[Federal Register Volume 65, Number 151 (Friday, August 4, 2000)]
[Rules and Regulations]
[Pages 47877-47882]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-19794]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-301019; FRL-6596-3]
RIN 2070-AB78


Diflubenzuron; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes a tolerance for combined residues 
of diflubenzuron and its metabolites in or on rangeland grass. 
Interregional Research Project Number 4 (IR-4) requested this tolerance 
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 August 4, 2000. Objections and 
requests for hearings, identified by docket control number OPP-301019, 
must be received by EPA on or before October 3, 2000.

ADDRESSES: Written objections and hearing requests may be submitted by 
mail, in person, or by courier. Please follow the detailed instructions 
for each method as provided in Unit VI. of the SUPPLEMENTARY 
INFORMATION To ensure proper receipt by EPA, your objections and 
hearing requests must identify docket control number OPP-301019 in the 
subject line on the first page of your response.

FOR FURTHER INFORMATION CONTACT: By mail: Shaja R. Brothers, 
Registration Division (7505C), Office of Pesticide Programs, 
Environmental Protection Agency, 1200 Pennsylvania Ave., 
NW.,Washington, DC 20460; telephone number: (703) 308-3194; and e-mail 
address: [email protected].

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

    You may be affected by this action if you are an agricultural 
producer, food manufacturer, or pesticide manufacturer. Potentially 
affected categories and entities may include, but are not limited to:

 
------------------------------------------------------------------------
                                                          Examples of
           Categories                 NAICS codes         potentially
                                                       affected entities
------------------------------------------------------------------------
Industry                          111                 Crop production
                                  112                 Animal production
                                  311                 Food manufacturing
                                  32532               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 the table could also be 
affected. The North American Industrial Classification System (NAICS) 
codes have been provided to assist you and others in determining 
whether or not this action might apply to certain entities. If you have 
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 Additional Information, Including Copies of this 
Document and Other Related Documents?

    1. Electronically. You may obtain electronic copies of this 
document, and certain other related documents that might be available 
electronically, from the EPA Internet Home Page at http://www.epa.gov/. 
To access this document, on the Home Page select ``Laws and 
Regulations,'' ``Regulations and Proposed Rules,'' and then look up the 
entry for this document under the `` Federal Register--Environmental 
Documents.'' You can also go directly to the Federal Register listings 
at http://www.epa.gov/fedrgstr/.
    2. In person. The Agency has established an official record for 
this action under docket control number OPP-301019. The official record 
consists of the documents specifically referenced in this action, and 
other information related to this action, including any information 
claimed as Confidential Business Information (CBI). This official 
record includes the documents that are physically located in the 
docket, as well as the documents

[[Page 47878]]

that are referenced in those documents. The public version of the 
official record does not include any information claimed as CBI. The 
public version of the official record, which includes printed, paper 
versions of any electronic comments submitted during an applicable 
comment period is available for inspection in the Public Information 
and Records Integrity Branch (PIRIB), Rm. 119, Crystal Mall #2 (CM#2), 
1921 Jefferson Davis Hwy., Arlington, VA, from 8:30 a.m. to 4 p.m., 
Monday through Friday, excluding legal holidays. The PIRIB telephone 
number is (703) 305-5805.

II. Background and Statutory Findings

    In the Federal Register of April 5, 2000 (65 FR 17872) (FRL-6550-
7), EPA issued a notice pursuant to section 408 of the FFDCA, 21 U.S.C. 
346a as amended by the FQPA (Public Law 104-170) announcing the filing 
of a pesticide petition (PP) for a tolerance by IR-4, 681 U.S. Highway 
#1 South, North Brunswick, NJ 08902-3390. This notice included a 
summary of the petition prepared by Uniroyal Chemical Company, the 
registrant.
    The petition requested that 40 CFR 180.377 be amended by 
establishing a tolerance for combined residues of the insecticide 
diflubenzuron, (N-[[4-chlorophenyl)amino]carbonyl]-2,6-
difluorobenzamide) and its metabolites, 4-chlorophenylurea (CPU) and 4-
chloroaniline (PCA), in or on rangeland grass at 6.0 parts per million 
(ppm).
    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).

