PMEP Home Page --> Pesticide Active Ingredient Information --> Herbicides, Growth Regulators and Desiccant --> sesone to vernolate (Vernam) --> sethoxydim (Poast) --> sethoxydim (Poast) Pesticide Tolerance 5/99

sethoxydim (Poast) Pesticide Tolerance 5/99

 

[Federal Register: June 16, 1999 (Volume 64, Number 115)]
[Rules and Regulations]               
[Page 32189-32196]
>From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr16jn99-10]

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

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-300859; FRL-6080-9]
RIN 2070-AB78

 
Sethoxydim; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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

SUMMARY: This regulation establishes tolerances for combined residues 
of sethoxydim and its metabolites containing the 2-cyclohexen-1-one 
moiety (calculated as the herbicide) in or on asparagus, carrot, 
cranberry, horseradish, peppermint tops and spearmint tops. The 
Interregional

[[Page 32190]]

Research Project Number 4 (IR-4) 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 June 16, 1999. Objections and 
requests for hearings must be received by EPA on or before August 16, 
1999.

ADDRESSES: Written objections and hearing requests, identified by the 
docket control number, [OPP-300859], 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-300859], 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. 119, Crystal 
Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA.
    A copy of objections and hearing requests filed with the Hearing 
Clerk may be submitted electronically by sending electronic mail (e-
mail) to: opp-docket@epa.gov. Copies of objections and hearing requests 
must be submitted as an ASCII file avoiding the use of special 
characters and any form of encryption. Copies of objections and hearing 
requests will also be accepted on disks in WordPerfect 5.1/6.1 file 
format or ASCII file format. All copies of objections and hearing 
requests in electronic form must be identified by the docket control 
number [OPP-300859]. No Confidential Business Information (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.

FOR FURTHER INFORMATION CONTACT: By mail: Hoyt Jamerson, 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: Rm. 272, Crystal Mall 
#2, 1921 Jefferson Davis Hwy., Arlington, VA, (703) 308-9368, 
jamerson.hoyt@epa.gov.

SUPPLEMENTARY INFORMATION: In the Federal Register of December 30, 1998 
(63 FR 71920) (FRL-6050-1), EPA issued a notice pursuant to section 408 
of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a as 
amended by the Food Quality Protection Act of 1996 (FQPA) (Pub. L. 104-
170) announcing the filing of pesticide petitions (PP 3E4162, 2E4092, 
0E3909, and 2E4052) for tolerances by Interregional Research Project 
Number 4 (IR-4), New Jersey Agricultural Experiment Station, Rutgers 
University, New Brunswick, New Jersey 08903. The notice included a 
summary of the petitions prepared by BASF Corporation, the registrant. 
There were no comments received in response to the notice of filing.
    The petitions requested that 40 CFR 180.412 be amended by removing 
the time limitations (expiration dates) on established tolerances for 
combined residues of the herbicide sethoxydim (2-[1-
(ethoxyimino]butyl)-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-
one) and its metabolites containing the 2-cyclohexen-1-one moiety 
(calculated as the herbicide), in or on asparagus (PP 3E4162) at 4.0 
parts per million (ppm), carrot (PP 2E4092) at 1.0 ppm, cranberry (PP 
0E3909) at 2.0 ppm, and peppermint and spearmint tops (PP 2E4052) at 30 
ppm. Since the tolerances for asparagus, carrot, cranberry, peppermint 
and spearmint tops expired December 31, 1998, after the notice of 
filing was published in the Federal Register, this rule establishes the 
tolerances without time limitations. In addition, in the Federal 
Register of January 29, 1999 (64 FR 4650) (FRL-6055-8), PP 9E5049 
proposed to amend 40 CFR 180.412 by establishing a tolerance for 
residues of sethoxydim and its metabolites in or on horseradish at 4 
ppm.

I. Background and Statutory Findings

    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) 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) 
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 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).

II. Aggregate Risk Assessment and Determination of Safety

    Consistent with section 408(b)(2)(D), 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 
sethoxydim and to make a determination on aggregate exposure, 
consistent with section 408(b)(2), for a tolerance for combined 
residues of (2-[1-(ethoxyimino]butyl)-5-[2-(ethylthio)propyl]-3-
hydroxy-2-cyclohexen-1-one) and its metabolites containing the 2-
cyclohexen-1-one moiety (calculated as the herbicide) in or on 
asparagus, carrot, cranberry, horseradish, and peppermint and spearmint 
tops. EPA's assessments of the dietary exposures and risks associated 
with establishing the tolerances are as 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 sethoxydim are 
discussed in this unit.
    1. Acute toxicity. Based on the available acute toxicity data, 
sethoxydim does not pose any acute dietary risks. A summary of the 
acute toxicity studies follows:
    i. Acute oral toxicity, rat: Toxicity Category III; 
LD<INF>50</INF>=3,125 milligrams/kilograms (mg/kg) (male), 2,676 mg/kg 
(female).
    ii. Acute dermal toxicity, rat: Toxicity Category III; 
LD<INF>50</INF> >5,000 mg/kg (male and female).
    iii. Acute inhalation toxicity, rat: Toxicity Category III; 
LC<INF>50</INF> (4-hour)=6.03 mg/liter (L) (male), 6.28 mg/L (female).

