[Federal Register Volume 62, Number 143 (Friday, July 25, 1997)]
[Rules and Regulations]
[Pages 39967-39974]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-19668]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-300516; FRL-5732-3]
RIN 2070-AB78


Sodium Salt of Acifluorfen; Pesticide Tolerances for Emergency 
Exemptions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes time-limited tolerances for the 
combined residues of the sodium salt of acifluorfen and its metabolites 
in or on lima beans, cowpeas, and southern peas . 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 lima beans, cowpeas, and southern peas. This 
regulation establishes a maximum permissible level for residues of the 
sodium salt of acifluorfen in these food commodities 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 tolerances will 
expire and are revoked on December 31, 1998.

DATES: This regulation is effective July 25, 1997. Objections and 
requests for hearings must be received by EPA on or before September 
23, 1997.

ADDRESSES: Written objections and hearing requests, identified by the 
docket control number, [OPP-300516], 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

[[Page 39968]]

by the docket control number, [OPP-300516], must also be submitted to: 
Public Information and Records Integrity Branch, Information Resources 
and Services Division (7506C), 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: [email protected]. 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 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-300516]. 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: Olga Odiott, 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) 308-9363, e-mail: 
[email protected].

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 tolerances for 
the combined residues of the herbicide sodium salt of acifluorfen and 
its metabolites (the corresponding acid, methyl ester and amino 
analogues), in or on lima beans, cowpeas, and southern peas at 0.1 part 
per million (ppm). These tolerances will expire and are revoked on 
December 31, 1998. EPA will publish a document in the Federal Register 
to remove the revoked tolerances from the Code of Federal Regulations.

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 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 the Sodium Salt of Acifluorfen on Lima 
Beans, Cowpeas, and Southern Peas and FFDCA Tolerances

    According to the Tennessee Extension Service the Hophornbeam 
copperleaf (Acalypha ostryaefolia) has become such an overwhelming pest 
that entire fields were abandoned in 1995. The fields in question 
constitute some of the most fertile agricultural land in West 
Tennessee, an area where farming and agriculturally related businesses 
are the primary sources of income. The Applicant stated that registered 
herbicides and/ or cultivation practices do not provide effective 
control of this weed. The State is concerned that uncontrolled 
Hophornbeam copperleaf could have a devastating effect for growers and 
the local economy. EPA has authorized under FIFRA section 18 the use of 
acifluorfen on lima beans, cowpeas, and southern peas for control of 
Hophornbeam copperleaf in Tennessee. After having reviewed the 
submission, EPA concurs that emergency conditions exist for this state.
    As part of its assessment of this emergency exemption, EPA assessed 
the potential risks presented by residues of the acifluorfen in or on 
lima beans, cowpeas, and southern peas. 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 December 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 lima beans, cowpeas, and southern peas 
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 acifluorfen meets EPA's 
registration requirements for use on

[[Page 39969]]

lima beans, cowpeas, and southern peas 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 
acifluorfen 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 Tennessee 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 acifluorfen, 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 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% 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.

[[Page 39970]]

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 (children 1 -6 
years 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 
acifluorfen and to make a determination on aggregate exposure, 
consistent with section 408(b)(2), for a time-limited tolerance for the 
combined residues of the sodium salt of acifluorfen and its metabolites 
( the corresponding acid, methyl ester, and amino analogues) in or on 
lima beans, cowpeas, and southern peas at 0.1 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 acifluorfen are 
discussed below.
    1. Acute toxicity. An acute dietary endpoint was not identified 
from the toxicity studies available to the Agency; therefore, this risk 
assessment was not conducted.
     2. Short - and intermediate - term toxicity. Based on the 
available data, the Office of Pesticide Programs (OPP) has determined 
that the NOEL of 300 mg/kg/day from a 21-day dermal toxicity study in 
rabbits should be used to assess risks from short- and intermediate-
term dermal exposures. The Lowest Effect Level (LEL) of 1,000 mg/kg/day 
was based on increased mortality (95%) by Day 8. For short- and 
intermediate-term inhalation toxicity, the OPP has determined that the 
NOEL of 20 mg/kg/day from a developmental toxicity study in rabbits 
should be used to assess risks for residential exposure scenarios. The 
LEL of 90 mg/kg/day was based on reduced mean fetal weights.
    3. Chronic toxicity. EPA has established the RfD for acifluorfen at 
0.013 milligrams/kilogram/day (mg/kg/day). This RfD is based on a 2-
generation reproductive toxicity study in rats. The NOEL (parental and 
reproductive) of 1.25 mg/kg/day was based on decreased survival and an 
increased incidence of kidney lesions at the LEL of 25.0 mg/kg/day. A 
100-fold uncertainty factor (UF) was added to account for inter-species 
extrapolation and intra-species variability .
    4. Carcinogenicity. Acifluorfen has been classified as a Group B2 
(probable human carcinogen) chemical by the OPP Cancer Peer Review 
Committee (CPRC), based on an increased number of liver tumors in both 
sexes of mice and a high incidence of uncommonly occurring stomach 
papillomas in male mice. The Committee recommended using the 
Q1* approach for quantification of human risk. The 
Q1* is 0.11 (mg/kg/day)-1.

