[Federal Register Volume 64, Number 2 (Tuesday, January 5, 1999)]
[Rules and Regulations]
[Pages 418-425]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-34830]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-300748; FRL-6039-4]
RIN 2070-AB78
Picloram; Time-Limited Pesticide Tolerances
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes time-limited tolerances for the
indirect or inadvertent residues of the herbicide, picloram, 4-amino-
3,5,6-trichloropicolinic acid and its potassium salt in or on certain
raw agricultural commodities. Dow AgroSciences requested this tolerance
under the Federal Food, Drug and Cosmetic Act (FFDCA), as amended by
the Food Quality Protection Act of 1996 (Pub. L. 104-170).
DATES: The effective date of this rule is December 31, 1998. Objections
and requests for hearings must be received by EPA on or before March 8,
1999.
ADDRESSES: Written objections and hearing requests, identified by the
docket control number, [OPP-300748], 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-300748], 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. 119, 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.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-300748]. 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: James A. Tompkins,
Registration Division 7505C, Office of Pesticide Programs,
Environmental Protection Agency, 401 M St., SW., Washington, DC 20460.
Office location, telephone number, and e-mail address: Crystal Mall #2,
1921 Jefferson Davis Hwy., Arlington, VA, (703) 305-5697, e-mail:
tompkins.jim@epamail.epa.gov.
SUPPLEMENTARY INFORMATION:In the Federal Register of May 13, 1997 (62
FR 26305), EPA issued a notice pursuant to section 408 of the Federal
Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a(e) announcing the
filing of a pesticide petition (PP 4F4412) for tolerances by DowElanco,
9330 Zionsville Road, Indianapolis, IN 46254. This notice included a
summary of the petition prepared by DowElanco, the registrant. The
petition requested that 40 CFR 180 be amended by establishing
tolerances for inadvertent residues of the herbicide, picloram, 4-
amino-3,5,6-trichloropicolinic acid, in or on sorghum grain at 0.3
parts per million (ppm), sorghum grain forage at 0.2 ppm, and sorghum
stover at 0.5 ppm.
In the Federal Register of November 20,1998 (63 FR 64494), EPA
issued a notice announcing that Dow AgroSciences amended the petition
by also proposing to established a tolerance for residues of the
herbicide picloram in or on the raw agricultural commodity aspirated
grain fractions at 4 ppm. There were no comments received in response
to the notices of filing. The tolerances will expire and will be
revoked on December 31, 2000.
I. Risk Assessment and Statutory Findings
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***.''
EPA performs a number of analyses to determine the risks from
aggregate exposure to pesticide residues. For further discussion of the
regulatory requirements of section 408 and a complete description of
the risk assessment process, see the Final Rule on Bifenthrin Pesticide
Tolerances (62 FR 62961, November 26, 1997) (FRL-5754-7).
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 adverse effect level'' or
``NOAEL'').
Once a study has been evaluated and the observed effects have been
determined to be threshold effects, EPA generally divides the NOAEL
from the study with the lowest NOAEL 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
[[Page 419]]
exposure into the NOAEL 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 NOAEL) 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/NOAEL 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 was not regionally based.
II. 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 picloram
and to make a determination on aggregate exposure, consistent with
section 408(b)(2), for a time-limited tolerance for indirect or
inadvertent residues of picloram and its potassium salt in certain raw
agricultural commodities when present therein as a result of the
application of picloram as a herbicide. EPA's assessment of the dietary
exposures and risks associated with establishing the tolerances
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 picloram acid
[[Page 420]]
and its salts and esters are discussed below:
1. Rat acute oral studies with LD50s greater than 5,000
milligrams (mg)/kilogram (kg) (males) and 4,012 mg/kg (females) with
picloram acid and greater than 5,000 mg/kg (males) and 3,536 mg/kg
(females) with the potassium salt of picloram
2. A 13-week rat feeding study with picloram acid with a No
Observed Adverse Effect Level (NOAEL) 50 mg/kg/day and with a Lowest
Observed Adverse Effect Level (LOAEL) of 150 mg/kg/day based on liver
weight increases and minimal microscopic changes in the liver.
3. A 13-week rat feeding study with the isooctyl ester of picloram
with a NOAEL 73 mg/kg/day and with a LOAEL of 220 mg/kg/day based on
increased liver weights accompanied by slight/very slight
hepatocellular hypertrophy and increased kidney weights in males only.
