[Federal Register Volume 64, Number 146 (Friday, July 30, 1999)]
[Rules and Regulations]
[Pages 41297-41305]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-19591]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-300881; FRL 6087-2]
RIN 2070-AB78


Diuron; Pesticide Tolerances for Emergency Exemptions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes a time-limited tolerance for 
combined residues of diuron in or on catfish. This action is in 
response to EPA's granting of an emergency exemption under section 18 
of the Federal Insecticide, Fungicide, and Rodenticide Act authorizing 
use of the pesticide in catfish ponds. This regulation establishes a 
maximum permissible level for residues of diuron in this food commodity 
pursuant to section 408(l)(6) of the Federal Food, Drug, and Cosmetic 
Act, as amended by the Food Quality Protection Act of 1996. The 
tolerance will expire and is revoked on June 30, 2001.

DATES: This regulation is effective July 30, 1999. Objections and 
requests for hearings must be received by EPA on or before September 
28, 1999.

ADDRESSES: Written objections and hearing requests, identified by the 
docket control number [OPP-300881], 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-300881], 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 also be submitted electronically by sending electronic mail 
(e-mail) to: [email protected]. Copies of electronic 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 
or ASCII file format. All copies of electronic objections and hearing 
requests must be identified by the docket control number [OPP-300881]. 
No Confidential Business Information (CBI) should be submitted through 
e-mail. Copies of electronic objections and hearing requests on this 
rule may be filed online at many Federal Depository Libraries.

FOR FURTHER INFORMATION CONTACT: By mail: David Deegan, 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. 286, Crystal Mall 
#2, 1921 Jefferson Davis Hwy., Arlington, VA, 703-308-9358; e-mail: 
[email protected].

SUPPLEMENTARY INFORMATION: EPA, on its own initiative, pursuant to 
sections 408(l)(6) of the Federal Food, Drug, and Cosmetic Act (FFDCA), 
21 U.S.C. 346a, is establishing a tolerance for combined residues of 
the herbicide diuron and its metabolites, convertible to 3,4-
dichloroaniline in or on catfish at 2.0 parts per million (ppm). This 
tolerance will expire and is revoked on June 30, 2001. EPA will publish 
a document in the Federal Register to remove the revoked tolerance from 
the Code of Federal Regulations.

I. Background and Statutory Findings

    The Food Quality Protection Act of 1996 (FQPA)(Public Law 104-170) 
was signed into law August 3, 1996. FQPA amends both the Federal Food, 
Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 301 et seq., and the Federal 
Insecticide, Fungicide, and Rodenticide Act (FIFRA), 7 U.S.C. 136 et 
seq. The FQPA amendments went into effect immediately. Among other 
things, FQPA amends FFDCA to bring all EPA pesticide tolerance-setting 
activities under a new section 408 with a new safety standard and new 
procedures. These activities are described in this preamble and 
discussed in greater detail in the final rule establishing the time-
limited tolerance associated with the emergency exemption for use of 
propiconazole on sorghum (61 FR 58135, November 13, 1996) (FRL-5572-9).
    New section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a 
tolerance (the legal limit for a pesticide chemical residue in or on a 
food) only if EPA determines that the tolerance is ``safe.'' Section 
408(b)(2)(A)(ii) 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. . . .''
    Section 18 of FIFRA authorizes EPA to exempt any Federal or State 
agency from any provision of FIFRA, if EPA determines that ``emergency 
conditions exist which require such exemption.'' This provision was not 
amended by FQPA. EPA has established regulations governing such 
emergency exemptions in 40 CFR part 166.
    Section 408(l)(6) of the FFDCA requires EPA to establish a time-
limited tolerance or exemption from the requirement for a tolerance for 
pesticide chemical residues in food that will result from the use of a 
pesticide under an emergency exemption granted by EPA under section 18 
of FIFRA. Such tolerances can be established without providing notice 
or period for public comment.

[[Page 41298]]

    Because decisions on section 18-related tolerances must proceed 
before EPA reaches closure on several policy issues relating to 
interpretation and implementation of the FQPA, EPA does not intend for 
its actions on such tolerances to set binding precedents for the 
application of section 408 and the new safety standard to other 
tolerances and exemptions.