[[Page 32191]]

    iv. Primary eye irritation, rabbit: Toxicity Category IV; no 
irritation.
    v. Primary dermal irritation, rabbit: Toxicity Category IV; no 
irritation.
    vi. Dermal sensitization, guinea pig: Waived because no 
sensitization was seen in guinea pigs dosed with the end-use product 
Poast (18% active ingredient).
    2. Genotoxicity. Ames assays were negative for gene mutation in 
Salmonella typhimurium strains TA98, TA100, TA1535, and TA 1537, with 
and without metabolic activity. A Chinese hamster bone marrow 
cytogenetic assay was negative for structural chromosomal aberrations 
at doses up to 5,000 mg/kg in Chinese hamster bone marrow cells in 
vivo. Recombinant assays and forward mutations tests in Bacillus 
subtilis, Escherichia coli, and S. typhimurium were all negative for 
genotoxic effects at concentrations of greater than or equal to 100%.
    3. Reproductive and developmental toxicity. A 2-generation 
reproduction study with rats fed diets containing 0, 150, 600, or 3,000 
ppm (approximately 0, 7.5, 30, or 150 mg/kg/day) with no reproductive 
effects observed under the conditions of the study.
    A developmental toxicity study in rats fed dosages of 0, 50, 180, 
650, or 1,000 mg/kg/day with a maternal no-observed-adverse-effect 
level (NOAEL) of 180 mg/kg/day and a maternal lowest-adverse-effect 
level (LAEL) of 650 mg/kg/day (irregular gait, decreased activity, 
excessive salivation, and anogenital staining); and a developmental 
NOAEL of 180 mg/kg/day, and a developmental LAEL of 650 mg/kg/day, 
based on a 21 to 22% decrease in fetal weights, filamentous tail, and 
lack of tail due to the absence of sacral and/or caudal vertebrae, and 
delayed ossification in the hyoids, vertebral centrum and/or transverse 
processes, sternebrae and/or metatarsal, and pubes). A developmental 
toxicity study in rabbits fed doses of 0, 80, 160, 320, or 400 mg/kg/
day with a maternal NOAEL of 320 mg/kg/day and a maternal lowest-
observed-adverse-effect level (LOAEL) of 400 mg/kg/day (37% reduction 
in body weight gain without significant differences in group mean body 
weights and decreased food consumption during dosing); and a 
developmental NOAEL greater than 400 mg/kg/day highest dose tested 
(HDT).
    4. Subchronic toxicity. A 21-day dermal study in rabbits with a 
NOAEL of >1,000 mg/kg/day (limit dose). The only dose-related finding 
was slight epidermal hyperplasia at the dosing site in nearly all males 
and females dosed at 1,000 mg/kg/day. This was probably an adaptive 
response.
    5. Chronic toxicity. A 1-year feeding study with dogs fed diets 
containing 0, 8.86/9.41, 17.5/19.9, and 110/129 mg/kg/day (males/
females) with a NOAEL of 8.86/9.41 mg/kg/day (males/females) based on 
equivocal anemia in male dogs at the 17.5-mg/kg/day dose level.
    A 2-year chronic feeding/carcinogenicity study with mice fed diets 
containing 0, 40, 120, 360, and 1,080 ppm (equivalent to 0, 6, 18, 54, 
and 162 mg/kg/day) with a systemic NOAEL of 120 ppm (18 mg/kg/day) 
based on non-neoplastic liver lesions in male mice at the 360-ppm (54 
mg/kg/day) dose level. There were no carcinogenic effects observed 
under the conditions of the study. The maximum tolerated dose (MTD) was 
not achieved in female mice. The need for a new study will be based on 
the adequacy of the rat study currently under review.
    A 2-year chronic feeding/carcinogenic study with rats fed diets 
containing 0, 2, 6, and 18 mg/kg/day with a systemic NOAEL greater than 
or equal to 18 mg/kg/day HDT. There were no carcinogenic effects 
observed under the conditions of the study. This study was reviewed 
under current guidelines and was found to be unacceptable because the 
doses used were insufficient to induce a toxic response and the MTD was 
not achieved.
    A second chronic feeding/carcinogenic study with rats fed diets 
containing 0, 360, or 1,080 ppm (equivalent to 18.2/23.0, or 55.9/71.8 
mg/kg/day (males/females). The dose levels were too low to elicit a 
toxic response in the test animals and failed to achieve the MTD or to 
define a LAEL. Slight decreases in body weight in rats at the 1,080-ppm 
dose level, although not biologically significant, support a free-
standing NOAEL of 1,080 ppm (55.9/71.8 mg/kg/day (males/females)). 
There were no carcinogenic effects observed under the conditions of the 
study.
    A third chronic feeding/carcinogenicity study in rats has been 
submitted. Male and female rats were dosed at nominal concentrations of 
0, 300, 1,000, or 3,000 ppm. Clinical findings at the high-dose 
included changes in food consumption, food efficiency, body weight, and 
liver pathology. Upon initial review, it appears that the dose 
selection was adequate, and that there was no evidence of 
carcinogenicity.
    6. Animal metabolism. In a rat metabolism study, excretion was 
extremely rapid and tissue accumulation was negligible.

