23898 Federal Register / Vol. 76, No. 83 / Friday, April 29, 2011 / Rules and Regulations 

PART 180—[AMENDED] 

■ 1. The authority citation for part 180 

continues to read as follows: 

Authority: 21 U.S.C. 321(q), 346a and 371. 

■ 2. Section 180.631 is amended by 

revising the introductory text and table 

in paragraph (a) to read as follows: 

§ 180.631 Pyrasulfotole; tolerances for 

residues. 

(a) General. Tolerances are 

established for residues of the herbicide 

pyrasulfotole, including its metabolites 

and degradates, in or on the 

commodities in the table below. 

Compliance with the tolerance levels 

specified below is to be determined by 

measuring only the sum of pyrasulfotole 

((5-hydroxy-1,3-dimethyl-1H-pyrazol-4- 

yl)[2-(methylsulfonyl)-4- 

(trifluoromethyl)phenyl]methanone) 

and its desmethyl metabolite (5- 

hydroxy-3-methyl-1H-pyrazol-4-yl)[2- 

(methylsulfonyl)-4- 

(trifluoromethyl)phenyl]methanone), 

calculated as the stoichiometric 

equivalent of pyrasulfotole, in or on the 

commodities: 

Commodity Parts per 

million 

Aspirated grain fractions ........... 0 .40 

Barley, grain ............................. 0 .02 

Barley, hay ................................ 0 .30 

Barley, straw ............................. 0 .20 

Cattle, fat .................................. 0 .03 

Cattle, liver ................................ 3 .0 

Cattle, meat .............................. 0 .02 

Cattle, meat byproducts, except 

liver ........................................ 0 .70 

Eggs .......................................... 0 .02 

Goat, fat .................................... 0 .03 

Goat, liver ................................. 3 .0 

Goat, meat ................................ 0 .02 

Goat, meat byproducts, except 

liver ........................................ 0 .70 

Grass, forage ............................ 25 

Grass, hay ................................ 3 .5 

Hog, fat ..................................... 0 .02 

Hog, liver .................................. 0 .30 

Hog, meat ................................. 0 .02 

Hog, meat byproducts, except 

liver ........................................ 0 .05 

Horse, fat .................................. 0 .03 

Horse, liver ............................... 3 .0 

Horse, meat .............................. 0 .02 

Horse, meat byproducts, except 

liver ........................................ 0 .70 

Milk ........................................... 0 .03 

Oat, forage ................................ 0 .10 

Oat, grain .................................. 0 .08 

Oat, hay .................................... 0 .50 

Oat, straw ................................. 0 .20 

Poultry, fat ................................ 0 .02 

Poultry, meat ............................ 0 .02 

Poultry, meat byproducts .......... 0 .20 

Rye, forage ............................... 0 .20 

Rye, grain ................................. 0 .02 

Rye, straw ................................. 0 .20 

Sheep, fat ................................. 0 .03 

Sheep, liver ............................... 3 .0 

Commodity Parts per 

million 

Sheep, meat ............................. 0 .02 

Sheep, meat byproducts, except liver ................................ 0 .70 

Sorghum, grain, forage ............. 1 .5 

Sorghum, grain, grain ............... 0 .70 

Sorghum, grain, stover ............. 0 .80 

Wheat, forage ........................... 0 .20 

Wheat, grain ............................. 0 .02 

Wheat, hay ............................... 0 .80 

Wheat, straw ............................. 0 .20 

* * * * * 

[FR Doc. 2011–10435 Filed 4–28–11; 8:45 am] 

BILLING CODE 6560–50–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 180 

[EPA–HQ–OPP–2010–0267; FRL–8870–9] 

Mefenpyr-diethyl; Pesticide Tolerances 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Final rule. 

SUMMARY: This regulation establishes 

tolerances for residues of mefenpyrdiethyl in or on multiple commodities. 

Bayer CropScience LLC requested these 

tolerances under the Federal Food, 

Drug, and Cosmetic Act (FFDCA). This 

regulation also moves established 

tolerances for canola and soybean 

commodities to correct an 

administrative error. 

DATES: This regulation is effective April 

29, 2011. Objections and requests for 

hearings must be received on or before 

June 28, 2011, and must be filed in 

accordance with the instructions 

provided in 40 CFR part 178 (see also 

Unit I.C. of the SUPPLEMENTARY

INFORMATION ). 

ADDRESSES: EPA has established a 

docket for this action under docket 

identification (ID) number EPA–HQ– 

OPP–2010–0267. All documents in the 

docket are listed in the docket index 

available at http://www.regulations.gov. 

Although listed in the index, some 

information is not publicly available, 

e.g., Confidential Business Information 

(CBI) or other information whose 

disclosure is restricted by statute. 

Certain other material, such as 

copyrighted material, is not placed on 

the Internet and will be publicly 

available only in hard copy form. 

