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sodium chlorate (Defol) Pesticide Tolerance Exemption 11/97

 

[Federal Register: December 3, 1997 (Volume 62, Number 232)]
[Rules and Regulations]               
[Page 63858-63863]
>From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr03de97-14]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-300574; FRL-5754-1]
RIN 2070-AB78

 
Sodium Chlorate; Exemption From Pesticide Tolerance for Emergency 
Exemptions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes a time-limited exemption from the 
requirement of a tolerance for residues of sodium chlorate in or on 
wheat. This action is in connection with crisis exemptions declared by 
the states of Arkansas and Mississippi under section 18 of the Federal 
Insecticide, Fungicide, and Rodenticide Act authorizing use of the 
pesticide on wheat in Arkansas and Mississippi. This regulation 
establishes an exemption from the requirement of a tolerance for 
residues of sodium chlorate 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 exemption will expire and 
is revoked on July 31, 1998.

DATES: This regulation is effective December 3, 1997. Objections and 
requests for hearings must be received by EPA on or before February 2, 
1998.

ADDRESSES: Written objections and hearing requests, identified by the 
docket control number, [OPP-300574], 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-300574], 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, Crystal 
Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA.
    A copy of objections and hearing requests filed with the Hearing 
Clerk may also be submitted electronically by sending electronic mail 
(e-mail) to: opp-docket@epamail.epa.gov. Copies of objections and 
hearing requests must be submitted as an ASCII file avoiding the use of 
special characters and any form of encryption. Copies of objections and 
hearing requests will also be accepted on disks in WordPerfect 5.1/6.1 
file format or ASCII file format. All copies of objections and hearing 
requests in electronic form must be identified by the docket control 
number [OPP-300574]. 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: Libby Pemberton, 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: CM #2, 1921 Jefferson Davis Hwy., 
Arlington, VA, (703) 308-9364, e-mail: pemberton.libby@epamail.epa.gov.

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 an exemption 
from the requirement of a tolerance for residues of the defoliant/
desiccant sodium chlorate, in or on wheat. This exemption will expire 
and is revoked on July 31, 1998. EPA will publish a document in the 
Federal Register to remove the revoked exemption 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(c)(2)(A)(i) of the FFDCA allows EPA to establish an

[[Page 63859]]

exemption from tolerance (the legal limit for a pesticide chemical 
residue in or on a food) only if EPA determines that the exemption from 
tolerance is ``safe.'' Section 408(c)(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. New section 408(c)(2)(B) requires EPA to take 
into account, among other relevant conditions, the considerations set 
forth in 408(c)(2)(C) and (D). 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 Sodium Chlorate on Wheat and FFDCA 
Tolerances

    On May 27 and June 6, 1997, the states of Mississippi and Arkansas, 
respectively, availed themselves of the authority to declare the 
existence of a crisis situation within each state, thereby authorizing 
use under FIFRA section 18 of sodium chlorate on wheat as a defoliant 
or desiccant to aid in the harvest of wheat. A cool, wet spring delayed 
the wheat harvest in these states. Continued heavy rains resulted in 
the need for a harvest aid to desiccate winter weeds which developed in 
the thin stands of an already diminished wheat crop.
    As part of its assessment of these crisis exemptions, EPA assessed 
the potential risks presented by residues of sodium chlorate in or on 
wheat. In doing so, EPA considered the new safety standard in FFDCA 
section 408(c)(2), and EPA decided that an exemption from the 
requirement for a 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 exemption from 
the requirement of a tolerance without notice and opportunity for 
public comment under section 408(e), as provided in section 408(l)(6). 
Although this exemption from the requirement of a tolerance will expire 
and is revoked on July 31, 1998, under FFDCA section 408(l)(5), 
residues of the pesticide remaining in or on wheat 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 exemption 
earlier if any experience with, scientific data on, or other relevant 
information on this pesticide indicate that the residues are not safe.
    Because this exemption from the requirement of a tolerance is being 
approved under emergency conditions EPA has not made any decisions 
about whether sodium chlorate meets EPA's registration requirements for 
use on wheat or whether a permanent exemption from the requirement of a 
tolerance for this use would be appropriate. Under these circumstances, 
EPA does not believe that this exemption serves as a basis for 
registration of sodium chlorate by a State for special local needs 
under FIFRA section 24(c). Nor does this exemption serve as the basis 
for any State other than Arkansas and Mississippi 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 sodium chlorate, 
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.