II. Emergency Exemption for Diuron on Catfish and FFDCA Tolerances

    EPA has authorized, under FIFRA section 18, the use of diuron in 
and on catfish ponds for control of algae in Mississippi, Louisiana, 
and Arkansas. After having reviewed the submissions, EPA concurs that 
emergency conditions exist in these States. The three applicants 
requested use of diuron in catfish ponds to control unwanted growth of 
blue-green algae. The rapid spread of the blue-green algae makes it a 
secondary food source--albeit undesirable--for the catfish. If algae is 
present in the ponds, the catfish consume large quantities of it, 
resulting in an undesirable flavor in the catfish fillet, when the fish 
are harvested and eaten. Fish with this off flavor are less marketable 
for producers.
    As part of its assessment of this emergency exemption, EPA assessed 
the potential risks presented by residues of diuron in or on catfish. 
In doing so, EPA considered the safety standard in FFDCA section 
408(b)(2), and EPA decided that the necessary tolerance under FFDCA 
section 408(l)(6) would be consistent with the safety standard and with 
FIFRA section 18. Consistent with the need to move quickly on the 
emergency exemption in order to address an urgent non-routine situation 
and to ensure that the resulting food is safe and lawful, EPA is 
issuing this tolerance without notice and opportunity for public 
comment under section 408(e), as provided in section 408(l)(6). 
Although this tolerance will expire and is revoked on June 30, 2001, 
under FFDCA section 408(l)(5), residues of the pesticide not in excess 
of the amounts specified in the tolerance remaining in or on catfish 
after that date will not be unlawful, provided the pesticide is applied 
in a manner that was lawful under FIFRA, and the residues do not exceed 
a level that was authorized by this tolerance at the time of that 
application. EPA will take action to revoke this tolerance earlier if 
any experience with, scientific data on, or other relevant information 
on this pesticide indicate that the residues are not safe.
    Because this tolerance is being approved under emergency 
conditions, EPA has not made any decisions about whether diuron meets 
EPA's registration requirements for use on catfish or whether a 
permanent tolerance for this use would be appropriate. Under these 
circumstances, EPA does not believe that this tolerance serves as a 
basis for registration of diuron by a State for special local needs 
under FIFRA section 24(c). Nor does this tolerance serve as the basis 
for any State other than Mississippi, Louisiana, and Arkansas to use 
this pesticide on this crop under section 18 of FIFRA without following 
all provisions of EPA's regulations implementing section 18 as 
identified in 40 CFR part 166. For additional information regarding the 
emergency exemption for diuron, contact the Agency's Registration 
Division at the address provided under the ``ADDRESSES'' section.

III. Aggregate Risk Assessment and Determination of Safety

    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).
    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 diuron 
and to make a determination on aggregate exposure, consistent with 
section 408(b)(2), for a time-limited tolerance for combined residues 
of diuron on catfish at 2.0 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 diuron are 
discussed in this unit.

B. Toxicological Endpoint

    1. Acute toxicity. Acute reference dose (RfD) 0.16 milligram/
kilogram/day (mg/kg/day). For acute dietary risk assessment, EPA has 
identified the no observed adverse effect level (NOAEL) of 16.0 mg/kg/
day, based on decreased body weight (beginning at gestation day 9) and 
food consumption (during gestation days 6-10) at the lowest observed 
adverse effect level (LOAEL) of 80 mg/kg/day, from the developmental 
study in the rat. EPA's risk assessment has evaluated acute dietary 
risk to all population subgroups.
    2. Chronic toxicity. EPA has established the RfD for diuron at 
0.003 mg/kg/day. This RfD is based on a 2-year chronic feeding/
oncogenicity study in the rat with a LOAEL of 1.02 mg/kg/day and an 
uncertainty factor (UF) of 300 (additional UF of 3 for the use of a 
LOAEL) based on decreased erythrocyte count in females, increased 
hemosiderin in the spleen, increased spleen weight, bone marrow 
activation, increased hematopoietic marrow, decreased fat marrow (% 
surface area of fat marrow in bone marrow) and thickened urinary 
bladder wall in males.
    3. Carcinogenicity. Diuron has been classified as a ``known/
likely'' human carcinogen by all routes, based on urinary bladder 
carcinomas in both sexes of the Wistar rat, kidney carcinomas in the 
male rat (a rare tumor), and mammary gland carcinomas in the female 
NMRI mouse. A Q1*(mg/kg/day)-1 of 1.91 x 
10-2 in human equivalents has been calculated based on the 
male rat urinary bladder carcinomas.

C. Exposures and Risks

    1. From food and feed uses. Tolerances have been established (40 
CFR 180.106) for the combined residues of diuron (3-(3,4-
dichlorophenyl)-1,1-dimethylurea), in or on a variety of raw 
agricultural commodities at levels ranging from 0.1 ppm in nuts and 
peaches to 7 ppm in bermuda grass. The residues of concern for diuron 
in plant commodities are the parent compound and all metabolites 
convertible to 3,4-dichloroaniline (DCA). Although the Code of Federal 
Regulations (CFR) only mentions diuron in the tolerance expression, the 
analytical methods determine all metabolites convertible to 3,4-
dichloroaniline. The parent compound usually comprises only a small 
portion of the total residue or of the DCA-containing residues. For 
both the acute and chronic dietary risk assessments it was assumed that 
total residues of the closely related herbicides, linuron and propanil 
will contribute to the toxicological effects of concern (with the acute 
dietary analysis, there were two exceptions: residues of linuron on 
potatoes and soybeans where metabolism studies were examined to 
determine which metabolites are common to those from diuron). It was

