (All populations) NOAEL= 7.5 mg/kg/day FQPA SF = 1x Chronic Oral Toxicity
UF = 100............... cPAD = chronic RfD / in Dogs.
Chronic RfD = NOAEL/UF FQPA SF = 0.075 mg/kg/ LOAEL = 75 mg/kg/day
= 0.075 mg/kg/day. day. based on alterations
in hematological
parameters [hematocrit
and hemoglobin
(males)], decreased
body weight/body
weight gain and
increases in several
organ weights.
-----------------------------------------------------------------------------------------
Short-Term Incidental Oral (1-30 NOAEL = 10 mg/kg/day Residential LOC for Developmental Toxicity
days) MOE = 100 study in rabbits.
LOAEL = 30 mg/kg/day
based on decreases in
body weight gain and
food consumption.
-----------------------------------------------------------------------------------------
Intermediate-Term Incidental Oral (1- NOAEL = 7.5 mg/kg/day Residential LOC for MOE Chronic Oral Toxicity
6 months) = 100 in Dogs.
LOAEL = 75 mg/kg/day
based on alterations
in hematological
parameters [hematocrit
and hemoglobin
(males)], decreased
body weight/body
weight gain and
increases in several
organ weights.
-----------------------------------------------------------------------------------------
Short-, Intermediate- and Long-Term NA NA No hazard was
Dermal identified via the
dermal route of
exposure.
-----------------------------------------------------------------------------------------
Short-Term Inhalation (1 to 30 days) Inhalation (oral) study Residential LOC for MOE Chronic Oral Toxicity
NOAEL = 10 mg/kg/day = 100 in Dogs.
(inhalation absorption LOAEL = 75 mg/kg/day
rate = 100%) based on alterations
in hematological
parameters [hematocrit
and hemoglobin
(males)], decreased
body weight/body
weight gain and
increases in several
organ weights.
-----------------------------------------------------------------------------------------
Intermediate-Term Inhalation (1 to 6 Inhalation (or oral) Residential LOC for MOE Chronic Oral Toxicity
months) study NOAEL = 7.5 mg/ = 100 in Dogs.
kg/day (inhalation LOAEL = 75 mg/kg/day
absorption rate = based on alterations
100%) in hematological
parameters [hematocrit
and hemoglobin
(males)], decreased
body weight/body
weight gain and
increases in several
organ weights.
-----------------------------------------------------------------------------------------

[[Page 55265]]

Long-Term Inhalation (> 6 months) Inhalation (or oral) Occupational LOC for Chronic Oral Toxicity
study NOAEL = 7.5 mg/ MOE = 100 in Dogs.
kg/day (inhalation Residential LOC for MOE LOAEL = 75 mg/kg/day
absorption rate = = 100. based on alterations
100%) in hematological
parameters [hematocrit
and hemoglobin
(males)], decreased
body weight/body
weight gain and
increases in several
organ weights.
-----------------------------------------------------------------------------------------
Cancer (oral, dermal, inhalation) NA NA Group E carcinogen -
evidence of non-
carcinogenicity for
humans.
----------------------------------------------------------------------------------------------------------------