Publicly available docket materials are 

available in the electronic docket at 

http://www.regulations.gov, or, if only 

available in hard copy, at the OPP 

Regulatory Public Docket in Rm. S– 

4400, One Potomac Yard (South Bldg.), 

2777 S. Crystal Dr., Arlington, VA. The 

Docket Facility is open from 8:30 a.m. 

to 4 p.m., Monday through Friday, 

excluding legal holidays. The Docket 

Facility telephone number is (703) 305– 

5805. 

FOR FURTHER INFORMATION CONTACT: 

Bethany Benbow, Registration Division 

(7505P), Office of Pesticide Programs, 

Environmental Protection Agency, 1200 

Pennsylvania Ave., NW., Washington, 

DC 20460–0001; telephone number: 

(703) 347–8072; e-mail address: 

benbow.bethany@epa.gov. 

SUPPLEMENTARY INFORMATION: 

I. General Information 

A. Does this action apply to me? 

You may be potentially affected by 

this action if you are an agricultural 

producer, food manufacturer, or 

pesticide manufacturer. Potentially 

affected entities may include, but are 

not limited to those engaged in the 

following activities: 

• Crop production (NAICS code 111). 

• Animal production (NAICS code 

112). 

• Food manufacturing (NAICS code 

311). 

• Pesticide manufacturing (NAICS 

code 32532). 

This listing is not intended to be 

exhaustive, but rather to provide a guide 

for readers regarding entities likely to be 

affected by this action. Other types of 

entities not listed in this unit could also 

be affected. The North American 

Industrial Classification System 

(NAICS) codes have been provided to 

assist you and others in determining 

whether this action might apply to 

certain entities. If you have any 

questions regarding the applicability of 

this action to a particular entity, consult 

the person listed under FOR FURTHER

INFORMATION CONTACT. 

B. How can I get electronic access to 

other related information? 

You may access a frequently updated 

electronic version of EPA’s tolerance 

regulations at 40 CFR part 180 through 

the Government Printing Office’s e-CFR 

site at http://www.gpoaccess.gov/ecfr. 

C. How can I file an objection or hearing 

request? 

Under FFDCA section 408(g), 21 

U.S.C. 346a, any person may file an 

objection to any aspect of this regulation 

and may also request a hearing on those 

objections. You must file your objection 

or request a hearing on this regulation 

in accordance with the instructions 

provided in 40 CFR part 178. To ensure 

proper receipt by EPA, you must 

identify docket ID number EPA–HQ– 


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OPP–2010–0267 in the subject line on 

the first page of your submission. All 

objections and requests for a hearing 

must be in writing, and must be 

received by the Hearing Clerk on or 

before June 28, 2011. Addresses for mail 

and hand delivery of objections and 

hearing requests are provided in 40 CFR 

178.25(b). 

In addition to filing an objection or 

hearing request with the Hearing Clerk 

as described in 40 CFR part 178, please 

submit a copy of the filing that does not 

contain any CBI for inclusion in the 

public docket. Information not marked 

confidential pursuant to 40 CFR part 2 

may be disclosed publicly by EPA 

without prior notice. Submit a copy of 

your non-CBI objection or hearing 

request, identified by docket ID number 

EPA–HQ–OPP–2010–0267, by one of 

the following methods: 

• Federal eRulemaking Portal: http:// 

www.regulations.gov. Follow the on-line 

instructions for submitting comments. 

• Mail: Office of Pesticide Programs 

(OPP) Regulatory Public Docket (7502P), 

Environmental Protection Agency, 1200 

Pennsylvania Ave., NW., Washington, 

DC 20460–0001. 

• Delivery: OPP Regulatory Public 

Docket (7502P), Environmental 

Protection Agency, Rm. S–4400, One 

Potomac Yard (South Bldg.), 2777 S. 

Crystal Dr., Arlington, VA. Deliveries 

are only accepted during the Docket 

Facility’s normal hours of operation 

(8:30 a.m. to 4 p.m., Monday through 

Friday, excluding legal holidays). 

Special arrangements should be made 

for deliveries of boxed information. The 

Docket Facility telephone number is 

(703) 305–5805. 

II. Summary of Petitioned-For 

Tolerance 

In the Federal Register of June 23, 

2010 (75 FR 35804) (FRL–8831–3), EPA 

issued a notice pursuant to section 

408(d)(3) of FFDCA, 21 U.S.C. 

346a(d)(3), announcing the filing of a 

pesticide petition (PP 9F7679) by Bayer 

CropScience LLC, 2 T.W. Alexander 

Drive, Research Triangle Park, NC 

27709. The petition requested that 40 

CFR 180.509 be amended by 

establishing tolerances for residues of 

the herbicide safener, mefenpyr-diethyl 

including its metabolites and degradates 

with compliance to be determined by 

measuring residues of mefenpyr-diethyl, 

(1-(2,4-dichlorophenyl)-4,5-dihydro-5- 

methyl-1H-pyrazole-3,5-dicarboxylic 

acid, diethyl ester) and its 

dichlorophenyl-pyrazoline metabolites, 

in or on grass, forage at 1.5 parts per 

million (ppm); grass, hay at 0.05 ppm; 

sorghum, forage at 0.1 ppm; sorghum, 

grain at 0.01 ppm; and sorghum, stover 

at 0.05 ppm. That notice referenced a 

summary of the petition prepared by 

Bayer CropScience LLC, the registrant, 

which is available in the docket, 

http://www.regulations.gov. There were 

no comments received in response to 

the notice of filing. 

