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mepiquat chloride (Mepichlor) Pesticide Tolerances for Emergency Exemptions 9/98

  


[Federal Register: September 29, 1998 (Volume 63, Number 188)]
[Rules and Regulations]               
[Page 51841-51848]
>From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr29se98-26]


[[Page 51841]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-300719; FRL-6032-6]
RIN 2070-AB78

 
Mepiquat Chloride; Pesticide Tolerances for Emergency Exemptions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This regulation establishes time-limited tolerances for 
residues of mepiquat chloride, N,N-dimethylpiperidinium chloride) in or 
on grapes and raisins. This action is in response to EPA's granting of 
an emergency exemption under section 18 of the Federal Insecticide, 
Fungicide, and Rodenticide Act authorizing use of the pesticide on 
grapes. This regulation establishes a maximum permissible level for 
residues of mepiquat chloride in this food commodity pursuant to 
section 408(l)(6) of the Federal Food, Drug, and Cosmetic Act, as 
amended by the Food Quality Protection Act of 1996. The tolerance will 
expire and is revoked on March 1, 2000.

DATES: This regulation is effective September 29, 1998. Objections and 
requests for hearings must be received by EPA on or before November 30, 
1998.

ADDRESSES: Written objections and hearing requests, identified by the 
docket control number, [OPP-300719] 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-300719], must also be submitted to: Public Information and 
Records Integrity Branch, Information Resources and Services Division 
(7502C), Office of Pesticide Programs, Environmental Protection Agency, 
401 M St., SW., Washington, DC 20460. In person, bring a copy of 
objections and hearing requests to Rm. 119, Crystal Mall #2, 1921 
Jefferson Davis Hwy., Arlington, VA.
    A copy of objections and hearing requests filed with the Hearing 
Clerk may also be submitted electronically by sending electronic mail 
(e-mail) to: opp-docket@epamail.epa.gov. Copies of objections and 
hearing requests must be submitted as an ASCII file avoiding the use of 
special characters and any form of encryption. Copies of objections and 
hearing requests will also be accepted on disks in WordPerfect 5.1/6.1 
file format or ASCII file format. All copies of objections and hearing 
requests in electronic form must be identified by the docket control 
number [OPP-300719]. 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: Andrew Ertman, Registration 
Division 7505C, Office of Pesticide Programs, Environmental Protection 
Agency, 401 M St., SW., Washington, DC 20460. Office location, 
telephone number, and e-mail address: Crystal Mall #2, 1921 Jefferson 
Davis Hwy., Arlington, VA, (703) 308-9367, e-mail: 
ertman.andrew@epamail.epa.gov.

SUPPLEMENTARY INFORMATION: EPA, on its own initiative, pursuant to 
sections 408(e) and (l)(6) of the Federal Food, Drug, and Cosmetic Act 
(FFDCA), 21 U.S.C. 346a(e) and (l)(6), is establishing a tolerance for 
residues of the plant regulator mepiquat chloride (N,N-
dimethylpiperidinium chloride), in or on grapes at 1.0 part per million 
(ppm) and raisins at 6.0 ppm. These tolerances will expire and is be 
revoked on March 1, 2000. EPA will publish a document in the Federal 
Register to remove the revoked tolerance from the Code of Federal 
Regulations.

I. Background and Statutory Authority

    The Food Quality Protection Act of 1996 (FQPA) (Pub. L. 104-170) 
was signed into law August 3, 1996. FQPA amends both the Federal Food, 
Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 301 et seq., and the Federal 
Insecticide, Fungicide, and Rodenticide Act (FIFRA), 7 U.S.C. 136 et 
seq. The FQPA amendments went into effect immediately. Among other 
things, FQPA amends FFDCA to bring all EPA pesticide tolerance-setting 
activities under a new section 408 with a new safety standard and new 
procedures. These activities are described below and discussed in 
greater detail in the final rule establishing the time-limited 
tolerance associated with the emergency exemption for use of 
propiconazole on sorghum (61 FR 58135, November 13, 1996)(FRL-5572-9).
    New section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a 
tolerance (the legal limit for a pesticide chemical residue in or on a 
food) only if EPA determines that the tolerance is ``safe.'' Section 
408(b)(2)(A)(ii) defines ``safe'' to mean that ``there is a reasonable 
certainty that no harm will result from aggregate exposure to the 
pesticide chemical residue, including all anticipated dietary exposures 
and all other exposures for which there is reliable information.'' This 
includes exposure through drinking water and in residential settings, 
but does not include occupational exposure. Section 408(b)(2)(C) 
requires EPA to give special consideration to exposure of infants and 
children to the pesticide chemical residue in establishing a tolerance 
and to ``ensure that there is a reasonable certainty that no harm will 
result to infants and children from aggregate exposure to the pesticide 
chemical residue. . . .''
    Section 18 of FIFRA authorizes EPA to exempt any Federal or State 
agency from any provision of FIFRA, if EPA determines that ``emergency 
conditions exist which require such exemption.'' This provision was not 
amended by FQPA. EPA has established regulations governing such 
emergency exemptions in 40 CFR part 166.
    Section 408(l)(6) of the FFDCA requires EPA to establish a time-
limited tolerance or exemption from the requirement for a tolerance for 
pesticide chemical residues in food that will result from the use of a 
pesticide under an emergency exemption granted by EPA under section 18 
of FIFRA. Such tolerances can be established without providing notice 
or period for public comment.
    Because decisions on section 18-related tolerances must proceed 
before EPA reaches closure on several policy issues relating to 
interpretation and implementation of the FQPA, EPA does not intend for 
its actions on such tolerances to set binding precedents for the 
application of section 408 and the new safety standard to other 
tolerances and exemptions.