C. Exposure Assessment

1. Dietary exposure from food and feed uses. Tolerances have been
established (40 CFR 180.414) for the residues of cyromazine, in or on
the following raw agricultural commodities: dry bean, except cowpea,
cabbage, chinese; mustard greens, mango, potato, leafy vegetables
(except Brassica) group, cucurbit vegetables group, tomato, onions,
mushroom, lima beans and pepper. Cyromazine tolerances are established
for milk and tissues of cattle, goat, hog, horse, and sheep as a result
of feeding cyromazine treated feed items. Rotational crop tolerances
are established for sweet corn, radishes, and cotton. Additionally,
cyromazine is registered for use as a feed through treatment for
poultry for the control of flies and maggots in poultry manure. As a
result of the feed-through use, tolerances are established for residues
of cyromazine in egg and poultry tissues. Risk assessments were
conducted by EPA to assess dietary exposures from cyromazine in food as
follows:
i. Acute exposure. Quantitative 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 one day or single exposure. For this assessment, an appropriate
endpoint attributable to a single dose (exposure) of cyromazine was not
observed in oral toxicity studies.
ii. Chronic exposure. In conducting this acute dietary risk
assessment EPA used the Dietary Exposure Evaluation Model software with
the Food Commodity Intake Database (DEEM-FCID\TM\) which incorporates
food consumption data as reported by respondents in the USDA 1994-1996
and 1998 nationwide Continuing Surveys of Food Intake by Individuals
(CSFII) and accumulated exposure to the chemical for each commodity.
The following assumptions were made for the chronic exposure
assessment: An unrefined chronic exposure analysis (Tier 1) was
conducted for cyromazine using the DEEM software. The assumptions of
the chronic dietary exposure assessment are tolerance-level residues
and one hundred percent crop-treated.
iii. Cancer. Cyromazine is classified as a Group E carcinogen
(evidence of non-carcinogenicity for humans), and was shown not to be
carcinogenic in mice or rats following long-term dietary
administration. The available mutagenicity data suggest that cyromazine
does not have genotoxic activity.
2. Dietary exposure from drinking water. The Agency lacks
sufficient monitoring exposure data to complete a comprehensive dietary
exposure analysis and risk assessment for cyromazine in drinking water.
Because the Agency does not have comprehensive monitoring data,
drinking water concentration estimates are made by reliance on
simulation or modeling taking into account data on the physical
characteristics of cyromazine.
The Agency uses the FQPA Index Reservoir Screening Tool (FIRST) or
the Pesticide Root Zone model/Exposure Analysis Modeling System (PRZM/
EXAMS), to produce estimates of pesticide concentrations in an index
reservoir. The SCI-GROW model is used to predict pesticide
concentrations in shallow groundwater. For a screening-level assessment
for surface water EPA will use FIRST (a tier 1 model) before using
PRZM/EXAMS (a tier 2 model). The FIRST model is a subset of the PRZM/
EXAMS model that uses a specific high-end runoff scenario for
pesticides. FIRST and PRZM/EXAMS incorporate an index reservoir
environment, and a percent crop area factor as an adjustment to account
for the maximum percent crop coverage within a watershed or drainage
basin.
None of these models include consideration of the impact processing
(mixing, dilution, or treatment) of raw water for distribution as
drinking water would likely have on the removal of pesticides from the
source water. The primary use of these models by the Agency at this
stage is to provide a screen for sorting out pesticides for which it is
unlikely that drinking water concentrations would exceed human health
levels of concern.
Since the models used are considered to be screening tools in the
risk assessment process, the Agency does not use estimated
environmental concentrations (EECs) from these models to quantify
drinking water exposure and risk as a %RfD or %PAD. Instead drinking
water levels of comparison (DWLOCs) are calculated and used as a point
of comparison against the model estimates of a pesticide's
concentration in water. DWLOCs are theoretical upper limits on a
pesticide's concentration in drinking water in light of total aggregate
exposure to a pesticide in food, and from residential uses. Since
DWLOCs address total aggregate exposure to cyromazine they are further
discussed in the aggregate risk sections in Unit III.E.
In soil, cyromazine is stable to hydrolysis and photolysis and is
rather persistent in aerobic soil (half-life value of 150 days). The
field studies confirmed this half-life value, where average half-lives
varied from 75 days to more than 250 days. Soil adsorption coefficients
are generally low. This would indicate that cyromazine has the
potential to leach through soils, especially sand and silt loam soils.
The EECs for cyromazine reflect six applications of cyromazine at
0.125 lbs ai/A. For surface water, the annual average of 15.5 [mu]g/L
(or ppb) is based on use of the FIRST model. The groundwater EEC of 5.3
[mu]g/L has been estimated by the SCI-GROW2 program. Both of these
surface and groundwater values represent upper-bound conservative
estimates for concentrations that might be found in

[[Page 55266]]

surface water and groundwater due to the use of cyromazine.
3. From non-dietary exposure. The term ``residential exposure'' is
used in this document to refer to non-occupational, non-dietary
exposure (e.g., for lawn and garden pest control, indoor pest control,
termiticides, and flea and tick control on pets).
Cyromazine is not registered for use on any sites that would result
in residential exposure. There are no currently existing or proposed
uses for cyromazine in residential or public sites and therefore no
residential risk assessment was performed.
4. Cumulative effects from substances with a 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.''
EPA does not have, at this time, available data to determine
whether cyromazine has a common mechanism of toxicity with other
substances. Unlike other pesticides for which EPA has followed a
cumulative risk approach based on a common mechanism of toxicity, EPA
has not made a common mechanism of toxicity finding as to cyromazine
and any other substances and cyromazine does not appear to produce a
toxic metabolite produced by other substances. EPA has determined,
however, that there is no known mechanism of toxicity that would
support grouping cyromazine by a common mechanism with atrazine,
simazine, and cyanazine. For the purposes of this tolerance action,
therefore, EPA has not assumed that cyromazine has a common mechanism
of toxicity with other substances. For information regarding EPA's
efforts to determine which chemicals have a common mechanism of
toxicity and to evaluate the cumulative effects of such chemicals, see
the policy statements released by EPA's Office of Pesticide Programs
concerning common mechanism determinations and procedures for
cumulating effects from substances found to have a common mechanism on
EPA's website at http://www.epa.gov/pesticides/
cumulative/.