B. Toxicological Endpoints

    1. Acute toxicity. In a rat developmental study rats received doses 
of 0, 50, 180, 650, and 1,000 mg/kg/day. The maternal toxicity NOAEL 
was 180 mg/kg/day and the LOAEL was 650 mg/kg/day based on irregular 
gait, decreased activity, excessive salivation, and ano-genital 
staining. For developmental toxicity the NOAEL was 180 mg/kg/day and 
the LOAEL was 650 mg/kg/day based on 21-22% decrease in fetal weights, 
filamentous tail and lack of tail due to the absence of accral and /or 
caudal vertebrae, and delayed ossification in the hyoids, vertebral 
centrum and/or transverse processes, sternebrae and/or metatarsal, and 
pubes. The end point for use in the risk assessment is the maternal 
NOAEL of 180 mg/kg/day. The end point is set on maternal effects 
because the NOAEL for developmental effects is also 180 mg/kg/day.
    2. Short- and intermediate-term toxicity. No short or intermediate 
dermal or inhalation endpoints were identified. In a 21-day dermal 
study with rabbits dosed at 0, 40, 200, or 1,000 mg/kg/day, there was 
no evidence of compound related toxicity on clinical signs, body 
weights, food consumption, food efficiency, eye health, clinical 
pathology, organ weights, or gross pathology. The NOAEL was greater 
than 1,000 mg/kg/day (limit dose). In the acute inhalation study with 
rats the LC<INF>50</INF> was 6.03 mg/L (males) and 6.28 mg/L (females 
placing sethoxydim in category IV.
    3. Chronic toxicity. EPA has established the Reference Dose (RfD) 
for sethoxydim at 0.9 mg/kg/day. This RfD is based on a finding of 
equivocal anemia in the 1-year dog study. The NOAEL was 8.86 mg/kg in 
males and 9.41 mg/kg in females.
    4. Carcinogenicity. Sethoxydim is not classified. Available studies 
show no evidence of carcinogenicity in rats or mice.

C. Exposures and Risks

    1. From food and feed uses. Tolerances have been established (40 
CFR 180.412) for the combined residues of (2-[1-(ethoxyimino]butyl)-5-
[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one) and its metabolites 
containing the 2-cyclohexen-1-one moiety (calculated as the herbicide), 
in or on a variety of raw agricultural commodities. Risk assessments 
conducted by EPA to assess dietary exposures from sethoxydim are as 
follows:
    i. Acute exposure and risk. Acute dietary risk assessments are 
performed

[[Page 32192]]