[[Page 41299]]

also assumed that the tolerances for linuron and propanil represent 
total residues convertible to 3,4-dichloroaniline, although petition 
files and residue data were not examined for linuron to confirm this. 
The propanil residue studies which were reviewed for chronic 
anticipated residues did involve determination of total base-released 
3,4-dichloroaniline. Risk assessments were conducted by EPA to assess 
dietary exposures and risks from diuron as follows:
    i. Acute exposure and risk. Acute dietary risk assessments are 
performed for a food-use pesticide if a toxicological study has 
indicated the possibility of an effect of concern occurring as a result 
of a 1-day or single exposure. For this risk assessment of the section 
18 requests to use diuron, EPA has identified an acute RfD of 0.16 mg/
kg/day. In conducting this acute dietary risk analysis, EPA used 
partially refined, i.e., percent crop treated data. In those cases 
where data indicated <1% crop treated, a value of 1% was used for the 
analysis. For those crops where information was not available to EPA, a 
default value of 100% crop treated was used for this risk assessment, 
EPA assumed that 100% of catfish would contain residues of diuron. At 
the time the anticipated residues (ARs) were developed for the acute 
dietary risk assessment, percent crop treated data were not available 
for linuron and propanil; therefore, it was assumed that 100% of the 
crop was treated for commodities having tolerances for those 
herbicides. The Novigen DEEM (Dietary Exposure Evaluation Model) system 
was used for the acute dietary exposure analysis, utilizing mixtures of 
tolerances/anticipated residues and percent crop treated data for 
diuron, linuron and propanil. With respect to fruit juices, the default 
concentration factors in the DEEM run were used except for grape juice 
and pineapple juice.
    The population subgroup with the highest acute dietary exposure 
(food only) is non-nursing infants. With a high-end anticipated residue 
contribution (ARC) exposure estimate of 0.03810 mg/kg/day, it was 
estimated that only 24% of the acute RfD population adjusted dose (PAD) 
would be utilized for this population subgroup. This acute dietary risk 
estimate (food only) should be viewed as a partially refined risk 
estimate (the diuron assessment was highly refined); further refinement 
using additional anticipated residue values and percent crop treated 
data for linuron and propanil in conjunction with another Monte Carlo 
analysis would result in a lower acute dietary exposure estimate. To 
arrive at this conclusion, EPA determined that for this tolerance 
action only, the FQPA Safety Factor be removed (1x) in assessing the 
risk posed by diuron (see aggregate risk section for infants and 
children). Therefore, the acute RfD is identical to the acute PAD.
    ii. Chronic exposure and risk. For this risk assessment, EPA has 
identified a chronic RfD of 0.003 mg/kg/day. For this risk assessment, 
EPA has utilized the Novigen DEEM system for the chronic dietary 
exposure analysis. In conducting the chronic dietary risk analysis, EPA 
used highly refined data. As stated previously, EPA included percent 
crop treated data for diuron (see acute risk section, above). Percent 
crop treated data for linuron uses were taken from the dietary risk 
evaluation system (DRES) run conducted in 1995 and propanil uses (1995-
98) were also utilized by EPA in this risk assessment. For those crops 
where EPA did not have information, a default value of 100% crop 
treated was used. Anticipated residues of diuron have been developed 
previously for numerous commodities. These anticipated residues were 
used with the following additions: 0.03 ppm for alfalfa sprouts (1% 
crop treated) and 0.92 ppm for fish-finfish/freshwater (76% crop 
treated). For the purposes of the present section 18 use, an updated 
analysis of linuron residues in food was not conducted; therefore, the 
most recent percent crop treated data for linuron (1995-97) was not 
used. Chronic exposures from linuron for various populations were taken 
from the DRES analysis conducted in 1995 in support of the increase in 
the asparagus tolerance. That analysis used anticipated residues (mean 
field trial values) and percent crop treated available at that time for 
numerous crops. For propanil, the chronic anticipated residues and 
percent crop treated have also been calculated by EPA. The chronic 
dietary risk analysis includes monitoring data for residues in drinking 
water. Therefore, in this document EPA summarizes risk of exposure for 
both food and water in the aggregate risk section.
    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 crop treated (PCT) for assessing chronic dietary risk 
only if the Agency can make the following findings: 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; that the exposure estimate does not underestimate exposure for 
any significant subpopulation group; and 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 the section 408(b)(2)(F), EPA may require 
registrants to submit data on PCT.
    The Agency used PCT information as follows:
     As detailed above, in conducting both the acute and chronic 
dietary risk analyses, EPA used PCT data. In order to conduct such a 
refined analysis, EPA utilized the Novigen DEEM system for the dietary 
exposure analysis, with which EPA calculated mixtures of tolerances/
anticipated residues and percent crop treated data for diuron, linuron 
uses taken from the DRES run conducted in 1995, and propanil uses 
(1995-98). With respect to fruit juices, the default concentration 
factors in the DEEM run were used except for grape juice and pineapple 
juice. Processing studies indicated that residues did not concentrate 
in the latter two juices. In those cases where data indicated <1% crop 
treated, a value of 1% was used for the analysis. For those crops where 
information was not available to EPA, a default value of 100% crop 
treated was used. At the time the anticipated residues were developed 
for the acute dietary risk assessment, percent crop treated data were 
not available for linuron and propanil; therefore, it was assumed that 
100% of the crop was treated for commodities having tolerances for 
those herbicides.
    Anticipated residues of diuron have been developed previously for 
numerous commodities. These anticipated residues were used with the 
following additions: 0.03 ppm for alfalfa sprouts (1% crop treated) and 
0.92 ppm for fish-finfish/freshwater (76% crop

