[Federal Register Volume 62, Number 242 (Wednesday, December 17, 1997)]
[Rules and Regulations]
[Pages 66014-66020]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-32937]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-300573; FRL 5753-6]
RIN 2070-AB78


Primisulfuron-methyl; 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 
residues of primisulfuron-methyl in or on bluegrass grown for seed. 
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 on bluegrass grown for seed. This 
regulation establishes a maximum permissible level for residues of 
primisulfuron-methyl 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 October 31, 1998.

DATES: This regulation is effective December 17, 1997. Objections and 
requests for hearings must be received by EPA on or before February 17, 
1998.

ADDRESSES:  Written objections and hearing requests, identified by the 
docket control number, [OPP-300573], 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-300573], must also be submitted to: Public 
Information and Records Integrity Branch, Information Resources and 
Services Division (7502C), Office of Pesticide Programs, Environmental 
Protection Agency, 401 M St., SW., Washington, DC 20460. In person, 
bring a copy of objections and hearing requests to Rm. 1132, CM #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: <a href="/cdn-cgi/l/email-protection#fc938c8cd198939f979988bc998c9d919d9590d2998c9dd29b938a"><span class="__cf_email__" data-cfemail="d0bfa0a0fdb4bfb3bbb5a490b5a0b1bdb1b9bcfeb5a0b1feb7bfa6">[email protected]</span></a>. Copies of objections and 
hearing requests must be submitted as an ASCII file avoiding the use of 
special characters and any form of encryption. Copies of objections and 
hearing requests will also be accepted on disks in WordPerfect 5.1/6.1 
file format or ASCII file format. All copies of objections and hearing 
requests in electronic form must be identified by the docket control 
number [OPP-300573]. No Confidential Business Information (CBI) should 
be submitted through e-mail. Electronic copies of objections and 
hearing requests on this rule may be filed online at many Federal 
Depository Libraries.

FOR FURTHER INFORMATION CONTACT:  By mail: Pat Cimino, Registration 
Division 7505C, Office of Pesticide Programs, Environmental Protection 
Agency, 401 M St., SW., Washington, DC 20460. Office location, 
telephone number, and e-mail address: Crystal Mall #2, 1921 Jefferson 
Davis Hwy., Arlington, VA, (703) 308-9357; e-mail: 
<a href="/cdn-cgi/l/email-protection#24474d494d4a4b0a5445506441544549454d480a4154450a434b52"><span class="__cf_email__" data-cfemail="aecdc7c3c7c0c180decfdaeecbdecfc3cfc7c280cbdecf80c9c1d8">[email protected]</span></a>.

SUPPLEMENTARY INFORMATION: EPA, on its own initiative, pursuant to 
section 408(e) and (l)(6) of the Federal Food, Drug, and Cosmetic Act 
(FFDCA), 21 U.S.C. 346a(e) and (l)(6), is establishing a tolerance for 
residues of the herbicide primisulfuron-methyl, in or on bluegrass 
grown for seed at 0.10 parts per million (ppm). This tolerance will 
expire and is revoked on October 31, 1998. EPA will publish a document 
in the Federal Register to remove the revoked tolerance from the Code 
of Federal Regulations.


[[Page 66015]]



I. Background and Statutory Authority

    The Food Quality Protection Act of 1996 (FQPA) (Pub. L. 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 below 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.
    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 tolerance to set binding precedents for the 
application of section 408 and the new safety standard to other 
tolerances and exemptions.