B. Exposures and Risks

    1. From food and feed uses. Tolerances have been established (40 
CFR 180.383) for the combined residues of the sodium salt of 
acifluorfen and its metabolites (the acid, methyl ester, and amino 
analogues), in or on peanuts, rice, and soybeans at 0.1 ppm; 
strawberries at 0.05 ppm; and, animal commodities at 0.02 ppm. Risk 
assessments were conducted by EPA to assess dietary exposures and risks 
from acifluorfen as follows:
    Chronic exposure and risk. This chronic dietary risk assessment was 
partially refined using percent crop-treated estimates and anticipated 
residue values for selected commodities. Expansion of these refinements 
to the remaining commodities would result in a lower chronic dietary 
exposure estimate. The risk assessment took into account the published 
tolerances (none are currently pending) for the regulable residues of 
the sodium salt of acifluorfen, plus this Section 18 tolerance. The 
population subgroup with the largest percentage of the RfD occupied is 
children 1 to 6 year old, at 0.4% of the RfD.
    2. From drinking water. Based on available data used in EPA's 
assessment of environmental risk, acifluorfen (acid) is persistent, 
readily leaches, and is highly mobile. No Maximum Contaminant Level is 
established for acifluorfen residues in drinking water. Health Advisory 
Levels for acifluorfen residues in drinking water are established as 
follows: for a 10-kg child, a range of 2 mg/L from 1-day exposure to 
0.1 mg/L for longer-term exposure up to 7 years; for a 70-kg adult, 0.4 
mg/L for longer-term exposure.
    Information in the EPA Pesticides in Groundwater Database indicates 
that a total of 1,185 discrete wells in 8 states (AR, CA, GA, IA, LA, 
MS, VA, WA) were sampled for residues of acifluorfen during the period 
1984-1991. Detectable residues were reported (0.003-0.025 g/L) 
in only 0.3% of the sampled wells.
    Chronic exposure and risk. The EPA has calculated chronic exposure 
levels to acifluorfen residues in drinking water for the U.S. 
population and children. The Agency estimated adult exposure to be 0.7 
x  10-6 mg/kg/day and child exposure to be 2.5  x  
10-6 mg/kg/day. The Agency used very conservative 
assumptions for the exposure assessments. EPA used the highest 
acifluorfen residue level (0.025 ug/L) found from the monitoring of 
1,185 wells over an 8-year period in the 8 states mentioned above to 
estimate exposure. In addition, all the drinking water consumed in the 
US was assumed to contain this high end level of acifluorfen residues 
(even though only 0.3% of all the wells monitored from 1984-91 
contained detectable residues of acifluorfen). The Agency estimated 
that the chronic dietary risks from drinking water will utilize <0.01% 
of

[[Page 39971]]

