A. PHYSICIANS COMMITTEE FOR RESPONSIBLE MEDICINE (PCRM)

COMMENTS: 

1. PCRM Comment: 

“As stated in the Summary Document the Agency may require the ‘(850.1075) Acute Fish 

Toxicity Study.’ We believe that the number of animals used can be reduced by following an 

acute threshold or ‘limit test’ approach” 

EFED Response 

The results from a limit test could be used to fulfill the data requirement for an Acute Fish 

Toxicity Study (850.1075) if it is conducted as described in the 850.1075 guidelines and is 

classified as acceptable. 

2. PCRM Comment: 

“We also encourage the use of (Q)SAR data either in place of, or addition to, the fish 

experimental data.” 

EFED Response 

The Agency is actively working with the Federal Drug Administration (FDA) and the Pest 

Management Regulatory Agency (PMRA) of Health Canada, through the North American Free 

Trade Agreement (NAFTA) Technical Working Group on Pesticides (Quantitative) Structure 

Activity Relationship [(Q)SAR] Guidance Document to develop guidance for the use of (Q)SAR 

to support pesticide risk assessment. We will consider the recommendations provided in the 

guidance document (once it is finalized) when conducting the ecological risk assessment for the 

Registration Review of methiocarb. 

B. AMERICAN BIRD CONSERVANCY (ABC) COMMENTS: 

1. ABC Comment: 

“We also ask that during registration review, and the data call-in period, all backyard uses of 

methiocarb be suspended to protect birds.” 

EFED Response: 

EFED defers the response to this comment to PRD since it relates directly to pesticide 

registration issues. 

2. ABC Comment: 

“We want EPA to require the registrant to conduct: 

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... Reproductive toxicity test with passerines... 

EFED Response: 

EFED is not aware of any data to show that methiocarb is more toxic to passerine species than it 

is to bobwhite quail (Colinus virginianus) or mallard ducks (Anas platyrhynchos) on a chronic 

exposure basis as it relates to reproductive endpoints. Therefore, at this time, EFED believes that 

the data from reproductive studies in the bobwhite quail (see below) and mallard duck studies 

will be adequate for assessing potential risks of methiocarb to birds from chronic exposure. 

Furthermore, EFED does not have a validated protocol for a chronic reproduction study in 

passerines, and is not prepared at this time to make recommendations regarding such a protocol. 

Any protocol developed would need to go through a process of scientific peer review. 

Therefore, EFED will not recommend requesting a chronic reproductive study using passerines 

for methiocarb at this time. 

3. ABC Comment: 

“We want EPA to require the registrant to conduct: 

... Developmental toxicity test with a passerine model...” 

EFED Response: 

EFED is not aware of a validated protocol for a developmental toxicity study with a passerine, 

and is not prepared at this time to make recommendations regarding such a protocol. Any 

protocol developed would need to go through a process of scientific peer review. EFED, 

however, will check relevant Office of Pesticide Programs’ (OPP) databases for existing data on 

passerine developmental toxicity for methiocarb. If data are available, EFED will consider the 

potential for inclusion of such data in the risk assessment for methiocarb. However, the toxicity 

endpoints from available passerine developmental toxicity data will not be used quantitatively by 

EFED in risk assessment unless the endpoints are related directly to the survival, growth, or 

reproduction. 

4. ABC Comment: 

“We want EPA to require the registrant to conduct: 

... Reproductive toxicity test with bobwhite. There is no defined NOAEC for 

methiocarb on bobwhites.” 

EFED Response: 

EFED did recommend requesting an Avian Reproduction Test with bobwhite quail (850.2300) in 

its Problem Formulation for methiocarb. Therefore, we concur with ABC on this comment, but 

no changes need to be made to the Problem Formulation for methiocarb (since EFED already 

recommended requesting these data). 

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5. ABC Comment: 

“... ABC requests the following tests be required for registration review: 

... Acute Oral Toxicity Tests on upland game species, waterfowl species and passerine 

species with: 

a. MP 

b. MSO 

c. MSOP 

d. MSO2 

e. MSO2P” 

EFED Response: 

As stated in the Problem Formulation for methiocarb, the parent compound degrades in the 

environment to the major degradates methiocarb phenol (MP), methiocarb sulfoxide (MSO), and 

methiocarb sulfoxide phenol (MSOP); and to the minor degradates methiocarb sulfone (MSO2) 

and methiocarb sulfone phenol (MSO2P). For the ecological risk assessment conducted as part 

of the Registration Review process, all of the degradates listed above will be considered and the 

degradates of concern will be identified. 

Some toxicity data for MSO2, MSO, MSO2P, and MSOP are available through the European 

Union’s Pesticide Properties Database (PPDB) 

(http://sitem.herts.ac.uk/aeru/footprint/en/index.htm). The studies from which these endpoints 

are derived were not available for review at this time. Taken at face value, however, the data 

suggest that the degradates are not more toxic than the parent for the taxa considered, with the 

exception of the acute toxicity values for earthworms (see Table 1). 

The residues of concern for exposure and risk assessment will be reconsidered prior to analysis. 