Based upon review of the data 

supporting the petition, EPA has 

increased the proposed tolerance for all 

proposed commodities as follows: 

Grass, forage from 1.5 to 1.6 ppm; grass, 

hay from 0.05 to 0.2 ppm; sorghum, 

forage from 0.1 to 0.4 ppm; sorghum, 

grain from 0.01 to 0.04 ppm; and 

sorghum, stover from 0.05 to 0.2 ppm. 

The reasons for these changes are 

explained in Unit IV.C. 

In the Federal Register of December 

10, 2008 (73 FR 74977) (FRL–8390–8), 

EPA established tolerances for residues 

of mefenpyr-diethyl in or on canola, 

seed; soybean, forage; soybean, hay; and 

soybean, seed. These tolerances were 

identified as rotational crop tolerances 

in the final rule; however, they were 

placed in paragraph (a) of 40 CFR 

180.509 in error. They should have been 

placed in paragraph (d) as tolerances for 

indirect or inadvertent residues. EPA is 

moving these tolerances from paragraph 

(a) to paragraph (d) to correct this 

administrative error. Moving these 

tolerances between subsections has no 

substantive effect, it merely makes them 

easier to identify as rotational crop 

tolerances. 

III. Aggregate Risk Assessment and 

Determination of Safety 

Section 408(b)(2)(A)(i) of 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) of FFDCA 

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) of FFDCA 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. * * *’’ 

Consistent with section 408(b)(2)(D) 

of FFDCA, and the factors specified in 

section 408(b)(2)(D) of FFDCA, 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 

and to make a determination on 

aggregate exposure for mefenpyr-diethyl 

including exposure resulting from the 

tolerances established by this action. 

EPA’s assessment of exposures and risks 

associated with mefenpyr-diethyl 

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. 

Mefenpyr-diethyl has low acute 

toxicity by the oral, dermal, and 

inhalation routes of exposure. It is not 

a dermal irritant but is a slight ocular 

irritant and dermal sensitizer. Repeated 

exposure of rats via the dermal route did 

not induce any treatment-related effects 

at dose levels up to and including the 

limit dose. Repeated exposure studies 

via the oral route demonstrate that the 

target organs are the liver and 

hematopoietic system in dogs, mice, and 

rats. Effects observed in dogs included 

increased liver weight and alkaline 

phosphatase activity (both sexes), focal 

liver lesions (females), slight anemia 

(both sexes), decreased mean body 

weight and body weight gain (females) 

and decreased food consumption (both 

sexes). Effects observed in mice 

included decreased body weight and 

kidney weight, increased liver weight, 

and hepatocyte hypertrophy (males), as 

well as decreased bilirubin and 

increased lactic acid dehydrogenase 

values (females). Effects observed in rats 

included increases in reticulocyte 

counts (both sexes), and decreased red 

blood count, hemoglobin, and 

hematocrit values (females). Mefenpyrdiethyl was negative for carcinogenicity 

in rats and mice, and is classified as 

‘‘not likely to be carcinogenic to 

humans.’’ The available studies did not 

indicate any genotoxic or neurotoxic 

potential. Developmental toxicity was 

not observed in the rat but was observed 

in the rabbit (abortions) at the same dose 

level producing maternal toxicity. 

Mefenpyr-diethyl did not induce any 

signs of reproductive toxicity. The 

developmental toxicity studies in rats 

and rabbits, as well as the reproductive 

toxicity study in rats, did not 

demonstrate any pre- or post-natal 

sensitivity. 


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Specific information on the studies 

received and the nature of the adverse 

effects caused by mefenpyr-diethyl as 

well as the no-observed-adverse-effectlevel (NOAEL) and the lowest-observedadverse-effect-level (LOAEL) from the 

toxicity studies can be found at http:// 

www.regulations.gov in document, 

Mefenpyr-diethyl (HOE 107892) Safener: 

Revised Human Health Risk Assessment 

to Support the New use Petition on 

Sorghum [grain, stover, and forage] and 

Grass Grown for Seed (including 

Conservation Reserve Program areas), at 

pages 31–36 in docket ID number EPA– 

HQ–OPP–2010–0267. 

B. Toxicological Points of Departure/ 

Levels of Concern 

Once a pesticide’s toxicological 

profile is determined, EPA identifies 

toxicological points of departure (POD) 

and levels of concern to use in 

evaluating the risk posed by human 

exposure to the pesticide. For hazards 

that have a threshold below which there 

is no appreciable risk, the toxicological 

POD is used as the basis for derivation 

of reference values for risk assessment. 