[[Page 41300]]

treated). For the purposes of the present action, an updated analysis 
of linuron residues in food was not conducted; therefore, the most 
recent percent crop treated data for linuron (1995-97) was not used. 
Chronic exposures from linuron for various populations were taken from 
EPA's Dietary Risk Evaluation System (DRES) analysis conducted in 1995 
in support of the increase in the asparagus tolerance. That analysis 
used anticipated residues (mean field trial values) and percent crop 
treated available at that time for numerous crops. For propanil, the 
chronic anticipated residues and percent crop treated have also been 
calculated by EPA. The chronic dietary risk analysis includes 
monitoring data for residues in drinking water.
    The Agency believes that the three conditions, discussed in section 
408(2)(F) in this unit concerning the Agency's responsibilities in 
assessing chronic dietary risk findings, have been met. The PCT 
estimates are derived from Federal and private market survey data, 
which are reliable and have a valid basis. Typically, a range of 
estimates are supplied and the upper end of this range is assumed for 
the exposure assessment. By using this upper end estimate of the PCT, 
the Agency is reasonably certain that the percentage of the food 
treated is not likely to be underestimated. The 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 diuron may be applied in a particular area.
    2. From drinking water. EPA conducted an analysis of the 
contribution of residues of diuron from drinking water based upon 
monitoring data for water with emphasis on the US Geological Survey 
(USGS) National Water Quality Assessment Program (NAWQA) surface water 
sampling in central California. The NAWQA program analyzed 3,417 
samples of surface water for diuron throughout the United States. 
Approximately 13% of the samples (429) contained detectable diuron 
residues (only parent compound analyzed) ranging from 0.001 to 14 parts 
per billion (ppb). The average value for the detectable samples was 0.8 
ppb. The 95th percentile value for the surface water samples was 0.2 
ppb. For ground water there were 2,726 samples analyzed and about 2% 
(51) contained diuron residues with values ranging from 0.002 to 2 ppb.
    However, EPA's analysis has concluded that the above data may 
underestimate or under represent concentrations of diuron to be 
expected in surface water, due to low recovery rates and incomplete 
sampling in some areas. Furthermore, estimates for diuron degradates in 
drinking water could not be provided due to the small amount of data 
and the data not being representative of drinking water. In light of 
these factors, EPA has concluded that the highest value of 14 ppb of 
all surface water samples having detectable residues should be used for 
acute risk assessment and that the average value of 0.8 ppb of all the 
surface water samples having detectable residues should be used for 
chronic risk assessment. By using these upper end values of diuron 
parent in surface water as the estimates, at least some compensation 
can be made for the poor recoveries of the analytical method and the 
lack of sufficient data to predict levels of diuron degradates, many of 
which are likely to be formed by linuron and propanil as well. For the 
acute dietary aggregate risk analysis, 14 ppb was used as a value for 
comparison in calculating a drinking water level of comparison (DWLOC). 
When the acute DEEM run was conducted, it was determined at that point 
that the percentage of the acute RfD (PAD) taken up by residue exposure 
in food only was sufficiently low such that a DWLOC could be calculated 
in lieu of conducting a probabilistic analysis with inclusion of water. 
However, for the chronic dietary aggregate risk analysis, 0.8 ppb was 
incorporated into the DEEM assessment as a value taken from monitoring 
data.
    The above risk assessment is sufficient for the purposes of the 
related section 18 emergency exemption authorized by the Agency. 
However, EPA expects that for it to take action on a registration and 
establishment of a permanent tolerance for the catfish pond use, a more 
thorough analysis would be undertaken to determine which degradates of 
diuron, linuron and propanil would be included in drinking water 
residue estimates.
    3. From non-dietary exposure. Diuron is currently not registered 
for use on any residential sites.
    4. Cumulative exposure to substances with a common mechanism of 
toxicity. Diuron is a member of the phenylurea class of pesticides. 
Other members of this class include fluometuron, fenuron-TCA, linuron, 
siduron and tebuthiuron. 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.''
    The Agency believes that ``available information'' in this context 
might include not only toxicity, chemistry, and exposure data, but also 
scientific policies and methodologies for understanding common 
mechanisms of toxicity and conducting cumulative risk assessments. For 
most pesticides, although the Agency has some information in its files 
that may turn out to be helpful in eventually determining whether a 
pesticide shares a common mechanism of toxicity with any other 
substances, EPA does not at this time have the methodologies to resolve 
the complex scientific issues concerning common mechanism of toxicity 
in a meaningful way. EPA has begun a pilot process to study this issue 
further through the examination of particular classes of pesticides. 
The Agency hopes that the results of this pilot process will increase 
the Agency's scientific understanding of this question such that EPA 
will be able to develop and apply scientific principles for better 
determining which chemicals have a common mechanism of toxicity and 
evaluating the cumulative effects of such chemicals. The Agency 
anticipates, however, that even as its understanding of the science of 
common mechanisms increases, decisions on specific classes of chemicals 
will be heavily dependent on chemical-specific data, much of which may 
not be presently available.
    Although at present the Agency does not know how to apply the 
information in its files concerning common mechanism issues to most 
risk assessments, there are pesticides as to which the common mechanism 
issues can be resolved. These pesticides include those that are 
toxicologically dissimilar to existing chemical substances (in which 
case the Agency can conclude that it is unlikely that a pesticide 
shares a common mechanism of activity with other substances) and 
pesticides that produce a common toxic metabolite (in which case common 
mechanism of activity will be assumed).