III. 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 and to 
make a determination on aggregate exposure, consistent with section 
408(b)(2), for a tolerance for combined residues of diflubenzuron and 
its metabolites on rangeland grass at 6.0 ppm. EPA's assessment of the 
dietary exposures and risks associated with establishing the tolerance 
follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its 
validity, completeness, and reliability as well as the relationship of 
the results of the studies to human risk. EPA has also considered 
available information concerning the variability of the sensitivities 
of major identifiable subgroups of consumers, including infants and 
children. The nature of the toxic effects caused by diflubenzuron are 
discussed in Unit II.A. of the Final Rule on Diflubenzuron Pesticide 
Tolerance published in the Federal Register of April 19, 1999 (64 FR 
19050) (FRL-6075-4).

B. Toxicological Endpoints

    1. Acute toxicity. A toxicological endpoint for acute dietary 
exposure (1 day) was not established since 1 day single dose oral 
studies in rats and mice indicated only marginal effects on 
methemoglobin levels at a dose level of 10,000 milligrams/kilograms 
(mg/kg) of diflubenzuron.
    2. Short- and intermediate-term toxicity. The toxicological 
endpoint for short-term occupational or residential exposure (1 to 7 
days) is sulfhemoglobinemia observed in the 14-day subchronic oral 
study in mice dosed with technical grade diflubenzuron. The no observed 
adverse effect level (NOAEL) in this study was 40 mg/kg/day and the 
lowest observed adverse effect level (LOAEL) was 200 mg/kg/day.
    The toxicological endpoint for intermediate-term occupational or 
residential exposure (1 week to several months) is methemoglobinemia 
observed in the 13-week subchronic feeding study in dogs. For the 
purpose of risk assessments, the NOAEL of 1.64 mg/kg/day in this study 
was considered to be 2 mg/kg/day so as to be consistent with the NOAEL 
of 2 mg/kg/day in the chronic study used to calculate the Reference 
Dose (RfD). The LOAEL in this study was 6.24 mg/kg/day.
    Since an oral NOAEL was selected for a dermal endpoint, a dermal 
absorption factor of 0.5% was used for this risk assessment when 
converting dermal exposure to oral equivalents. Therefore, the dermal 
equivalent dose producing a NOAEL by the oral route is 400.0 mg/kg/day 
(i.e., 2.0 mg/kg/day divided by 0.005 = 400.0 mg/kg/day).
    3. Chronic toxicity. EPA has established the RfD for diflubenzuron 
at 0.02 mg/kg/day. This RfD is based on the NOAEL of 2.0 mg/kg/day in 
the 52-week chronic oral study in dogs. An uncertainty factor of 100 
(10X for interspecies extrapolation and 10X for intraspecies variation) 
was used to determine the chronic Reference Dose (cRfD) of 0.02 mg/kg/
day. The chronic Population Adjusted Dose (cPAD) is equal to the cRfD 
divided by the FQPA Safety Factor. Since the FQPA Safety Factor was 
reduced to 1X, the cPAD is equal to the cRfD.
    4. Carcinogenicity. Based on the available evidence, which included 
adequate carcinogenicity studies in rats and mice and a battery of 
negative mutagenicity studies, diflubenzuron per se has been classified 
as Group E (evidence of non-carcinogenicity for humans). However, p-
chloroaniline (PCA), a metabolite of diflubenzuron, is classified as a 
Group B2 carcinogen (probable human carcinogen). See Unit II. B. in the 
Final Rule on Diflubenzuron Pesticide Tolerance published in the 
Federal Register of April 19, 1999 (64 FR 19050).
    For the purpose of calculating dietary risk assessments from 
exposure through food to these metabolites of diflubenzuron, the 
following procedure was used:
    i. P-chlorophenylurea (CPU) and p-chloroacetanilide (PCAA), 
additional metabolites of diflubenzuron that are closely related to PCA 
and for which there are no adequate carcinogenicity data available, was 
considered to be potentially carcinogenic and to have the same 
carcinogenic potency (Q1*) as PCA.
    ii. The sum of PCA, CPU, and PCAA residues in ingested food was 
used to estimate the dietary exposure of humans to the carcinogenic 
metabolites of diflubenzuron in food.
    iii. In addition to ingested residues of these three metabolites, 
amounts of PCA, CPU, and/or PCAA formed in vivo following ingestion of 
diflubenzuron was also included when estimating the total exposure of 
humans to the

[[Page 47879]]

carcinogenic metabolites of diflubenzuron. The in vivo conversion of 
ingested diflubenzuron to PCA and/or CPU was estimated to be 2.0%, 
based on data in the rat metabolism study.
    The Q1* (estimated unit risk) for PCA, based upon spleen 
sarcoma rates in male rats, was calculated to be 6.38 x 10-2 
(mg/kg/day) in human equivalents. It has been determined that PCAA does 
not occur in animal or plant tissues in significant amounts.