II. Emergency Exemption for Mepiquat Chloride on Grapes and FFDCA 
Tolerances

    The applicants state that grape growers in Ohio, New York and 
Pennsylvania are facing an emergency situation brought on by freezing 
weather conditions that occurred on four days in April 1998. Regional 
experts called the frosts the most damaging freeze experienced in the 
past 30 years. The effects of the frost on the grapes include poor 
fruit set which will thus reduce fruit yield, with estimates of yield 
reductions in the 25% range. According to the applicants, there are no 
other registered alternative products available

[[Page 51842]]

to address this need other than mepiquat chloride. The use of mepiquat 
chloride could result in increased fruit set, and offset some of the 
damage caused by the late frost. EPA has authorized under FIFRA section 
18 the use of mepiquat chloride on grapes for control of frost damage 
in Ohio, New York, and Pennsylvania. After having reviewed the 
submission, EPA concurs that emergency conditions exist for this state.
    As part of its assessment of this emergency exemption, EPA assessed 
the potential risks presented by residues of mepiquat chloride in or on 
grapes. In doing so, EPA considered the safety standard in FFDCA 
section 408(b)(2), and EPA decided that the necessary tolerance under 
FFDCA section 408(l)(6) would be consistent with the safety standard 
and with FIFRA section 18. Consistent with the need to move quickly on 
the emergency exemption in order to address an urgent non-routine 
situation and to ensure that the resulting food is safe and lawful, EPA 
is issuing this tolerance without notice and opportunity for public 
comment under section 408(e), as provided in section 408(l)(6). 
Although this tolerance will expire and is revoked on March 1, 2000, 
under FFDCA section 408(l)(5), residues of the pesticide not in excess 
of the amounts specified in the tolerance remaining in or on grapes 
after that date will not be unlawful, provided the pesticide is applied 
in a manner that was lawful under FIFRA, and the residues do not exceed 
a level that was authorized by this tolerance at the time of that 
application. EPA will take action to revoke this tolerance earlier if 
any experience with, scientific data on, or other relevant information 
on this pesticide indicate that the residues are not safe.
    Because this tolerance is being approved under emergency conditions 
EPA has not made any decisions about whether mepiquat chloride meets 
EPA's registration requirements for use on grapes or whether a 
permanent tolerance for this use would be appropriate. Under these 
circumstances, EPA does not believe that this tolerance serves as a 
basis for registration of mepiquat chloride by a State for special 
local needs under FIFRA section 24(c). Nor does this tolerance serve as 
the basis for any State other than Ohio, New York, and Pennsylvania to 
use this pesticide on this crop under section 18 of FIFRA without 
following all provisions of EPA's regulations implementing section 18 
as identified in 40 CFR part 166. For additional information regarding 
the emergency exemption for mepiquat chloride, contact the Agency's 
Registration Division at the address provided above.