II. Emergency Exemption for Primisulfuron-methyl on Bluegrass Grown 
for Seed and FFDCA Tolerances

    The applicant asserts that recent growing conditions and 
curtailment of burning, a cultural weed control method, by the federal, 
state, and/or county Clean Air Act requirements have created 
unacceptable levels of weedy grasses proliferating in Kentucky 
bluegrass fields. There are no effective registered pesticides or 
alternative control practices available which will provide adequate 
control of the weeds. EPA has authorized under FIFRA section 18 the use 
of primisulfuron-methyl on bluegrass grown for seed for control of 
quackgrass, windgrass, downey brome, wild oat, and other weeds in 
Washington and Idaho. After having reviewed the submission, EPA concurs 
that emergency conditions exist for these states.
    As part of its assessment of this emergency exemption, EPA assessed 
the potential risks presented by residues of primisulfuron-methyl in or 
on bluegrass grown for seed. In doing so, EPA considered the new 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 
new 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 October 31, 1998, under FFDCA section 408(l)(5), residues of the 
pesticide not in excess of the amounts specified in the tolerance 
remaining in or on bluegrass grown for seed after that date will not be 
unlawful, provided the pesticide is applied in a manner that was lawful 
under FIFRA. 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 primisulfuron-methyl meets 
EPA's registration requirements for use on bluegrass grown for seed 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 primisulfuron-methyl by a State for special 
local needs under FIFRA section 24(c). Nor does this tolerance serve as 
the basis for any States other than Washington and Idaho to use this 
pesticide on this crop under section 18 of FIFRA without following all 
provisions of section 18 as identified in 40 CFR part 166. For 
additional information regarding the emergency exemption for 
primisulfuron-methyl, contact the Agency's Registration Division at the 
address provided above.

III. Risk Assessment and Statutory Findings

    EPA performs a number of analyses to determine the risks from 
aggregate exposure to pesticide residues. First, EPA determines the 
toxicity of pesticides based primarily on toxicological studies using 
laboratory animals. These studies address many adverse health effects, 
including (but not limited to) reproductive effects, developmental 
toxicity, toxicity to the nervous system, and carcinogenicity. Second, 
EPA examines exposure to the pesticide through the diet (e.g., food and 
drinking water) and through exposures that occur as a result of 
pesticide use in residential settings.

A. Toxicity

    1. Threshold and non-threshold effects. For many animal studies, a 
dose response relationship can be determined, which provides a dose 
that causes adverse effects (threshold effects) and doses causing no 
observed effects (the ``no-observed effect level'' or ``NOEL'').
    Once a study has been evaluated and the observed effects have been 
determined to be threshold effects, EPA generally divides the NOEL from 
the study with the lowest NOEL by an uncertainty factor (usually 100 or 
more) to determine the Reference Dose (RfD). The RfD is a level at or 
below which daily aggregate exposure over a lifetime will not pose 
appreciable risks to human health. An uncertainty factor (sometimes 
called a ``safety factor'') of 100 is commonly used since it is assumed 
that people may be up to 10 times more sensitive to pesticides than the 
test animals, and that one person or subgroup of the population (such 
as

[[Page 66016]]

infants and children) could be up to 10 times more sensitive to a 
pesticide than another. In addition, EPA assesses the potential risks 
to infants and children based on the weight of the evidence of the 
toxicology studies and determines whether an additional uncertainty 
factor is warranted. Thus, an aggregate daily exposure to a pesticide 
residue at or below the RfD (expressed as 100 percent or less of the 
RfD) is generally considered acceptable by EPA. EPA generally uses the 
RfD to evaluate the chronic risks posed by pesticide exposure. For 
shorter term risks, EPA calculates a margin of exposure (MOE) by 
dividing the estimated human exposure into the NOEL from the 
appropriate animal study. Commonly, EPA finds MOEs lower than 100 to be 
unacceptable. This 100-fold MOE is based on the same rationale as the 
100-fold uncertainty factor.
    Lifetime feeding studies in two species of laboratory animals are 
conducted to screen pesticides for cancer effects. When evidence of 
increased cancer is noted in these studies, the Agency conducts a 
weight of the evidence review of all relevant toxicological data 
including short-term and mutagenicity studies and structure activity 
relationship. Once a pesticide has been classified as a potential human 
carcinogen, different types of risk assessments (e.g., linear low dose 
extrapolations or MOE calculation based on the appropriate NOEL) will 
be carried out based on the nature of the carcinogenic response and the 
Agency's knowledge of its mode of action.
    2. Differences in toxic effect due to exposure duration. The 
toxicological effects of a pesticide can vary with different exposure 
durations. EPA considers the entire toxicity data base, and based on 
the effects seen for different durations and routes of exposure, 
determines which risk assessments should be done to assure that the 
public is adequately protected from any pesticide exposure scenario. 
Both short and long durations of exposure are always considered. 
Typically, risk assessments include ``acute,'' ``short-term,'' 
``intermediate term,'' and ``chronic'' risks. These assessments are 
defined by the Agency as follows.
    Acute risk, by the Agency's definition, results from 1-day 
consumption of food and water, and reflects toxicity which could be 
expressed following a single oral exposure to the pesticide residues. 
High end exposure to food and water residues are typically assumed.
    Short-term risk results from exposure to the pesticide for a period 
of 1-7 days, and therefore overlaps with the acute risk assessment. 
Historically, this risk assessment was intended to address primarily 
dermal and inhalation exposure which could result, for example, from 
residential pesticide applications. However, since enaction of FQPA, 
this assessment has been expanded to include both dietary and non-
dietary sources of exposure, and will typically consider exposure from 
food, water, and residential uses when reliable data are available. In 
this assessment, risks from average food and water exposure, and high-
end residential exposure, are aggregated. High-end exposures from all 3 
sources are not typically added because of the very low probability of 
this occurring in most cases, and because the other conservative 
assumptions built into the assessment assure adequate protection of 
public health. However, for cases in which high-end exposure can 
reasonably be expected from multiple sources (e.g. frequent and 
widespread homeowner use in a specific geographical area), multiple 
high-end risks will be aggregated and presented as part of the 
comprehensive risk assessment/characterization. Since the toxicological 
endpoint considered in this assessment reflects exposure over a period 
of at least 7 days, an additional degree of conservatism is built into 
the assessment; i.e., the risk assessment nominally covers 1-7 days 
exposure, and the toxicological endpoint/NOEL is selected to be 
adequate for at least 7 days of exposure. (Toxicity results at lower 
levels when the dosing duration is increased.)
    Intermediate-term risk results from exposure for 7 days to several 
months. This assessment is handled in a manner similar to the short-
term risk assessment.
    Chronic risk assessment describes risk which could result from 
several months to a lifetime of exposure. For this assessment, risks 
are aggregated considering average exposure from all sources for 
representative population subgroups including infants and children.