C. Exposure Assessment

    1. From food and feed uses. Tolerances have been established (40 
CFR 180.377) for the combined residues of diflubenzuron and its 
metabolites, in or on rice grain, rice straw, citrus, artichokes, 
walnuts, mushrooms, cottonseed, soybeans, and associated livestock. For 
the dietary risk assessment, anticipated residue levels were calculated 
for livestock, citrus and mushroom commodities. Anticipated residue 
estimates for diflubenzuron were not calculated for other raw 
agricultural commodities. Percent crop treated (PCT) data were utilized 
where available.
    Risk assessments were conducted by EPA to assess dietary exposures 
in food from diflubenzuron and its metabolites as follows:
    Section 408(b)(2)(E) authorizes EPA to use available data and 
information on the anticipated residue levels of pesticide residues in 
food and the actual levels of pesticide chemicals that have been 
measured in food. If EPA relies on such information, EPA must require 
that data be provided 5 years after the tolerance is established, 
modified, or left in effect, demonstrating that the levels in food are 
not above the levels anticipated. Following the initial data 
submission, EPA is authorized to require similar data on a time frame 
it deems appropriate. As required by section 408(b)(2)(E), EPA will 
issue a Data Call-In for information relating to anticipated residues 
to be submitted no later than 5 years from the date of issuance of this 
tolerance.
    Section 408(b)(2)(F) states that the Agency may use data on the 
actual percent of food treated for assessing chronic dietary risk only 
if the Agency can make the following findings: Condition 1, that the 
data used are reliable and provide a valid basis to show what 
percentage of the food derived from such crop is likely to contain such 
pesticide residue; Condition 2, that the exposure estimate does not 
underestimate exposure for any significant subpopulation group; and 
Condition 3, if data are available on pesticide use and food 
consumption in a particular area, the exposure estimate does not 
understate exposure for the population in such area. In addition, the 
Agency must provide for periodic evaluation of any estimates used. To 
provide for the periodic evaluation of the estimate of PCT as required 
by section 408(b)(2)(F), EPA may require registrants to submit data on 
PCT.
    The Agency used PCT information to conduct a routine chronic 
dietary exposure analysis for diflubenzuron based on likely maximum PCT 
as follows: 1% rangeland grass, 3% cottonseed, 8% grapefruit, 3.1% 
mushrooms, 2% oranges, 4% tangerines, 1% soybean, and 5% cattle bolus. 
Other commodities were assumed to be 100% treated.
    The Agency believes that the three conditions listed above have 
been met. With respect to Condition 1, PCT estimates are derived from 
Federal and private market survey data, which are reliable and have a 
valid basis. EPA uses a weighted average PCT for chronic dietary 
exposure estimates. This weighted average PCT figure is derived by 
averaging State-level data for a period of up to 10 years, and 
weighting for the more robust and recent data. A weighted average of 
the PCT reasonably represents a person's dietary exposure over a 
lifetime, and is unlikely to underestimate exposure to an individual 
because of the fact that pesticide use patterns (both regionally and 
nationally) tend to change continuously over time, such that an 
individual is unlikely to be exposed to more than the average PCT over 
a lifetime. The Agency is reasonably certain that the percentage of the 
food treated is not likely to be underestimated. As to Conditions 2 and 
3, regional consumption information and consumption information for 
significant subpopulations is taken into account through EPA's 
computer-based model for evaluating the exposure of significant 
subpopulations including several regional groups. Use of this 
consumption information in EPA's risk assessment process ensures that 
EPA's exposure estimate does not understate exposure for any 
significant subpopulation group and allows the Agency to be reasonably 
certain that no regional population is exposed to residue levels higher 
than those estimated by the Agency. Other than the data available 
through national food consumption surveys, EPA does not have available 
information on the regional consumption of food to which diflubenzuron 
and its metabolites may be applied in a particular area.
    i. Acute exposure. A risk assessment for acute dietary exposure (1 
day) was not conducted. One day single dose oral studies in rats and 
mice indicated only marginal effects on methemoglobin levels at a dose 
level of 10,000 mg/kg of diflubenzuron.
    ii. Chronic exposure. The RfD used for the chronic dietary analysis 
for diflubenzuron is 0.02 mg/kg bwt/day. The chronic Dietary Exposure 
Evaluation Model (DEEM) analysis used mean estimates of consumption (3-
day average). Anticipated residues and PCT information for select 
commodities were used. Since EPA determined to reduce the 10X FQPA 
Safety factor to 1X, the cPAD and the cRfD are the same. The results of 
the analyses indicate that the chronic dietary risks from food 
associated with the existing and proposed uses of diflubenzuron and its 
metabolites do not exceed EPA's level of concern for the U.S. 
population or any population subgroup.
    Cancer risk from consumption of PCA and related metabolites. The 
Agency has determined that there are three possible sources for dietary 
exposure to PCA and related compounds (CPU and PCAA) from food: 
residues in plants/fungi (mushrooms), residues in animal commodities 
(milk and liver) and in vivo conversion of diflubenzuron.
    2. From drinking water. The Agency uses the Generic Estimated 
Environmental Concentration (GENEEC) or the Pesticide Root Zone/
Exposure Analysis Modeling System (PRZM/EXAMS) to estimate pesticide 
concentrations in surface water and SCI-GROW, which predicts pesticide 
concentrations in ground water. In general, EPA will use GENEEC (a tier 
1 model) before using PRZM/EXAMS (a tier 2 model) for a screening-level 
assessment for surface water. The GENEEC model is a subset of the PRZM/
EXAMS model that uses a specific high-end runoff scenario for 
pesticides. GENEEC incorporates a farm pond scenario, while PRZM/EXAMS 
incorporate an index reservoir environment in place of the previous 
pond scenario. The PRZM/EXAMS model includes 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 coarse screen for sorting out pesticides for 
which it is highly unlikely that drinking water concentrations would 
ever exceed human health levels of concern.