III. Aggregate Risk Assessment and Determination of Safety

    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).
    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 mepiquat 
chloride and to make a determination on aggregate exposure, consistent 
with section 408(b)(2), for a time-limited tolerance for residues of 
N,N-dimethylpiperidinium chloride on grapes at 1.0 ppm and raisins at 
6.0 ppm. EPA's assessment of the dietary exposures and risks associated 
with establishing the tolerance follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its 
validity, completeness, and reliability as well as the relationship of 
the results of the studies to human risk. EPA has also considered 
available information concerning the variability of the sensitivities 
of major identifiable subgroups of consumers, including infants and 
children. The nature of the toxic effects caused by mepiquat chloride 
are discussed below.
    1. Acute toxicity. For acute dietary risk assessment, the results 
from two 1-year feeding studies in the dog were combined with the 
results from a 90-day feeding study in the dog. The NOAEL for the acute 
dietary endpoint is 58.4 milligrams/kilogram/day (mg/kg/day) and the 
LOAEL is 95.3 mg/kg/day based on salivation and sedation. In the second 
1-year study, salivation (an indicator of impaired neurological 
function) was observed in all dogs at 2 hours after each feeding. 
Salivation was slight at first, moderate to severe during the next 4 
hours and then gradually disappeared. In the subchronic feeding study, 
sedation (also a neurotoxic sign) was observed for 1-6 hours after each 
dosing with 95.3 mg/kg/day, the LOAEL for the 3 studies combined. Using 
the hundredfold uncertainty factor (to account for both inter-species 
extrapolation and intra-species variability), the acute Reference dose 
(RfD) is calculated to be 0.6 mg/kg/day. This risk assessment will 
evaluate acute dietary risk to all population subgroups.
     2. Short - and intermediate - term toxicity. The NOAEL is 58.4 mg/
kg/day and the LOAEL is 95.3 mg/kg/day based on the combined results 
from two 1-year feeding studies and one 90-day feeding study in dogs. 
This endpoint is the same as that used for acute dietary and chronic 
RfD.
    3. Chronic toxicity. EPA has established the RfD for mepiquat 
chloride at 0.6 (mg/kg/day). This RfD is based on the combined 1-year 
and subchronic feeding studies in the dog. The NOAEL is 58.4 mg/kg/day 
and the LOAEL is 95.3 mg/kg/day based on clinical signs of toxicity 
(salivation, sedation, abdominal and lateral positions, and xonoclonic 
spasms), decreased body weight, and hematological changes at 95.3 mg/
kg/day. An uncertainty factor (UF) of 100 was applied to account for 
both inter-species extrapolation and intra-species variability. This 
risk assessment will evaluate chronic dietary risk to all population 
subgroups.
    4. Carcinogenicity. EPA has classified mepiquat chloride as a Group 
E chemical - ``no evidence of carcinogenicity to humans.''
    5. FQPA safety factor. The Agency removed the required 10x safety 
factor for all population subgroups except females and children.

B. Exposures and Risks

    1. From food and feed uses. Tolerances have been established (40 
CFR 180.384) for the residues of N,N-dimethylpiperidinium chloride, in 
or on a variety of raw agricultural commodities at levels ranging from 
3.0 ppm in cotton seed to 0.05 ppm in eggs and milk. Risk assessments 
were conducted by EPA to assess dietary exposures and risks from 
mepiquat chloride as follows:
    i.  Acute exposure and risk. Acute dietary risk assessments are 
performed for a food-use pesticide if a toxicological study has 
indicated the possibility of an effect of concern occurring as a result 
of a 1 day or single exposure. The acute RfD = 0.6 mg/kg/day. The acute 
dietary (food only) risk assessment used the Dietary Exposure 
Evaluation Model (DEEM). In conducting this chronic dietary risk 
assessment, EPA has made very conservative assumptions -- 100% of 
grapes and all other commodities having mepiquat chloride tolerances 
will contain mepiquat chloride residues and those residues would be at 
the level of the tolerance -- which result in an overestimation of 
human dietary exposure. The results of the DEEM are summarized below. 
These estimates

[[Page 51843]]

should be viewed as a conservative risk estimate; further refinement 
using anticipated residue values and percent crop-treated data in 
conjunction with Monte Carlo analysis would result in a lower acute 
dietary exposure estimate. For acute dietary exposure, the Agency 
determined that the 10X safety factor is applicable to the 
subpopulations females (13+ years), as well as infants and children 
because of a lack of developmental toxicity data.
    Application of the 10X safety factor to the Acute RfD of 0.6 mg/kg/
day results in an acceptable acute dietary exposure of 10% of the Acute 
RfD for the subpopulations females (13+ years old), infants, and 
children (1-6 years old). For the general U.S. Population and other 
subpopulations to whom the 10X factor does not apply, 100% or less of 
the Acute RfD would be acceptable. As shown in the following table 1, 
the amount of acute RfD utilized does not exceed HED's level of 
concern.

            Table 1.--Acute Dietary Exposure and Percent RfD
    (Total from new and published tolerances at the 99th percentile)
------------------------------------------------------------------------
                                                    TMRC\2\   Percent of
             Population of Concern\1\               (mg/kg/   Acute RfD
                                                      day)      (%)\3\
------------------------------------------------------------------------
U.S. Population...................................   0.0092            2
Children (1-6 years old)..........................   0.024             4
Females (13 + years old)..........................   0.012            2
------------------------------------------------------------------------
\1\ Population for which the Acute RfD applies.
\2\ TMRC - Theoretical Maximum Residue Concentration from DEEM.
\3\ Percentage of reference dose (% RfD) = (TMRC/RfD) x 100%.

