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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF 

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

MEMORANDUM

Subject: Minutes of the 6/10/2009 ChemSAC Meeting 

From: Chemistry Science Advisory Council (ChemSAC)

Office of Pesticide Programs (OPP)

Health Effects Division (HED)

To: Residue Chemistry Interest Group

Office of Pesticide Programs

Attendees: Will Donovan (Chair), Rick Loranger, Leung Cheng, Mike Doherty (Minutes), Julie 

Langsdale, Tom Bloem, Meheret Negussie, Bill Drew, Nancy Dodd, Debra Rate, 

Chris Olinger, Bill Cutchin, Dave Soderberg, Bernie Schneider, Barbara Madden, 

Sue Hummel, Mohsen Sahafeyan

1. Review Minutes from the 3 June 2009 Meeting

The minutes were approved with minor revisions.

2. Removal of 40 CFR 180.1 Paragraph h (B. Schneider)

The Code of Federal Regulations, Title 40, Part 180.1(h) states, “Unless otherwise specified, 

tolerances and exemptions established under the regulations in this part apply to residues 

from only preharvest application of the chemical.” As a general policy OPP has been 

working to not put use information into the tolerance declarations in 40 CFR 180. With the 

language in 180.1(h), tolerances associated with post-harvest uses of a pesticide are required 

to be designated as such. Revisions to the CFR will be made in connection with crop 

grouping revisions and there is an opportunity to remove 180.1(h) from the regulations.

In order to have 180.1(h) removed from the regulation, HED needs to provide assurance that 

having tolerances decoupled from post-harvest-use designations will not result in increased 

human health risk estimates or in an expanded use profile for the active ingredient. 

ChemSAC noted that tolerances established under FFDCA are simply the maximum 

allowable concentration of a compound in/on a food. The tolerances themselves have no 

bearing on the use pattern that resulted in the presence of residues. The allowed use patterns 

for a pesticide are enforceable via FIFRA and are designated on the pesticide label. Thus, the 
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pre-harvest use of a product on a crop or commodity that is approved only for post-harvest 

use would be a violation of FIFRA and not necessarily FFDCA (note that FFDCA violations 

are indicative of FIFRA violations). Therefore, removing 180.1(h) from the regulations does 

not imply the approval of pre-harvest uses. Since removing 180.1(h) does not constitute an 

expanded use profile for compounds with post-harvest-specific tolerances, risk estimates for 

those compounds are not affected. ChemSAC further noted that 180.1(h) was developed 

prior to the current regulatory scheme and that, from a practical standpoint, it is often not 

possible to know whether a food-borne chemical residue originated from a pre- or a postharvest use. The SAC will issue a memorandum to RD in support of having 40 CFR 

180.1(h) removed from the regulations, and this memo will be posted on the ChemSAC 

database.

3. Substitution of U.S. for Mexican Crop Field Trials for Determining a Tolerance on 

Imported Commodities (R. Loranger).

A consultant for a pesticide registrant has asked if we would accept 100% U.S. field trials for 

establishing an “import tolerance” for a use in Mexico. The request is based on conditions in 

Mexico related to violence and swine flu. The consultant noted that the Agency has allowed 

Columbia to be excluded as a location due to violence and travel advisories. The proposal is 

that the Mexican trials be conducted in Arizona and the southern part of Texas. The crops of 

interest are cucurbits, tomatoes, and peppers. The consultant further states that of the 

tomatoes grown in Mexico for export, 80% are grown in greenhouses. Current NAFTA 

guidelines allow for up to 1⁄2 of the trials to be conducted outside of the exporting country. 

The SAC is willing to consider alternate study sites, provided such sites can be shown to 

provide equivalent information. In order to make that determination, the SAC is requesting 

that more information be provided regarding the environmental conditions and cultural 

practices for each crop in the affected areas of Mexico. Ideally, trials that are proposed for 

the U.S. would be in the same NAFTA zone in which the crop is grown in Mexico. The SAC 

also noted that there may be other countries that would be a more suitable surrogate than the 

U.S.

With regard to the extent of conducting 50-75% of the tomato trials in greenhouses, the SAC 

noted that information available to the group indicates that much less than 80% of the 

tomatoes in Mexico grown for export come from greenhouses and that Mexican production 

data (field versus greenhouse and % of each exported to the U.S.) are needed for all crops of 

interest, not just tomato.

4. Residue Testing with Surfactants (R. Loranger)

A registrant has asked for guidance regarding inclusion of surfactants in residue field trials. 

The registrant intends to include surfactants in all trials for a new insecticide, with 

approximately 25% using MSO, a blend of methylated seed oil and nonylphenol ethoxylate. 

The surfactant in the remaining 75% would be selected in accordance with the local 
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practices.

The SAC concluded that the proposed scheme is acceptable, provided that the 75% address 

the other two major classes of surfactants (crop oil concentrate and non-ionic surfactant). 

Information on the use rates for the various surfactants should be included in the submission 

in order to meaningfully assess the impact of different surfactants on pesticide residue levels.

5. Chemical Names in Tolerance Expressions: CAS vs. IUPAC.

The SAC discussed whether CAS or IUPAC names are preferred for inclusion in the 

tolerance expression. There appears to be no requirement for one over the other and there 

were situations discussed where one might be preferred vs. the other. No consensus was 

reached other than a noted need for a reliable source of up-to-date names for active 

ingredients.