[Federal Register Volume 62, Number 234 (Friday, December 5, 1997)]
[Rules and Regulations]
[Pages 64287-64294]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-31553]
-----------------------------------------------------------------------
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 180 and 185
[OPP-300587; FRL-5754-5]
RIN 2070-AB78
Maleic hydrazide; Pesticide Tolerances for Emergency Exemptions
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: This regulation establishes time-limited tolerances for
residues of maleic hydrazide (1,2-dihydro-3,6-pyridazinedione) in or on
rice commodities as well as tolerances for secondary residues in animal
commodities. 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 rice
in Louisiana. This regulation establishes a maximum permissible level
for residues of maleic hydrazide 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 September 30, 1998.
DATES: This regulation is effective December 5, 1997. Objections and
requests for hearings must be received by EPA on or before February 3,
1998.
ADDRESSES: Written objections and hearing requests, identified by the
docket control number, [OPP-300587], 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-300587], must also be submitted to: Public
Information and Records Integrity Branch, Information Resources and
Services Division (7502C), Office of Pesticide Programs, Environmental
Protection Agency, 401 M St., SW., Washington, DC 20460. In person,
bring a copy of objections and hearing requests to Rm. 1132, CM #2,
1921 Jefferson Davis Hwy., Arlington, VA.
A copy of objections and hearing requests filed with the Hearing
Clerk may also be submitted electronically by sending electronic mail
(e-mail) to: opp-docket@epamail.e. 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-300587]. 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: Stephen Schaible,
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) 308-9362, e-mail:
schaible.stephen@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 tolerances for
residues of the herbicide maleic hydrazide (1,2-dihydro-3,6-
pyridazinedione), in or on rice, grain at 105 part per million (ppm);
rice, straw at 75 ppm; rice, hulls at 240 ppm; and rice, bran at 180
ppm. Additionally, the Agency is establishing tolerances for secondary
residues in milk at 1.0 ppm; at 2.5 ppm in meat, 7 ppm in liver, 32 ppm
in kidney, and 3 ppm in fat of cattle, goats, hogs, horses, and sheep;
at 0.5 ppm in meat, liver, and fat of poultry; 1.4 ppm in poultry meat
byproducts; and 0.5 ppm in eggs. These tolerances will expire and are
revoked on September 30, 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
[[Page 64288]]
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 Maleic Hydrazide on Rice and FFDCA
Tolerances
On June 19, 1997, the Louisiana Department of Agriculture and
Forestry availed of itself the authority to declare the existence of a
crisis situation within the State, thereby authorizing use under FIFRA
section 18 of maleic hydrazide on rice to control red rice. Red rice is
normally controlled by flood water management and rotating the rice
crop to soybeans, where soybean herbicides are used that control red
rice but are also phytotoxic to commercial rice. Over the last 5 years,
farm land to be rotated into rice in 1997 has experienced three
consecutive soybean seasons with poor control of red rice. This has
resulted in increasing red rice infestations in the two intervening
rice crop seasons, and a buildup of red rice seed in the soil. This
situation gives rise to the possibility of an unprecedentedly high red
rice infestation in 1997. Economic loss due to red rice occurs both
through reductions in the yield of the rice crop and through reductions
in the quality of the harvested crop. Because red rice and cultivated
rice are closely related, there are few selective herbicides available;
those that are have limited efficacy against red rice. The use of
maleic hydrazide would not only increase yield and quality of the
harvested crop this year, but would reduce red rice seed in the soil
and therefore reduce the level of red rice infestation in the next rice
crop. EPA has authorized under FIFRA section 18 the use of maleic
hydrazide on rice for control of red rice in Louisiana. 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 maleic hydrazide in or on
rice. In doing so, EPA considered the new safety standard in FFDCA
section 408(b)(2), and EPA decided that the necessary tolerances 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 these tolerances without notice and opportunity
for public comment under section 408(e), as provided in section
408(l)(6). Although these tolerances will expire and are revoked on
September 30, 1998, under FFDCA section 408(l)(5), residues of the
pesticide not in excess of the amounts specified in the tolerances
remaining in or on rice grain, bran, hulls and straw or in meat, milk,
poultry or eggs 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 these tolerances earlier if any experience with,
scientific data on, or other relevant information on this pesticide
indicate that the residues are not safe.