4. A 13-week rat feeding study with the triisopropanolamine salt of
picloram with a NOAEL 90 mg/kg/day and with a LOAEL of 550 mg/kg/day
based on hepatocellular hypertrophy; decreased body weight gain and
increased liver and kidney weights (females only) at 1,800 mg/kg/day.
5. A 6 month dog feeding study with picloram acid with a NOAEL of
35 mg/kg/day and a LOAEL of 175 mg/kg/day based on decreased mean body
weight gain and food consumption.
6. A 21-day dermal study with potassium salt of picloram in rabbits
with a NOAEL for systemic effects greater than 753 mg/kg/day, the
maximum amount of test material that could be practically maintained at
the test site - limit of test.
7. A 21-day dermal study with triisopropanolamine salt of picloram
in rabbits with a NOAEL for systemic effects greater than 1,320 mg/kg/
day - limit of test.
8. A dog chronic feeding study with picloram acid with a NOAEL of
35 mg/kg/day and a LOAEL of 175 mg/kg/day based on increased absolute
and relative liver weights.
9. A rat chronic feeding/carcinogenicity study with picloram acid
with a systemic NOAEL of 20 mg/kg/day and a systemic LOAEL of 60 mg/kg/
day based on increased size and altered staining properties of
centrilobular hepatocytes and increased absolute and/or relative liver
weights in both sexes. Negative for carcinogenicity.
10. A second rat chronic feeding/carcinogenicity study with
picloram acid with a systemic NOAEL less than 250 mg/kg/day and a
systemic LOAEL of 250 mg/kg/day based on increases in the incidence and
severity of glomerulonephritis, blood in the urine, decreased specific
gravity of the urine, increased size of hepatocytes that often had
altered staining properties, increase in the incidence of unilateral or
bilateral renal papillary necrosis and increases in absolute and
relative kidney weights. There was no evidence of increased tumor
incidence.
11. A mouse carcinogenicity study with picloram acid with a NOAEL
was 500 mg/kg/day and the LOAEL was 1,000 mg/kg/day based on increased
absolute and relative kidney weights in males. There was no evidence of
carcinogenicity.
12. A two-generation rat reproduction study with picloram acid with
a parental systemic NOAEL of 200 mg/kg/day and a reproductive NOAEL of
1,000 mg/kg/day [Highest Dose Tested (HDT)] and a Parental Systemic
LOAEL of 1,000 mg/kg/day based on microscopic lesions in male (and some
female) kidneys, blood in urine, decreased urine specific gravity,
increased absolute and relative kidney weights.
13. A rat developmental study (picloram acid) with a maternal NOAEL
of 500 mg/kg/day and a developmental LOAEL of 500 mg/kg/day [Lowest
Dose Tested] based on transient delayed ossification of 5th sternebrae
(fetuses but not litters) and with a maternal LOAEL of 750 mg/kg/day
based on hyperactivity and mild diarrhea and deaths.
14. A rat developmental study with the potassium salt of picloram
with a maternal NOAEL of 174 mg/kg/day and a developmental NOAEL of 347
mg/kg/day [HDT] and with a maternal LOAEL of 347 mg/kg/day based on
excessive salivation.
15. A rabbit developmental study with the potassium salt of
picloram with a maternal NOAEL of 40 mg/kg/day and a developmental
NOAEL of 400 mg/kg/day [HDT] and with a maternal LOAEL of 200 mg/kg/day
based on reduced maternal weight gain during gestation.
16. A rat developmental study with the isooctyl ester of picloram
with a maternal NOAEL of 100 mg/kg/day and a developmental NOAEL of
1,000 mg/kg/day [HDT] and with a maternal LOAEL of 500 mg/kg/day based
on decreased body weight gain during early gestation.
17. A rabbit developmental study with the isooctyl ester of
picloram with a maternal NOAEL of 20 mg/kg/day and a developmental
NOAEL of 500 mg/kg/day [HDT] and with a maternal LOAEL of 100 mg/kg/day
based on an increase in incidence of clinical signs (decreased feces at
500 and decreased body weight gain at 100 mg/kg/day and above).
