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The Physicians Committee for Responsible Medicine (PCRM) has submitted a response to the 

Bensulfuron-methyl docket (Docket ID: EPA-HQ-OPP-2011-0663) regarding HED’s human 

health risk assessment scoping document. While the PCRM response included information 

pertaining to environmental fate and effects, this document addresses only those comments 

pertinent to human health aspects of the preliminary work plan (PWP) for bensulfuron-methyl.

CONCLUSIONS/RECOMMENDATIONS

The Agency thanks The Physicians Committee for Responsible Medicine for their comments 

regarding bensulfuron-methyl. The Agency will consider these comments, along with any 

responses from the registrant, during the development of the final work plan for bensulfuronmethyl registration review.

DETAILED CONSIDERATIONS 

The Physicians Committee for Responsible Medicine to the Office of Pesticide Programs 

(OPP) Regulatory Public Docket (7502P). Registration Review docket for Chlorimuron 

ethyl Docket Opened for Review and Comment. Docket Number: Docket ID: EPA-HQOPP-2011-0663. 

The Physicians Committee for Responsible Medicine’s comment:

1. We also wish to comment on the 21/28 day dermal toxicity study (870.3250). The study, as 

proposed by the Agency, will eliminate uncertainty in the direction of a less conservative risk 

assessment. Given the low dermal toxicity as found in the rabbit study discussed in the 

Human Health Scoping Document, a finding of low dermal absorption can be reasonably 

inferred to predict low systemic toxicity by the dermal route. This could be assessed using 

in-vitro or in-silico dermal penetration models (see OECD Test Guideline 428, for example) 

to assess the extent of dermal penetration likely for Bensulfuron methyl.

2. Finally, we wish to comment broadly on the proposed Acute and Subchronic Neurotoxicity 

(870.6200(a)(b)) and Immunotoxicity (870.7800) studies. Bensulfuron-methyl shows no 

indication of neurotoxicity or immunotoxicity. Requesting these studies is a check-the-box 

exercise and not in line with the Agency’s stated priority to minimize animal testing and 

conduct targeted testing. The Agency should not require these focused studies for specific 

mechanisms of action for all pesticides, without justification based on existing data or 

information indicating potential concern for neuro- or immunotoxicity.

HED’s Response:

1. The Agency currently utilizes in-vitro dermal penetration models in conjunction with in-vivo

dermal absorption data. HED will consider the comments from the PCRM as the risk 

assessment is developed for bensulfuron-methyl registration review. Although we will 

accept studies using OECD guidelines, at present OPP does not use in-vitro studies alone to 

estimate dermal absorption. An in-vivo dermal absorption study is needed as well.
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2. Although there was no evidence of neurotoxicity or immunotoxicity in the bensulfuronmethyl toxicology database, the submitted studies are not designed to specifically assess 

neurotoxicity parameters and histopathology or to assess functions of the immune system. 

Further, the acute/subchronic neurotoxicity and immunotoxicity studies are considered to be 

required studies under the updated Part 158 Toxicology Data Requirements for conventional 

pesticides. Nonetheless, HED will consider the comments from the PCRM as risk 

assessment is developed for bensulfuron-methyl registration review. The Agency is currently 

working on a retrospective analysis to determine whether or not these studies will be required 

and the decision may affect Bensulfuron's registration review.