    ii. Chronic exposure and risk. The chronic RfD = 0.6 mg/kg/day. A 
DEEM chronic exposure analysis was performed using tolerance level 
residues, and 100% crop treated to estimate the Theoretical Maximum 
Residue Concentration (TMRC) for the general population and subgroups 
of interest. In conducting this chronic dietary risk assessment, EPA 
has made very conservative assumptions -- 100% of grapes and all other 
commodities having mepiquat chloride tolerances will contain mepiquat 
chloride residues and those residues would be at the level of the 
tolerance -- which result in an overestimation of human dietary 
exposure. Thus, in making a safety determination for this tolerance, 
EPA is taking into account this conservative exposure assessment.
    The existing mepiquat chloride tolerances (published, pending, and 
including the necessary section 18 tolerance(s)) result in a TMRC that 
is equivalent to the percentages of the Chronic RfD listed the 
following table 2 below. Application of the 10X safety factor to the 
Chronic RfD of 0.6 mg/kg/day results in an acceptable chronic dietary 
exposure of 10% or less of the chronic RfD for the subpopulations 
females (13+ years old), infants, and children (1-6 years old). For the 
general U.S. Population and other subpopulations to whom the 10X factor 
does not apply, 100% or less of the chronic RfD would be acceptable. As 
shown in the following table 2, the amount of chronic RfD utilized does 
not exceed HED's level of concern.

          Table 2.--Chronic Dietary Exposure and Percent of RfD
------------------------------------------------------------------------
                                                      TMRC    Percentage
             Population of Concern\1\               (mg/kg/   of Chronic
                                                    day)\2\   RfD (%)\3\
------------------------------------------------------------------------
U.S. Population (48 States).......................   0.0010           <1
Nursing Infants (<1 year old).....................   0.0011           <1
Non-Nursing Infants (<1 year old).................   0.0024           <1
Children (1-6 years old)..........................   0.0034           <1
Females (13 years +, nursing).....................   0.0014          <1
------------------------------------------------------------------------
\1\ The subgroups listed above are: (1) The U.S. population (48 states);
  (2) those for infants and children; and, (3) the other subgroups for
  which the percentage of the RfD occupied is greater than that occupied
  by the subgroup U.S. population (48 states). The Chronic RfD applies
  to all popuplation subgroups.
\2\ TMRC - Theoretical Maximum Residue Concentration from DEEM.
\3\ Percentage of reference dose (% RfD) = (TMRC/RfD) x 100%.

    2. From drinking water. Mepiquat chloride is stable to hydrolysis 
and photolysis. Soil and aqueous photolysis are not routes of 
dissipation. Under aerobic conditions, mepiquat chloride appears to 
degrade rapidly to CO<INF>2</INF>. Under anaerobic conditions, it 
appears stable. Based on study results, mepiquat chloride is considered 
to be relatively non-mobile, and is not expected to accumulate in fish. 
Since the other mepiquat chloride metabolites also degrade rapidly to 
CO<INF>2</INF>, parent mepiquat chloride is the only residue of 
concern. There are no established Maximum Contaminant Levels or health 
advisory levels for residues of mepiquat chloride in drinking water. 
Furthermore, mepiquat chloride is considered to have limited potential 
for groundwater contamination. Because of mepiquat chloride's low usage 
rate and its rapid degradation, significant migration to surface water 
is not expected.
    i. Acute exposure and risk. Drinking water levels of concern 
(DWLOC) for acute and chronic dietary exposure are included as the 
following Tables 3 and 4.

                 Table 3.-- Drinking Water Levels of Concern (DWLOC) for ACUTE Dietary Exposure
----------------------------------------------------------------------------------------------------------------
                                                      Acute
                                                       RfD    Acute RfD      Acute      Max Water       Acute
                    Population\7\                      (mg/   with FQPA     Dietary    Exposure\3\   DWLOC<SUP>4,5,6
                                                       kg/    factor\1\   Exposure\2\  (mg/kg/day)  (<greek-m>g/
                                                       day)  (mg/kg/day)  (mg/kg/day)                    L)
----------------------------------------------------------------------------------------------------------------
U.S. Population.....................................   0.6     0.6 (FQPA
                                                             factor does
                                                              not apply)     0.0092       0.59            21,000
Females 13 years +..................................   0.6          0.06     0.012        0.048            1,400
Children/Infants....................................   0.6          0.06     0.024        0.036             360
----------------------------------------------------------------------------------------------------------------
\1\ Acute RfD with FQPA factor = Acute RfD/FQPA Safety Factor (10x).
\2\ Acute Dietary Exposure from DEEM analysis.

[[Page 51844]]

\3\ Max Water Exposure = Acute RfD with FQPA factor - Acute Dietary Exposure (mg/kg/day).
\4\ Acute DWLOC(<greek-m>g/L) = Max. water exposure (mg/kg/day) * body wt (kg)/(10<SUP>-3 mg/<greek-m>g) * water
  consumed daily (L/day).
\5\ HED Default body weights are 70 kg for General US Population; 60 kg for females 13+ and 10 kg for infants
  and children.
\6\ HED Default Daily Drinking Rates are 2 L/day for Adults and 1 L/day for infants and children.
\7\ Within each of these categories, the subgroup with the highest food exposure was given.