B. Aggregate Exposure

    In examining aggregate exposure, FFDCA section 408 requires that 
EPA take into account available and reliable information concerning 
exposure from the pesticide residue in the food in question, residues 
in other foods for which there are tolerances, residues in groundwater 
or surface water that is consumed as drinking water, and other non-
occupational exposures through pesticide use in gardens, lawns, or 
buildings (residential and other indoor uses). Dietary exposure to 
residues of a pesticide in a food commodity are estimated by 
multiplying the average daily consumption of the food forms of that 
commodity by the tolerance level or the anticipated pesticide residue 
level. The Theoretical Maximum Residue Contribution (TMRC) is an 
estimate of the level of residues consumed daily if each food item 
contained pesticide residues equal to the tolerance. In evaluating food 
exposures, EPA takes into account varying consumption patterns of major 
identifiable subgroups of consumers, including infants and children. 
The TMRC is a ``worst case'' estimate since it is based on the 
assumptions that food contains pesticide residues at the tolerance 
level and that 100% of the crop is treated by pesticides that have 
established tolerances. If the TMRC exceeds the RfD or poses a lifetime 
cancer risk that is greater than approximately one in a million, EPA 
attempts to derive a more accurate exposure estimate for the pesticide 
by evaluating additional types of information (anticipated residue data 
and/or percent of crop treated data) which show, generally, that 
pesticide residues in most foods when they are eaten are well below 
established tolerances.
    Percent of crop treated estimates are derived from federal and 
private market survey data. 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 percent of crop 
treated, the Agency is reasonably certain that exposure is not 
understated for any significant subpopulation group. Further, regional 
consumption information is taken into account through EPA's computer-
based model for evaluating the exposure of significant subpopulations 
including several regional groups, to pesticide residues. For this 
pesticide, the most highly exposed population subgroup non-nursing 
infants <1 year old was not regionally based.