the RfD for adults and <0.02% of the RfD for children.
    3. From non-dietary exposure. Acifluorfen is currently registered 
for use on the following outdoor residential sites: ornamentals 
(flowering plants, plants, lawns, woody shrubs); mulch; and, walkways, 
paths, trails, lanes, and private roads. Based on the nature of the 
outdoor uses, the EPA concludes that acute and chronic exposure 
scenarios do not exist for acifluorfen. A short- and/or intermediate-
term exposure scenario may exist.
    Short- and intermediate-term exposure and risk.  The outdoor 
residential uses of acifluorfen may constitute a short- and/or 
intermediate-term exposure scenario, but the Agency currently lacks 
residential-related exposure data to complete a comprehensive 
residential risk assessment of acifluorfen.
    4. 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).
    Acifluorfen is a member of the diphenyl ether group of herbicides. 
Other members include bifenox, diclofop methyl, fomesafen, lactofen, 
nitrofen, and oxyfluorfen. Acifluorfen is a major metabolite of 
lactofen in plants, and is assumed to share a common mechanism of 
toxicity with lactofen. At present, there is not sufficient information 
to determine if any other pesticides may also share this common 
mechanism of toxicity. For purposes of this Section 18 time-limited 
tolerance action, the Agency has not assumed that acifluorfen and 
lactofen have a common mechanism of toxicity with any other substances.
    To estimate the cumulative (acifluorfen + lactofen) aggregate (food 
+ water) dietary and cancer exposures, estimates for lactofen on its 
regulated commodities (snap beans, soybeans, and cottonseed) were added 
to estimates for acifluorfen (encompassing all its established plant 
and animal commodity tolerances and the tolerance proposed for this 
Section 18 use).

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

    1. Chronic risk. Using the ARC exposure assumptions described 
above, and taking into account the completeness and reliabilty of the 
toxicity data, EPA has concluded that aggregate exposure to acifluorfen 
from food and water will utilize 0.2% (0.2% from 
food + 0.01% from water) of the RfD for the U.S. population.
    The chronic dietary (food only) risk assessment for lactofen was 
based on percent crop-treated values for soybeans and anticipated 
residue estimates for soybeans, snap beans, and cottonseed. Using these 
partially refined exposure assumptions, the Agency determined that 
chronic dietary (food only) exposure will utilize <1% of the RfD for 
lactofen (established at 0.02 mg/kg/day) for the U.S. population. The 
Agency determined that exposure to lactofen from drinking water will 
utilize <1% of the RfD. This assessment was based on acifluorfen 
monitoring data. The aggregate chronic (food + water) dietary exposure 
contributed by lactofen residues will utilize <2% (<0.0004 mg/kg/day) 
of the lactofen RfD (and corresponds to 3% of the acifluorfen RfD). The 
cumulative (acifluorfen + lactofen) aggregate chronic dietary (food + 
water) exposure was estimated to be on the order of 3 - 4% of the RfD 
for acifluorfen. 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.
    There are no registered indoor residential uses of acifluorfen and 
the Agency has determined that chronic exposure scenarios do not exist 
for the the outdoor residential uses of acifluorfen. Lactofen is not 
registered for residential uses.Therefore, residential exposure is not 
considered to be a contributing factor to cumulative aggregate chronic 
exposure.
    The Agency concludes that there is a reasonable certainty that no 
harm will result from cumulative chronic aggregate exposure to lactofen 
and the sodium salt of acifluorfen residues.
    2. Short- and intermediate-term risk. Short- and intermediate-term 
aggregate exposure takes into account chronic dietary food and water 
(considered to be a background exposure level) plus indoor and outdoor 
residential exposure.
    There are no registered residential uses of lactofen. There are no 
registered indoor uses of acifluorfen. Although the outdoor residential 
uses of acifluorfen may constitute a short- and/or intermediate-term 
exposure scenario, the Agency currently lacks sufficient residential-
related exposure data to complete a comprehensive residential risk 
assessment for many pesticides, including acifluorfen.
    Based on the low percentage (3 - 4%) of the RfD occupied 
by the cumulative (lactofen + acifluorfen) aggregate dietary exposure, 
and in the best scientific judgment of the EPA, the short- and 
intermediate-term aggregate exposure to residues of lactofen and the 
sodium salt of acifluorfen will not exceed the Agency's level of 
concern.

D. Aggregate Cancer Risk for U.S. Population

    Based on published tolerances (none are currently pending), and 
this proposed Section 18 use, the dietary (food only) cancer risk from 
/acifluorfen residues was calculated as 0.65  x  10-6 (upper 
bound estimate). The calculation used the partially refined exposure