[[Page 41301]]

    Diuron shares a common metabolite with linuron and propanil. The 
non-cancer dietary risk assessments take this into consideration. For 
the purposes of this section 18, residues from linuron and propanil 
were not taken into consideration for the carcinogenicity risk 
assessment because the target organs (i.e., the tumors) for diuron 
versus linuron and propanil are of different origins and because 
metabolism and mechanistic data indicate that the mechanism of action 
for tumor induction are different for diuron when compared to linuron 
and propanil.
    The residues of concern for diuron are the parent compound and all 
metabolites convertible to 3,4-dichloroaniline (DCA). There are two 
closely related herbicides which are also metabolized to DCA and/or 
other residues convertible to DCA (linuron and propanil). Therefore, it 
was assumed that residues from the use of these two pesticides will 
contribute to the toxicological effects of concern for the dietary risk 
analyses (for further explantion, see exposure discussion in section 
III. C. below). The toxicological data bases for these two pesticides 
were examined to see if there are similar target organs. For the acute 
dietary risk analysis, the toxicological endpoint, decreased bodyweight 
and food consumption, is not specific enough for comparison. 
Nevertheless, it was still assumed that residues from all three 
herbicides will contribute to the same acute effects. For chronic 
exposure, these three pesticides share a similar toxicological 
endpoint: hematological effects, particularly methemoglobinemia. These 
effects were observed in chronic feeding studies, in either the rat, 
dog or mouse. The target organs for carcinogenicity may be similar for 
linuron and propanil, but not for diuron. Diuron induces urinary 
bladder carcinomas in rats (both sexes) and mammary gland carcinomas in 
female mice. In addition, an increase in the incidence of a rare kidney 
tumor was observed in male rats. Linuron induces testicular 
interstitial cell adenomas in rats and hepatocellular adenomas in mice. 
Available mechanistic and metabolism data indicate that linuron and 
diuron may be inducing tumors through different mechanisms of action. 
Propanil has not been reviewed by the Office of Pesticide Programs 
Cancer Assessment Review Committee (CARC). However, two new studies 
have been received which indicate that it may induce malignant 
lymphomas of the spleen in female mice, testicular interstitial cell 
tumors in male rats and hepatocellular adenomas in female rats, the 
latter at a dose level which probably exceeds the maximum tolerated 
dose. Therefore, since the target organs for tumor induction for diuron 
are different than those for linuron and propanil, and data are 
available which indicate that the mechanism of action may be different 
for diuron, for the purpose of this tolerance action, the estimated 
dietary carcinogenic risk will not include residues from linuron and 
propanil. However, for any future permanent tolerance requests, a 
detailed analysis of any potential contribution of residues from 
linuron and propanil to the dietary carcinogenic risk will be 
conducted, including examination of available toxicological and 
mechanistic data.
    EPA does not have, at this time, available data to determine 
whether diuron has a common mechanism of toxicity with any other 
substances or how to include this pesticide in a cumulative risk 
assessment. For the purposes of this tolerance action, therefore, EPA 
has not assumed that diuron has a common mechanism of toxicity with 
substances other than linuron and propanil. For more 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. The acute dietary risk analysis estimated that the 
acute dietary exposure (food only) for the U.S. Population will utilize 
17% of the acute RfD, which, because there is no FQPA 10x Safety Factor 
added to this risk assessment, is identical to the acute population 
adjusted dose (PAD). All other adult population subgroups have acute 
risk estimates (food only) below that of the U.S. population. As stated 
previously, the acute dietary risk analysis used partially refined ARC 
exposure estimates and percent crop treated values. The analysis 
included total residues convertible to the diuron metabolite, DCA from 
food. Residue contributions from diuron, linuron and propanil uses were 
taken into account. For DCA-convertible residues from diuron, linuron 
and propanil, it was determined that an acute dietary exposure (food 
plus water) of 100% or less of the acute RfD (PAD) is acceptable to 
protect the safety of all population subgroups. The estimated exposures 
at the 99.9th percentile for all population subgroups utilize less than 
100% of the acute RfD (PAD).
    Monitoring data were available for drinking water for the acute 
aggregate risk estimate. However, since the percentage of the acute RfD 
(PAD) taken up by exposure to DCA residues from food only was 
sufficiently low, it was decided that a DWLOC would be calculated. 
Therefore, for this tolerance, the estimated maximum concentration of 
14 ppb from the monitoring data was used for comparison to the back 
calculated human health DWLOC for the acute endpoint. The DWLOCs for 
the specific population subgroups are calculated as follows:
    The maximum water exposure (acute) (mg/kg/day) = acute PAD - food 
exposure (mg/kg/day) from acute DEEM run.
    The DWLOC (g/L) = max. water exposure (mg/kg/day) x body 
wt (kg)  (10-3 mg/g) x water consumption 
(L/day).
    EPA used the following default body weights in these calculations: 
General U.S. population, 70 kg; males (13+ years old), 70 kg; females 
(13+ years old), 60 kg; and other adult populations, 70 kg.
    EPA's default daily drinking rates are 2L/day for adults.
    The DWLOCs are between 4,300 and 5,000 ppb for acute dietary risk. 
Based on a comparison of the calculated DWLOCs and the estimated 
exposure to diuron in drinking water (14 ppb), EPA does not expect the 
aggregate exposure to exceed 100% of the Acute RfD for any of the U.S. 
population. The DWLOCs are at least 100 times higher than the maximum 
value observed in monitoring studies. Therefore, EPA concludes that 
there is a reasonable certainty that no harm will result to the U.S. 
population from acute aggregate exposure to diuron residues.
    2. Chronic risk. EPA determined that for this tolerance, the FQPA 
Safety Factor can be removed (1x) in assessing the risk posed by 
diuron. Therefore, because there is not a FQPA 10x Safety Factor added 
to this risk assessment, the chronic RfD is identical to the chronic 
PAD. EPA has calculated that chronic dietary exposure to diuron alone 
from food and water will utilize 4.7% of the chronic RfD (PAD) for the 
U.S. population. When residues from linuron and propanil are included, 
the dietary exposure to residues convertible to the metabolite (DCA) 
from food and water will utilize 12% of the chronic RfD (PAD) for the 
U.S. population and 15% of the chronic RfD (PAD) for the non-hispanic, 
non-white, non-black U.S. population.
    As stated previously, the chronic dietary risk analysis used highly 
refined