IV. 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 
primisulfuron-methyl and to make a determination on aggregate exposure, 
consistent with section 408(b)(2), for a time-limited tolerance for 
residues of primisulfuron-methyl on bluegrass grown for seed at 0.10 
ppm. EPA's assessment of the dietary

[[Page 66017]]

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 primisulfuron-
methyl are discussed below.
    1. Acute toxicity. For acute dietary risk assessment, the Agency 
used a NOEL of 100 mg/kg/day, based on delayed or absent ossification 
effects in fetuses at the LEL of 500 mg/kg/day, from the oral 
developmental study in rats. This risk assessment will evaluate acute 
dietary risk to the population subgroup of concern, females 13+ years 
of age.
    2. Chronic toxicity. EPA has established the RfD for primisulfuron-
methyl at 0.006 milligrams/kilogram/day (mg/kg/day). This RfD is based 
on an 80-week mouse feeding study with a LOEL of 1.7 mg/kg/day based on 
increased absolute and relative liver weights. An uncertainty factor of 
300 was used because a NOEL was not achieved.
    3. Carcinogenicity. Primisulfuron-methyl has been classified as a 
Group D chemical incomplete evidence based on liver tumors in mice.

B. Exposures and Risks

    1. From food and feed uses. Tolerances have been established (40 
CFR 180.452) for the residues of primisulfuron-methyl, in or on the raw 
agricultural commodities fresh corn and corn forage and fodder. 
Tolerances are also established on cattle, goat, hog, horse, sheep, and 
poultry commodities as well as milk and eggs. Risk assessments were 
conducted by EPA to assess dietary exposures and risks from 
primisulfuron-methyl 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 one day or single exposure. The acute dietary food only risk 
assessment used tolerance level residues for all commodities with 
primisulfuron-methyl tolerances. Therefore, the resulting exposure 
estimates should be viewed as conservative; further refinement using 
anticipated residues and/or Monte Carlo and percent of crop-treated 
would result in lower dietary exposure estimates. Since the acute 
dietary effect is based on delayed or absent ossification effects in 
fetuses, the subgroup of concern is females 13+ years of age. For 
females 13+ years of age, an MOE value of 71,000 was calculated using 
the high-end exposure value of 0.0014 mg/kg/day.
    ii. Chronic exposure and risk. Because there are no human food 
items associated with bluegrass and existing meat/milk/poultry/egg 
tolerances are adequate to cover secondary residues, a new chronic 
Dietary Risk Evaluation System (DRES) run was not performed for this 
section 18 request. The latest chronic DRES run was performed in 
conjunction with the registration of primisulfuron-methyl on corn. The 
chronic dietary exposure estimates were not refined using anticipated 
residues and percent crop treated data. The existing primisulfuron-
methyl tolerances result in a Theoretical Maximum Residue Contribution 
(TMRC) that is equivalent to the following percentages of the RfD:

                                                                        
------------------------------------------------------------------------
                                            TMRCfood  Value(mg/         
              Subpopulation                       kg/day)         % RfD 
------------------------------------------------------------------------
U.S. Population..........................              0.000571      10%
                                                                        
Nursing Infants..........................              0.000484       8%
                                                                        
Non-Nursing Infants < 1 year old.........              0.001732      29%
                                                                        
Children 1-6 years old...................              0.001327      22%
                                                                        
Children 7-12 years old..................              0.000876      15%
                                                                        
Hispanics................................              0.000723      12%
Non-Hispanic Others......................              0.000644      11%
------------------------------------------------------------------------

    The subgroups listed above are: (1) the U.S. population (48 
states); (2) those for infants and children; and (3) the other 
subgroups for which the percentage of the RfD occupied is greater than 
that occupied by the subgroup U.S. population (48 states).
    2. From drinking water. Based on information available to the 
Agency, primisulfuron-methyl is moderately persistent and highly 
mobile. There is no established Maximum Concentration Level for 
residues of primisulfuron-methyl in drinking water. No health advisory 
levels for primisulfuron-methyl in drinking water have been 
established. Based on ``Pesticides in Groundwater Database'' (EPA 734-
12-92-001, Sept 1992), primisulfuron-methyl has not been analyzed for 
in water.
    3. Chronic exposure and risk. Because the Agency lacks sufficient 
water-related exposure data to complete a comprehensive drinking water 
risk assessment for many pesticides, EPA has commenced and nearly 
completed a process to identify a reasonable yet conservative bounding 
figure for the potential contribution of water-related exposure to the 
aggregate risk posed by a pesticide. In developing the bounding figure, 
EPA estimated residue levels in water for a number of specific 
pesticides using various data sources. The Agency then applied the 
estimated residue levels, in conjunction with appropriate toxicological 
endpoints (RfD's or acute dietary NOEL's) and assumptions about body 
weight and consumption, to calculate, for each pesticide, the increment 
of aggregate risk contributed by consumption of contaminated water. 
While EPA has not yet pinpointed the appropriate bounding figure for 
exposure from contaminated water, the ranges the Agency is continuing 
to examine are all below the level that would cause primisulfuron-
methyl to exceed the RfD if the tolerance being considered in this 
document were granted. The Agency has therefore concluded that the 
potential exposures associated with primisulfuron-methyl in water, even 
at the higher levels the Agency is considering as a conservative upper 
bound, would not prevent the Agency from determining that there is a 
reasonable certainty of no harm if the tolerance is granted.
    4. From non-dietary exposure. Primisulfuron-methyl is not 
registered for uses that would be expected to result