[[Page 63860]]

    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 
three 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 (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 sodium 
chlorate and to make a determination on aggregate exposure, consistent 
with section 408(b)(2), for a time-limited exemption from the 
requirement of a tolerance for residues of sodium chlorate on wheat. 
EPA's assessment of the dietary exposures and risks associated with 
establishing the tolerance exemption 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 sodium chlorate are 
discussed below.
    1. Acute toxicity. No acute dietary endpoint was identified. This 
conclusion was based on a developmental toxicity study in which rats 
were dosed at the limit dose of 1,000 mg/kg/day without any ill effects 
to the dams or their fetuses.
    2. Short - and intermediate - term non-dietary toxicity. The 
available acute

[[Page 63861]]

dermal and inhalation studies are of dilute mixtures with other active 
ingredients. The Toxicity Categories were III for the dermal studies, 
and IV for the inhalation studies. Aqueous sodium chlorate has been 
used as an antiseptic wash for the skin and mucous membranes. 
Considering the low toxicity of sodium chlorate, non-dietary exposure 
is not a concern.
    3. Chronic toxicity. EPA has not established an RfD for sodium 
chlorate. For purposes of this exemption, based upon available toxicity 
data, an RfD for sodium chlorate of 0.1 milligrams/kilogram/day (mg/kg/
day) was used. This RfD is based on a 90-day oral toxicity study in 
rats with a NOEL of 100 mg/kg/day and an uncertainty factor of 1,000 
(10-fold each for inter and intra-species extrapolation, and use of a 
less-than-chronic endpoint) based on anemia, reticulocytosis, and 
depressed adrenal weights at the LOEL of 1,000 mg/kg/day.
    4. Carcinogenicity. Sodium chlorate is used as a desiccant. Because 
it is chemically similar to chlorine dioxide and chlorite which are not 
carcinogenic, and dietary exposure is virtually eliminated by 
hydrolysis during cooking, carcinogenicity is not a concern.

B. Exposures and Risks

    1. From food and feed uses. Exemptions from the requirement of 
tolerances have been established (40 CFR 180.1020) for the residues of 
sodium chlorate, in or on a variety of raw agricultural commodities, 
including corn, rice, safflower, and sorghum. Risk assessments were 
conducted by EPA to assess dietary exposures and risks from sodium 
chlorate 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.
    ii. Chronic exposure and risk. Field trial residue values were non-
detectable at the limit of detection of 2 ppm, even at the 2 x  rate. 
The risk assessment assumed that 100% of all wheat commodities will 
contain sodium chlorate residues and those residues would all be at 2 
ppm, which results in an overestimate of human dietary exposure. 
Additionally, residues of sodium chlorate would likely be substantially 
reduced through hydrolysis during cooking, although this reduction was 
not taken into account for this conservative risk assessment.
    2. From drinking water. There is no established Maximum 
Concentration Level for residues of sodium chlorate in drinking water. 
No drinking water health advisory levels have been established for 
sodium chlorate.
     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 (RfDs or acute dietary NOELs) 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 sodium chlorate to 
exceed the RfD if the exemption being considered in this document were 
granted. The Agency has therefore concluded that the potential 
exposures associated with sodium chlorate 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 exemption is granted.
    3. From non-dietary exposure. Sodium chlorate is currently 
registered for use on the following residential non-food sites: wood 
treatment, outdoor turf, and ornamental perennials, shrubs, and trees. 
The available acute dermal and inhalation studies are of dilute 
mixtures with other active ingredients. The Toxicity Categories are III 
for the dermal studies, and IV for the inhalation studies. Aqueous 
sodium chlorate has been used as an antiseptic wash for the skin and 
mucous membranes. Agricultural workers would be exposed to aqueous 
solutions containing a low percentage of sodium chlorate. Considering 
the low toxicity of sodium chlorate, non-dietary exposure is not a 
concern.
    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).
    EPA does not have, at this time, available data to determine 
whether sodium chlorate 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, 
sodium chlorate does not appear to produce a toxic metabolite produced 
by other substances. For the purposes of this tolerance action, 
therefore, EPA has not

[[Page 63862]]

assumed that sodium chlorate has a common mechanism of toxicity with 
other substances.

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

    1. Chronic risk. Using the very conservative TMRC exposure 
assumptions described above, EPA has concluded that aggregate exposure 
to sodium chlorate from food will utilize 3% of the RfD for the U.S. 
population. The major identifiable subgroup with the highest aggregate 
exposure is children (1-6 years old) discussed below. EPA generally has 
no concern for exposures below 100% of the RfD because the RfD 
represents the level at or below which daily aggregate dietary exposure 
over a lifetime will not pose appreciable risks to human health. 
Despite the potential for exposure to sodium chlorate in drinking water 
and from non-dietary, non-occupational exposure, EPA does not expect 
the aggregate exposure to exceed 100% of the RfD. EPA concludes that 
there is a reasonable certainty that no harm will result from aggregate 
exposure to sodium chlorate 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.