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 endpoint is 180 mg/kg/day based on 
NOAEL's of 180 mg/kg/day for maternal and developmental effects in the 
rabbit developmental study. The FQPA safety factor of 3x was applied to 
females 13+ only because the endpoint (based on decrease in fetal 
weights, filamentous tail and lack of tail due to absence of sacral 
and/or caudal vertebrae, delayed ossification in the hyoids, vertebral 
centrum and/or transverse processes, sternebrae and/or metatarsal) 
occurs only during in urtero exposure and is not a postnatal effect. 
Since the effects occur during in urtero exposure, it is not an 
appropriate endpoint for acute dietary risk assessment of infants and 
children.
    In conducting this acute dietary risk assessment, the Agency made 
very conservative assumptions--100% of all commodities having 
sethoxydim tolerances will contain sethoxydim regulable residues and 
those residues will be at the level of the tolerance which result in an 
over estimation of human dietary exposure.
    From the acute dietary (food only) risk assessment, a high-end 
exposure estimate of 0.2 mg/kg/day was calculated. This exposure 
yielded dietary (food only) margins of exposure (MOEs) ranging from 420 
for children (1-6 years old) to 622 for female 13+ and greater than 500 
for all other subgroups.
    ii. Chronic exposure and risk. The FQPA Safety Factor will not be 
applied for chronic dietary risk assessment because the endpoint is 
based on anemia in male dogs. The endpoint for which the FQPA safety 
factor is based is an in utero effect and cannot result from postnatal 
exposure. There was no indication of increased susceptibility in the 
prenatal developmental study in rabbits following in utero exposure. In 
the 2-generation reproduction study in rats, effects in offspring were 
observed only at above treatment levels which resulted in evidence of 
appreciable parental toxicity. No increased susceptibility was 
demonstrated in the developmental toxicity study with rats when the 
maternal and developmental NOAELs/LOAELs were compared. In conducting 
this chronic dietary risk assessment, the Agency has made very 
conservative assumptions no percent crop-treated data were used and all 
commodities having sethoxydim tolerances will contain sethoxydim 
residues and those residues will be at the level of the tolerance which 
will result in an overestimate of human dietary exposure.
    The sethoxydim tolerances (published and pending) result in a 
Theoretical Maximum Residue Contribution (TMRC) that is equivalent to 
the following percentages of the RfD:


------------------------------------------------------------------------
                Subgroup                         TMRC            %RFD
------------------------------------------------------------------------
U.S. Population.........................           0.039187           44
Nursing Infants.........................          00.018957           21
Non-Nursing Infants (<1 year old).......          00.072949           81
Children (1-6 years old)................          00.085308           95
Children (7-12 years old)...............          00.058101           65
Female (13+, nursing)...................          00.040144           45
Males (13-19 years old).................          00.040429           45
U.S Population (Summer Season)..........          00.039408           44
Hispanics...............................          00.039428           44
Non-Hispanic Others.....................          00.040452           45
Non-Hispanic Whites.....................          00.039238           44
------------------------------------------------------------------------

    The subgroups listed above are: (1) the U.S. population (48 
states); and (2) those for infants, children, females, 13+ nursing; and 
other subgroups for which the percentage of RfD occupied is greater 
than occupied by the subgroup U.S. population.
    2. Carcinogenic risk. Sethoxydim has not been classified. At the 
present time, studies do not show evidence of carcinogenicity in rats 
or mice.
    3. From drinking water. Limited monitoring data of ground water and 
surface water are available for sethoxydim. The modeling data estimates 
maximum concentrations in ground water of 0.84 microgram (<greek-m>g)/
liter (L) and in surface water 59.4 <greek-m>g/L and 56-day EECs of 
37.3 <greek-m>g/L. The modeling data were compared to the results of 
the following equations used to calculate acute and chronic drinking 
water level of concern (DWLOC) for sethoxydim in ground and surface 
water (Standard Operating Procedures for Drinking Water Exposure and 
Risk Assessments, November 20, 1997). Models used were SCI-GROW and 
GENEC to provide estimates of ground and surface water contamination 
respectively from sethoxydim, but did not consider the behavior of 
degradates. Agency default weights and water consumption used in the 
calculations were 70 kg(2L) for adult males, 60 kg(2L) for adult 
females, and 10 kg (1L) for child.
    i. Acute exposure and risk. Based on acute dietary exposure and 
using default body weights and water consumption values stated above, 
acute DWLOC were calculated using the following equation.
    DWLOC (acute) = (NOAEL divided by uncertainty factor) - (acute food 
+ residential exposure (mg/kg/day) x (body weight) divided by 
consumption(L) x 10<SUP>-3</SUP> mg/<greek-m>g.
    Acute dietary water levels of concern were calculated to be 525,000 
<greek-m>g/L for the U.S. population, 56,000 <greek-m>g/L for adult 
males 13+, 12,000 <greek-m>g/L for adult females 13+ (including 3x 
safety factor) and 14,000 <greek-m>g/L for child (infant < 1 year old).
    ii. Chronic exposure and risk. Based on acute dietary exposure and 
using default body weights and water consumption values stated above, 
acute DWLOC were calculated using the following equation.
    DWLOC (chronic) = (NOEL divided by uncertainty factor) - (chronic 
food + residential exposure (mg/kg/day) x (body weight) divided by 
consumption(L) x 10<SUP>-3</SUP> mg/<greek-m>g.
    Chronic DWLOCs were calculated to be 1,760 <greek-m>g/L for the 
U.S. population, 1,780 <greek-m>g/L for adult males 13+, 1,700 
<greek-m>g/L for adult females 13+ (including 3x safety factor) and 
14,000 <greek-m>g/L for child (infant < 1 year old).
    4. From non-dietary exposure. Sethoxydim is currently registered 
for use on the following residential non-food sites: ornamentals and 
flowering plants, recreational areas, and buildings/structures (outdoor 
non-agricultural). These residential uses comprise a short- and 
intermediate-term exposure scenario, but do not comprise a chronic 
exposure scenario.
    i. Acute exposure and risk. There is a potential for exposure to 
sethoxydim by homeowner mixers/applicators. However, since no endpoints 
for dermal or inhalation were selected, the use on residential non-food 
sites is not