[[Page 66018]]

in indoor or outdoor residential exposure.
    5. Cumulative exposure to substances with common mechanism of 
toxicity. Section 408(b)(2)(D)(v) requires that, when considering 
whether to establish, modify, or revoke a tolerance, the Agency 
consider ``available information'' concerning the cumulative effects of 
a particular pesticide's residues and ``other substances that have a 
common mechanism of toxicity.'' 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 pesticides 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).
    EPA does not have, at this time, available data to determine 
whether primisulfuron-methyl 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, 
primisulfuron-methyl 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 primisulfuron-methyl has a 
common mechanism of toxicity with other substances.

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

    1. Acute risk. The acute aggregate risk assessment takes into 
account exposure from dietary food and water only. As noted earlier, 
the MOE for females 13+ years of age was calculated to be 71,000. 
Therefore, EPA does not have an acute aggregate risk concern.
    2. Chronic risk. Using the conservative TMRC exposure assumptions 
described above, and taking into account the completeness and 
reliability of the toxicity data, EPA has calculated that dietary 
exposure to primisulfuron-methyl from food will utilize 10% of the RfD 
for the U.S. population. The Agency 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 primisulfuron-methyl in drinking water, EPA does not expect 
the aggregate exposure to exceed 100% of the RfD. EPA concludes that 
there is a reasonable certainty that no harm will result from chronic 
aggregate exposure to primisulfuron-methyl residues.

D. 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 primisulfuron-methyl, EPA considered data from 
developmental toxicity studies in the rat and rabbit and a two-
generation reproduction study in the rat. The developmental toxicity 
studies are designed to evaluate adverse effects on the developing 
organism resulting from pesticide exposure during prenatal development 
to one or both parents. Reproduction studies provide information 
relating to effects from exposure to the pesticide on the reproductive 
capability of mating animals and data on systemic toxicity.
    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 post-natal toxicity and the 
completeness of the database unless EPA determines that a different 
margin of safety will be safe for infants and children. Margins of 
safety are incorporated into EPA risk assessments either directly 
through use of a MOE analysis or through using uncertainty (safety) 
factors in calculating a dose level that poses no appreciable risk to 
humans. EPA believes that reliable data support using the standard MOE 
and uncertainty factor (usually 100 for combined inter- and intra-
species variability)) and not the additional 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. From the rat developmental 
study, the maternal (systemic) NOEL was less than 100 mg/kg/day, based 
on decreased weight gain during dosing at the LOEL of 100 mg/kg/day. 
The developmental (fetal) NOEL was 100 mg/kg/day, based on delayed or 
absent ossification at the LOEL of 500 mg/kg/day.
    From the rabbit developmental study, the maternal (systemic) NOEL 
was 10 mg/kg/day, based on abortions, decreased weight gain and loose 
stool at the LOEL of 300 mg/kg/day. The developmental (fetal) NOEL was 
600 mg/kg/day highest dose tested.
    iii. Reproductive toxicity study. From the rat reproductive study, 
the parental (systemic) NOEL was 50 mg/kg/day, based on decreased 
weight gain at the LOEL of 250 mg/kg/day. The developmental (pup) NOEL 
was 50 mg/kg/day, based on decreased pup body weight findings at the 
LOEL of 250 mg/kg/day. The reproductive NOEL was 50 mg/kg/day, based on 
decrease in testicular/spermatic function at the LOEL of 250 mg/kg/day.
    iv. Pre- and post-natal sensitivity. In rats, although the 
developmental and maternal NOELs and LOELs were at the same dose 
levels, the finding of developmental effects [absent ossification] 
required that an acute dietary risk assessment be performed for females 
13+ years of age. The calculated MOE of 71,000 demonstrated that acute 
pre-natal developmental risks were below EPA's level of concern. There 
were no pre-natal developmental concerns in rabbits, since the 
developmental NOEL was greater than 600 mg/kg/day (HDT).
    Similarly, there were no post-natal rat reproductive study findings 
that