18. A rat developmental study with the triisopropanolamine salt of
picloram with a maternal NOAEL of 500 mg/kg/day and a developmental
NOAEL of 1,000 mg/kg/day [HDT] and with a maternal LOAEL of 1,000 mg/
kg/day based on excessive salivation, decreased body weight gain and
food consumption.
19. A rabbit developmental study with the triisopropanolamine salt
of picloram with a maternal NOAEL of 54 mg/kg/day and a developmental
NOAEL of 1,000 mg/kg/day [HDT] and with a maternal LOAEL of 180 mg/kg/
day based on increased rate of abortions at 1,000 mg/kg/day, increased
clinical signs at 538 mg/kg/day and above and decreased food
consumption and body weight gain at 180 mg/kg/day and above.
20. In a gene mutation assay (Ames assay) picloram acid did not
produce a mutagenic response either in the presence or absence of
activation. In a gene mutation assay in Chinese hamster ovary (CHO)
cells picloram acid was found to be negative for inducing forward
mutation with and without metabolic activation. In gene mutation assay
with CHO/HGPRT+ cells picloram acid did not induce a mutagenic response
at doses up to and including those generally associated with severe
cytotoxicity. In a cytogenetics in vivo study picloram acid did not
produce cytogenetic effects. In an other genotoxic effects study
picloram acid was negative for unscheduled DNA synthesis treated up to
cytotoxic levels. In a gene mutation assay (Ames test) the isooctyl
ester of picloram did not induce a mutagenic response in the presence
or absence of metabolic activation. In a gene mutation assay (mammalian
CHO cells) isooctyl ester of picloram there was no evidence of a
mutagenic response at any dosage level in either the S9 activated
trials or the non-activated trials. In a structural chromosomal
aberration assay isooctyl ester of picloram demonstrated no potential
for inducing chromosomal aberrations. In a micronucleus test in mice
the isooctyl ester was found not to be clastogenic. In a gene mutation
assay (Ames test) the triisopropanolamine salt of picloram did not
produce a mutagenic response either in the presence or absence of
activation. In a cytogenetics assay the triisopropanolamine salt of
picloram was non-clastogenic in mice, as determined by lack of
mutagenic effect at doses up to lethality. In another genotoxic effects
assay the triisopropanolamine salt of picloram was negative for
inducing unscheduled
[[Page 421]]
DNA synthesis at doses up to toxic levels.
21. A rat metabolism study showed that radio-labeled
14C-picloram acid is rapidly absorbed, distributed and
excreted following oral and intra-venous (i.v.) administration. A rat
metabolism study demonstrated that isooctyl ester of picloram is
hydrolyzed rapidly to picloram (free acid) and 2-ethyl hexanol, and
that picloram isooctyl ester does not influence the excretion of
picloram in the rat. For the triisopropanolamine salt of picloram, the
metabolism study showed that the conversion of the salt to picloram was
not affected by the presence of triisopropanolamine.
B. Toxicological Endpoints
1. Acute toxicity. EPA could not identify any toxicological effects
that could be attributable to a single oral exposure (dose) in any of
the available toxicological studies.
2. Short- and intermediate-term toxicity. EPA could not identify
any toxicological effects that could be attributable to short- or
intermediate-term dermal or inhalation exposure. No systemic effects
were observed in available dermal studies. In addition, no endpoints
for short- or intermediate-term exposure could be identified from
available oral studies.
3. Chronic toxicity. EPA has established the RfD for picloram at
0.2 mg/kg/day. This RfD is based on NOAEL of 20 mg/kg/day in the
combined chronic toxicity/carcinogenicity study in rats with a 100-fold
safety factor to account for inter-species extrapolation (10x) and
intra-species variability (10x).
4. Carcinogenicity. The Health Effects Division Carcinogenicity
Peer Review Committee has classified picloram acid and its potassium
salt as Group E ``no evidence of carcinogenicity'' to humans based on
the lack of carcinogenicity in rats and mice. A carcinogenicity risk
assessment is required for hexachlorobenzene (HCB) a process impurity
in picloram.