[[Page 32193]]

expected to pose an unacceptable acute risk.
    ii. Chronic exposure and risk. The registered uses for sethoxydim 
do not comprise a chronic exposure scenario. A chronic non-dietary 
endpoint was not selected; therefore, the use on residential non-food 
sites is not expected to pose an unacceptable chronic risk.
    iii. Short- and intermediate-term exposure and risk. Short-term or 
intermediate term endpoints were not identified. However, the following 
scenarios may result if herbicides containing sethoxydim are applied to 
residential turf, and/or ornamental plants: incidental non-dietary 
ingestion of residues on lawns from hand-to-mouth transfer, ingestion 
of pesticide-treated turfgrass, and incidental ingestion of soil from 
treated lawns. A residential exposure estimate and risk assessment was 
conducted for postapplication exposure following the application of 
sethoxydim on turf and ornamental gardens. The acute dietary endpoint 
was used for this risk assessment because the acute dietary endpoint 
provides the worst case estimate of risk and exposure for these use 
patterns. The assessment was performed using Draft SOPs for Residential 
Exposure Assessments (December 18, 1998). The proposed postapplication 
aggregate exposure assessment takes into account chronic dietary 
exposure plus outdoor residential exposures. These exposure assessments 
assume that 20% of the application rate is available from the turf 
grass as dislodgeable residue and 2 hours as the duration of exposure. 
These assumptions are considered conservative and protective.
    Exposures and MOEs were calculated to be 0.053 mg/kg/day (MOE of 
3,400) for hand to mouth transfer for treated lawns (toddlers), 0.0012 
mg/kg/day (MOE of 15,000) for ingestion of treated turf grass 
(toddler), and 0.000025 (MOE of 7,000,000) for incidental ingestion of 
soil (toddlers). MOEs exceeded 100 for all three scenarios. MOEs 
greater or equal to 100 do not exceed the Agency's level of concern.
    5. Cumulative exposure to substances with common mechanism of 
toxicity. Section 408(b)(2)(D)(v) 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 sethoxydim has a common mechanism of toxicity with other 
substances or how to include this pesticide in a cumulative risk 
assessment. Unlike other pesticides for which EPA has followed a 
cumulative risk approach based on a common mechanism of toxicity, 
sethoxydim does not appear to produce a toxic metabolite produced by 
other substances. For the purposes of this tolerance action; therefore, 
EPA has not assumed that sethoxydim 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 final rule 
for Bifenthrin Pesticide Tolerances (62 FR 62961, November 26, 1997).

D. Aggregate Risks and Determination of Safety for U.S. Population

    1. Acute risk. Using the published and pending tolerances, the 
dietary (food only) acute MOEs range from 420 for children (1-6 year) 
to 622 for females 13+ years. The level of concern for females 13+ 
years is 300 (includes 3x safety factor) for acute sethoxydim exposure 
and 100 for all other population subgroups. This risk estimate should 
be viewed as highly conservative; refinement using anticipated residue 
values and percent crop treated data in conjunction with Monte Carlo 
analysis will result in a lower acute dietary exposure estimate. The 
dietary exposure does not exceed the Agency's level of concern.
    Sethoxydim is a nonpersistent, but highly mobile compound in soil 
and water environments. The modeling data for sethoxydim in drinking 
water indicate levels less than OPP`s DWLOC for acute exposure. Since a 
refined acute risk for food only would not exceed EPA's levels of 
concern for acute dietary exposures and the monitoring and modeling 
levels in water are less than the acute DWLOC, EPA does not expect 
aggregate acute exposure to sethoxydim will pose an unacceptable risk 
to human health.
    2. Chronic risk. Using the TMRC exposure assumptions described in 
this unit, EPA has concluded that aggregate exposure to sethoxydim from 
food will utilize 44% of the RfD for the U.S. population. The major 
identifiable subgroup with the highest aggregate exposure is 95% for 
children 1 to 6 years; discussed below. 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. Despite the 
potential for exposure to sethoxydim in drinking water and from non-
dietary, non-occupational exposure, EPA does not expect the aggregate 
exposure to exceed 100% of the RfD. EPA concludes that there is a 
reasonable certainty that no harm will result from aggregate exposure 
to sethoxydim 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 indoor and outdoor 
residential exposure.
    Endpoints for short or intermediate term were not selected. An 
aggregate exposure estimate and risk assessment was conducted for 
postapplication exposure to sethoxydim on turf and ornamental plants 
taking into account chronic exposure from food and the acute dietary 
NOAEL. The resulting MOEs (1,390-2,350) are not of concern to the 
Agency.
    4. Aggregate cancer risk for U.S. population. Sethoxydim has not 
been classified. Available studies do not show evidence of 
carcinogenicity in rats or mice.
    5. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
from aggregate exposure to sethoxydim residues.