[[Page 66019]]

required additional safety factors, since the maternal and pup NOEL and 
LOEL of 50 and 250 mg/kg/day, respectively, occurred at the same dose 
levels and both adult and pup animals had similar toxic effects 
(decreased weight gain).
    v. Conclusion. The pre- and post-natal toxicology data base for 
primisulfuron-methyl is complete with respect to current toxicological 
data requirements. The Agency concludes that reliable data support use 
of the standard 100-fold margin of exposure/uncertainty factor and that 
an additional margin/factor is not needed to protect infants and 
children.
    2. Acute risk. The finding of developmental effects in the rat 
study absent ossification required that an acute dietary risk 
assessment be performed for females 13+ years of age. The calculated 
MOE of 71,000 demonstrated that acute pre-natal developmental risks 
were below EPA's level of concern.
    3. Chronic risk. Using the conservative exposure assumptions 
described above, EPA has concluded that aggregate exposure to 
primisulfuron-methyl from food will utilize from 8% of the RfD for 
nursing infants up to 29% of the RfD for non-nursing infants < 1 year 
old. EPA generally has no concern for exposures below 100% of the RfD 
because the RfD represents the level at or below which daily aggregate 
dietary exposure over a lifetime will not pose appreciable risks to 
human health.

V. Other Considerations

A. Metabolism In Plants and Animals

    The nature of the residue in corn and animals is adequately 
understood. The residue of concern is the parent compound only, as 
specified in 40 CFR 180.452.

B. Analytical Enforcement Methodology

    Adequate enforcement methodology (HPLC) has been submitted for 
inclusion in PAM Vol. II to enforce the tolerance expression. Method I 
of PAM II (Method AG-499A) has been validated on corn commodities and 
Method II (Method AG-506) has been validated on livestock commodities. 
Method A of PAM II is a confirmation method for plant commodities.

C. Magnitude of Residues

    Residues of primisulfuron-methyl are not expected to exceed 0.10 
ppm in/on bluegrass hay as a result of this section 18 use. A time-
limited tolerance will be established at this level. Secondary residues 
in animal commodities are not expected to exceed existing tolerances as 
a result of this section 18 use.

D. International Residue Limits

    No Codex (MRLs) have been established for residues of 
primisulfuron-methyl on grasses.

VI. Conclusion

    Therefore, the tolerance is established for residues of 
primisulfuron-methyl in bluegrass grown for seed at 0.10 ppm.

VII. Objections and Hearing Requests


    The new FFDCA section 408(g) provides essentially the same process 
for persons to ``object'' to a tolerance regulation issued by EPA under 
new section 408(e) and (l)(6) 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 February 17, 1998, file written objections to 
any aspect of this regulation and may also request a hearing on those 
objections. Objections and hearing requests must be filed with the 
Hearing Clerk, at the address given above (40 CFR 178.20). A copy of 
the objections and/or hearing requests filed with the Hearing Clerk 
should be submitted to the OPP docket for this rulemaking. The 
objections submitted must specify the provisions of the regulation 
deemed objectionable and the grounds for the objections (40 CFR 
178.25). Each objection must be accompanied by the fee prescribed by 40 
CFR 180.33(i). If a hearing is requested, the objections must include a 
statement of the factual issues on which a hearing is requested, the 
requestor's contentions on such issues, and a summary of any evidence 
relied upon by the requestor (40 CFR 178.27). A request for a hearing 
will be granted if the Administrator determines that the material 
submitted shows the following: There is genuine and substantial issue 
of fact; there is a reasonable possibility that available evidence 
identified by the requestor would, if established, resolve one or more 
of such issues in favor of the requestor, taking into account 
uncontested claims or facts to the contrary; and resolution of the 
factual issues in the manner sought by the requestor would be adequate 
to justify the action requested (40 CFR 178.32). Information submitted 
in connection with an objection or hearing request may be claimed 
confidential by marking any part or all of that information as CBI. 
Information so marked will not be disclosed except in accordance with 
procedures set forth in 40 CFR part 2. A copy of the information that 
does not contain CBI must be submitted for inclusion in the public 
record. Information not marked confidential may be disclosed publicly 
by EPA without prior notice.