In the absence of confirmatory data indicating low toxicity concerns for the major degradates of 

methiocarb (i.e., MP, MSO, MSOP, MSO2, and MSO2P), they will be assumed of equal toxicity 

as the parent. Therefore, EFED does not recommend calling-in acute avian toxicity data on 

methiocarb degradates at this time. 

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Table 1. Toxicity Data for Methiocarb Degradates. 

SOURCE METHIOCARB 

METHIOCARB 

SULFONE 

(MSO2) 

METHIOCARB 

SULFOXIDE 

(MSO) 

METHIOCARB 

SULFONE 

PHENOL 

(MSO2P) 

METHIOCARB 

SULFOXIDE 

PHENOL 

(MSOP) 

PPDB (EU) WEBSITE1

Acute oral Rat 

(LD50; mg/kg-bw) 19 -- -- -- >3160 

Acute oral Avian 

(LD50; mg/kg-bw) 5 -- -- -- -- 

Acute Fish 

(LC50; mg/L) 0.65 -- 6.6 68.7 >106 

Chronic Fish 

(NOAEC; mg/L) 0.05 -- -- -- -- 

Acute FW Invertebrate 

(EC50; mg/L) 0.008 -- 0.056 54 157 

Chronic FW 

Invertebrate (NOAEC) 0.0001 -- -- -- -- 

NV Aquatic Plant 

(EC50; mg/L) 2.2 -- 2.75 120 >100 

Acute Honeybees 

(LD50; μg/bee) 0.23 -- -- -- -- 

Acute Earthworms 

(LC50; mg/kg) 1322 -- 78 >1000 >1000 

1 Pesticide Properties Database (PPDB) (http://sitem.herts.ac.uk/aeru/footprint/en/index.htm) 

6. ABC Comment: 

“... ABC requests the following tests be required for registration review: 

... Reproductive Toxicity Tests on upland game species, waterfowl species and passerine 

species with: 

a. MP 

b. MSO 

c. MSOP 

d. MSO2 

e. MSO2P” 

EFED Response: 

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As stated above and in the Problem Formulation for methiocarb, the residues of concern for 

exposure and risk assessment will be reconsidered prior to analysis. In the absence of 

confirmatory data indicating low toxicity concerns for the major degradates of methiocarb (i.e., 

MP, MSO, MSOP, MSO2, and MSO2P), they will be assumed of equal toxicity as the parent. 

Additionally, as stated above, EFED does not have a validated protocol for a chronic 

reproduction study in passerines, and is not prepared at this time to make recommendations 

regarding such a protocol (see above). Therefore, EFED will not recommend requesting a 

chronic reproductive study for methiocarb degradates at this time. 

7. ABC Comment: 

“... ABC requests the EPA to suspend uses of methiocarb for reduction of predation on the eggs 

of federally-listed birds.” 

EFED Response: 

EFED defers the response to this comment to PRD since it relates directly to pesticide 

registration issues. 

8. ABC Comment: 

“ABC recommends setting up a schedule for data call-ins for pesticides to go through the EDSP 

as soon as possible.” 

EFED Response: 

The Agency is currently and actively involved in the Tier I screening process for chemicals that 

have been identified for screening as potential endocrine disruptors. The second EDSP list of 

chemicals for Tier I screening was published in the Federal Register on November 17, 2010 (FR 

Vol. 75, No. 221; see page 70252). 

B. FIFRA ENDANGERED SPECIES TASK FORCE (FESTF) COMMENTS: 

1. FESTF Comment: 

“In June of 2004, March of 2005, and October 19, 2007, the FIFRA Endangered Species Task Force 

(FESTF) submitted its Information Management System (FESTF Information Management System 

(IMS): Documentation of Structure and Function of IMS 1.1, MRID # 46325901) and documentation of 

the beta-tested IMS, NatureServe data (FESTF Task Force Information Management System (IMS): BetaTested IMS 2.0 and Access to NatureServe Data - Final Report, MRID #46486301) and NatureServe 

Data Evaluation and Review (MRID #47260101). These data fulfill the data requirements spelled out in 

Pesticide Registration Notice 2000-2 and provide the best available data necessary for the proximity 

analysis of Methiocarb use and listed species locations.” 

EFED Response: 

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EFED will consider the data included in the FESTF Information Management System when 

conducting the endangered species assessment for methiocarb during the Registration Review 

process. 

2. FESTF Comment: 

“The leading registrant, as identified on the fact sheet included in the Registration Review Summary, is 

Gowan Company, an FESTF member. Gowan Company is entitled to rely on FESTF ... For those 

registrants who are not currently eligible to rely on FESTF data, FESTF is making every effort to inform 

them of the role of FESTF data in listed species assessments, while also affording them various options 

for reliance on that data, since these data are necessary not only to fulfill EPA data requirements, but also 

to develop the assessments required to support the Registration Review process. It is imperative for EPA 

to assure that any company relying upon FESTF data, but not listed in Attachment A, has filed with 

FESTF a proper offer to pay for data compensation.”

EFED Response: 

EFED defers the response to this comment to PRD since it relates directly to data compensation 

issues. 

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