PODs are developed based on a careful 

analysis of the doses in each 

toxicological study to determine the 

dose at which no adverse effects are 

observed (the NOAEL) and the lowest 

dose at which adverse effects of concern 

are identified (the LOAEL). Uncertainty/ 

safety factors are used in conjunction 

with the POD to calculate a safe 

exposure level—generally referred to as 

a population-adjusted dose (PAD) or a 

reference dose (RfD)—and a safe margin 

of exposure (MOE). For non-threshold 

risks, the Agency assumes that any 

amount of exposure will lead to some 

degree of risk. Thus, the Agency 

estimates risk in terms of the probability 

of an occurrence of the adverse effect 

expected in a lifetime. For more 

information on the general principles 

EPA uses in risk characterization and a 

complete description of the risk 

assessment process, see http://

www.epa.gov/pesticides/factsheets/

riskassess.htm. 

A summary of the toxicological 

endpoints for mefenpyr-diethyl used for 

human risk assessment is shown in 

Table 1 of this unit. 

TABLE 1—SUMMARY OF TOXICOLOGICAL DOSES AND ENDPOINTS FOR MEFENPYR-DIETHYL FOR USE IN HUMAN HEALTH

RISK ASSESSMENT

Exposure/scenario Point of departure and 

uncertainty/safety factors 

RfD, PAD, LOC for risk 

assessment Study and toxicological effects 

Acute dietary (Females 13–50 

years of age).

No hazard was identified in any toxicity study for this duration of exposure. 

Acute dietary (General population 

including infants and children).

No hazard was identified in any toxicity study for this duration of exposure. 

Chronic dietary (All populations) .... NOAEL = 51 mg/kg/day ...............

UFA = 10x 

UFH = 10x 

FQPA SF = 1x 

Chronic RfD = 0.51 mg/kg/day .....

cPAD = 0.51 mg/kg/day 

chronic oral toxicity study (dog). 

LOAEL = 260 mg/kg/day, based 

on increased liver weight in 

both sexes, cholestasis, and increased alkaline phosphatase. 

chronic toxicity/carcinogenicity 

study (rat). 

LOAEL = 252 (males)/318 (females) mg/kg/day, based on 

statistically significant increases 

in reticulocyte counts in both 

sexes, and decreased RBC, hemoglobin, and hematocrit values in females. NOAEL = 48.5 

(males)/60 (females) mg/kg/day. 

Cancer (oral) .................................. Classification: Not likely to be carcinogenic to humans. 

UFA = extrapolation from animal to human (interspecies). UFH = potential variation in sensitivity among members of the human population 

(intraspecies). UFL = use of a LOAEL to extrapolate a NOAEL. UFS = use of a short-term study for long-term risk assessment. UFDB = to account for the absence of data or other data deficiency. FQPA SF = Food Quality Protection Act Safety Factor. PAD = population adjusted dose 

(a = acute, c = chronic). RfD = reference dose. MOE = margin of exposure. LOC = level of concern. 

C. Exposure Assessment 

1. Dietary exposure from food and 

feed uses. In evaluating dietary 

exposure to mefenpyr-diethyl, EPA 

considered exposure under the 

petitioned-for tolerances as well as all 

existing mefenpyr-diethyl tolerances in 

40 CFR 180.509. EPA assessed dietary 

exposures from mefenpyr-diethyl in 

food as follows: 

i. Acute exposure. Quantitative acute 

dietary exposure and 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 such effects were 

identified in the toxicological studies 

for mefenpyr-diethyl; therefore, a 

quantitative acute dietary exposure 

assessment is unnecessary. 

ii. Chronic exposure. In conducting 

the chronic dietary exposure assessment 

EPA used the food consumption data 

from the USDA 1994–1996 and 1998 

CSFII. As to residue levels in food, EPA 

conducted a highly conservative chronic 

dietary risk assessment for mefenpyrdiethyl using tolerance level residues 

and assuming 100% crop treated for all 

commodities. 

iii. Cancer. Based on the data 

summarized in Unit III.A., EPA 

classified mefenpyr-diethyl as ‘‘not 

likely to be carcinogenic to humans.’’ 

Therefore, an exposure assessment to 

evaluate cancer risk is unnecessary for 

this chemical. 

2. Dietary exposure from drinking 

water. The Agency used screening level 

water exposure models in the dietary 

exposure analysis and risk assessment 

for mefenpyr-diethyl in drinking water. 

These simulation models take into 


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account data on the physical, chemical, 

and fate/transport characteristics of 

mefenpyr-diethyl. Further information 

regarding EPA drinking water models 

used in pesticide exposure assessment 

can be found at http://www.epa.gov/

oppefed1/models/water/index.htm. 