D. Safety Factor for Infants and Children

1. In general. Section 408 of the FFDCA provides that EPA shall
apply an additional 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 data base on toxicity and exposure
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.
2. Prenatal and postnatal sensitivity. There is no evidence of
susceptibility and no residual uncertainties for pre- and post-natal
toxicity resulting from exposure to cyromazine.
3. Conclusion. There is a complete toxicity data base for
cyromazine and exposure data are complete or are estimated based on
data that reasonably accounts for potential exposures. EPA determined
that the 10X Safety factor to protect infants and children should be
reduced to 1X because:
? There is no evidence of increased susceptibility
(quantitative or qualitative) to rats or rabbits following in utero
exposure or post-natal exposure to rats. In the prenatal developmental
toxicity study in rats, the NOAEL for developmental toxicity was higher
than the maternal NOAEL. In the developmental toxicity study in
rabbits, no evidence of developmental toxicity was noted. For
developmental toxicity, the NOAEL was > 60 mg/kg/day highest dose
tested (HDT). In the two-generation reproduction study in rats no
reproductive effects were observed. In this study, the reproductive
NOAEL is >= 150 mg/kg/day (HDT). No neurotoxic effects were observed in
the available data, and there is no requirement for a developmental
neurotoxicity study. Further, exposure assessments have been conducted
in a manner unlikely to underestimate exposure.
? The dietary drinking water assessment utilizes water
concentration values generated by models and associated modeling
parameters which are designed to provide conservative, health
protective, high-end estimates of water concentrations which will not
likely be exceeded.
? The dietary food exposure assessment is based on current
and proposed registrations and is completely unrefined (i.e. tolerance
level residues and 100% crop treated). The dietary exposure analysis
will not underestimate exposure/risk.
? No residual uncertainties were identified in the exposure
database.
? There are no residential uses for cyromazine.

E. Aggregate Risks and Determination of Safety

To estimate total aggregate exposure to a pesticide from food,
drinking water, and residential uses, the Agency calculates DWLOCs
which are used as a point of comparison against the model estimates of
a pesticide's concentration in water (EECs). DWLOC values are not
regulatory standards for drinking water. DWLOCs are theoretical upper
limits on a pesticide's concentration in drinking water in light of
total aggregate exposure to a pesticide in food and residential uses.
In calculating a DWLOC, the Agency determines how much of the
acceptable exposure (i.e., the PAD) is available for exposure through
drinking water [e.g., allowable chronic water exposure (mg/kg/day) =
cPAD - (average food + residential exposure)]. This allowable exposure
through drinking water is used to calculate a DWLOC.
A DWLOC will vary depending on the toxic endpoint, drinking water
consumption, and body weights. Default body weights and consumption
values as used by the USEPA Office of Water are used to calculate
DWLOCs: 2 liter (L)/70 kg (adult male), 2L/60 kg (adult female), and
1L/10 kg (child). Default body weights and drinking water consumption
values vary on an individual basis. This variation will be taken into
account in more refined screening-level and quantitative drinking water
exposure assessments. Different populations will have different DWLOCs.
Generally, a DWLOC is calculated for each type of risk assessment used:
Acute, short-term, intermediate-term, chronic, and cancer.
When EECs for surface water and groundwater are less than the
calculated DWLOCs, OPP concludes with reasonable certainty that
exposures to the pesticide in drinking water (when considered along
with other sources of exposure for which OPP has reliable data) would
not result in unacceptable levels of aggregate human health risk at
this time. Because OPP considers the aggregate risk resulting from
multiple exposure pathways associated with a pesticide's uses, levels
of comparison in drinking water may vary as those uses change. If new
uses are added in the future, OPP will reassess the potential impacts
of residues of the pesticide in drinking water as a part of the
aggregate risk assessment process.
1. Acute risk. An appropriate endpoint attributable to a single
dose (exposure) of cyromazine was not observed in oral toxicity
studies. Thus, an acute dietary endpoint was not chosen, and cyromazine
is not expected to pose an acute risk.

