OFFICE OF PREVENTION,

PESTICIDES, AND TOXIC

SUBSTANCES

Chemical: Sulfometuron Methyl

PC Code: 122001

MEMORANDUM

DATE: November 20, 2009

SUBJECT: Response to Comments Received Following the Publication ofthe

Sulfometuron Methyl Reregistration Eligibility Document

FROM: Russell asem cf2-. Risk Management and Implementation Branch I

Pesticide Re-evaluation Division (75 9P)

TURD: Anne Overstreet, Acting Chief

Risk Management and Implem ation Branch I

Pesticide Re-evaluation Division (7509P)

TO: Sulfometuron Methyl Docket (EPA-HQ-OPP-2008-0129)

In Septemeber 2008, EPA issued the reregistration eligibility decision (RED) for

sulfometuron methyl. The public, including users, the technical registrant, and trade

representative groups, submitted comments on that document during a 60-day comment

period. The comments were compiled and assigned to the appropriate division within the

Office of Pesticide Programs for response i.e., the Health Effects Division, the Ecological

Fate and Effects Division, or the Pesticide Re-evaluation Division. Where comments

were similar in nature, they were grouped together and addressed as a single comment.

All comments can be found in the sulfometuron methyl docket at: \V\V\v.rcgulations.gov:

docket number: EPA-HQ-OPP-2008-0l29.
1. Summary of Public Comment(s):

Several commenters expressed concern that mitigation measures indicated in the 

Sulfometuron Methyl Reregistration Eligibility Decision (SMM RED) were a reaction to 

specific environmental incident(s) cited in the SMM RED. 

EPA Response:

The Office of Pesticide Programs (OPP) generally uses incident data in support of its risk 

assessment. The risk assessment conducted to support the reregistration of sulfometuron 

methyl identified unacceptable risks (expressed as a risk quotient (RQ)) to non-target 

plants and were the primary factor that compelled the Agency to implement risk 

mitigation measures. In addition to direct risk to non-target plants, the Agency also noted 

that sulfometuron methyl use posed indirect risk to terrestrial and aquatic organisms that 

rely upon vegetation for growth reproduction or survival. 

2. Summary of Public Comment(s)

One commenter expressed concern that the mitigation measures would further limit the 

number of products that can be use for vegetation management in California Ground 

Water Protection Areas. 

EPA Response

The Agency acknowledges this concern and, based upon substantive public comments 

and other information received, has revised its risk assessment and mitigation 

requirements. 

3. Summary of Public Comment(s)

Several commenters had questions regarding the label language that requires a “60% 

chance of rain within 48 hours of the time of application” when making applications to 

soils subject to erosion. 

EPA Response

The Agency believes that standard local weather forecasts available via the internet, 

newspaper, radio, or television are suitable for determining the percent chance for rainfall 

in the local area. National weather sources are also available and suitable. It is the role 

of the State to enforce the legal use of a pesticide and the subject label statement is 

intended to provide the professional applicator a parameter to help him/her make the best 

decision about how and when to apply sulfometuron methyl. 

4. Summary of Public Comment(s)

The Agency received comments regarding the Agency’s mitigation measures in relation 

to best management practices (BMP) associated with state requirements to reduce nonpoint source pollutants from forestry activities. Commenters argued that the mitigation 
measures imposed by the 2008 SMM RED were duplicative, overly protective, and not 

necessary in light of BMPs currently required by individual states. 

EPA Response: 

In its February 25, 2009 meeting with National Alliance of Forest Owners (NAFO) and 

National Council for Air and Stream Improvement (NCASI), the Agency discussed state 

management plans, and NCASI indicated that it was currently preparing a document, 

Compendium of Forestry BMPs for Controlling Nonpoint Source Pollution in North 

America, to summarize BMPs for forestry activities mandated by state plans. The 

NCASI provided a courtesy copy of this document to the Agency, and it is available from 

NCASI upon request (technical bulletin no. 966, Sep. 2009). The Agency notes, as it is 

also indicated in NCASI’s document, that while States have their respective management 

practices for nonpoint source pollution associated with commercial forestry practices, 

which includes pesticides, State and Federal regulations clearly state that the use of a 

pesticide is regulated by the Federal Insecticide, Fungicide, Rodenticide Act, and that 

federal pesticide label requirements must be followed when using these products. The 

revised mitigation measures in the Amendment to the SMM RED fall within the range of 

typically found in state regulations and BMPs. Therefore, the Agency believes that the 

amended sulfometuron methyl requirements will not present an undue hardship, or 

conflict with BMP’s specified in respective State management plans. 

5. Summary of Public Comment(s)

Several commenters expressed concern that the mitigation specified in the SMM RED, 

specifically the 500 foot aerial buffer from water, may lead to an increase of backpack 

application of herbicides and mechanical and manual removal of weed pests in forestry 

settings. The commenters believe this will increase the number of workers, and therefore 

also increase potential occupational risks. 

EPA Response:

The Agency is concerned about occupational risk whether it is from direct exposure to an 

active ingredient, or physical conditions related to the use of a pesticide product. Based 

upon comments received, the Agency has revised its mitigation requirements for 

sulfometuron methyl. The Agency believes that the revised application requirements will 

not lead to a greater reliance on manual application and consequently will not 

inadvertently increase potential risk to hand-held applicators. 

6. Summary of Public Comment(s)

Several commenters expressed concern that the Agency employed an overly narrow 

interpretation of the results from the AgDrift model, and this interpritation led to the 100 

and 500 foot buffer zone requirements required by the SMM RED. 

EPA Response: 

When developing ecological mitigation for sulfometuron methyl, the Agency not only 

considered the potential risks from use of sulfometuron methyl, but also the benefits of 
the product, typical application patterns, and the comments and input of industry and 

stakeholders. The Agency strives to reach a balanced decision that is consistent with its 

statutory requirements, transparent, and involves all stakeholders. 

7. Summary of Public Comment(s)

Multiple commenters believe the mitigation contained in the SMM RED will lead to an 

increased reliance on older pesticides that require higher application rates, cost more to 

use, and have a less desirable impact on human health and the environment. 

EPA Response:

The Agency strives to encourage the use of “safe” pesticides (i.e., pesticides that present 

a reduced risk to the user, or non-target organism given the use scenario). The Agency 

acknowledges this concern and based on substantive public comments, has revised the 

mitigation for sulfometuron methyl and believes that the revised requirements are in line 

with current use patterns and, therefore, will not cause a shift in market and/or potential 

risk. 

8. Summary of Public Comment(s) 

During the comment period the Agency received multiple requests to extend the 

comment period beyond the initial closing date of January 12, 2009. 

EPA Response: 

While the Agency did not extend or reopen the comment period, it accepted and 

considered late comments it received. 

9. Summary of Public Comment(s)

Several commenters believe that the phrase “under the forest canopy” is broad or vague 

and does not contribute to clear label language. 

EPA Response: 

The language “except for under forest canopy” is standard language from the Agency’s 

Label Review Manual (LRM). The purpose of the LRM is to encourage consistency 

across all labels.