Based on the First Index Reservoir 

Screening Tool (FIRST) and Screening 

Concentration in Ground Water (SCI– 

GROW2) models, the estimated drinking 

water concentrations (EDWCs) of 

mefenpyr-diethyl for chronic exposures 

for non-cancer assessments are 

estimated to be 3 ppb for surface water 

and 4 ppb for ground water. 

Modeled estimates of drinking water 

concentrations were directly entered 

into the dietary exposure model. For 

chronic dietary risk assessment, the 

water concentration of value 4 ppb was 

used to assess the contribution to 

drinking water. 

3. From non-dietary exposure. The 

term ‘‘residential exposure’’ is used in 

this document to refer to nonoccupational, non-dietary exposure 

(e.g., for lawn and garden pest control, 

indoor pest control, termiticides, and 

flea and tick control on pets). Mefenpyrdiethyl is not registered for any specific 

use patterns that would result in 

residential exposure. 

4. Cumulative effects from substances 

with a common mechanism of toxicity. 

Section 408(b)(2)(D)(v) of FFDCA 

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 has not 

found mefenpyr-diethyl to share a 

common mechanism of toxicity with 

any other substances, and mefenpyrdiethyl does not appear to produce a 

toxic metabolite produced by other 

substances. For the purposes of this 

tolerance action, therefore, EPA has 

assumed that mefenpyr-diethyl does not 

have 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 EPA’s Web site at 

http://www.epa.gov/pesticides/ 

cumulative. 

D. Safety Factor for Infants and 

Children 

1. In general. Section 408(b)(2)(C) of 

FFDCA provides that EPA shall apply 

an additional tenfold (10X) margin of 

safety for infants and children in the 

case of threshold effects to account for 

prenatal and postnatal toxicity and the 

completeness of the database on toxicity 

and exposure unless EPA determines 

based on reliable data that a different 

margin of safety will be safe for infants 

and children. This additional margin of 

safety is commonly referred to as the 

FQPA Safety Factor (SF). In applying 

this provision, EPA either retains the 

default value of 10X, or uses a different 

additional safety factor when reliable 

data available to EPA support the choice 

of a different factor. 

2. Prenatal and postnatal sensitivity. 

There is little concern for prenatal 

toxicity resulting from exposure to 

mefenpyr-diethyl. There is no evidence 

of increased susceptibility [qualitative 

and quantitative] following in utero 

exposure to mefenpyr-diethyl in either 

the rat or rabbit developmental toxicity 

study, and there is no evidence of 

increased susceptibility [qualitative or 

quantitative] following in utero and/or 

pre-/post-natal exposure in the 

2-generation reproduction study in rats. 

Developmental toxicity was not 

observed in the rat at the limit dose 

(1000 mg/kg/day) in one of two 

available rat developmental studies. In 

the second study, the only effects 

observed were decreased body-weight 

gain and food efficiency during the first 

week of dosing and increased spleen 

weights in the maternal animal and a 

marginal decrease in fetal body weight/ 

body-weight gain during lactation 

(postnatal study). Developmental 

toxicity (abortions) was observed in the 

rabbit at a dose level of 250 mg/kg/day. 

In the reproduction study, decreased 

body weight and body-weight gain 

(parental animal and offspring) and an 

increase in spleen weight and in the 

severity (not incidence) of splenic 

extramedullary hematopoiesis were 

observed in females. There is no 

evidence of neurotoxicity, and there are 

no residual concerns. 

3. Conclusion. EPA has determined 

that reliable data show the safety of 

infants and children would be 

adequately protected if the FQPA safety 

factor were reduced to 1X. That decision 

is based on the following findings: 

i. The toxicology database for 

mefenpyr-diethyl is largely complete, 

missing only acute and subchronic 

neurotoxicity studies and an 

immunotoxicity study. EPA has 

determined that an additional 

uncertainty factor is not needed to 

account for the lack of these studies for 

the following reasons: 

• There is no evidence in the existing 

studies to suggest that mefenpyr-diethyl 

targets either the immune system or the 

nervous system. EPA considered the 

entire toxicity database (subchronic, 

chronic, carcinogenicity, developmental 

and reproductive studies) of mefenpyrdiethyl for evidence of potential 

immunotoxic and neurotoxic effects. 

EPA did note that enlarged spleens, 

more severe hematopoiesis and 

hemosiderin deposits, and increased 

spleen weights were observed in mice at 

doses greater than the limit dose. 

However, these were determined to be 

non-specific changes not indicative of 

immunotoxicity. Additionally, no 

evidence of neurotoxicity was found. 

Therefore, based on the above 

considerations, EPA does not believe 

that conducting acute and subchronic 

neurotoxicity or immunotoxicity studies 

will result in a NOAEL less than the 

NOAEL of 51 mg/kg/day already set for 

mefenpyr-diethyl. 

• Overall, the toxicity of mefenpyrdiethyl is low. The endpoints were 

assumed by EPA to be treatment-related, 

a conservative assumption intended to 

ensure the risk assessment is protective 

of potential effects. 