Because these tolerances are being approved under emergency
conditions EPA has not made any decisions about whether maleic
hydrazide meets EPA's registration requirements for use on rice or
whether permanent tolerances for this use would be appropriate. Under
these circumstances, EPA does not believe that these tolerances serve
as a basis for registration of maleic hydrazide by a State for special
local needs under FIFRA section 24(c). Nor do these tolerances serve as
the basis for any State other than Louisiana 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 maleic hydrazide, 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 percent or less of the
RfD) is generally considered acceptable by EPA. EPA generally uses the
RfD to evaluate the chronic risks posed by pesticide exposure. For
shorter term risks, EPA calculates a margin of exposure (MOE) by
dividing the estimated human exposure into the NOEL from the
appropriate animal study. Commonly, EPA finds MOEs lower than 100 to be
unacceptable. This hundredfold MOE is based on the same rationale as
the hundredfold uncertainty factor.
[[Page 64289]]
Lifetime feeding studies in two species of laboratory animals are
conducted to screen pesticides for cancer effects. When evidence of
increased cancer is noted in these studies, the Agency conducts a
weight of the evidence review of all relevant toxicological data
including short-term and mutagenicity studies and structure activity
relationship. Once a pesticide has been classified as a potential human
carcinogen, different types of risk assessments (e.g., linear low dose
extrapolations or MOE calculation based on the appropriate NOEL) will
be carried out based on the nature of the carcinogenic response and the
Agency's knowledge of its mode of action.
2. Differences in toxic effect due to exposure duration. The
toxicological effects of a pesticide can vary with different exposure
durations. EPA considers the entire toxicity data base, and based on
the effects seen for different durations and routes of exposure,
determines which risk assessments should be done to assure that the
public is adequately protected from any pesticide exposure scenario.
Both short and long durations of exposure are always considered.
Typically, risk assessments include ``acute,'' ``short-term,''
``intermediate term,'' and ``chronic,'' risks. These assessments are
defined by the Agency as follows.
Acute risk, by the Agency's definition, results from 1-day
consumption of food and water, and reflects toxicity which could be
expressed following a single oral exposure to the pesticide residues.
High end exposure to food and water residues are typically assumed.
Short-term risk results from exposure to the pesticide for a period
of 1-7 days, and therefore overlaps with the acute risk assessment.
Historically, this risk assessment was intended to address primarily
dermal and inhalation exposure which could result, for example, from
residential pesticide applications. However, since enaction of FQPA,
this assessment has been expanded to include both dietary and non-
dietary sources of exposure, and will typically consider exposure from
food, water, and residential uses when reliable data are available. In
this assessment, risks from average food and water exposure, and high-
end residential exposure, are aggregated. High-end exposures from all 3
sources are not typically added because of the very low probability of
this occurring in most cases, and because the other conservative
assumptions built into the assessment assure adequate protection of
public health. However, for cases in which high-end exposure can
reasonably be expected from multiple sources (e.g. frequent and
widespread homeowner use in a specific geographical area), multiple
high-end risks will be aggregated and presented as part of the
comprehensive risk assessment/characterization. Since the toxicological
endpoint considered in this assessment reflects exposure over a period
of at least 7 days, an additional degree of conservatism is built into
the assessment; i.e., the risk assessment nominally covers 1-7 days
exposure, and the toxicological endpoint/NOEL is selected to be
adequate for at least 7 days of exposure. (Toxicity results at lower
levels when the dosing duration is increased.)
Intermediate-term risk results from exposure for 7 days to several
months. This assessment is handled in a manner similar to the short-
term risk assessment.
Chronic risk assessment describes risk which could result from
several months to a lifetime of exposure. For this assessment, risks
are aggregated considering average exposure from all sources for
representative population subgroups including infants and children.