[[Page 39972]]

assumptions described above for generating ARCs, and amortized the 
cancer risk over a 70-year lifetime. The drinking water cancer risk 
from acifluorfen residues was estimated as 0.08  x  10-6. 
The aggregate dietary (food + water) cancer risk from exposure to 
acifluorfen residues is thus 0.73  x  10-6.
    Based on the tolerances for lactofen (a B2 carcinogen with a 
Q1* of 0.17 (mg/kg/day)-1) in/on snap beans, 
soybeans, and cottonseed, the dietary (food only) cancer risk from 
residues of lactofen was estimated as 0.45  x  10-6 (upper 
bound) for the U.S. population. For this analysis the Agency used 
percent crop-treated values for soybeans only and anticipated residue 
estimates for all 3 crops. The drinking water cancer risk estimate for 
lactofen was based on the acifluorfen monitoring data discussed above. 
As previously indicated, the drinking water cancer risk from 
acifluorfen residues was estimated as 0.08  x  10-6. The 
cumulative (lactofen + acifluorfen) aggregate (food + water) upper 
bound lifetime dietary cancer risk for the U.S. population from 
exposure to acifluorfen and lactofen residues is thus the sum of:
Acifluorfen (food)--0.65  x  10-6
Lactofen (food)--0.45  x  10-6
Acifluorfen/Lactofen (water)--0.08  x  10-6
Cumulative Aggregate Total:--1.2  x  10-6
This cumulative aggregate dietary cancer risk of 1.2  x  
10-6 for the U.S. population from exposure to acifluorfen 
and lactofen is considered by EPA to be a very conservative estimate 
because:
    (1) The chronic/cancer analyses for acifluorfen and lactofen were 
only partially refined by use of anticipated residue estimates and 
percent crop-treated (%CT) values on selected commodities, and are thus 
over-estimates of exposure.
    (2) Lactofen use on snap beans is currently limited to Oregon and 
Tennesse, which comprises only approximately 20% of the U.S. production 
(for processing, in tons; approximately 12% based on acres planted; Ag. 
Stat. 1992), so use of actual %CT values would be expected to 
significantly reduce the estimate of exposure; snap beans represents 
88% of the lactofen dietary (food) cancer risk contributions.
    (3) Exposure estimates for lactofen/soybeans and acifluorfen/
soybeans were treated as additive for purposes of assessing cumulative 
risk, and thus are likely an over-estimate of exposure,
    (4) Tolerance levels for acifluorfen and lactofen are based on a 
summing of the method sensitivity levels for each component of their 
respective regulable residues, and do not reflect the presence of 
detectable residues.
In fact, there is a consistent absence of quantifiable residues in 
crops treated with either acifluorfen or lactofen.
    For these reasons, the EPA considers that the cumulative (lactofen 
+ acifluorfen) aggregate (food + water) upper bound dietary cancer risk 
estimate of 1.2  x  10-6 for the U.S. population from 
exposure to acifluorfen and lactofen represents a worst case scenario. 
Further refinement would result in a lower risk estimate. In the best 
scientific judgment of the Agency, this cumulative aggregate dietary 
cancer risk estimate does not exceed the Agency's level of concern, and 
EPA concludes that there is a reasonable certainty that no harm in the 
form of cancer will result from cumulative aggregate exposure to 
acifluorfen and lactofen residues.
    The EPA notes that there are no registered indoor or outdoor 
residential uses of lactofen, no registered indoor uses of acifluorfen, 
and that the registered outdoor residential uses of acifluorfen are not 
considered by the Agency to constitute a chronic exposure scenario. 
Thus, no non-dietary, non-occupational chronic exposure to acifluorfen 
or lactofen is expected, or is a factor in cumulative aggregate cancer 
risk.