                                     Table 4.--Drinking Water Levels of Concern (DWLOC) for CHRONIC Dietary Exposure
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                         Chronic RfD with   Chronic Dietary       Max Water
                     Population                       Chronic RfD (mg/    FQPA factor\1\    Exposure\2\ (mg/   Exposure\3\ (mg/    Chronic DWLOC<SUP>4,5,6,7
                                                          kg/day)          (mg/kg/day)          kg/day)            kg/day)            (<greek-m>g/L)
--------------------------------------------------------------------------------------------------------------------------------------------------------
U.S. Population....................................                0.6   0.6 (FQPA factor
                                                                          does not apply)             0.0010              0.599                   21,000
Females 13 years +.................................                0.6               0.06             0.0014             0.0586                    1,800
Children/Infants...................................                0.6               0.06             0.0034             0.0566                     570
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Acute RfD with FQPA factor = Acute RfD/FQPA Safety Factor (10x).
\2\ Acute Dietary Exposure from DEEM analysis.
\3\ Max Water Exposure = Acute RfD with FQPA factor - Acute Dietary Exposure (mg/kg/day).
\4\ Chronic DWLOC(<greek-m>g/L) = Max. water exposure (mg/kg/day) * body wt (kg)/(10<SUP>-3 mg/<greek-m>g) * water consumed daily (L/day).
\5\ HED Default body weights are 70 kg for General US Population; 60 kg for females 13+ and 10 kg for infants and children.
\6\ HED Default Daily Drinking Rates are 2 L/day for Adults and 1 L/day for infants and children.
\7\ Within each of these categories, the subgroup with the highest food exposure was given.

    ii. Chronic exposure and risk. ``The Interim Guidance for 
Conducting Drinking Water Exposure and Risk Assessments`` issued on 
November 24, 1997 was followed for this assessment. Thus, the generic 
expected environmental concentration (GENEEC) model and the SCI-GROW 
model were run to produce estimates of mepiquat chloride concentrations 
in surface and ground water, respectively. The primary use of these 
models is to provide a coarse screen for sorting out pesticides for 
which EPA has a high degree of confidence that the true levels of the 
pesticide in drinking water will be less than the human health drinking 
water levels of concern (DWLOCs). A DWLOC is the concentration of a 
pesticide in drinking water which would be acceptable as an upper limit 
in light of total aggregate exposure to that chemical from food, water, 
and non-occupational (residential) sources.
    The DWLOC is the concentration in drinking water as a part of the 
aggregate chronic exposure that occupies no more than 100% of the RfD. 
The Agency's default body weights and water consumption values used to 
calculate DWLOCs are as follows: 70 kg/2L (adult male), 60 kg/2L (adult 
female), and 10 kg/1L (child).
    For chronic (non-cancer) exposure to mepiquat chloride in surface 
and ground water, the drinking water levels of concern are 21,000 
<greek-m>g/L for the U.S. population, 1,800 <greek-m>g/L for females 
(13+ years old), and 570 <greek-m>g/L for children (1-6 years old). To 
calculate the DWLOC for chronic (non-cancer) exposure relative to a 
chronic toxicity endpoint, the chronic dietary food exposure (from 
DEEM) was subtracted from the RfD to obtain the acceptable chronic 
(non-cancer) exposure to mepiquat chloride in drinking water. DWLOCs 
were then calculated using default body weights and drinking 
consumption figures.
    Estimated average concentrations of mepiquat chloride in surface 
and groundwater are 1.99 parts per billion (ppb) and 0.008 ppb, 
respectively. The DWLOCs are as stated above. The estimated average 
concentrations of mepiquat chloride in surface and groundwater are less 
than OPP EPA's level of concern for mepiquat chloride in drinking water 
as a contribution to chronic aggregate exposure.
    3. From non-dietary exposure. Mepiquat Chloride is currently not 
registered for use on any sites that present a risk of non-
occupational, non-dietary exposure.
    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.''
    EPA does not have, at this time, available data to determine 
whether mepiquat chloride 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, 
mepiquat chloride 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 mepiquat chloride has a 
common mechanism of toxicity with other substances. For more 
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).

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

    1. Acute risk. The acute risk for ``food only'' does not exceed 
EPA's level of concern. Since estimates of mepiquat chloride in 
drinking water do not exceed acute drinking water levels of concern 
(DWLOC) listed in Table 3 of this preamble, the Agency does not expect 
the acute aggregate risk to exceed the level of concern.
    2. Chronic risk. Using the TMRC exposure assumptions described 
above, EPA has concluded that aggregate exposure to mepiquat chloride 
from food will utilize < 1% of the RfD for the U.S. population. The 
major identifiable subgroup with the highest aggregate exposure is 
discussed below. EPA generally has no concern for exposures below 100% 
of the RfD because the RfD represents the level at or below which daily 
aggregate dietary exposure over a lifetime will not pose appreciable 
risks to human health. Despite the potential for exposure to mepiquat 
chloride in drinking water and from non-dietary, non-occupational 
exposure, EPA does not expect the aggregate exposure to exceed 100% of 
the RfD.
    3. Short- and intermediate-term risk. Short- and intermediate-term 
aggregate exposure takes into account chronic dietary food and water 
(considered to be a background exposure level) plus indoor and outdoor 
residential uses. There are no registered residential uses of mepiquat 
chloride. Therefore, a

[[Page 51845]]

Short- and Intermediate-Term Aggregate Risk assessment is not 
applicable.
    4. Aggregate cancer risk for U.S. population. The Agency has 
classified mepiquat chloride as a Group E chemical, ``no evidence of 
carcinogenicity to humans.'' Therefore, a risk assessment is not 
required.
    5. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
from aggregate exposure to mepiquat chloride residues.