B. Aggregate Exposure
In examining aggregate exposure, FFDCA section 408 requires that
EPA take into account available and reliable information concerning
exposure from the pesticide residue in the food in question, residues
in other foods for which there are tolerances, residues in groundwater
or surface water that is consumed as drinking water, and other non-
occupational exposures through pesticide use in gardens, lawns, or
buildings (residential and other indoor uses). Dietary exposure to
residues of a pesticide in a food commodity are estimated by
multiplying the average daily consumption of the food forms of that
commodity by the tolerance level or the anticipated pesticide residue
level. The Theoretical Maximum Residue Contribution (TMRC) is an
estimate of the level of residues consumed daily if each food item
contained pesticide residues equal to the tolerance. In evaluating food
exposures, EPA takes into account varying consumption patterns of major
identifiable subgroups of consumers, including infants and children.
The TMRC is a ``worst case'' estimate since it is based on the
assumptions that food contains pesticide residues at the tolerance
level and that 100% of the crop is treated by pesticides that have
established tolerances. If the TMRC exceeds the RfD or poses a lifetime
cancer risk that is greater than approximately one in a million, EPA
attempts to derive a more accurate exposure estimate for the pesticide
by evaluating additional types of information (anticipated residue data
and/or percent of crop treated data) which show, generally, that
pesticide residues in most foods when they are eaten are well below
established tolerances.
Percent of crop treated estimates are derived from Federal and
private market survey data. Typically, a range of estimates are
supplied and the upper end of this range is assumed for the exposure
assessment. By using this upper end estimate of percent of crop
treated, the Agency is reasonably certain that exposure is not
understated for any significant subpopulation group. Further, regional
consumption information is taken into account through EPA's computer-
based model for evaluating the exposure of significant subpopulations
including several regional groups, to pesticide residues. For this
pesticide, the most highly exposed population subgroup non-nursing
infants less than 1 year 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 maleic
hydrazide and to make a determination on aggregate exposure, consistent
with section 408(b)(2), for time-limited tolerances for residues of
maleic hydrazide (1,2-dihydro-3,6-pyridazinedione) on rice, grain at
105 ppm; rice, straw at 75 ppm; rice, hulls at 240 ppm; rice, bran at
180 ppm; time-limited tolerances are set at 2.5 ppm in meat, 7.0 ppm in
liver, 32.0 ppm in kidney, and 3.0 ppm in fat of cattle, goats, hogs,
horses, and sheep; 1.0 ppm in milk; 0.5 ppm in meat, liver, and fat of
poultry; 1.4 ppm in poultry meat byproducts (except liver), and 0.5 ppm
in eggs. 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 maleic hydrazide
are discussed below.
[[Page 64290]]
1. Acute toxicity. The Agency has determined that an acute dietary
risk assessment is not required for this chemical.
2. Short - and intermediate - term toxicity. Based on the
available data base, the Agency has concluded that determination of
short-term Margin of Exposure (MOE) calculations is not required. For
intermediate-term MOE calculations, the Agency recommends use of the
NOEL of 29 milligrams/kilogram/day (mg/kg/day) from the 1-year feeding
study in dogs. Decreased weight gain and reduced heart weight are the
effects observed at the Lowest Effect Level (LEL) of 87 mg/kg/day.
3. Chronic toxicity. EPA has established the RfD for maleic
hydrazide at 0.25 mg/kg/day. This RfD is based on a NOEL of 25 mg/kg/
day taken from a 2-year feeding study in rats in which decreased weight
gain in males was the effect observed at the LEL of 500 mg/kg/day. An
uncertainty factor of 100 was assigned to allow for inter- and intra-
species variability.
4. Carcinogenicity. Maleic hydrazide has been classified as a Group
E--evidence of non-carcinogenicity for humans in two species--chemical
by the Agency. A carcinogenic risk assessment is not required.
B. Exposures and Risks
1. From food and feed uses. Tolerances have been established (40
CFR 180.175) for the residues of maleic hydrazide (1,2-dihydro-3,6-
pyridazinedione), in or on dry bulb onions, potatoes and cranberries.
Risk assessments were conducted by EPA to assess dietary exposures and
risks from maleic hydrazide as follows:
i. Acute exposure and risk. Acute dietary risk assessments are
performed for a food-use pesticide if a toxicological study has
indicated the possibility of an effect of concern occurring as a result
of a 1 day or single exposure. The Agency has determined that this risk
assessment is not required.
ii. Chronic exposure and risk. Refined residue and percent of crop
treated information were used in the chronic exposure analysis to
calculate the Anticipated Residue Contribution (ARC) from published and
proposed uses of maleic hydrazide. The use of tolerance level residues
for potatoes and dry bulb onions as well as the use of high end
anticipated residues for animal commodities results in overestimation
of chronic dietary risk.