C. Exposures and Risks
1. From food and feed uses. Tolerances have been established (40
CFR 180.292) previously for the residues of picloram, and its salts in
or on raw agricultural commodities from use on barley, grasses, oats
and wheat. Appropriate tolerances are established for secondary
residues of picloram and its salts occurring in meat, milk, poultry, or
eggs. Risk assessments were conducted by EPA to assess dietary
exposures and risks from picloram from the proposed and registered uses
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. No toxicological effect that could be
attributable to a single oral exposure was identified, and therefore
picloram is not expected to present an acute dietary risk.
ii. Picloram chronic exposure and risk. The Reference Dose (RfD)
for picloram is 0.02 mg/kg/day. This value is based on the systemic
LOAEL of 200 mg/kg/day in the rat chronic feeding/carcinogenicity study
with a 100-fold safety factor to account for interspecies extrapolation
(10x) and intraspecies variability (10x). start
A Dietary Risk Evaluation System (DRES) chronic exposure analysis
was conducted using established tolerance levels for proposed
tolerances, meat, milk and eggs, and percent crop treated information
for cereal grains to estimate dietary for the general population and 22
subgroups. The chronic analysis showed that dietary exposure for non-
nursing infants (the subgroup with the highest exposure) would be 2% of
the Reference Dose (RfD). The exposure for the general U.S. population
would be less than 1% of the RfD.
Section 408(b)(2)(F) states that the Agency may use data on the
actual percent of food treated for assessing chronic dietary risk only
if the Agency can make the following findings: (1) That the data used
are reliable and provide a valid basis to show what percentage of the
food derived from such crop is likely to contain such pesticide
residue; (2) that the exposure estimate does not underestimate exposure
for any significant subpopulation group; and (3) if data are available
on pesticide use and food consumption in a particular area, the
exposure estimate does not understate exposure for the population in
such area. In addition, the Agency must provide for periodic evaluation
of any estimates used.
The Agency used percent crop treated (PCT) information as follows.
A routine chronic dietary exposure analysis for picloram was based on
2% of cereal grain crop treated. The Agency believes that the three
conditions listed above have been met. With respect to (1), EPA finds
that the (PCT) information described above for picloram used on cereal
grains is reliable and has a valid basis based on past pesticide use
surveys. Approval of crop rotation of the minor use corp sorghum after
treatment with picloram is not likely to significant increase the
percentage of the total U.S. cereal grains treated with picloram. As to
(2) and (3), regional consumption information and consumption
information for significant subpopulations is taken into account
through EPA's computer-based model for evaluating the exposure of
significant subpopulations including several regional groups. Use of
this consumption information in EPA's risk assessment process ensures
that EPA's exposure estimate does not understate exposure for any
significant subpopulation group and allows the Agency to be reasonably
certain that no regional population is exposed to residue levels higher
than those estimated by the Agency. Other than the data available
through national food consumption surveys, EPA does not have available
information on the regional consumption of food to which picloram may
be applied in a particular area.
iii. HCB (hexachlorobenzene) chronic exposure and risk. EPA
calculated the chronic dietary carcinogenic risk from all known
pesticidal sources of HCB, including picloram. Eight pesticides were
included in the calculations, three of which were major contributors to
HCB levels in the diet: chlorothalonil, pentachloronitrobenzene and
picloram. The estimated dietary carcinogenic risk for HCB from all
known pesticidal sources is 6.3 x 10-7 which is less than
the 1 x 10-6 point which is generally considered to be
negligible.
2. From drinking water- i. Acute risk. Because no acute dietary
endpoint was determined, no acute risk is expected.
ii. Chronic risk. Based on the chronic dietary (food) exposure and
using default body weights and water consumption figures [70 kg weight/
2L water consumed (adult male), 60 kg/2L (adult female), and 10 kg/1L
(child)], the chronic drinking water levels of concern (DWLOC) for
drinking water were calculated. To calculate the DWLOC, the chronic
dietary food exposure was subtracted from the RfD.