[[Page 47880]]

    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 (DWLOC) 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.
    To calculate the DWLOC for chronic (non-cancer) exposure relative 
to a chronic toxicity endpoint, the chronic dietary food exposure (from 
DEEM) was subtracted from the RfD to obtain the acceptable chronic 
(non-cancer) exposure to diflubenzuron in drinking water. To calculate 
the DWLOC for chronic exposures relative to a carcinogenic toxicity 
endpoint, the chronic (cancer) dietary food exposure was subtracted 
from the ratio of the negligible cancer risk to the Q* to obtain the 
maximum allowable chronic exposure to diflubenzuron in drinking water. 
DWLOCs were then calculated using default body weights and drinking 
water consumption figures.
    EPA has calculated DWLOCs for chronic (non-cancer) dietary exposure 
to diflubenzuron in surface and ground water for the U.S. population 
and children (1-6 yrs). They are 700 and 200 parts per billion (ppb), 
respectively. For chronic (cancer) exposure to CPU in surface and 
ground water, the DWLOC is 0.30 ppb for the U.S. population.
    Tier II PRZM-EXAM modeling using the index reservoir (IR) scenario 
and the percent crop area adjustment factor for the use of 
diflubenzuron on cotton and citrus was modeled. The concentration of 
diflubenzuron in drinking water in a Mississippi cotton index reservoir 
scenario adjusted for a percent crop area factor of 0.49 is not 
expected to exceed 1.66 g/L for the 1 in 10-year annual peak 
(acute) concentration, 0.12 g/L for the 1 in 10-year annual 
mean (chronic) concentration, and 0.06 g/L for the 36-year 
average concentration. The concentration of CPU in drinking water from 
the same application on cotton is not expected to exceed 0.23 
g/L for the 36-year average concentration.
    Based on the PRZM-EXAMS and SCI-GROW models, the EECs of 
diflubenzuron for chronic exposure are estimated to be 0.06 ppb for 
surface water and 0.0023 ppb for ground water.
    3. From non-dietary exposure. Diflubenzuron is a restricted use 
pesticide and therefore not available for use by homeowners. However, 
non-agricultural uses of diflubenzuron may expose people in residential 
locations. Based on the low dermal absorption rate (0.5%), and the 
extremely low dermal and inhalation toxicity, exposure through these 
uses is expected to be insignificant.
    4. Cumulative exposure to substances with a 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 diflubenzuron 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, 
diflubenzuron 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 diflubenzuron 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. There is no risk from acute dietary exposure (1 day) 
to diflubenzuron as there is no toxic endpoint identified.
    2. Chronic risk. Using the exposure assumptions described in this 
unit for chronic exposure, EPA has concluded that exposure to 
diflubenzuron from food will utilize 1% of the cPAD for the U.S. 
population, for infants 1 year old, and children 1-6 years old. There 
are no residential uses for diflubenzuron that result in chronic 
residential exposure. In addition, despite the potential for chronic 
dietary exposure to diflubenzuron in drinking water, after calculating 
the DWLOCs and comparing them to conservative model EECs of 
diflubenzuron in surface water 0.06 ppb and ground water 0.0023 ppb. 
EPA does not expect the aggregate exposure to exceed 100% of the cPAD.
    3. Aggregate cancer risk for U.S. population. For the U.S. 
population, cancer risk resulting from food exposure is 4.5 x 
10-7. The estimated 36-year average concentration (0.23 ppb) 
of CPU in surface water does not exceed EPA's level of concern (DWLOC) 