2. From drinking water. Review of available data indicate that
maleic hydrazide is neither mobile nor persistent. There is no
established Maximum Contaminant Level for residues of maleic hydrazide
in drinking water. Health advisory levels for maleic hydrazide in
drinking water have been established at the following levels: for a 10
kg child, 10 mg/liter (1-day and 10-day levels) and 5 mg/liter (long
term level); for a 70 kg adult, 20 mg/liter (long term level).
Chronic exposure and risk. Because the Agency lacks sufficient
water-related exposure data to complete a comprehensive drinking water
risk assessment for many pesticides, EPA has commenced and nearly
completed a process to identify a reasonable yet conservative bounding
figure for the potential contribution of water-related exposure to the
aggregate risk posed by a pesticide. In developing the bounding figure,
EPA estimated residue levels in water for a number of specific
pesticides using various data sources. The Agency then applied the
estimated residue levels, in conjunction with appropriate toxicological
endpoints (RfD's or acute dietary NOEL's) and assumptions about body
weight and consumption, to calculate, for each pesticide, the increment
of aggregate risk contributed by consumption of contaminated water.
While EPA has not yet pinpointed the appropriate bounding figure for
exposure from contaminated water, the ranges the Agency is continuing
to examine are all below the level that would cause maleic hydrazide to
exceed the RfD if the tolerance being considered in this document were
granted. The Agency has therefore concluded that the potential
exposures associated with maleic hydrazide in water, even at the higher
levels the Agency is considering as a conservative upper bound, would
not prevent the Agency from determining that there is a reasonable
certainty of no harm if the tolerance is granted.
3. From non-dietary exposure. Maleic hydrazide is currently
registered for use on the following residential non-food sites: outdoor
non-food sites such as non-bearing citrus and ornamentals.
i. Chronic exposure and risk. Based on the uses registered, a
chronic, non-dietary exposure scenario is not expected.
ii. Short- and intermediate-term exposure and risk. Maleic
hydrazide is currently registered for use on outdoor non-food sites
such as non-bearing citrus, ornamental shade trees and plants, turf,
lawns, utility and highway rights of way, industrial areas and
airports. There are no indoor uses.
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).
Maleic hydrazide is a member of the hydrazide class of pesticides;
another member of this class is Alar (daminozide). EPA does not have,
at this time, available data to determine whether maleic hydrazide 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
[[Page 64291]]
risk approach based on a common mechanism of toxicity, maleic hydrazide
does not appear to produce a toxic metabolite produced by other
substances. For the purposes of this tolerance action, therefore, EPA
has not assumed that maleic hydrazide 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 ARC exposure assumptions described in
Unit IV.B. of this preamble, EPA has concluded that aggregate exposure
to maleic hydrazide from food will utilize 14% of the RfD for the U.S.
population. The major identifiable subgroup with the highest aggregate
exposure is non-nursing infants less than 1 year old (discussed in Unit
IV.E. of this preamble). 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 maleic hydrazide 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 maleic
hydrazide 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. Data to quantify intermediate-term exposure from
non-occupational, non-dietary uses are not available at this time. In
the absence of a quantitative estimate of exposure, the Agency believes
that the large MOEs calculated for mixers, loaders and applicators of
the product (1,000 to 1,800, where 100 is considered to be the level at
which the Agency has reasonable certainty of no harm resulting from
occupational exposure to the chemical) demonstrate that intermediate
aggregate risk from non-occupational uses of maleic hydrazide is below
the Agency's level of concern.
D. Aggregate Cancer Risk for U.S. Population
Maleic hydrazide has been classified as a Group E chemical. A
carcinogenic risk assessment is not required for this chemical.