DWLOCchronic = [chronic water exposure (mg/kg/day) x
(body weight)]/[consumption (L) x 10-3 mg/g]
where chronic water exposure (mg/kg/day) = [RfD - (chronic food +
residential exposure) (mg/kg/day)]
The results are summarized in the following Table:
[[Page 422]]
----------------------------------------------------------------------------------------------------------------
Chronic Scenario
--------------------------------------------------------------------------------
Maximum SCI-GROW2
Population Subgroup\1\ RfD mg/kg/ Food Water DWLOC EEC (g/ m>g/L)\3\ (g/
kg/day kg/day\2\ L) L)\3\
----------------------------------------------------------------------------------------------------------------
U.S. Population................ 0.20 0.0011 0.20 7000 379 103.1
Females (13-19 years old, not
pregnant or nursing).......... 0.20 0.00090 0.20 6000 379 103.1
Non-Nursing Infants (< 1yr="" old)="" 0.20="" 0.0043="" 0.20="" 2,000="" 379="" 103.1="" ----------------------------------------------------------------------------------------------------------------="" \1\="" population="" subgroups="" chosen="" were="" u.s.="" population="" (70="" kg.="" body="" weight="" assumed),="" the="" adult="" female="" subgroup="" with="" the="" highest="" food="" exposure="" (60="" kg.="" body="" weight="" assumed)="" and="" the="" infant/child="" subgroup="" with="" the="" highest="" food="" exposure="" (10="" kg.="" body="" weight="" assumed).="" \2\="" maximum="" water="" exposure="" (mg/kg/day)="RfD" (mg/kg/day)="" -="" arc="" from="" dres="" (mg/kg/day).="" \3\="" the="" crop="" producing="" the="" highest="" level="" was="" used.="" for="" the="" most="" highly="" exposed="" populations="" subgroup,="" non-nursing="" infants="">< 1="" year="" old),="" chronic="" dietary="" (food="" only)="" exposure="" occupies="" 2%="" of="" the="" rfd.="" the="" chronic="" drinking="" water="" level="" of="" concern="" (dwloc)="" for="" non-nursing="" infants="">< 1="" yr="" old)="" is="" 2,000="">g/L (ppb). The
GENEEC model predicted that with the present use pattern, the 56-day
average picloram surface water concentration for the highest
application rate (2 lbs/A) would be 103.1 g/L (ppb). The SCI-
GROW2 model estimated that the ground water concentration from the
current uses of picloram for the highest application rate would be 379
g/L (ppb). Therefore, exposure from water is below DWLOC for
chronic dietary exposure for any of the populations examined.
iii. Dietary cancer risk for hexachlorobenzene (HCB) - (combined
food and water). HCB is persistent and relatively immobile in the
environment. Based on the high binding potentials of HCB, contamination
of ground water resources is relatively unlikely. The dietary cancer
risk for HCB from all pesticidal uses is 6.3 x 10-7. In
order to calculate a DWLOC for HCB, the Anticipated Residue
Contribution (ARC's) for each of the pesticides included in the risk
calculation are needed. Although a few significant figures are lost
with this calculation, an estimate of the overall dietary exposure can
be made by dividing the risk value by the Q*. The
calculation is as follows: (6.3 x 10-7/1.02 = 6.2 x
10-7). Based on summaries of monitoring data and fate
properties, long term concentrations of HCB in filtered surface water
are not likely to exceed 10 ppt or 0.01 ppb. The amount of HCB in water
is also estimated from uses of other chemicals with HCB as an impurity,
not just picloram. The chronic water exposure is calculated by dividing
the negligible risk (1.0 x 10-6) by the Q* and subtracting
from that the chronic food plus residential exposure. 1.0 x
10-6/1.02 mg/kg/day-1 = 9.8 x 10-7 mg/
kg/day. Using the equation for calculating the DWLOC (ppb), the DWLOC
for the general population for dietary cancer risk for HCB from all
pesticidal uses is calculated as follows:
9.8 x 10-7 mg/kg/day x 70kg/2L x 10-3 mg/
g = 0.034 g/L (ppb)
The DWLOC of 0.034 ppb is greater than 0.01 ppb, the maximum
concentration of HCB estimated in surface water.
3. From non-dietary exposure. Picloram is a Restricted Use
Pesticide that has no residential uses. For uses currently registered
under the Federal Insecticide, Fungicide and Rodenticide Act, rights-
of-way, forestry, pastures, range lands, and small grains; entry into a
treated area soon after the application of picloram is limited by the
re-entry restrictions on the picloram labels. Non-dietary exposure to
picloram will be minimal for the general population.
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.'' Picloram is a pyridine carboxylic acid
herbicide. Other herbicides in this class include clopyralid,
quinclorac and thiazopyr.
EPA does not have, at this time, available data to determine
whether picloram 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,
picloram 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 picloram has a common mechanism of toxicity
with other substances. For information regarding EPA's efforts to
determine which chemicals have a common mechanism of toxicity and to
evaluate the cumulative effects of such chemicals, see the Final Rule
for Bifenthrin Pesticide Tolerances (62 FR 62961, November 26, 1997).