[[Page 41302]]

ARC exposure estimates and percent crop treated values. EPA generally 
has no concern for exposures below 100% of the chronic RfD (PAD) 
because the chronic RfD (PAD) represents the level at or below which 
daily aggregate dietary exposure over a lifetime will not pose 
appreciable risks to human health. There are no registered residential 
uses for diuron. Therefore, EPA concludes that there is a reasonable 
certainty that no harm to adults will result from chronic aggregate 
exposure to DCA-convertible residues from diuron, linuron and propanil.
    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 non-dietary, non-
occupational exposures. Since there are no registered uses of diuron 
that would result in such exposures, short- and intermediate-term 
aggregate risk estimates were not conducted.
    4. Aggregate cancer risk for U.S. population. The dietary cancer 
risk for the U.S. population is calculated by multiplying the 
Q1* by the dietary exposure value. The Q1*(mg/kg/
day)-1 for diuron is 1.91 x 10-2. The dietary 
exposure value for registered food crops for the U.S. population is 
0.000092 mg/kg/day. This highly refined value does not include either 
the drinking water exposure value or the catfish exposure that was 
included in the exposure values described above in the discussion on 
chronic aggregate risk. Multiplying the Q1* by the dietary 
exposure value for the U.S. population, the cancer risk for the U.S. 
population is 1.76 x 10-6 for all registered foods. Adding 
in calculated risks from catfish and the average monitoring value of 
0.8 ppb diuron parent in all drinking water, the total estimation of 
cancer risk for the U.S. population is 2.71 x 10-6. This 
value does not include contributions from linuron and propanil 
metabolites because, as explained in the toxicological endpoints 
section, the tumor target organs are different for diuron when compared 
to linuron and propanil and because mechanistic and metabolism data 
indicate that diuron may be inducing tumors through a different 
mechanism of action. Metabolites in water are also not included; 
however, EFED's upper end value of diuron parent in surface water 
partially compensates for not including metabolites in water.
    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 diuron 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 diuron, 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 during 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 
appreciable risk to humans. EPA believes that reliable data support 
using the standard MOE and uncertainty factor (usually 100 for combined 
inter- and intra-species variability) and not the additional 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. Developmental toxicity studies--Rats. In the developmental 
study in rats, the maternal (systemic) NOAEL was 16 mg/kg/day, based on 
reduction in body weight and food consumption at the LOAEL of 80 mg/kg/
day. The developmental (fetal) NOAEL was 80 mg/kg/day, based on 
increases in delayed ossification of vertebrae and sternebrae as well 
as decreased fetal weights at the LOAEL of 400 mg/kg/day.
    Rabbits. In the developmental toxicity study in rabbits, the 
maternal (systemic) NOAEL was 10 mg/kg/day, based on decreased body 
weight and food comsumption at the LOAEL of 50 mg/kg/day. The 
developmental (pup) NOAEL was 50 mg/kg/day, the highest dose tested. 
There were no developmental effects.
    iii. Reproductive toxicity study--Rats. In the 2-generation 
reproductive toxicity study in rats, the parental (systemic) NOAEL was 
16.9 (males) and 20.3 (females) mg/kg/day, based on decreased body 
weight, body weight gain and food consumption in both sexes at the 
LOAEL of 120 (males) and 144 (females) mg/kg/day. The developmental 
(pup) NOAEL was 20.3 mg/kg/day, based on decreased pup body weight 
during the lactation period for both sexes and generations at the LOAEL 
of 144 mg/kg/day. The reproductive NOAEL was 120 (males) and 144 
(females) mg/kg/day, the highest dose tested. There were no 
reproductive effects.
    iv. Pre- and postnatal sensitivity. The toxicological data base for 
evaluating pre- and postnatal toxicity for diuron is complete with 
respect to current data requirements. Based on the developmental and 
reproductive toxicity studies discussed above for diuron, there does 
not appear to be an extra sensitivity for pre- or postnatal effects. 
EPA has concluded that the FQPA Safety Factor can be removed (1x) in 
assessing the risk posed by this chemical. The decision applies only to 
this tolerance action.
    v. Conclusion. There is a complete toxicity data base for diuron 
and exposure data are complete or are estimated based on data that 
reasonably accounts for potential exposures.
    2. Acute risk. The acute dietary risk analysis using partially 
refined data estimated that the acute dietary exposure (food only) for 
the population subgroup, non-nursing infants will utilize 24% of the 
acute RfD (PAD). All other infant and children population subgroups 
have acute risk estimates (food only) below that of non-nursing infants 
(see discussion on residue contributions in the Acute Aggregate Risk 
section for the U.S. population). For DCA-convertible residues from 
diuron, linuron and propanil, it was determined that an acute dietary 
exposure (food plus water) of 100% or less of the acute RfD (PAD) is 
acceptable to protect the safety of all infant and children population 
subgroups. The estimated exposures at the 99.9th percentile for all 
infant and children population subgroups utilize less than 100% of the 
Acute RfD, which, because there is no FQPA 10x Safety Factor, is 
identical to the acute PAD.
    As stated in the aggregate risk section for the U.S. population, 
for purposes of risk assessment, the estimated maximum concentration of 
14 ppb from the monitoring data will be used for comparison to the 
back-calculated human health DWLOC for the acute endpoint. For the 
DWLOC calculations, the EPA default body weights are:

[[Page 41303]]

Females (13+ years old), 60 kg and all infants/children, 10 kg.
    EPA has used daily drinking rates of 2L/day for adults and 1L/day 
for children.
    The DWLOCs are between 1,200 and 4,300 ppb for acute dietary risk. 
Based on a comparison of the calculated DWLOCs and the estimated 
exposure to diuron in drinking water (14 ppb), EPA does not expect the 
aggregate exposure to exceed 100% of the Acute RfD for either infants 
or children. The DWLOCs are approximately 100 times higher than the 
maximum value observed in monitoring studies. Therefore, EPA concludes 
that there is a reasonable certainty that no harm will result to either 
infants or children from acute aggregate exposure to diuron residues.
    3. Chronic risk. Using the exposure assumptions described in this 
unit, EPA has concluded that aggregate exposure to diuron from food 
will utilize 28% of the chronic RfD for non-nursing infants, which is 
the highest exposed population subgroup. All other infant and children 
population subgroups have lower chronic dietary exposure. EPA generally 
has no concern for exposures below 100% of the chronic RfD (PAD) 
because the chronic RfD (PAD) represents the level at or below which 
daily aggregate dietary exposure over a lifetime will not pose 
appreciable risks to human health. There are no registered residential 
uses for diuron. EPA concludes that there is a reasonable certainty 
that no harm will result to infants and children from chronic aggregate 
exposure to DCA residues from diuron, linuron and propanil. Despite the 
potential for exposure to diuron in drinking water and from non-
dietary, non-occupational exposure, EPA does not expect the aggregate 
exposure to exceed 100% of the RfD/PAD.
    4. Short- or intermediate-term risk. Short- and intermediate-term 
aggregate exposure takes into account chronic dietary food and water 
(considered to be a background exposure level) plus non-dietary, non-
occupational exposures. Since there are no registered uses of diuron 
which would result in such exposures, short- and intermediate- term 
aggregate risk estimates were not conducted.
    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 diuron residues.

IV. Other Considerations

A. Metabolism in Plants and Animals

    The nature of the residue in plants is adequately understood. The 
parent compound usually comprises only a small portion of the total 
residue. Significant residues formed by demethylation include 
dichlorophenylmethylurea (DCPMU) and dichlorophenylurea (DCPU). 
Although tolerances in 40 CFR 180.106 are expressed simply as 
``residues of the herbicide diuron,'' as part of the reregistration 
process EPA has noted that the residue to be regulated in plants is 
diuron and its related compounds convertible to 3,4-dichloroaniline as 
determined by the enforcement and data collection methods. The 
tolerance expression should be revised in this manner when 
reregistration eligibility decisions are made for diuron. For the 
purposes of the current action, the tolerance will be based on the 
combined residues of diuron and its metabolites convertible to 3,4-
dichloroaniline.
    EPA addressed the residues of concern in livestock commodities. 
While DCPMU and DCPU are also formed in livestock, five hydroxylated 
metabolites are found that are not observed in plants. EPA concluded 
these residues are not of concern in livestock tissues and eggs as the 
DCA method determined 80% or more of the total radioactive residue in 
these commodities. In milk the DCA method recovered only 10% of the TRR 
and EPA concluded that while the remaining 90% of the residue need not 
be quantified using a different method, the diuron residues observed in 
milk (by conversion to DCA) in the feeding study will be multiplied by 
10 for purposes of risk assessment. Although livestock are not directly 
involved in this tolerance action, a tolerance is being established for 
residues in catfish. For the purposes of this tolerance, the residue of 
concern in catfish will be considered the same as in plants and 
livestock tissues (i.e., diuron and it metabolites convertible to DCA).