E. Aggregate Risks and Determination of Safety for Infants and Children
1. Safety factor for infants and children-- i. In general. In
assessing the potential for additional sensitivity of infants and
children to residues of maleic hydrazide, EPA considered data from
developmental toxicity studies in the rat and rabbit and a two-
generation reproduction study in the rat. The developmental toxicity
studies are designed to evaluate adverse effects on the developing
organism resulting from pesticide exposure during prenatal development
to one or both parents. Reproduction studies provide information
relating to effects from exposure to the pesticide on the reproductive
capability of mating animals and data on systemic toxicity.
FFDCA section 408 provides that EPA shall apply an additional
tenfold margin of safety for infants and children in the case of
threshold effects to account for pre-and post-natal toxicity and the
completeness of the database unless EPA determines that a different
margin of safety will be safe for infants and children. Margins of
safety are incorporated into EPA risk assessments either directly
through use of a MOE analysis or through using uncertainty (safety)
factors in calculating a dose level that poses no appreciable risk to
humans. EPA believes that reliable data support using the standard MOE
and uncertainty factor (usually 100 for combined inter- and intra-
species variability)) and not the additional tenfold MOE/uncertainty
factor when EPA has a complete data base under existing guidelines and
when the severity of the effect in infants or children or the potency
or unusual toxic properties of a compound do not raise concerns
regarding the adequacy of the standard MOE/safety factor.
ii. Developmental toxicity studies. In the developmental toxicity
study in rats, the maternal (systemic) NOEL was 1,600 mg/kg/day, the
highest dose tested (HDT). The developmental NOEL was 1,200 mg/kg/day,
based on minor skeletal variations at the LOEL of 1,600 mg/kg/day. In a
second developmental toxicity study in rats, the maternal and
developmental NOELs were greater than 1,000 mg/kg/day, the HDT. The
Agency concluded that skeletal variations observed in the first study
occurred at doses above 1 mg/kg/day, the limit dose, and therefore were
of minimal concern. In the developmental toxicity study in rabbits, the
maternal and developmental NOELs were 1,000 mg/kg/day, the HDT.
iii. Reproductive toxicity study. In the 2-generation reproductive
toxicity study in rats, the maternal NOEL was 500 mg/kg/day, based on
decreased body weight at the LOEL of 1,500 mg/kg/day. The reproductive/
developmental NOEL was 500 mg/kg/day, based on post-natal decrease in
body weight of pups during lactation at the LOEL of 1,500 mg/kg/day.
iv. Pre- and post-natal sensitivity. The toxicity data base for
evaluating pre- and post-natal toxicity for maleic hydrazide is
complete with respect to current data requirements. There are no pre-
or post-natal toxicity concerns for infants and children, based on the
results of the rat and rabbit developmental toxicity studies and the 2-
generation rat reproductive toxicity study.
v. Conclusion. Based on review of the required studies, EPA
concludes that reliable data support use of the standard hundredfold
MOE/uncertainty factor and that an additional margin/factor is not
needed to protect infants and children.
2. Chronic risk. Using the conservative exposure assumptions
described above, EPA has concluded that aggregate exposure to maleic
hydrazide from food will utilize between 14 and 54% of the RfD for
infants and children. EPA generally has no concern for exposures below
100% of the RfD because the RfD represents the level at or below which
daily aggregate dietary exposure over a lifetime will not pose
appreciable risks to human health. Despite the potential for exposure
to maleic hydrazide 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 maleic hydrazide residues.
V. Other Considerations
A. Metabolism In Plants and Animals
The nature of the residue in plants is adequately understood. The
residue of concern is maleic hydrazide (as specified in 40 CFR
180.175). The nature of the residue in animals is adequately understood
for this section 18. The residue of concern is maleic hydrazide .
B. Analytical Enforcement Methodology
Adequate enforcement methodology (with spectrophotometric
detection) for plants is available in PAM II to enforce the tolerance
expression. An enforcement method has not been validated for animal
commodities. However, a method for animal commodities is available, see
Wood,
[[Page 64292]]
P.R., ``Determination of Maleic Hydrazide Residues in Plant and Animal
Tissue,'' Analytical Chemistry, 25, 1879 (1953).