D. Aggregate Risks and Determination of Safety for U.S. Population
1. Acute risk. Picloram is not expected to pose an acute risk.
2. Chronic risk. The Reference Dose (RfD) for picloram is 0.02 mg/
kg/day. This value is based on the systemic LOAEL of 200 mg/kg/day in
the rat chronic feeding/carcinogenicity study with a 100-fold safety
factor to account for interspecies extrapolation (10x) and intraspecies
variability (10x). The dietary exposure for non-nursing infants (the
subgroup with the highest exposure) is 2% of the Reference Dose (RfD).
The exposure for the general U.S. population would be less than 1% of
the RfD.
The drinking water level of concerns (DWLOCs) for chronic exposure
to picloram in drinking water calculated for U.S. population was 7,000
parts per billion (ppb) assuming that an adult weighs 70 kg and
consumes a maximum of 2 liters of water per day, for females 13-19
years old (not pregnant or nursing) the DWLOC was 6,000 assuming that
an adult female weighs 60 kg and consumes a maximum of 2 liters of
water per day, and for children (1 - 6 years old) the DWLOC was 2,000
ppb assuming that a child weighs 10 kg and consumes a maximum of 1
liter of water per day.
The drinking water estimated concentration (DWECs) for groundwater
(picloram acid) calculated from the highest application rate for the 56
day average is 379 ppb which does not exceed DWLOC of 2,000 ppb for
children (1-6 years old). The DWEC for surface water based on the
computer model Generic Expected Environmental Concentration (GENEEC)
was calculated to be 103.1 ppb for chronic concentration (parent
picloram and degradate thiadone) which does not exceed the DWLOC of
2,000 ppb for children (1-6 years old). From
[[Page 423]]
groundwater monitoring the maximum concentration reported was 4.6 ppb.
Picloram is regulated under the Safe Drinking Water Act (SDWA). Water
supply systems are required to sample for it. A Maximum Contaminate
Level (MCL) of 500 ppb and a 1-10 day health advisory of 20,000 ppb
have been established.
EPA concludes that there is a reasonable certainty that no harm
will result from aggregate exposure to picloram residues.
E. Aggregate Risks and Determination of Safety for Infants and
Children
In assessing the potential for additional sensitivity of infants
and children to residues of picloram, 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. There is no
indication of increased sensitivity to young rats or rabbits following
pre- and/or post-natal exposure to picloram in the standard
developmental and reproductive toxicity studies, there was no
indication that picloram is a neurotoxic herbicide. Therefore, a 10-
fold safety factor for children and infants is not required to be used
in the aggregate dietary acute and chronic risk assessments.
III. Other Considerations
A. Metabolism In Plants and Animals
The nature of the residue in rotated sorghum is adequately
understood. The residues of concern for the tolerance expression are
picloram and its salts. Appropriate tolerances are established to cover
any secondary residues which would occur in animal commodities from the
proposed and registered uses.
B. Analytical Enforcement Methodology
An adequate analytical method, gas chromatography/mass spectrometry
with selected ion monitoring, is available for enforcement purposes.
Because of the long lead time from establishing these tolerances to
publication of the enforcement methodology in the Pesticide Analytical
Manual, Vol. II, the analytical methodology is being made available in
the interim to anyone interested in pesticide enforcement when
requested from: Calvin Furlow, 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. Office location and telephone number: Room 101FF,
CM #2, 1921 Jefferson Davis Highway, Arlington, VA 22202, (703-305-
5229).
C. Endocrine Effects
EPA is required to develop a screening program to determine whether
certain substances (including all pesticides and inerts) ``may have an
effect in humans that is similar to an effect produced by a naturally
occurring estrogen, or such other effect***.'' The Agency is currently
working with interested stakeholders, including other government
agencies, public interest groups, industry and research scientists in
developing a screening and testing program and a priority setting
scheme to implement this program. Congress has allowed 3 years from the
passage of FQPA (August 3, 1999) to implement this program. At that
time, EPA may require further testing of this active ingredient and end
use products for endocrine disrupter effects.