B. Analytical Enforcement Methodology

    Adequate enforcement methodology (example - gas chromotography) is 
available to enforce the tolerance expression. The method may be 
requested from: Calvin Furlow, PIRIB, IRSD (7502C), Office of Pesticide 
Programs, Environmental Protection Agency, 401 M St., SW., Washington, 
DC 20460. Office location and telephone number: Rm 101FF, Crystal Mall 
#2, 1921 Jefferson Davis Hwy., Arlington, VA, (703) 305-5229.

C. Magnitude of Residues

    Residue data were provided for four different application schemes 
to catfish ponds. In all cases, the application rate or concentration 
(0.01 ppm) in the water was the same as that authorized in the section 
18 exemptions. In three ponds, the treatments were made every 5 days 
(versus proposed 7-day interval) with the total number of applications 
being 7, 13 or 19 (for total treatment periods of 30, 60 or 90 days). 
The maximum DCA-containing residues in catfish fillets for the three 
treatment patterns were 0.90, 1.76 and 1.52 ppm, respectively. The 
values apparently reflect averages of triplicate analyses. The highest 
residue from an individual analysis is 1.88 ppm. The fourth pond 
(described as an efficacy study) more closely resembled the proposed 
emergency use in that the 0.01 ppm water treatments were made every 7 
days, although more applications were made (17 over 112 days versus 
maximum of 9 requested in the section 18). Fillets were collected after 
the final treatment and found to contain 0.59-1.16 ppm total DCA-
containing residues. Based on these data, EPA concludes that a 2.0 ppm 
time-limited tolerance should be established for residues of diuron and 
its metabolites convertible to 3,4-dichloroaniline in catfish fillets.
    There are no livestock feed items associated with the proposed use 
in catfish ponds. Therefore, tolerances are not required for residues 
of diuron and metabolites in meat, milk, poultry and eggs. Tolerances 
of 1 ppm are established for residues of diuron in the meat, fat and 
meat byproducts of cattle, goats, hogs, horses and sheep (40 CFR 
180.106) in conjunction with registered uses of the herbicide.

D. International Residue Limits

    There are no Codex, Canadian, or Mexican tolerances or maximum 
residue limits for diuron in catfish. Therefore, harmonization with 
international tolerances is not an issue for this tolerance.

E. Rotational Crop Restrictions

    Since the requested use is for catfish ponds, which are essentially 
permanent structures, there are no rotational crops that would be 
planted in the treated areas. Thus, no plantback intervals need to be 
specified for rotational crops.

V. Conclusion

    Therefore, the tolerance is established for combined residues of 
diuron and its metabolites convertible to 3,4-dichloroaniline in 
catfish fillets at 2.0 ppm.

[[Page 41304]]

VI. 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 September 28, 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 
rulemaking. The objections submitted must specify the provisions of the 
regulation deemed objectionable and the grounds for the objections (40 
CFR 178.25). Each objection must be accompanied by the fee prescribed 
by 40 CFR 180.33(i). 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, [email protected]. 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.

VII. Public Record and Electronic Submissions

    EPA has established a record for this regulation under docket 
control number [OPP-300881] (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:
    [email protected]
    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.

VIII. Regulatory Assessment Requirements

A. Certain Acts and Executive Orders

    This final rule establishes a tolerance under section 408 of the 
FFDCA. 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 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 
under FFDCA section 408(l)(6), 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 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

[[Page 41305]]

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.

IX. 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: July 14, 1999.

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), 346(a) and 371.


    2. Section Sec. 180.106, is amended by adding new paragraph (b) to 
read as follows.


Sec. 180.106   Diuron; tolerances for residues.

*    *    *    *    *
    (b) Section 18 emergency exemptions. Time-limited tolerances are 
established for combined residues of the herbicide diuron and its 
metabolites convertible to 3,4-dichloroaniline in connection with use 
of the pesticide under section 18 emergency exemptions granted by EPA. 
These tolerances will expire and are revoked on the dates specified in 
the following table.

------------------------------------------------------------------------
                                                     Parts   Expiration/
                     Commodity                        per     Revocation
                                                    million      date
------------------------------------------------------------------------
Catfish fillets...................................    2.0       06/30/01
------------------------------------------------------------------------

*    *    *    *    *

[FR Doc. 99-19591 Filed 7-29-99; 8:45 am]
BILLING CODE 6560-50-F