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

    1. Safety factor for infants and children-- a. In general. In 
assessing the potential for additional sensitivity of infants and 
children to residues of acifluorfen, 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 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 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 100-
fold safety factor (usually for combined inter- and intra-species 
variability) and not the additional 10-fold safety 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 safety factor.
    b. Developmental toxicity studies--Rats. The maternal (systemic) 
NOEL was 90 mg/kg/day, based on decreased body weight at the Lowest 
Observed Effect Level (LOEL) of 180 mg/kg/day, the highest dose tested 
(HDT). The developmental (fetal) NOEL was 20 mg/kg/day, based on 
decreased fetal weight at the LOEL of 90 mg/kg/day.
    Rabbits. Both the maternal (systemic) and developmental NOEL were 
36 mg/kg/day at the HDT.
    c. Reproductive toxicity study. In a 2-generation reproductive 
toxicity study in rats, both the parental (systemic) and reproductive 
(pup) NOEL were 1.25 mg/kg/day, based on decreased survival and an 
increased incidence of kidney lesions at the LOEL of 25.0 mg/kg/day.
    d. Pre- and post-natal sensitivity. The toxicological data base for 
evaluating pre- and post-natal toxicity for acifluorfen is complete 
with respect to current data requirements. The available data indicate 
that no developmental or maternal toxicity was observed in rabbits at 
the highest dose tested (36 mg/kg/day).
    In the developmental toxicity study in rats, an increased 
sensitivity to acifluorfen was seen in developing fetuses as evidenced 
by decreased fetal weights at the NOEL of 20 mg/kg/day (LOEL = 90 mg/
kg/day). Maternal toxicity was observed at the highest dose tested 
(LOEL = 180 mg/kg/day) and was based on decreased body weight. Based on 
these findings, an additional UF (3X or 10X) would be justified in 
order to be protective of infants and children. However, a 100-fold UF 
has already been applied to the RfD NOEL of 1.25 mg/kg/day, and the 
developmental NOEL is more than 16-fold greater than the RfD NOEL. 
Therefore, an additional UF does not appear to be necessary.
    There was no parental or reproductive toxicity observed in a 2-
generation reproductive toxicity study in rats at doses up to 150 mg/
kg/day (HDT).
    e. Conclusion. The cumulative data discussed above indicates 
minimal concern for developmental or reproductive toxicity. Thus, these 
data

[[Page 39973]]

support use of the standard uncertainty factor of 100 and an additional 
safety factor is not needed to protect infants and children.
    2. Chronic risk. Using the conservative exposure assumptions 
described above, EPA has concluded that aggregate dietary (food + 
water) exposure to acifluorfen will utilize 0.4% (up to 
0.4% from food + 0.02% from water) of the RfD for 
any of the infant and children subgroups of the U.S. population.
    The Agency estimated that the dietary (food) exposure to lactofen 
residues willl utilize <1% of the RfD (the RfD for lactofen is 0.02 mg/
kg/day) for any of the infant and children subgroups of the U.S. 
population (based on percent crop-treated values for soybeans and 
anticipated residue estimates for soybeans, snap beans, and 
cottonseed). The dietary (water) exposure of children to lactofen was 
based on acifluorfen monitoring data, and estimated as <1% of the RfD. 
The chronic aggregate (food + water) dietary exposure contributed by 
lactofen tolerances is thus <2% (<0.0004 mg/kg/day) of the lactofen RfD 
(and corresponds to 3% of the acifluorfen RfD).
    Cumulative (acifluorfen + lactofen) chronic aggregate (food + 
water) dietary exposure for infants and children is thus on the order 
of 3-4% of the RfD of acifluorfen.
    There are no registered indoor residential uses of acifluorfen. EPA 
believes that the outdoor residential uses of acifluorfen do not 
constitute a chronic exposure scenario. Lactofen is not registered for 
residential uses. Therefore, residential exposure will not be a 
contributing factor to cumulative chronic aggregate exposure to infants 
and children.
    EPA concludes that there is a reasonable certainty that no harm 
will result to infants and children from cumulative chronic aggregate 
exposure to lactofen and acifluorfen residues.
    3. Short- or intermediate-term risk. There are outdoor residential 
uses of acifluorfen, and these may constitute a short- and/or 
intermediate-term exposure scenario, but the Agency currently lacks 
residential-related exposure data to complete a comprehensive 
residential risk assessment of acifluorfen. Based on the lack of an 
identified acute toxicological endpoint for acifluorfen, and the low 
(3-4%) percentage of the acifluorfen RfD occupied by 
cumulative (lactofen + acifluorfen) aggregate (food + water) dietary 
exposure for any of the infant and children subgroups of the U.S. 
population, in the best scientific judgment of EPA, short- and/or 
intermediate-term cumulative aggregate exposure of acifluorfen and 
lactofen to infants and children will not exceed the Agency's level of 
concern.

V. Other Considerations

A. Metabolism In Plants and Animals

    The nature of the residue in rice and goats is adequately 
understood. Additional metabolism studies have been requested. At 
present, the residue of concern in plants and animals is considered to 
be as specified in 40 CFR 180.383 .

B. Analytical Enforcement Methodology

    Adequate enforcement methodology (GLC/ECD and GLC/MS) is available 
in the Pesticide Analytical Manual, Volume II, Methods 180.383 I and A, 
to enforce the tolerance expression of 40 CFR 180.383.