D. Magnitude of Residues
Due to the data gap, an aspirated grain fraction study; EPA
believes it is inappropriate to establish permanent tolerances for the
proposed use of picloram at this time. EPA believes that the existing
data support tolerances to December 31, 2000. The nature of the residue
in plants is adequately understood for the purposes of these
tolerances.
E. International Residue Limits
There are no Codex Alimentarius Commission (Codex) Maximum Residue
Levels (MRLs) for picloram.
F. Rotational Crop Restrictions
Tolerances for indirect or inadvertent residues of picloram and its
potassium salt established by this regulation will cover any residues
in sorghum planted in treated fields in accordance with the
restrictions that appear on the labeling proposed for registration
under the Federal Insecticide Fungicide and Rodenticide Act (FIFRA), as
amended.
IV. Conclusion
The analysis for picloram and its salts using crop tolerances,
percentage of crop estimates, and estimated drinking water
concentrations for all population subgroups examined by EPA shows the
proposed rotation to sorghum from the registered uses of picloram will
not cause exposure at which the Agency believes there is an appreciable
risk during the period of time for the tolerance. Therefore EPA
concludes there is a reasonable certainty of no harm from aggregate
exposure to picloram. Based on the information cited above, EPA has
determined that establishing tolerances for the residues of the
herbicide, picloram in or on aspirated grain fractions at 4.0 ppm,
sorghum grain at 0.3 ppm, sorghum grain forage at 0.2 ppm and sorghum
grain stover at 0.5 ppm will be safe. These tolerances will expire and
be revoked on December 31, 2000. Therefore, the tolerances are
established as set forth below.
V. 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 March 8, 1999, file written objections to any
aspect of this regulation and may also request a hearing on those
objections. Objections and hearing requests must be filed with the
Hearing Clerk, at the address given 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) or a request for a fee waiver. 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
[[Page 424]]
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.
VI. Public Record and Electronic Submissions
EPA has established a record for this rulemaking under docket
control number [OPP-300748]. A public version of this record, including
printed, paper versions of electronic comments, which does not include
any information claimed as CBI, is available for inspection from 8:30
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The
public record is located in Room 119 of the Public Information and
Records Integrity Branch, Information Resources and Services Division
(7502C), Office of Pesticide Programs, Environmental Protection Agency,
Crystal Mall #2, 1921 Jefferson Davis Highway, Arlington, VA.
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.
VII. Regulatory Assessment Requirements
A. Certain Acts and Executive Orders
This final rule establishes tolerances under FFDCA section 408(d)
in 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 special considerations as required by Executive
Order 12898, entitled Federal Actions to Address Environmental Justice
in Minority Populations and Low-Income Populations (59 FR 7629,
February 16, 1994), or require OMB review in accordance with Executive
Order 13045, entitled Protection of Children from Environmental Health
Risks and Safety Risks (62 FR 19885, April 23, 1997).
In addition, since tolerances and exemptions that are established
on the basis of a petition under FFDCA section 408(d), such as the
tolerance in this final rule, do not require the issuance of a proposed
rule, the requirements of the Regulatory Flexibility Act (RFA) (5
U.S.C. 601 et seq.) do not apply. Nevertheless, the Agency has
previously assessed whether establishing tolerances, exemptions from
tolerances, raising tolerance levels or expanding exemptions might
adversely impact small entities and concluded, as a generic matter,
that there is no adverse economic impact. The factual basis for the
Agency's generic certification for tolerance actions published on May
4, 1981 (46 FR 24950) and was provided to the Chief Counsel for
Advocacy of the Small Business Administration.
B. Executive Order 12875
Under Executive Order 12875, entitled Enhancing the
Intergovernmental Partnership (58 FR 58093, October 28, 1993), EPA may
not issue a regulation that is not required by statute and that creates
a mandate upon a State, local, or tribal government, unless the Federal
government provides the funds necessary to pay the direct compliance
costs incurred by those governments. If the mandate is unfunded, EPA
must provide to OMB a description of the extent of EPA's prior
consultation with representatives of affected State, local, and tribal
governments, the nature of their concerns, copies of any written
communications from the governments, and a statement supporting the
need to issue the regulation. In addition, Executive Order 12875
requires EPA to develop an effective process permitting elected
officials and other representatives of State, local, and tribal
governments ``to provide meaningful and timely input in the development
of regulatory proposals containing significant unfunded mandates.''