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

    1. Safety factor for infants and children-- i. In general. In 
assessing the potential for additional sensitivity of infants and 
children to residues of mepiquat chloride, EPA considered data from 
developmental toxicity studies in the rat and rabbit and a two-
generation reproduction study in the rat. The developmental toxicity 
studies are designed to evaluate adverse effects on the developing 
organism resulting from maternal pesticide exposure during gestation. 
Reproduction studies provide information relating to effects from 
exposure to the pesticide on the reproductive capability of mating 
animals and data on systemic toxicity.
    FFDCA section 408 provides that EPA shall apply an additional 
tenfold margin of safety for infants and children in the case of 
threshold effects to account for pre-and post-natal toxicity and the 
completeness of the data base unless EPA determines that a different 
margin of safety will be safe for infants and children. Margins of 
safety are incorporated into EPA risk assessments either directly 
through use of a margin of exposure (MOE) analysis or through using 
uncertainty (safety) factors in calculating a dose level that poses no 
appreciable risk to humans. EPA believes that reliable data support 
using the standard MOE and uncertainty factor (usually 100 for combined 
inter- and intra-species variability) and not the additional tenfold 
MOE/uncertainty factor when EPA has a complete data base under existing 
guidelines and when the severity of the effect in infants or children 
or the potency or unusual toxic properties of a compound do not raise 
concerns regarding the adequacy of the standard MOE/safety factor.
     ii. Developmental toxicity studies.--a. Rats. In a developmental 
toxicity study, Wistar rats were dosed by oral gavage at levels of 0, 
50, 150, or 300 mg/kg/day during gestation days 6 through 15. Based on 
the clinical signs of toxicity and decreases in the food consumption 
and body weight gains, the Maternal Toxicity LOAEL is 300 mg/kg/day and 
the Maternal Toxicity NOAEL is 150 mg/kg/day. Since developmental 
toxicity was not observed in this study, the Developmental Toxicity 
NOEL is <gr-thn-eq> 300 mg/kg/day (Hight Dose Tested).
    b. Rabbits. In a developmental toxicity study, mepiquat chloride 
was administered to Himalayan rabbits at dose levels of 0 (untreated 
control), 0 (vehicle control), 50, 100 and 150 mg/kg/day during 
gestation days 6-18. The maternal NOAEL is 50 mg/kg/day (borderline 
value) and the LOAEL is 100 mg/kg/day based on body weight loss and 
decreased body weight gain; decreased food consumption; amber-colored 
liquid in the abdomens of six rabbits; diarrhea, trembling and apathy 
in one rabbit; and six abortions. Developmental effects were not 
observed in the 50 mg/kg group. Because of the high abortion rate in 
the 100 mg/kg group (37.5%) and high death and abortion rate in the 150 
mg/kg group (58.8%), inadequate numbers of fetuses in the mid-dose and 
high-dose groups preclude the meaningful evaluation of developmental 
toxicity in this study. In order to evaluate developmental toxicity in 
the rabbit, the current study was to be considered with another study 
in which two doses of mepiquat chloride (75 and 100 mg/kg) were tested. 
However, because the results were reported only in the form of a brief 
summary, the second study cannot be presently evaluated. The 
developmental toxicity study in the rabbit is classified as 
supplementary/unacceptable and does not satisfy the guideline 
requirement 83-3b (OPPTS 870.3700). The study is upgradable following 
the review and acceptance of the second study.
    iii. Reproductive toxicity study.-- Rats. In the 2-generation 
reproductive toxicity study, groups of 25 male and 25 female Wistar 
rats were fed mepiquat chloride in their diets at concentrations of 0, 
500, 1,500, or 5,000 ppm for 10 weeks (F<INF>0</INF>) or 14 weeks 
(F<INF>1</INF>) before mating, and during mating, gestation, and 
lactation. The doses corresponding to the dietary concentrations are 
51.2 and 48.6, 153.1 and 146.6, and 499.3 and 574.5 mg/kg/day, 
respectively for F<INF>0</INF> and F<INF>1</INF> males and 54.0 and 
53.3, 163.6 and 162.0, and 530.0 and 626.5 mg/kg/day, respectively for 
F<INF>0</INF> and F<INF>1</INF> females.
    The LOAEL for parental (systemic) toxicity is 5,000 ppm (499 mg/kg/
day) for male and female rats based on neurological impairment, 
decreased body weight and body weight gain in the adults, and retarded 
growth of F<INF>1</INF> and F<INF>2</INF> pups. The parental (systemic) 
NOAEL is 1,500 ppm (147 mg/kg/day). There were no treatment-related 
effects on reproductive parameters. The NOAEL for reproductive toxicity 
is > 5,000 ppm (499 mg/kg/day).
    iv. Pre- and post-natal sensitivity. The toxicological data base 
for evaluating pre- and post-natal toxicity for mepiquat chloride is 
incomplete with respect to current data requirements. There are no pre- 
or post-natal toxicity concerns for infants and children, based on the 
results of the rat developmental toxicity study and the 2-generation 
rat reproductive toxicity study. However the developmental toxicity 
study in rabbits was unacceptable and requires a new study.
    v. Conclusion. Based on the above, the Agency determined that the 
10X safety factor for protection of infants and children should be 
retained and applied to all population subgroups involving women and 
children.
    2. Acute risk. The acute risk for food and drinking water do not 
exceed EPA's level of concern and therefore the acute aggregate risk 
does not exceed the Agency's level of concern.
    3. Chronic risk. Using the exposure assumptions described above, 
EPA has concluded that aggregate exposure to mepiquat chloride from 
food will utilize < 1% of the RfD for infants and children. EPA 
generally has no concern for exposures below 100% of the RfD because 
the RfD represents the level at or below which daily aggregate dietary 
exposure over a lifetime will not pose appreciable risks to human 
health.
    4. Short- or intermediate-term risk. Short- and intermediate-term 
aggregate exposure takes into account chronic dietary food and water 
(considered to be a background exposure level) plus indoor and outdoor 
residential uses. There are no registered residential uses of mepiquat 
chloride. Therefore, a Short- and Intermediate-Term Aggregate Risk 
assessment is not applicable.
    5. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
to infants and children from aggregate exposure to mepiquat chloride 
residues.

