5/17/06

MEMORANDUM

SUBJECT:	Minutes of 4/19/06 ChemSAC meeting

TO:		HED’s Chemistry Interest Group

FROM:	HED’s Chemistry Science Advisory Council

Attendees: Chris Olinger (Minutes), Will Donovan, George Kramer, Tom
Bloem, P. Yvonne Barnes, Bernie Schneider, Leung Cheng, Rick Loranger,
Dave Soderberg, Mike Doherty (Chair), Doug Dotson, Toiya Goodlow, Rame
Cromwell, Steve Funk, and Hong Chen (IR-4, via phone)

[Note:  This is the last ChemSAC meeting held at Crystal Mall II.]

1.  Revision of Berry Crop Group (B. Schneider and H. Chen).   Bernie
provided a brief history of the berry crop group and outlined the
proposed changes developed by the EPA/IR-4 workgroup. Fresh fruit and
jam samples were provided as well. The new group will be called the
Berries and Small Fruits Group and will include several subgroups and
fruits that were previously excluded from any groups.  Details of the
proposal may be found in a memo from B. Schneider to B. Madden dated
3/28/06, entitled “Crop Grouping – Part II:  Analysis of the USDA
IR-4 Petition to Amend the Crop Group Regulation 40 CFR § 180.41
(c)(13) and Commodity Definitions [40 CFR § 180.1(h)] Related to Crop
Group 13 Berry”.  The ChemSAC concurred with the proposal and
recommended that the changes be adopted.

2.  Thiabendazole Mushroom Nutrient Supplement Use (W. Donovan).  Will
Donovan presented a proposal from IR-4 regarding the use of
thiabendazole (TBZ) in mushroom houses, using thiophanate-methyl residue
data to support the tolerance proposal.  Currently there are Section 24
(c) registrations for this use but IR-4 would like to extend the
registration for a national Section 3 use.  The ChemSAC decided there
was insufficient information to support IR-4’s proposal to translate
data from thiophanate-methyl to TBZ.  IR-4 should provide a more
detailed rationale in their Section 3 amended registration request to
justify the requested data translation and provide more detailed use
information.  Lacking a convincing rationale for translating from
thiophanate-methyl to TBZ, the request should be supported by field
trial data similar to what IR-4 has provided for thiophanate-methyl.  

3.  Non-food-use Request for Applications with Shielded Sprayers (W.
Donovan).  Nichino America, Inc., submitted a rationale for considering
application of pyraflufen-ethyl using a hooded sprayer to row middles
between vegetable crops as a non-food use.  The rationale was based on
the cited 1) low probability of chemical drift from the hooded sprayer
to the vegetable crops, 2)  low probability of absorption from the soil
as demonstrated by confined accumulation in rotational crop studies, and
3) lack of translocation of pyraflufen-ethyl within plants as
demonstrated by nature of the residue studies in/on cotton, potato, and
wheat.  Applications to fields of crops well into the growing season are
virtually always considered food uses.  The ChemSAC did not consider the
use of hooded or shielded spray equipment for weed control in row
middles of vegetable crops to be sufficient to ensure that residues will
not occur in the harvested commodities.  However, a reduced data set may
be considered if the registrant conducts exaggerated rate, worst case
studies on representative crops from the crop groups proposed.

4.  Follow-up on Prothioconazole Issues (S. Funk).  Steve Funk updated
the ChemSAC on the issues raised when ChemSAC reviewed the draft Residue
Chemistry Chapter for the new chemical prothioconazole on March 29,
2006.  The ChemSAC recommended the team review the ruminant metabolism
and feeding studies for the metabolite desthio-prothioconazole.  The
transfer factor is greater for the metabolite than the parent compound
in the metabolism study, but is about the same or somewhat less in the
feeding studies.  The ChemSAC concluded that the results of the
supplementary studies when considered together do not alter the values
for the total levels of residue of concern in ruminant commodities,
i.e., the primary studies on parent metabolism and feeding in ruminants
adequately define the situation.  The outputs from the MRL calculator
were added to the chemistry summary document.  In general, the outputs
were used with the exception of the commodities for which there were
high levels of non-detectable residues.

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