[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: [email protected]. Copies of objections and 
hearing requests must be submitted as an ASCII file avoiding the use of 
special characters and any form of encryption. Copies of objections and 
hearing requests will also be accepted on disks in WordPerfect 5.1/6.1 
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: 
[email protected].
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