C. Magnitude of Residues
Residues of maleic hydrazide at a 14-day PHI are not expected to
exceed 105.0 ppm on rice grain, 75.0 ppm on rice straw, 240.0 ppm on
rice hulls, 180.0 ppm on rice bran, and 75.0 on the processed commodity
polished rice as a result of this section 18 use. Time-limited
tolerances should be established for rice grain, straw, bran, and hulls
at these levels.
No tolerances on animal commodities have been established for
maleic hydrazide. Secondary residues in animal commodities resulting
from this use on rice and the registered use on potatoes are not
expected to exceed 2.5 ppm in meat, 7.0 ppm in liver, 32.0 ppm in
kidney, and 3.0 ppm in fat of cattle, goats, hogs, horses, and sheep;
1.0 ppm in milk; 0.5 ppm in meat, liver, and fat of poultry; 1.4 ppm in
poultry meat byproducts (except liver), and 0.5 ppm in eggs.
D. International Residue Limits
There are currently no Codex, Canadian, or Mexican limits for
residues of maleic hydrazide in or on rice or animal commodities.
Therefore, establishment of time-limited tolerances will not pose a
concern for international harmonization.
E. Rotational Crop Restrictions.
There are no rotational crop restrictions in the section 18 or
Federal label.
VI. Conclusion
Therefore, tolerances are established for residues of maleic
hydrazide (1,2-dihydro-3,6-pyridazinedione) in rice, grain at 105 ppm,
rice, straw at 75 ppm, rice, hulls at 240 ppm, and rice, bran at 180
ppm. Additionally, tolerances are established for secondary residues of
maleic hydrazide at 2.5 ppm in meat, 7 ppm in liver, 32 ppm in kidney,
and 3 ppm in fat of cattle, goats, hogs, horses, and sheep; 1 ppm in
milk; 0.5 ppm in meat, liver and fat of poultry; 1.4 ppm in poultry
meat byproducts; and 0.5 ppm in eggs.
In addition because FQPA has eliminated the distinctions between
tolerances for raw and processed food, OPP is transferring the food
additive tolerances now found in Sec. 185.3900 to Sec. 180.175, and is
removing Sec. 185.3900.Therefore, to accomplish the transfer, and for
the convenience of the user, OPP is revising Sec. 180.175 in its
entirety, although only paragraph (b) of Sec. 180.175 is new.
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 3, 1998, file written objections to any
aspect of this regulation and may also request a hearing on those
objections. Objections and hearing requests must be filed with the
Hearing Clerk, at the address given above (40 CFR 178.20). A copy of
the objections and/or hearing requests filed with the Hearing Clerk
should be submitted to the OPP docket for this rulemaking. The
objections submitted must specify the provisions of the regulation
deemed objectionable and the grounds for the objections (40 CFR
178.25). Each objection must be accompanied by the fee prescribed by 40
CFR 180.33(i). If a hearing is requested, the objections must include a
statement of the factual issues on which a hearing is requested, the
requestor's contentions on such issues, and a summary of any evidence
relied upon by the requestor (40 CFR 178.27). A request for a hearing
will be granted if the Administrator determines that the material
submitted shows the following: There is genuine and substantial issue
of fact; there is a reasonable possibility that available evidence
identified by the requestor would, if established, resolve one or more
of such issues in favor of the requestor, taking into account
uncontested claims or facts to the contrary; and resolution of the
factual issues in the manner sought by the requestor would be adequate
to justify the action requested (40 CFR 178.32). Information submitted
in connection with an objection or hearing request may be claimed
confidential by marking any part or all of that information as
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 inclusion in the public record. Information not marked
confidential may be disclosed publicly by EPA without prior notice.
VIII. Public Docket and Electronic Submissions
EPA has established a record for this rulemaking under docket
control number [OPP-300587] (including any comments and data submitted
electronically). A public version of this record, including printed,
paper versions of electronic comments, which does not include any
information claimed as CBI, is available for inspection from 8:30 a.m.
to 4 p.m., Monday through Friday, excluding legal holidays. The public
record is located in Room 1132 of the Public Information and Records
Integrity Branch, Information Resources and Services Division (7502C),
Office of Pesticide Programs, Environmental Protection Agency, Crystal
Mall #2, 1921 Jefferson Davis Highway, Arlington, VA.