VIII. Public Docket

    EPA has established a record for this rulemaking under docket 
control number [OPP-300573] (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 1132 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 Highway, Arlington, VA.
    Electronic comments may be sent directly to EPA at:
    <a href="/cdn-cgi/l/email-protection#6d021d1d4009020e0608192d081d0c000c040143081d0c430a021b"><span class="__cf_email__" data-cfemail="4a253a3a672e2529212f3e0a2f3a2b272b2326642f3a2b642d253c">[email protected]</span></a>.


    Electronic comments must be submitted as an ASCII file avoiding the 
use of special characters and any form of encryption.
    The official record for this rulemaking, as well as the public 
version, as described above 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 rulemaking record which 
will also include all comments submitted directly in writing. The 
official rulemaking record is the paper record maintained at the 
Virginia address in ``ADDRESSES'' at the beginning of this document.

IX. Regulatory Assessment Requirements

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

[[Page 66020]]

not contain any information collections subject to OMB approval under 
the Paperwork Reduction Act (PRA), 44 U.S.C. 3501 et seq., or impose 
any enforceable duty or contain any unfunded mandate as described under 
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA) (Pub. L. 
104-4). Nor does it require any prior consultation as specified by 
Executive Order 12875, entitled Enhancing the Intergovernmental 
Partnership (58 FR 58093, October 28, 1993), or special considerations 
as required by Executive Order 12898, entitled Federal Actions to 
Address Environmental Justice in Minority Populations and Low-Income 
Populations (59 FR 7629, February 16, 1994), or require OMB review in 
accordance with Executive Order 13045, entitled Protection of Children 
from Environmental Health Risks and Safety Risks (62 FR 19885, April 
23, 1997).
    In addition, since these tolerances and exemptions that are 
established 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 has previously assessed 
whether establishing tolerances, exemptions from tolerances, raising 
tolerance levels or expanding exemptions might adversely impact small 
entities and concluded, as a generic matter, that there is no adverse 
economic impact. The factual basis for the Agency's generic 
certification for tolerance actions published on May 4, 1981 (46 FR 
24950), and was provided to the Chief Counsel for Advocacy of the Small 
Business Administration.

X. Submission to Congress and the General Accounting Office

    Under 5 U.S.C. 801(a)(1)(A), as added by the Small Business 
Regulatory Enforcement Fairness Act of 1996, the Agency has submitted a 
report containing this rule and other required information to the U.S. 
Senate, the U.S. House of Representatives, and the Comptroller General 
of the General Accounting Office prior to publication of this rule in 
today's Federal Register. This is not a ``major rule'' as defined by 5 
U.S.C. 804(2).

List of Subjects in 40 CFR Part 180

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

    Dated: November 18, 1997.

James Jones,

Acting Director, Registration Division, Office of Pesticide Programs.

    Therefore, 40 CFR chapter I is amended as follows:

PART 180--[AMENDED]

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

    Authority: 21 U.S.C. 346a and 371.


    2. Section 180.452, is amended as follows:
    i. By designating the existing text as paragraph (a) and adding a 
heading.
    ii. By adding new paragraph (b).
    iii. By adding and reserving new paragraphs (c) and (d) with 
headings to read as follows.


Sec. 180.452  Primisulfuron-methyl; tolerances for residues.

    (a)  General. * * *
    (b)  Section 18 emergency exemptions. Time-limited tolerances are 
established for residues of the herbicide primisulfuron-methyl 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.

                                                                        
------------------------------------------------------------------------
                                                          Expiration/   
            Commodity              Parts per million    revocation date 
------------------------------------------------------------------------
Bluegrass hay...................  0.10                10/31/1998        
------------------------------------------------------------------------

    (c) Tolerances with regional registrations. [Reserved]
    (d) Indirect or inadvertent residues. [Reserved]

[FR Doc. 97-32937 Filed 12-16-97; 8:45 am]
BILLING CODE 6560-50-F


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