for CPU in drinking water (0.30 ppb) as a contribution to chronic 
(cancer) aggregate exposure. EPA has calculated that the cancer risk 
resulting from 0.23 ppb of CPU in drinking water is 4.2 x 
10-7. The aggregate cancer risk is thus 8.7 x 
10-7 (4.5 x 10-7 for food + 4.2 x 10-7 
for water).
    4. 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 residues of diflubenzuron and its 
metabolites.

E. Aggregate Risks and Determination of Safety for Infants and Children

    1. Safety factor for infants and children in general. In assessing 
the potential for additional sensitivity of infants and children to 
residues of diflubenzuron and its metabolites, 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 prenatal 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 appreciable risk to humans. EPA believes that reliable data 
support using the standard uncertainty factor (usually 100 for combined 
interspecies and intraspecies 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.

[[Page 47881]]

    2. Developmental toxicity studies --i. Rats. In the developmental 
study in rats, the maternal (systemic) NOAEL was 1,000.0 mg/kg/day 
highest dose tested (HDT). The developmental (fetal) NOAEL was 1,000.0 
mg/kg/day, (HDT).
    ii. Rabbits. In the developmental toxicity study in rabbits, the 
maternal (systemic) NOAEL was 1,000.0 mg/kg/day, HDT. The developmental 
(pup) NOAEL was 1,000.0 mg/kg/day, HDT.
    iii. Reproductive toxicity study. In the 2-generation reproductive 
toxicity study in rats, the maternal (systemic) NOAEL was  36 and  42 
mg/kg/day male and female, respectively. Lowest dose tested (LDT) based 
on hematological effects at all dose levels tested. The reproductive 
(pup) NOAEL was 427.0 mg/kg/day, based on decreases in the F-1 pup 
weight at the LOAEL of 2,454.0 mg/kg/day HDT.
    iv. Conclusion. The toxicological data base for evaluating prenatal 
and postnatal toxicity for diflubenzuron is complete with respect to 
current data requirements. Based on the developmental and reproductive 
toxicity studies discussed above, there does not appear to be increased 
sensitivity to diflubenzuron for prenatal or postnatal effects. Based 
on the above, EPA concludes that reliable data support use of a 100-
fold margin of exposure/uncertainty factor, rather than the 1,000-fold 
margin/factor, to protect infants and children.
    3. Acute risk. There is no risk from acute dietary exposure (1 day) 
to diflubenzuron as there is no toxicological endpoint identified which 
could be attributable to a single dietary exposure. Therefore, a risk 
assessment for this exposure scenario was not conducted.
    4. Chronic risk. Using the exposure assumptions described in this 
unit, EPA has concluded that aggregate exposure to diflubenzuron from 
food will utilize  1 % of the RfD for infants and children. 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 diflubenzuron in drinking 
water and from non-dietary, non-occupational exposure, EPA does not 
expect the aggregate exposure to exceed 100% of the RfD.
    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 diflubenzuron 
residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    Adequate methods are available for the analysis of diflubenzuron 
and its metabolites in rice grain (0.01 ppm), rice straw (0.01 ppm) and 
water (0.001 ppm). Three enforcement methods for diflubenzuron are 
published in PAM, Vol. II as Methods I, II, and III. Method II is a GC/
ECD method that can separately determine residues of diflubenzuron, 
CPU, and PCA in eggs, milk, and animal tissues. All three methods have 
undergone successful Agency validations and are acceptable for 
enforcement purposes.