Electronic comments may be sent directly to EPA at:
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 action finalizes a tolerance requirement under FFDCA section
408(e). 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). In
addition, 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
[[Page 64293]]
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 special 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, under the Regulatory Flexibility Act (RFA) (5 U.S.C.
601 et seq.), the Agency previously assessed whether establishing
tolerances, exemptions from tolerances, raising tolerance levels or
expanding exemptions might adversely impact small entities and
concluded, as a generic matter, that there is no adverse economic
impact. The factual basis for the Agency's generic certification for
tolerance actions published on May 4, 1981 (46 FR 24950), and was
provided to the Chief Counsel for Advocacy of the Small Business
Administration.
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
40 CFR Part 180
Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and
recordkeeping requirements.
40 CFR Part 185
Environmental protection, Food additives, 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. In part 180:
i. The authority citation for part 180 continues to read as
follows:
Authority: 21 U.S.C. 346a and 371.
ii. Section 180.175 is revised to read as follows:
Sec. 180.175 Maleic hydrazide; tolerances for residues.
(a) General. (1) Tolerances for residues of the herbicide and
plant regulator maleic hydrazide (1,2-dihydro-3,6-pyridazinedione) are
established in or on the following raw agricultural commodities:
------------------------------------------------------------------------
Parts per
Commodity million
------------------------------------------------------------------------
Onions, dry bulb............................................. 15.0
Potatoes..................................................... 50.0
------------------------------------------------------------------------
(2) A food additive known as maleic hydrazide (1,2-dihydro-3,6-
pyridazinedione) may be present in potato chips when used in accordance
with the following conditions:
(i) The food additive is present as a result of the application of
a pesticide formulation containing maleic hydrazide to the growing
potato plant in accordance with directions registered by the U.S.
Environmental Protection Agency.
(ii) The label of the pesticide formulation containing the food
additive conforms to labeling registered by the U.S. Environmental
Protection Agency.
(iii) The food additive is present in an amount not to exceed 160
parts per million by weight of the finished food.
(b) Section 18 emergency exemptions. Time-limited tolerances are
established for residues of the herbicide maleic hydrazide (1,2-
dihydro-3,6-pyridazinedione) 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
------------------------------------------------------------------------
Cattle, fat..................... 3 9/30/98
Cattle, liver................... 7 9/30/98
Cattle, kidney.................. 32 9/30/98
Cattle, meat.................... 2.5 9/30/98
Eggs............................ 0.5 9/30/98
Goats, fat...................... 3 9/30/98
Goats, liver.................... 7 9/30/98
Goats, kidney................... 32 9/30/98
Goats, meat..................... 2.5 9/30/98
Hogs, fat....................... 3 9/30/98
Hogs, liver..................... 7 9/30/98
Hogs, kidney.................... 32 9/30/98
Hogs, meat...................... 2.5 9/30/98
Horses, fat..................... 3 9/30/98
Horses, liver................... 7 9/30/98
Horses, kidney.................. 32 9/30/98
Horses, meat.................... 2.5 9/30/98
Milk............................ 1 9/30/98
Poultry, fat.................... 0.5 9/30/98
Poultry, liver.................. 0.5 9/30/98
Poultry, meat................... 0.5 9/30/98
Poultry, meat byproducts (except 1.4 9/30/98
liver).
Rice, bran...................... 180 9/30/98
Rice, grain..................... 105 9/30/98
Rice, hulls..................... 240 9/30/98
Rice, straw..................... 75 9/30/98
Sheep, fat...................... 3 9/30/98
[[Page 64294]]
Sheep, liver.................... 7 9/30/98
Sheep, kidney................... 32 9/30/98
Sheep, meat..................... 2.5 9/30/98
------------------------------------------------------------------------
(c) Tolerances with regional registrations. [Reserved]
(d) Indirect or inadvertent residues. [Reserved]
PART 185--[Amended]
2. In part 185:
i. The authority citation for part 185 continues to read as
follows:
Authority: 21 U.S.C. 348.
Sec. 185.3900 [Removed]
ii. Section 185.3900 is removed.
[FR Doc. 97-31553 Filed 12-4-97; 8:45 am]
BILLING CODE 6560-50-F