IV. Other Considerations

A. Metabolism in Plants and Animals

    A previously submitted study of the metabolism of mepiquat chloride 
in grapes was found to be adequate. The residue-of-concern in grapes is 
considered to be the parent compound only. Secondary residues are not 
expected in animal commodities as no feed items are associated with 
this section 18 use.

B. Analytical Enforcement Methodology

    The analytical method gas chromatography/nitrogen phosphorus

[[Page 51846]]

detector (GC/NPD) for mepiquat chloride in/on grapes was previously 
reviewed and found to be adequate for tolerance enforcement. The limit 
of quantification (LOQ) for this method was reported as 0.05 ppm in 
grapes, 0.1 ppm in grape juice, and 0.25 ppm in raisins.

C. Magnitude of Residues

    The grape residue data provided with this action appear to be a 
summary of the data that were supplied with a previously submitted 
petition (PP 1F3955/1H5610). In support of that petition, 28 field 
trials in 8 different states (California, New York, Pennsylvania, 
Oregon, Michigan, New Jersey, Ohio, and Georgia) were conducted in 1984 
and 1985. Residues of mepiquat chloride in/on grapes ranged from < 0.05 
to 0.76 ppm with PHIs ranging from 77 to 135 days. The highest value, 
0.76 ppm, is from a 0.4 lb/A treatment (1.6 times the recommended rate) 
and was found 106 days after application. In Ohio, residues of mepiquat 
chloride were 0.1 and 0.15 ppm for PHIs of 112 and 106 days, 
respectively.
    A time-limited tolerance of 1 ppm for residues of mepiquat chloride 
in/on grapes will be established for purposes of this section 18 use 
only. Grapes processed from the field trials indicate that production 
of raisins resulted in a sixfold increase in mepiquat chloride 
residues. Mepiquat chloride did not concentrate in grape juice. A time-
limited tolerance of 6 ppm for residues of mepiquat chloride in/on 
raisins will be established to support this section 18 use. Secondary 
residues are not expected in animal commodities as no feed items are 
associated with this section 18 use.

D. International Residue Limits

    There are no Codex, Canadian, or Mexican tolerances established for 
mepiquat chloride on grapes. Thus, international harmonization is not 
an issue for these time-limited tolerances.

E. Rotational Crop Restrictions

    Since grapes are not rotated to other crops, a discussion of 
rotational crop restrictions is not germane to this action.

V. Conclusion

    Therefore, the tolerance is established for residues of N,N-
dimethylpiperidinium chloride in grapes at 1.0 ppm and raisins at 6.0 
ppm.