E. 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 sethoxydim, EPA considered data from 
developmental toxicity studies in the rat and rabbit and a 2-generation 
reproduction study in the rat. The developmental toxicity studies are 
designed to evaluate adverse effects on the developing organism 
resulting from maternal pesticide exposure gestation. Reproduction 
studies provide information relating to effects from exposure to the 
pesticide on the reproductive capability of mating animals and data on 
systemic toxicity.
    FFDCA section 408 provides that EPA shall apply an additional 
tenfold margin of safety for infants and children in the case of 
threshold effects to account for pre- and postnatal 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 margin of exposure (MOE) analysis or through using 
uncertainty (safety) factors in calculating a dose level that poses no

[[Page 32194]]

appreciable risk to humans. EPA believes that reliable data support 
using the standard uncertainty factor (usually 100 for combined inter- 
and intra-species variability) and not the additional tenfold 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. Pre- and postnatal sensitivity. There was no indication of 
increased susceptibility in the prenatal developmental toxicity study 
in rabbits following in utero exposure. In the 2-generation 
reproduction study in rats, effects in the offspring were observed only 
at or above treatment levels which resulted in evidence of appreciable 
parental toxicity. No increased susceptibility was demonstrated in the 
developmental toxicity studies; however developmental toxic effects, 
were observed at the HDT.
    Acceptable developmental toxicity studies have been performed in 
rats and rabbits; an acceptable 2-generation reproduction study has 
also been performed in rats. A chronic feeding/carcinogenicity 
guideline study in rats has been submitted and is currently undergoing 
review. An initial examination of the study supports the current 
findings of no evidence of carcinogenicity. There is a complete 
toxicity data base for sethoxydim and exposure data are complete or are 
estimated based on data that reasonably accounts for potential 
exposures.
    The FQPA Safety Factor is to be retained in case of developmental 
toxicity in the absence of maternal toxicity. Since malformations were 
seen in the rat study at levels that produced minimal maternal 
toxicity. The Agency concluded that an FQPA factor is needed. However, 
it was determined that the 10x factor need not be retained, instead 
should be reduced to 3x based on the following weight of evidence 
considerations: (1) developmental toxicity was seen in only one 
species, in the presence of maternal toxicity, and at a very high dose 
(650 mg/kg/day) that approached the Limit-Dose of 1,000 mg/kg/day; (2) 
no developmental toxicity was observed in the rabbit study at the HDT 
(400 mg/kg/day); (3) there was no increased susceptibility seen in the 
2-generation reproduction study in rats at doses up to 150 mg/kg/day 
HDT; and (4) lack of concern for structure activity relationship (i.e., 
no significant developmental or reproductive toxicity was seen with the 
structural analog, clethodim.)
    Exposure assessments do not indicate a concern for potential risk 
to infants and children based on: (1) the dietary exposure assessments 
use field study data and assume 100% crop treated which results in an 
overestimate of dietary exposure; (2) limited monitoring data are used 
for ground and surface source drinking water exposure assessments, 
resulting in estimates considered to be reasonable upper-bound 
concentrations; (3) there is a potential for postapplication hand-to-
mouth exposure to toddlers associated with lawn use; however, the use 
of conservative models and/or assumptions in the residential exposure 
assessment provide adequate protection of infants and children.
    The FQPA safety factor is applicable for acute dietary risk 
assessment for females 13+ because the endpoint occurs only during in 
urtero exposure and is not a postnatal effect. Since the effects occur 
during in urtero exposure, it is not an appropriate endpoint for acute 
dietary risk assessment of infants and children. The FQPA safety factor 
is not applied for chronic risk assessment because the endpoint is an 
in urtero effect and cannot result from postnatal exposure. The FQPA 
safety factor is not applicable to the postapplication hand-to-mouth 
exposure associated with the lawn use since this exposure scenario 
would only be expected for toddlers and not for females 13+.
    iii. Conclusion. Acceptable developmental toxicity studies have 
been performed in rats and rabbits; an acceptable 2-generation 
reproduction study has also been performed in rats. A chronic feeding/
carcinogenicity guideline study in rats has been submitted and is 
currently undergoing review. An initial examination of the study 
supports the current findings of no evidence of carcinogenicity. There 
is a complete toxicity data base for sethoxydim and exposure data are 
complete or are estimated based on data that reasonably accounts for 
potential exposures.
    2. Acute risk. Using the conservative exposure assumptions that 
100% of the commodities having sethoxydim tolerances will contain 
sethoxydim regulable residues and that those residues will be at the 
level of the tolerance, EPA calculated acute dietary (food only) MOEs 
ranging from 420 for children (1-6 years old) to 622 for females 13+ 
years. The level of concern is 300 (3x safety factor x 100) for females 
13+ years and 100 for all other subgroups.
    3. Chronic risk. Using the exposure assumptions described in this 
unit, EPA has concluded that aggregate exposure to sethoxydim from food 
will utilize less than 100% of the RfD for nursing infants, non-nursing 
infants (<1 years old), children (1-6 years old), and children (7-12 
years old). 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. Despite the potential for exposure to sethoxydim 
in drinking water and from non-dietary, non-occupational exposure, EPA 
does not expect the aggregate exposure to exceed 100% of the RfD.
    4. Short- or intermediate-term risk. An aggregate exposure estimate 
and risk assessment was conducted for postapplication exposure to 
sethoxydim on turf and ornamental plants taking into account chronic 
exposure from food and the acute dietary NOAEL. The resulting MOEs 
(1,390-2,350) are not of concern to EPA.
    5. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
to infants and children from aggregate exposure to sethoxydim residues.