[[Page 55267]]

2. Chronic risk. Using the exposure assumptions described in this
unit for chronic exposure, EPA has concluded that exposure to
cyromazine from food will utilize 8.3% of the cPAD for the U.S.
population, 5.0% of the cPAD for all infants (< 1 year old), 13% of the
cPAD for children 1-2 years old, and 7.5% of the cPAD for females 13-49
years old. Based on the use pattern, chronic residential exposure to
residues of cyromazine is not expected. In addition, there is potential
for chronic dietary exposure to cyromazine in drinking water. After
calculating DWLOCs and comparing them to the EECs for surface and
ground water, EPA does not expect the aggregate exposure to exceed 100%
of the cPAD, as shown in Table 3 of this unit:

Table 3.--Aggregate Risk Assessment for Chronic (Non-Cancer) Exposure to Cyromazine
----------------------------------------------------------------------------------------------------------------
Ground Surface
Population Subgroup cPAD (mg/kg/ % cPAD Water EEC Water EEC Chronic
day) (Food) (ppb) (ppb) DWLOC (ppb)
----------------------------------------------------------------------------------------------------------------
General U.S. Population 0.075 8.3 5.3 15.5 2.4 x 10\3\
---------------------------------------------------------------------------
All Infants (< 1 year old) 0.075 5.0 5.3 15.5 7.1 x 10\2\
---------------------------------------------------------------------------
Children 1-2 years old 0.075 13 5.3 15.5 6.5 x 10\2\
---------------------------------------------------------------------------
Females 13-49 years old 0.075 7.5 5.3 15.5 2.1 x 10\3\
----------------------------------------------------------------------------------------------------------------

3. Aggregate cancer risk for U.S. population. Cyromazine is not
expected to pose a cancer risk to humans.
4. Determination of safety. Based on these risk assessments, EPA
concludes that there is a reasonable certainty that no harm will result
to the general population, and to infants and children from aggregate
exposure to cyromazine residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

Methods AG-408 (HPLC,/UV) and AG-417A (GLC/NPD) are the tolerance
enforcement methods for cyromazine as published in the Pesticide
Analytical Manual (PAM), Vol. II. These methods combined and with minor
modifications comprise Method AG-621. The residue data submitted in
support of these petitions were generated using Methods AG-408 and AG-
621. Method AG-621 has been adequately validated for use for the
determination of residues of cyromazine in/on bulb vegetables, leafy
Brassica vegetables, and turnip greens. Method AG-408 is adequate for
enforcement of the proposed tolerance for residues of cyromazine.
The method may be requested from: Chief, Analytical Chemistry
Branch, Environmental Science Center, 701 Mapes Rd., Ft. Meade, MD
20755-5350; telephone number: (410) 305-2905; e-mail address:
residuemethods@epa.gov.

B. International Residue Limits

Codex, Canadian or Mexican Maximum Residue Limits (MRLs) are not
established for cyromazine in/on leafy Brassica vegetables, bulb
vegetables, and turnip greens. Therefore, no compatability problems
exist for the tolerances established by this rule.

V. Conclusion

Therefore, the tolerances are established for residues of
cyromazine, (N-cyclopropyl-1,3,5-triazine-2,4,6-triamine) in or on
leek; onion, green; onion, potato; onion, tree; onion, welsh; and
shallot, fresh leaves at 3.0 ppm, garlic, bulb; garlic, great-headed,
bulb; onion, dry bulb; rakkyo, bulb; and shallot, bulb at 0.2 ppm,
vegetable, brassica, leafy, group 5, except broccoli at 10.0 ppm,
broccoli at 1.0 ppm, turnip, greens; cabbage, abyssinian; cabbage,
seakale; and hanover salad, leaves at 10.0 ppm, and kidney of cattle,
goat, hog, horse, and sheep at 0.2 ppm, and meat byproducts, except
kidney, of cattle, goat, hog, horse, and sheep at 0.05 ppm.

VI. Objections and Hearing Requests

Under section 408(g) of the FFDCA, as amended by the FQPA, any
person may file an objection to any aspect of this regulation and may
also request a hearing on those objections. The EPA procedural
regulations which govern the submission of objections and requests for
hearings appear in 40 CFR part 178. Although the procedures in those
regulations require some modification to reflect the amendments made to
the FFDCA by the FQPA, EPA will continue to use those procedures, with
appropriate adjustments, until the necessary modifications can be made.
The new section 408(g) of the FFDCA provides essentially the same
process for persons to ``object'' to a regulation for an exemption from
the requirement of a tolerance issued by EPA under new section 408(d)
of FFDCA, as was provided in the old sections 408 and 409 of the FFDCA.
However, the period for filing objections is now 60 days, rather than
30 days.

