June 17, 2011

Attachment 2

Examples of Testing Guidelines Inapplicable to Antimicrobial Use
Patterns

Post-Application Exposure, Descriptions of Human Activity, 875.2800

The guideline is described as relevant only for determining reentry
intervals following crop treatments.

See generally Appendix G, page 5-10.  Also see Appendix G, page 8
regarding the data requirement associated with this testing guideline.

Environmental Fate, laboratory studies (currently proposed as required
for all uses)

Ready Biodegradability, 835.3100; Porous Pot Test, 835.3220

At the dosing level necessary to see CO2 evolution caused by the
compound above background evolution, many biocides will be toxic to the
microbial community.  Also may not be suitable or practical for
antimicrobial testing, including biodegradability testing with inorganic
chemicals or chemical elements.  

See Appendix H, page 4 and 5

Environmental Fate, Transformation in Water and Soil

Aerobic Soil Metabolism, Anaerobic Soil Metabolism, Aerobic Aquatic
Metabolism, Anaerobic Aquatic Metabolism (OPPTS 835.4100 through
835.4400)

These are clearly identified as designed for terrestrial applications to
crops and non-crop areas and provide no guidance for antimicrobial
pesticides uses.  They also depend on maintenance of an appropriate
microbial population in the soils.  Since antimicrobial pesticides are
designed to control microorganisms, the relevance of these testing
protocols is questionable, particularly given what likely are
significant limitations on the dosing levels to avoid toxicity to the
microorganisms.

See Appendix H, page 5-6.

Mutagenicity Testing, particularly 870.5100 (Ames assay)

Inclusion is inconsistent with the Agency’s prior conclusions on the
relevance of assay for antimicrobial pesticides.  It would be more
appropriate to provide other options and allow the registrant to conduct
the appropriate study for the compound of concern.  

See Appendix E, page 18

Companion Animal Safety Testing 870.7200

Application of antimicrobials to companion animals removes those uses
from the definition of pesticide, as such uses would be considered as
animal drugs.  This testing guidance is not applicable to antimicrobial
pesticides.

Residue Chemistry

Residues in Meat/Milk/Poultry/Eggs 860.1480

Addresses direct application to livestock or addition to livestock
feed.  If there is such an application of an antimicrobial pesticide,
it would be exempt from FIFRA because it would be regulated as an animal
drug.  Similarly, direct application of an antimicrobial pesticide to
livestock feed is not subject to FIFRA, but instead is regulated by FDA
as an animal feed additive.

Plant Metabolism (860.1300)

Crop Field Trials (860.1500), Processed Food or Feed (860.1520)

Data requirements currently proposed to be required or conditionally
required are for agricultural premises, indirect food contact uses,
‘direct’ food contact uses, and aquatic uses.  Direct application to
edible crops removes the product from the definition of an antimicrobial
pesticide; the use then would be regulated as a conventional chemical by
the Registration Division. 

See generally Appendix A, pages 1-4 and Appendix I, pages 2-3.

Steven Bradbury, Ph.D. and Joan Harrigan-Farrelly

Attachment 2

June 17, 2011

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