C. Magnitude of Residues

     Combined residues of the sodium salt of acifluorfen and its 
regulated metabolites are not expected to exceed 0.1 ppm in/on lima 
beans, southern peas, or cowpeas as a result of use under this Section 
18 program. According to Table 1 of the OPPTS Test Guidelines, Series 
860, Residue Chemistry, 8/96, there are no processed commodities 
associated with lima beans, southern peas, or cowpeas. Cowpea seed, 
forage, and hay are the only livestock feedstuffs associated with this 
Section 18 action and, in the absence of residue data, their use for 
feed or forage is being restricted under this Section 18 program. For 
the purpose of this Section 18 program and its limited acreage, the EPA 
will prohibit the use of treated plants for feed or forage. Thus, 
secondary residues in animal commodities are not expected to exceed 
existing tolerances as a result of this Section 18 use.

D. International Residue Limits

    There are no Codex, Canadian, or Mexican maximum residue limits 
established for acifluorfen.

E. Rotational Crop Restrictions

    Under this Section 18 use, in case of crop failure, only peanuts, 
soybeans, rice, lima beans, southern peas, or cowpeas may be 
immediately replanted. Further plantback restrictions, applying to 
crops without acifluorfen tolerances, are listed on the federal label, 
and are also to be followed under this Section 18 program.

VI. Conclusion

    Therefore, the tolerance is established for the combined residues 
of the sodium salt of acifluorfen and its metabolites (the acid, methyl 
ester, and amino analogues) in or on lima beans, cowpeas, and southern 
peas at 0.1 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 September 23, 1997, 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 
Confidential Business Information (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

[[Page 39974]]

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-300516] (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 (7506C), 
Office of Pesticide Programs, Environmental Protection Agency, Crystal 
Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA.
    Electronic comments may be sent directly to EPA at:
    [email protected].

    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 time-limited tolerances under FFDCA 
section 408(l)(6) response to a petition submitted to the Agency. The 
Office of Management and Budget (OMB) has exempted these types of 
actions from review under Executive Order 12866, entitled Regulatory 
Planning and Review (58 FR 51735, October 4, 1993). This final rule 
does not contain any information collections subject to OMB approval 
under the Paperwork Reduction Act (PRA), 44 U.S.C. 3501 et seq., or 
impose any enforceable duty or contain any unfunded mandate as 
described under Title II of the Unfunded Mandates Reform Act of 1995 
(UMRA) (Pub. L. 104-4). Nor does it require any prior consultation as 
specified by Executive Order 12875, entitled Enhancing the 
Intergovernmental Partnership (58 FR 58093, October 28, 1993), or 
special considerations as required by Executive Order 12898, entitled 
Federal Actions to Address Environmental Justice in Minority 
Populations and Low-Income Populations (59 FR 7629, February 16, 1994), 
or require OMB review in accordance with Executive Order 13045, 
entitled Protection of Children from Environmental Health Risks and 
Safety Risks (62 FR 19885, April 23, 1997).
    In addition, since these tolerances and exemptions that are 
established under FFDCA section 408 (l)(6), such as the tolerances 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 acations 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: July 10, 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 180.383 is amended as follows:
    i. By designating the existing text as paragraph (a) and adding a 
heading.
    ii. By adding paragraph (b).
    iii. By adding the headings and reserving paragraphs (c) and (d).
    Section 180.383, as amended, reads as follows:


Sec. 180.383 Sodium salt of acifluorfen; tolerances for residues.

    (a) General. *        *        *
    (b) Section 18 emergency exemptions. Time-limited tolerances are 
established for the combined residues of the herbicide sodium salt of 
acifluorfen and its metabolites (the corresponding acid, methyl ester, 
and amino analogues) in connection with use of the pesticide under 
section 18 emergency exemptions granted by EPA. The tolerances will 
expire and are revoked on the dates specified in the following table:

                                                                        
------------------------------------------------------------------------
                                                          Expiration/   
            Commodity              Parts per million    Revocation Date 
------------------------------------------------------------------------
 Cowpeas........................  0.1                 December 31, 1998 
Lima beans......................  0.1                 December 31, 1998 
Southern peas...................  0.1                 December 31, 1998 
------------------------------------------------------------------------

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

[FR Doc. 97-19668 Filed 7-24-97; 8:45 am]
BILLING CODE 6560-50-F