A. What Do I Need to Do to File an Objection or Request a Hearing?

You must file your objection or request a hearing on this
regulation in accordance with the instructions provided in this unit
and in 40 CFR part 178. To ensure proper receipt by EPA, you must
identify docket ID number OPP-2003-0269 in the subject line on the
first page of your submission. All requests must be in writing, and
must be mailed or delivered to the Hearing Clerk on or before November
24, 2003.
1. Filing the request. Your objection must specify the specific
provisions in the regulation that you object to, and the grounds for
the objections (40 CFR 178.25). If a hearing is requested, the
objections must include a statement of the factual issues(s) on which a
hearing is requested, the requestor's contentions on such issues, and a
summary of any evidence relied upon by the objector (40 CFR 178.27).
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.
Mail your written request to: Office of the Hearing Clerk (1900C),
Environmental Protection Agency, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460-0001. You may also deliver your request to the
Office of the Hearing Clerk in Rm.104, Crystal Mall #2, 1921
Jefferson Davis Hwy., Arlington, VA. The Office of the Hearing Clerk is
open from 8 a.m. to 4 p.m., Monday through

[[Page 55268]]

Friday, excluding legal holidays. The telephone number for the Office
of the Hearing Clerk is (703) 603-0061.
2. Tolerance fee payment. If you file an objection or request a
hearing, you must also pay the fee prescribed by 40 CFR 180.33(i) or
request a waiver of that fee pursuant to 40 CFR 180.33(m). You must
mail the fee to: EPA Headquarters Accounting Operations Branch, Office
of Pesticide Programs, P.O. Box 360277M, Pittsburgh, PA 15251. Please
identify the fee submission by labeling it ``Tolerance Petition Fees.''
EPA is authorized to waive any fee requirement ``when in the
judgement of the Administrator such a waiver or refund is equitable and
not contrary to the purpose of this subsection.'' For additional
information regarding the waiver of these fees, you may contact James
Tompkins by phone at (703) 305-5697, by e-mail at tompkins.jim@epa.gov,
or by mailing a request for information to Mr. Tompkins at Registration
Division (7505C), Office of Pesticide Programs, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001.
If you would like to request a waiver of the tolerance objection
fees, you must mail your request for such a waiver to: James Hollins,
Information Resources and Services Division (7502C), Office of
Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania
Ave., NW., Washington, DC 20460-0001.
3. Copies for the Docket. In addition to filing an objection or
hearing request with the Hearing Clerk as described in Unit VI.A., you
should also send a copy of your request to the PIRIB for its inclusion
in the official record that is described in Unit I.B.1. Mail your
copies, identified by docket ID number OPP-2003-0269, to: Public
Information and Records Integrity Branch, Information Resources and
Services Division (7502C), Office of Pesticide Programs, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001. In person or by courier, bring a copy to the location of the
PIRIB described in Unit I.B.1. You may also send an electronic copy of
your request via e-mail to: opp-docket@epa.gov. Please use an ASCII
file format and avoid the use of special characters and any form of
encryption. Copies of electronic objections and hearing requests will
also be accepted on disks in WordPerfect 6.1/8.0 or ASCII file format.
Do not include any CBI in your electronic copy. You may also submit an
electronic copy of your request at many Federal Depository Libraries.

B. When Will the Agency Grant a Request for a Hearing?

A request for a hearing will be granted if the Administrator
determines that the material submitted shows the following: There is a
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(s) in the manner sought
by the requestor would be adequate to justify the action requested (40
CFR 178.32).

