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

Attachment 2

June 17, 2011

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 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.