Based on these considerations, EPA 

does not expect the required studies to 

provide lower points of departure than 

those currently selected for risk 

assessment, and an additional 

uncertainty factor is not needed to 

account for the lack of these studies. 

ii. There is no evidence of 

neurotoxicity in the available toxicology 

database and no evidence of significant 

developmental toxicity in either the rat 

or rabbit developmental toxicity studies. 

Based on these considerations, there is 

no need for a developmental 

neurotoxicity study or additional UFs to 

account for neurotoxicity. 

iii. There is no evidence of increased 

susceptibility in in utero rats or rabbits 

in the prenatal developmental studies or 

in young rats in the 2-generation 

reproduction study. 

iv. There are no residual uncertainties 

identified in the exposure databases. 

The dietary food exposure assessments 

were performed based on 100% CT and 

tolerance-level residues. EPA made 

conservative (protective) assumptions in 

the ground and surface water modeling 

used to assess exposure to mefenpyrdiethyl in drinking water. These 

assessments will not underestimate the 

exposure and risks posed by mefenpyrdiethyl. 

E. Aggregate Risks and Determination of 

Safety 

EPA determines whether acute and 

chronic dietary pesticide exposures are 

safe by comparing aggregate exposure 

estimates to the acute PAD (aPAD) and 

chronic PAD (cPAD). For linear cancer 

risks, EPA calculates the lifetime 

probability of acquiring cancer given the 


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estimated aggregate exposure. Short-, 

intermediate-, and chronic-term risks 

are evaluated by comparing the 

estimated aggregate food, water, and 

residential exposure to the appropriate 

PODs to ensure that an adequate MOE 

exists. 

1. Acute risk. An acute aggregate risk 

assessment takes into account acute 

exposure estimates from dietary 

consumption of food and drinking 

water. No adverse effect resulting from 

a single oral exposure was identified 

and no acute dietary endpoint was 

selected. Therefore, mefenpyr-diethyl is 

not expected to pose an acute risk. 

2. Chronic risk. Using the exposure 

assumptions described in this unit for 

chronic exposure, EPA has concluded 

that chronic exposure to mefenpyrdiethyl from food and water will utilize 

less than 1% of the cPAD for infants, 

less than 1 year old, the population 

group receiving the greatest exposure. 

There are no residential uses for 

mefenpyr-diethyl. 

3. Short-term risk. Short-term 

aggregate exposure takes into account 

short-term residential exposure plus 

chronic exposure to food and water 

(considered to be a background 

exposure level). Because mefenpyrdiethyl does not have residential uses 

that would result in residential 

exposure and chronic dietary exposure 

has already been assessed under the 

appropriately protective cPAD (which is 

at least as protective as the POD used to 

assess short-term risk), no further 

assessment of short-term risk is 

necessary, and EPA relies on the 

chronic dietary risk assessment for 

evaluating short-term risk for, mefenpyrdiethyl. 

4. Intermediate-term risk. 

Intermediate-term aggregate exposure 

takes into account intermediate-term 

residential exposure plus chronic 

exposure to food and water (considered 

to be a background exposure level). 

Because mefenpyr-diethyl does not have 

residential uses that would result in 

residential exposure and chronic dietary 

exposure has already been assessed 

under the appropriately protective 

cPAD (which is at least as protective as 

the POD used to assess short-term risk), 

no further assessment of intermediateterm risk is necessary, and EPA relies on 

the chronic dietary risk assessment for 

evaluating intermediate-term risk for, 

mefenpyr-diethyl. 

5. Aggregate cancer risk for U.S. 

population. Based on the lack of 

evidence of carcinogenicity in two 

adequate rodent carcinogenicity studies, 

mefenpyr-diethyl is not expected to 

pose a cancer risk to humans. 

6. Determination of safety. Based on 

these risk assessments, EPA concludes 

that there is a reasonable certainty that 

no harm will result to the general 

population, or to infants and children 

from aggregate exposure to mefenpyrdiethyl residues. 

IV. Other Considerations 

A. Analytical Enforcement Methodology 

Adequate enforcement methodology 

is available to enforce the tolerance 

expression. An enforcement method for 

plants entitled ‘‘An Analytical Method 

for Determination of Residues of AE 

F107892 (mefenpyr-diethyl) and its 

Metabolites in Wheat and Barley by Gas 

Chromatography using Mass Selective 

Detection’’ is available. Radiovalidation 

and independent laboratory validation 

(ILV) data have been submitted for the 

plant method. The Agency determined 

that this method is suitable for food 

tolerance enforcement of mefenpyrdiethyl and the three metabolites AE 

F094270, AE F113225, and/or AE 

F109453. 

This method may be requested from: 

Chief, Analytical Chemistry Branch, 

Environmental Science Center, 701 

Mapes Rd., Ft. Meade, MD 20755–5350; 

telephone number: (410) 305–2905; email address: residuemethods@epa.gov. 