VI. 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 November 30, 1998, file written objections to 
any aspect of this regulation and may also request a hearing on those 
objections. Objections and hearing requests must be filed with the 
Hearing Clerk, at the address given above (40 CFR 178.20). A copy of 
the objections and/or hearing requests filed with the Hearing Clerk 
should be submitted to the OPP docket for this rulemaking. The 
objections submitted must specify the provisions of the regulation 
deemed objectionable and the grounds for the objections (40 CFR 
178.25). Each objection must be accompanied by the fee prescribed by 40 
CFR 180.33(i). If a hearing is requested, the objections must include a 
statement of the factual issues on which a hearing is requested, the 
requestor's contentions on such issues, and a summary of any evidence 
relied upon by the requestor (40 CFR 178.27). A request for a hearing 
will be granted if the Administrator determines that the material 
submitted shows the following: There is genuine and substantial issue 
of fact; there is a reasonable possibility that available evidence 
identified by the requestor would, if established, resolve one or more 
of such issues in favor of the requestor, taking into account 
uncontested claims or facts to the contrary; and resolution of the 
factual issues in the manner sought by the requestor would be adequate 
to justify the action requested (40 CFR 178.32). Information submitted 
in connection with an objection or hearing request may be claimed 
confidential by marking any part or all of that information as 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.

VII. Public Record and Electronic Submissions

    EPA has established a record for this rulemaking under docket 
control number [OPP-300719] (including any comments and data submitted 
electronically). A public version of this record, including printed, 
paper versions of electronic comments, which does not include any 
information claimed as CBI, is available for inspection from 8:30 a.m. 
to 4 p.m., Monday through Friday, excluding legal holidays. The public 
record is located in Room 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.
    Electronic comments may be sent directly to EPA at:
    opp-docket@epamail.epa.gov.

    Electronic comments must be submitted as an ASCII file avoiding the 
use of special characters and any form of encryption.
    The official record for this rulemaking, as well as the public 
version, as described above will be kept in paper form. Accordingly, 
EPA will transfer any copies of objections and hearing requests 
received electronically into printed, paper form as they are received 
and will place the paper copies in the official rulemaking record which 
will also include all comments submitted directly in writing. The 
official rulemaking record is the paper record maintained at the 
Virginia address in ``ADDRESSES'' at the beginning of this document. 
VIII.

VIII. Regulatory Assessment Requirements

A. Certain Acts and Executive Orders

    This final rule establishes a tolerance under FFDCA section 408 
(l)(6). The Office of Management and Budget (OMB) has exempted these 
types of actions from review under Executive Order 12866, entitled 
Regulatory Planning and Review (58 FR 51735, October 4, 1993). This 
final rule does not contain any information collections subject to OMB 
approval under the Paperwork Reduction Act (PRA), 44 U.S.C. 3501 et 
seq., or impose any enforceable duty or contain any unfunded mandate as 
described under Title II of the Unfunded Mandates Reform Act of 1995 
(UMRA) (Pub. L. 104-4). Nor does it require any prior consultation as 
specified by Executive

[[Page 51847]]

Order 12875, entitled Enhancing the Intergovernmental Partnership (58 
FR 58093, October 28, 1993), or special considerations as required by 
Executive Order 12898, entitled Federal Actions to Address 
Environmental Justice in Minority Populations and Low-Income 
Populations (59 FR 7629, February 16, 1994), or require OMB review in 
accordance with Executive Order 13045, entitled Protection of Children 
from Environmental Health Risks and Safety Risks (62 FR 19885, April 
23, 1997).
    In addition, since tolerances and exemptions that are established 
under FFDCA section 408 (l)(6), 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 Intergovernmental 
Partnerships (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 the Office of Management and Budget (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 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.

 IX. Submission to Congress and the Comptroller General

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small 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 to 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: September 18, 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. In Sec. 180.384 as follows:
    i. By designating the existing text as paragraph (a) and adding a 
paragraph heading.
    ii. By adding paragraph (b) and by adding and reserving with 
headings paragraphs (c) and (d).
    The added text reads as follows:


Sec. 180.384  N,N-Dimethylpiperidinium chloride; tolerances for 
residues.

    (a) General. *    *    *
    (b) Section 18 emergency exemptions. Time limited tolerances are 
established for residues of the plant growth regulator mepiquat 
chloride, N,N-Dimethylpiperidinium chloride under section 18 emergency 
exemptions granted by EPA when used on the commodities in the table 
below. The tolerances will expire and are revoked on the dates 
specified in the following table.

------------------------------------------------------------------------
                                                          Expiration/
            Commodity              Parts per million    Revocation Date
------------------------------------------------------------------------
Grapes..........................  1.0                 3/1/00
Raisins.........................  6.0                 3/1/00
------------------------------------------------------------------------


[[Page 51848]]

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

PART 186-- [AMENDED]

    2. In part 186:
    a. The authority citation for part 186 continues to read as 
follows;
    Authority:  21 U.S.C. 348.

Sec. 186.2275 [Partially Redesignated and Removed]

    b. In Sec. 186.2275 by transfering the entry for ``cottonseed'' 
from the table and adding it alphabetically to the table in newly 
designated paragraph (a) of Sec. 180.384, and by removing the remainder 
of Sec. 186.2275.
[FR Doc. 98-25984 Filed 9-28-98; 8:45 am]
BILLING CODE 6560-50-F