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 sodium chlorate, EPA considered data from 
developmental toxicity studies 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 100 for combined inter-and intra-species 
variability)) and not the additional tenfold 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.
    ii. Developmental toxicity studies. In the developmental study in 
rats, the maternal (systemic) NOEL was >1,000 mg/kg/day. The 
developmental (fetal) NOEl was also >1,000 mg/kg/day.
    iii. Pre- and post-natal sensitivity. Sodium chlorate is not a 
developmental toxicant in rats. EPA has already applied an additional 
10-fold uncertainty factor (resulting in a total 1,000-fold uncertainty 
factor) to the NOEL used to set the RfD. This additional 10-fold 
uncertainty factor should be adequate to protect infants and children.
    2. Chronic risk. Using the very conservative exposure assumptions 
described above, EPA has concluded that aggregate exposure to sodium 
chlorate from food will utilize from 1% of the RfD for nursing infants 
up to 6% for children 1-6 years old. EPA generally has no concern for 
exposures below 100% of the RfD because the RfD represents the level at 
or below which daily aggregate dietary exposure over a lifetime will 
not pose appreciable risks to human health. Despite the potential for 
exposure to sodium chlorate in drinking water and from non-dietary, 
non-occupational exposure, EPA does not expect the aggregate exposure 
to exceed 100% of the RfD. EPA concludes that there is a reasonable 
certainty that no harm will result to infants and children from 
aggregate exposure to sodium chlorate residues.

V. Other Considerations

A. Metabolism In Plants and Animals

    The metabolism of sodium chlorate in plants is adequately 
understood. The residue of concern is sodium chlorate and sodium 
chloride. The nature of the residue in animals is not applicable due to 
no reasonable expectation of transfer of residues to meat/milk/poultry/
eggs.

B. Analytical Enforcement Methodology

    Analytical methods for detecting and measuring the levels of the 
pesticide residue are not needed. The Agency proposes to establish an 
exemption from the requirement of a tolerance without any numerical 
limitation; therefore, the Agency has concluded that analytical methods 
are not required for enforcement purposes for sodium chlorate.

C. Magnitude of Residues

    No detectable residues were found in wheat grain or straw from 
wheat treated at the 2 x  rate. Considering that no detectable residues 
were found in wheat grain, it is unlikely that significant residues 
will occur in the processed fractions of wheat. There is no likelihood 
of transfer of residues to meat/milk/poultry/eggs. Therefore, magnitude 
of the residue data in those commodities is not required.

D. International Residue Limits

    No CODEX, Canadian, or Mexican maximum residue levels have been 
established for residues of sodium chlorate.

E. Rotational Crop Restrictions

    Considering the phytotoxic nature of sodium chlorate, which would 
preclude the planting of a crop soon after treatment of a previous 
crop, coupled with the fact that residues are below the limit of 
quantitation shortly after application to target crops, EPA does not 
believe measurable residues would be detected in rotational crops. For 
the purposes of this section 18 use, rotational crop tolerances and/or 
plant back restrictions will not be necessary.

VI. Conclusion

    Therefore, the exemption from the requirement of a tolerance is 
established for residues of sodium chlorate in wheat.

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 2, 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

[[Page 63863]]

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 Record and Electronic Submissions

    EPA has established a record for this rulemaking under docket 
control number [OPP-300574] (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, CM #2, 
1921 Jefferson Davis Hwy., Arlington, VA.
    Electronic comments may be sent directly to EPA at:
    opp-docket@epamail.epa.gov.


    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 time-limited exemption from the 
tolerance requirement 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 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 exemption 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 21, 1997.

Linda A. Travers,
Acting Director, 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 180.1020 is amended by designating the existing text as 
paragraph (a) and by adding paragraph (b) to read as follows:


Sec. 180.1020 Sodium chlorate; exemption from the requirement of a 
tolerance.

 *        *        *        *        *
    (b) A time-limited exemption from the requirement of a tolerance is 
established for residues of the defoliant/desiccant in connection with 
use of the pesticide under section 18 emergency exemptions granted by 
EPA. The exemption will expire and is revoked on the date specified in 
the following table:

                                                                        
------------------------------------------------------------------------
                                                          Expiration/   
            Commodity              Parts per million    revocation date 
------------------------------------------------------------------------
Wheat...........................  NA                  7/31/98           
------------------------------------------------------------------------


[FR Doc. 97-31547 Filed 12-2-97; 8:45 am]
BILLING CODE 6560-50-F