B. International Residue Limits

    There are no Codex proposals, Canadian, or Mexican limits for 
residues of diflubenzuron on rangeland grass. A compatibility issue is 
not relevant to the tolerance.

V. Conclusion

    Therefore, the tolerance is established for combined residues of 
diflubenzuron and its metabolites, in or on rangeland grass at 6.0 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 of 1996, EPA will continue to use those 
procedures, with appropriate adjustments, until the necessary 
modifications can be made. The new section 408(g) 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), as was provided in the old FFDCA sections 408 and 409. 
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 control number OPP-301019 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 October 
3, 2000.
    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 (1900), 
Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460. You may also deliver your request to the Office 
of the Hearing Clerk in Rm. C400, Waterside Mall, 401 M St., SW., 
Washington, DC 20460. The Office of the Hearing Clerk is open from 8 
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The 
telephone number for the Office of the Hearing Clerk is (202) 260-4865.
    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 [email protected], 
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.
    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

[[Page 47882]]

Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania 
Ave., NW., Washington, DC 20460.
    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.2. Mail your 
copies, identified by docket control number OPP-301019, 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. 
In person or by courier, bring a copy to the location of the PIRIB 
described in Unit I.B.2. You may also send an electronic copy of your 
request via e-mail to: [email protected]. 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 file format 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. Regulatory Assessment Requirements

    This final rule establishes a tolerance under FFDCA section 408(d) 
in response to a petition submitted to the Agency. The Office of 
Management and Budget (OMB) has exempted these types of actions from 
review under Executive Order 12866, entitled Regulatory Planning and 
Review (58 FR 51735, October 4, 1993). This final rule does not contain 
any information collections subject to OMB approval under the Paperwork 
Reduction Act (PRA), 44 U.S.C. 3501 et seq., or impose any enforceable 
duty or contain any unfunded mandate as described under Title II of the 
Unfunded Mandates Reform Act of 1995 (UMRA) (Public Law 104-4). Nor 
does it require any prior consultation as specified by Executive Order 
13084, entitled Consultation and Coordination with Indian Tribal 
Governments (63 FR 27655, May 19, 1998); 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 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 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. 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 FFDCA section 408(n)(4).

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 to the Comptroller General of the 
United States. EPA will submit a report containing this rule and other 
required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of this final rule in the Federal Register. This final 
rule is not a ``major rule'' as defined by 5 U.S.C. 804(2).

List of Subjects in 40 CFR Part 180

    Environmental protection, Administrative practice and procedure, 
Agricultural commodities, Pesticides and pests, Reporting and 
recordkeeping requirements.

    Dated: July 17, 2000
James Jones,
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. Section 180.377 is amended by revising paragraph (a)(2), and in 
the table in paragraph (c) removing the entry for ``Grass, range''.


Sec. 180.377  Diflubenzuron; tolerances for residues.

    (a) * * *
    (2) Tolerances are established for the combined residues of the 
insecticide diflubenzuron (N-[[(4-chlorophenyl)amino]carbonyl]-2,6-
difluorobenzamide) and its metabolites 4-chlorophenylurea and 4-
chloroaniline in or on the following food commodities:

 
------------------------------------------------------------------------
                 Commodity                       Parts per  million
------------------------------------------------------------------------
Grass, rangeland..........................  6.0
------------------------------------------------------------------------

* * * * *
[FR Doc. 00-19794 Filed 8-3-00; 8:45 am]
BILLING CODE 6560-50-F