B. International Residue Limits 

In making its tolerance decisions, EPA 

seeks to harmonize U.S. tolerances with 

international standards whenever 

possible, consistent with U.S. food 

safety standards and agricultural 

practices. EPA considers the 

international maximum residue limits 

(MRLs) established by the Codex 

Alimentarius Commission (Codex), as 

required by FFDCA section 408(b)(4). 

The Codex Alimentarius is a joint U.N. 

Food and Agriculture Organization/ 

World Health Organization food 

standards program, and it is recognized 

as an international food safety 

standards-setting organization in trade 

agreements to which the United States 

is a party. EPA may establish a tolerance 

that is different from a Codex MRL; 

however, FFDCA section 408(b)(4) 

requires that EPA explain the reasons 

for departing from the Codex level. The 

Codex has not established a MRL for 

mefenpyr-diethyl. 

C. Revisions to Petitioned-for Tolerances 

EPA has revised the sorghum 

commodity terms and the tolerances 

levels for both sorghum and grass 

commodities. The sorghum commodity 

terms have been revised from ‘‘sorghum, 

grain;’’ ‘‘sorghum, forage;’’ and ‘‘sorghum, 

stover’’ to ‘‘sorghum, grain, grain;’’ 

‘‘sorghum, grain, forage;’’ and ‘‘sorghum, 

grain, stover’’ respectively to agree with 

the accepted terminology in the 

Agency’s Food and Feed Vocabulary. 

EPA has increased the proposed 

tolerance for all proposed commodities 

as follows: Grass, forage from 1.5 to 1.6 

ppm; grass, hay from 0.05 to 0.2 ppm; 

sorghum, grain, forage from 0.1 to 0.4 

ppm; sorghum, grain, grain from 0.01 to 

0.04 ppm; and sorghum, grain, stover 

from 0.05 to 0.2 ppm. The grass, forage 

tolerance was increased from 1.5 ppm to 

1.6 ppm because total mefenpyr-diethyl 

resides were detected up to 1.59 ppm at 

the proposed pre-harvest interval of 0 

days in crop field trials. Since there 

were no detectible residues of parent or 

metabolites in the crop field trials for 

grass (hay) or sorghum, grain (forage; 

grain; or stover), the tolerances are being 

set based on the sum of the lowest level 

of method validation (LLMV) of the 

parent (mefenpyr-diethyl) and the three 

metabolites. The LLMV is 0.05 ppm for 

grass, hay and sorghum, grain, stover; 

0.10 ppm in sorghum, grain, forage; and 

0.01ppm in sorghum, grain, grain. 

Finally, as noted in Unit II, the 

petitioner requested that the proposed 

tolerances be established for residues of 

mefenpyr-diethyl, including its 

metabolites and degradates, but that 

compliance with the tolerance levels be 

determined by measuring only the sum 

of mefenpyr-diethyl and its 

dichlorophenyl-pyrazoline metabolites, 

calculated as the stoichiometric 

equivalent of mefenpyr-diethyl, in or on 

the commodities. EPA is revising the 

tolerance expression for existing 

tolerances in 40 CFR 180.509 to agree 

with the tolerance expression proposed 

in this petition. EPA has determined 

that it is reasonable to make this change 

final without prior proposal and 

opportunity for comment, because 

public comment is not necessary, in that 

the change has no substantive effect on 

the tolerance, but rather is merely 

intended to clarify the existing tolerance 

expression. 

V. Conclusion 

Therefore, tolerances are established 

for residues of the safener, mefenpyrdiethyl, including its metabolites and 

degradates, in or on grass, forage at 1.6 

ppm; grass, hay at 0.2 ppm; sorghum, 

grain, forage at 0.4 ppm; sorghum, grain, 

grain at 0.04 ppm; and sorghum, grain, 

stover at 0.2 ppm. Compliance with 

these tolerances is to be determined by 

measuring the sum of mefenpyr-diethyl, 

(1-(2,4-dichlorophenyl)-4,5-dihydro-5- 

methyl-1H-pyrazole-3,5-dicarboxylic 

acid, diethyl ester) and its 

dichlorophenyl-pyrazoline metabolites, 

calculated as the stoichiometric 


srobinson on DSKHWCL6B1PROD with RULES
Federal Register / Vol. 76, No. 83 / Friday, April 29, 2011 / Rules and Regulations 23903 

equivalent of mefenpyr-diethyl, in or on 

the commodity. 

VI. Statutory and Executive Order 

Reviews 

This final rule establishes tolerances 

under section 408(d) of FFDCA 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). Because this final rule 

has been exempted from review under 

Executive Order 12866, this final rule is 

not subject to Executive Order 13211, 

entitled Actions Concerning Regulations 

That Significantly Affect Energy Supply, 

Distribution, or Use (66 FR 28355, May 

22, 2001) or Executive Order 13045, 

entitled Protection of Children From 

Environmental Health Risks and Safety 

Risks (62 FR 19885, April 23, 1997). 