Today's rule does not create an unfunded Federal mandate on State,
local, or tribal governments. The rule does not impose any enforceable
duties on these entities. Accordingly, the requirements of section 1(a)
of Executive Order 12875 do not apply to this rule.
C. Executive Order 13084
Under Executive Order 13084, entitled Consultation and Coordination
with Indian Tribal Governments (63 FR 27655, May 19, 1998), EPA may not
issue a regulation that is not required by statute, that significantly
or uniquely affects the communities of Indian tribal governments, and
that imposes substantial direct compliance costs on those communities,
unless the Federal government provides the funds necessary to pay the
direct compliance costs incurred by the tribal governments. If the
mandate is unfunded, EPA must provide OMB, in a separately identified
section of the preamble to the rule, a description of the extent of
EPA's prior consultation with representatives of affected tribal
governments, a summary of the nature of their concerns, and a statement
supporting the need to issue the regulation. In addition, Executive
Order 13084 requires EPA to develop an effective process permitting
elected officials and other representatives of Indian tribal
governments ``to provide meaningful and timely input in the development
of regulatory policies on matters that significantly or uniquely affect
their communities.''
Today's rule does not significantly or uniquely affect the
communities of Indian tribal governments. This action does not involve
or impose any requirements that affect Indian tribes. Accordingly, the
requirements of section 3(b) of Executive Order 13084 do not apply to
this rule.
VIII. Submission to Congress and the Comptroller General
The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small
[[Page 425]]
Business Regulatory Enforcement Fairness Act of 1996, generally
provides that
before a rule may take effect, the Agency promulgating the rule must
submit a rule report, which includes a copy of the rule, to each House
of the Congress and the Comptroller General of the United States. EPA
will submit a report containing this rule and other required
information to the U.S. Senate, the U.S. House of Representatives and
the Comptroller General of the United States prior to publication of
the rule in the Federal Register. This rule is not a ``major rule'' as
defined by 5 U.S.C. 804(2).
List of Subjects in 40 CFR Part 180
Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and
recordkeeping requirements.
Dated: December 22, 1998.
James Jones,
Director, Registration Division, Office of Pesticide Programs.
Therefore, 40 CFR chapter I is amended as follows:
PART 180-[AMENDED]
1. In Part 180:
a. The authority citation for part 180 continues to read as
follows:
Authority: 21 U.S.C. 346a and 371.
b. Section 180.292 is amended by designating the existing text as
paragraph (a), adding a paragraph heading and designating the text
following the paragraph heading as paragraph (a)(1); by adding and
reserving with headings paragraphs (b) and (c); and by adding paragraph
(d) to read as follows:
Sec. 180.292 Picloram; tolerances for residues.
(a) General. (1) * * *
(b) Section 18 emergency exemptions. [Reserved]
(c) Tolerances with regional registrations. [Reserved]
(d) Indirect or inadvertent residues. Tolerances are established
for indirect or indadvertent residues of the herbicide picloram, 4-
amino-3,5,6-trichloropicolinic acid, from application of its potassium
form on barley, fallow cropland, oats, and wheat in or on the following
raw agricultural commodities:
------------------------------------------------------------------------
Expiration/
Commodity Parts per Revocation
million Date
------------------------------------------------------------------------
Aspirated grain fractions..................... 4.0 12/31/00
Sorghum grain................................. 0.3 12/31/00
Sorghum grain, forage......................... 0.2 12/31/00
Sorghum grain, stover......................... 0.5 12/31/00
------------------------------------------------------------------------
PART 185-[AMENDED]
2. In Part 185:
a. The authority citation continues to read as follows:
Authority: 21 U.S.C. 346a and 348.
Sec. 185.4850--[Partially Redesignated and Removed]
b. The text of Sec. 185.4850, including the table, is redesignated
as paragraph (a)(2) of Sec. 180.292. The remainder of Sec. 185.4850 is
removed.
PART 186-[AMENDED]
3. In Part 186:
a. The authority citation continues to read as follows:
Authority: 21 U.S.C. 342, 348, and 371.
Sec. 186.4850 [Partially Redesignated and Removed]
b. The text of Sec. 186.4850, including the table, is redesignated
as paragraph (a)(3) of Sec. 180.292. The remainder of Sec. 186.4850 is
removed.
[FR Doc. 98-34830 Filed 12-31-98; 8:45 am]
BILLING CODE 6560-50-F