III. Other Considerations

A. Metabolism In Plants and Animals

    The metabolism of sethoxydim in plants and animals is understood, 
the tolerances for plant and animal commodities are expressed as the 
combined residues of sethoxydim and its metabolites containing the 2-
cyclohexen-1-one moiety (calculated as the herbicide).

B. Analytical Enforcement Methodology

    BASF Method 30 as published in PAM Vol. II is adequate for 
tolerance enforcement in all raw agricultural commodities. Quantitation 
is accomplished by gas chromatography with flame photometric detection 
in the sulfur mode. Sethoxydim and its metabolites are not recovered or 
not likely to be recovered by FDA multiresidue methods.

C. Magnitude of Residues

    The available crop field data support the established tolerances 
for asparagus at 4.0 ppm, carrot at 1.0 ppm, cranberry at 2.0 ppm, and 
peppermint and spearmint tops at 30 ppm. Residue data submitted in 
support of existing tolerances for carrot at 1.0 ppm, potato at 4.0 
ppm, sugar beet at 1.0 ppm, and sweet potato at 4.0 ppm support the 
establishment of a tolerance for horseradish at 4.0 ppm.

[[Page 32195]]

D. International Residue Limits

    Maximum Residue Levels (MRLs) have not been established for 
residues of sethoxydim on asparagus, carrot, cranberry, horseradish, 
peppermint, or spearmint tops.

IV. Conclusion

    Therefore, the tolerances are established for combined residues of 
(2-[1-(ethoxyimino]butyl)-5-[2-(ethylthio)propyl]-3-hydroxy-2-
cyclohexen-1-one) and its metabolites containing the 2-cyclohexen-1-one 
moiety (calculated as the herbicide) in or on asparagus at 4.0 ppm, 
carrot at 1.0 ppm, cranberry at 2.0 ppm, horseradish at 4.0 ppm, and 
peppermint and spearmint tops at 30 ppm. at ppm.

V. Objections and Hearing Requests

    The new FFDCA section 408(g) provides essentially the same process 
for persons to ``object'' to a tolerance regulation as was provided in 
the old section 408 and in section 409. 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 August 16, 1999, 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 under the ``ADDRESSES'' section (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 
regulation. 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). 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 tolerance objection fee waivers, 
contact James Tompkins, 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: Rm. 239, Crystal Mall #2, 1921 Jefferson Davis Hwy., 
Arlington, VA, (703) 305-5697, tompkins.jim@epa.gov. Requests for 
waiver of tolerance objection fees should be sent to James Hollins, 
Information Resources and Services Division (7502C), Office of 
Pesticide Programs, Environmental Protection Agency, 401 M St., SW., 
Washington, DC 20460.
    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