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., nor does it require any special 

considerations under Executive Order 

12898, entitled Federal Actions To 

Address Environmental Justice in 

Minority Populations and Low-Income 

Populations (59 FR 7629, February 16, 

1994). 

Since tolerances and exemptions that 

are established on the basis of a petition 

under section 408(d) of FFDCA, 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. 

This final rule directly regulates 

growers, food processors, food handlers, 

and food retailers, not States or Tribes, 

nor does this action alter the 

relationships or distribution of power 

and responsibilities established by 

Congress in the preemption provisions 

of section 408(n)(4) of FFDCA. As such, 

the Agency has determined that this 

action will not have a substantial direct 

effect on States or Tribal governments, 

on the relationship between the national 

government and the States or Tribal 

governments, or on the distribution of 

power and responsibilities among the 

various levels of government or between 

the Federal Government and Indian 

Tribes. Thus, the Agency has 

determined that Executive Order 13132, 

entitled Federalism (64 FR 43255, 

August 10, 1999) and Executive Order 

13175, entitled Consultation and 

Coordination With Indian Tribal 

Governments (65 FR 67249, November 

9, 2000) do not apply to this final rule. 

In addition, this final rule does not 

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). 

This action does not involve any 

technical standards that would require 

Agency consideration of voluntary 

consensus standards pursuant to section 

12(d) of the National Technology 

Transfer and Advancement Act of 1995 

(NTTAA), Public Law 104–113, section 

12(d) (15 U.S.C. 272 note). 

VII. Congressional Review Act 

The Congressional Review Act, 

5 U.S.C. 801 et seq., generally provides 

that before a rule may take effect, the 

agency promulgating the rule must 

submit a rule report 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 this final rule in the 

Federal Register. This final 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: April 21, 2011. 

Lois Rossi, 

Director, Registration Division, Office of 

Pesticide Programs. 

Therefore, 40 CFR chapter I is 

amended as follows: 

PART 180—[AMENDED] 

■ 1. The authority citation for part 180 

continues to read as follows: 

Authority: 21 U.S.C. 321(q), 346a and 371. 

■ 2. Section 180.509 is amended by 

revising paragraph (a) and adding 

paragraph (d) to read as follows: 

§ 180.509 Mefenpyr-diethyl; tolerances for 

residues. 

(a) General. Tolerances are 

established for residues of the safener, 

mefenpyr-diethyl, including its 

metabolites and degradates, when 

applied at a rate no greater than 0.053 

pound safener per acre per growing 

season in or on the commodities in the 

table below. Compliance with the 

tolerance levels specified below is to be 

determined by measuring only the sum 

of mefenpyr-diethyl (1-(2,4- 

dichlorophenyl)-4,5-dihydro-5-methyl1H-pyrazole-3,5-dicarboxylic acid, 

diethyl ester) and its 2,4- 

dichlorophenyl-pyrazoline metabolites, 

calculated as the stoichiometric 

equivalent of mefenpyr-diethyl, in or on 

the commodity. 

Commodity Parts per 

million 

Barley, grain ............................. 0 .05 

Barley, hay ................................ 0 .2 

Barley, straw ............................. 0 .5 

Cattle, meat byproducts ........... 0 .1 

Goat, meat byproducts ............. 0 .1 

Grass, forage ............................ 1 .6 

Grass, hay ................................ 0 .2 

Hog, meat byproducts .............. 0 .1 

Horse, meat byproducts ........... 0 .1 

Sheep, meat byproducts .......... 0 .1 

Sorghum, grain, forage ............. 0 .4 

Sorghum, grain, grain ............... 0 .04 

Sorghum, grain, stover ............. 0 .2 

Wheat, forage ........................... 0 .2 

Wheat, grain ............................. 0 .05 

Wheat, hay ............................... 0 .2 

Wheat, straw ............................. 0 .5 

* * * * * 

(d) Indirect or inadvertent residues. 

Tolerances are established for the 

indirect or inadvertent residues of 

mefenpyr-diethyl, including its 

metabolites and degradates, when 

applied at a rate no greater than 0.053 

pound safener per acre per growing 

season in or on the commodities 

identified in the table below. 

Compliance with the tolerance levels 

specified below is to be determined by 

measuring only the sum of mefenpyrdiethyl (1-(2,4-dichlorophenyl)-4,5- 

dihydro-5-methyl-1H-pyrazole-3,5- 

dicarboxylic acid, diethyl ester) and its 

2,4-dichlorophenyl-pyrazoline 

metabolites, calculated as the 

stoichiometric equivalent of mefenpyrdiethyl, in or on the commodity. 

Commodity Parts per 

million 

Canola, seed ............................ 0 .02 

Soybean, forage ....................... 0 .1 

Soybean, hay ............................ 0 .1 

Soybean, seed .......................... 0 .02 

[FR Doc. 2011–10439 Filed 4–28–11; 8:45 am] 

BILLING CODE 6560–50–P 


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