VII. Statutory and Executive Order Reviews

This final rule establishes a tolerance under section 408(d) of the
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 rule has been
exempted from review under Executive Order 12866 due to its lack of
significance, this rule is not subject to Executive Order 13211,
Actions Concerning Regulations That Significantly Affect Energy Supply,
Distribution, or Use (66 FR 28355, May 22, 2001). 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) (Public Law
104-4). 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); or OMB review or any Agency action under Executive
Order 13045, entitled Protection of Children from Environmental Health
Risks and Safety Risks (62 FR 19885, April 23, 1997). 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). Since
tolerances and exemptions that are established on the basis of a
petition under section 408(d) of the 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. In addition, the Agency has determined that this
action will not have a substantial direct effect on States, on the
relationship between the national government and the States, or on the
distribution of power and responsibilities among the various levels of
government, as specified in Executive Order 13132, entitled Federalism
(64 FR 43255, August 10, 1999). Executive Order 13132 requires EPA to
develop an accountable process to ensure ``meaningful and timely input
by State and local officials in the development of regulatory policies
that have federalism implications.'' ``Policies that have federalism
implications'' is defined in the Executive order to include regulations
that have ``substantial direct effects on the States, on the
relationship between the national government and the States, or on the
distribution of power and responsibilities among the various levels of
government.'' This final rule directly regulates growers, food
processors, food handlers and food retailers, not States. This action
does not alter the relationships or distribution of power and
responsibilities established by Congress in the preemption provisions
of section 408(n)(4) of the FFDCA. For these same reasons, the Agency
has determined that this rule does not have any ``tribal implications''
as described in Executive Order 13175, entitled Consultation and
Coordination with Indian Tribal Governments (59 FR 22951, November 6,
2000). Executive Order 13175, requires EPA to develop an accountable
process to ensure ``meaningful and timely input by tribal officials in
the development of regulatory policies that have tribal implications.''
``Policies that have tribal implications'' is defined in the Executive
order to include regulations that have ``substantial direct effects on
one or more Indian tribes, on the relationship between the Federal
Government and the Indian tribes, or on the distribution of power and
responsibilities between the Federal Government and Indian tribes.''
This rule will not have substantial direct effects on tribal
governments, on the relationship between the Federal Government and
Indian tribes, or on the distribution of power and responsibilities
between the Federal Government and Indian tribes, as specified in
Executive Order 13175. Thus, Executive Order 13175 does not apply to
this rule.

[[Page 55269]]

VIII. Congressional Review Act

The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the Agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
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: September 10, 2003.
Debra Edwards,
Director, Registration Division, Office of Pesticide Programs.

? Therefore, 40 CFR part 180 is amended as follows:

PART 180--[AMENDED]

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

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

? 2. Section 180.414 is amended as follows:
? a. By revising the commodities cattle, goat, hog, horse, and sheep meat
byproducts in the table in paragraph (a).
? b. By revising the commodities onion, dry bulb and onion, green in the
table in paragraph (a).
? c. By alphabetically adding commodities in the table in paragraph (a).
? d. By removing and reserving paragraph (c).

Sec. 180.414 Cyromazine; tolerances for residues.

(a) * * *

------------------------------------------------------------------------
Parts per
Commodity million
------------------------------------------------------------------------
* * * * *
Broccoli................................................... 1.0
Cabbage, abyssinian........................................ 10.0
Cabbage, seakale........................................... 10.0
* * * * *
Cattle, kidney............................................. 0.2
* * * * *
Cattle, meat byproducts, except kidney..................... 0.05
* * * * *
Garlic, bulb............................................... 0.2
Garlic, great-headed, bulb................................. 0.2
* * * * *
Goat, kidney............................................... 0.2
* * * * *
Goat, meat byproducts, except kidney....................... 0.05
Hanover salad, leaves...................................... 10.0
* * * * *
Hog, kidney................................................ 0.2
* * * * *
Hog, meat byproducts, except kidney........................ 0.05
* * * * *
Horse, kidney.............................................. 0.2
* * * * *
Horse, meat byproducts, except kidney...................... 0.05
* * * * *
Leek....................................................... 3.0
* * * * *
Onion, dry bulb............................................ 0.2
Onion, green............................................... 3.0
Onion, potato.............................................. 3.0
Onion, tree................................................ 3.0
Onion, welsh............................................... 3.0
* * * * *
Rakkyo, bulb............................................... 0.2
Shallot, bulb.............................................. 0.2
Shallot, fresh leaves...................................... 3.0
* * * * *
Sheep, kidney.............................................. 0.2
* * * * *
Sheep, meat byproducts, except kidney...................... 0.05
* * * * *
Turnip, greens............................................. 10.0
Vegetable, brassica, leafy, group 5, except broccoli....... 10.0
* * * * *
------------------------------------------------------------------------

* * * * *
(c) Tolerances with regional registrations. [Reserved]
* * * * *

[FR Doc. 03-24012 Filed 9-23-03; 8:45 am]
BILLING CODE 6560-50-S

Notices For
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Cyromazine; Pesticide Tolerance

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