    EPA has established a record for this regulation under docket 
control number [OPP-300859] (including any comments and data submitted 
electronically). 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 public 
record is located in Room 119 of the Public Information and Records 
Integrity Branch, Information Resources and Services Division (7502C), 
Office of Pesticide Programs, Environmental Protection Agency, Crystal 
Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA.
    Objections and hearing requests may be sent by e-mail directly to 
EPA at:

    opp-docket@epa.gov



    E-mailed objections and hearing requests must be submitted as an 
ASCII file avoiding the use of special characters and any form of 
encryption.
    The official record for this regulation, as well as the public 
version, as described in this unit will be kept in paper form. 
Accordingly, EPA will transfer any copies of objections and hearing 
requests received electronically into printed, paper form as they are 
received and will place the paper copies in the official record which 
will also include all comments submitted directly in writing. The 
official record is the paper record maintained at the Virginia address 
in ``ADDRESSES'' at the beginning of this document.

VII. Regulatory Assessment Requirements

A. Certain Acts and Executive Orders

    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). 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 tolerances and exemptions that are established 
on the basis of a petition under FFDCA section 408(d), 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. Nevertheless, the Agency previously 
assessed whether establishing tolerances, exemptions from tolerances, 
raising tolerance levels or expanding exemptions might adversely impact 
small entities and concluded, as a

[[Page 32196]]

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.

B. Executive Order 12875

    Under Executive Order 12875, entitled Enhancing the 
Intergovernmental Partnership (58 FR 58093, October 28, 1993), EPA may 
not issue a regulation that is not required by statute and that creates 
a mandate upon a State, local or tribal government, unless the Federal 
government provides the funds necessary to pay the direct compliance 
costs incurred by those governments. If the mandate is unfunded, EPA 
must provide to OMB a description of the extent of EPA's prior 
consultation with representatives of affected State, local, and tribal 
governments, the nature of their concerns, copies of any written 
communications from the governments, and a statement supporting the 
need to issue the regulation. In addition, Executive Order 12875 
requires EPA to develop an effective process permitting elected 
officials and other representatives of State, local, and tribal 
governments ``to provide meaningful and timely input in the development 
of regulatory proposals containing significant unfunded mandates.''
    Today's rule does not create an unfunded Federal mandate on State, 
local, or tribal governments. The rule does not impose any enforceable 
duties on these entities. Accordingly, the requirements of section 1(a) 
of Executive Order 12875 do not apply to this rule.

C. Executive Order 13084

    Under Executive Order 13084, entitled Consultation and Coordination 
with Indian Tribal Governments (63 FR 27655, May 19, 1998), EPA may not 
issue a regulation that is not required by statute, that significantly 
or uniquely affects the communities of Indian tribal governments, and 
that imposes substantial direct compliance costs on those communities, 
unless the Federal government provides the funds necessary to pay the 
direct compliance costs incurred by the tribal governments. If the 
mandate is unfunded, EPA must provide OMB, in a separately identified 
section of the preamble to the rule, a description of the extent of 
EPA's prior consultation with representatives of affected tribal 
governments, a summary of the nature of their concerns, and a statement 
supporting the need to issue the regulation. In addition, Executive 
Order 13084 requires EPA to develop an effective process permitting 
elected officials and other representatives of Indian tribal 
governments ``to provide meaningful and timely input in the development 
of regulatory policies on matters that significantly or uniquely affect 
their communities.''
    Today's rule does not significantly or uniquely affect the 
communities of Indian tribal governments. This action does not involve 
or impose any requirements that affect Indian tribes. Accordingly, the 
requirements of section 3(b) of Executive Order 13084 do not apply to 
this rule.

VIII. Submission to Congress and the Comptroller General

    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 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 the rule in the Federal Register. This 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: May 20, 1999.

Peter Caulkins,

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. 321(q), (346a), and 371.

    2. In Sec.  180.412(a), by removing the expiration date for the 
entries asparagus, carrot, cranberry, peppermint, tops and spearmint 
tops and inserting <gr-thn-eq>None<gr-thn-eq> in each place and adding 
a new entry for horseradish at 4.0 ppm to read as follows:


Sec.  180.412   Sethoxydim; tolerances for residues.

    (a) * * *


------------------------------------------------------------------------
                                                     Parts   Expiration/
                     Commodity                        per     Revocation
                                                    million      Date
------------------------------------------------------------------------

                   *        *        *      *        *
Horseradish.......................................  4.0             None

                   *        *        *      *        *
------------------------------------------------------------------------

* * * * *
[FR Doc. 99-14865 Filed 6-15-99; 8:45 am]
BILLING CODE 6560-50-F