2 

registrants to work with the Agency to generate information that will fulfill both Agency and registration 

needs while killing the fewest number of birds possible.” 

Current policy within the Office of Pesticide Programs/Environmental Fate and Effects Division 

(EFED) regarding the acceptance of avian acute effects studies conducted using the TG 223 

protocol states the following: 

Until the OECD TG 223 validation process is completed and the guideline has been 

approved by OECD, studies that utilize this guideline should not be classified; pending 

results of the validation, they may then be classified as ‘acceptable,’ assuming that they 

meet all other guideline requirements. 

To date, the OECD has adopted the TG 223 guideline and has issued a validation report. At this 

time EFED is actively evaluating the results of the OECD validation report to determine if the 

TG 223 effects endpoints and dose/response information adequately address the purposes of the 

avian acute oral data requirement as described in 40 CFR Part 158. Until the Agency’s 

evaluation of that validation report is completed, EFED will not classify avian toxicity studies 

performed using the TG223 protocol and the studies cannot be used to fulfill data requirements. 

Therefore, we cannot say at this time whether or not avian toxicity studies done under TG 223 

will be acceptable to meet our data requirements. 

Validation work conducted on TG 223 test guideline to date has been limited to studies with the 

upland game birds (e.g., northern bobwhite). Because no work has been done to date to validate 

this guideline for passerine species, it is doubtful that we would accept studies done under this 

guideline for fulfilling requirements for passerine acute toxicity data unless additional validation 

work with passerines is done. 

ABC Comment: 

“1) ABC requests an avian oral toxicity test using a passerine species.” 

EFED concurs with this request. The Preliminary Work Plan (DP 368178) identified an avian acute 

oral toxicity test with a passerine species as a data requirement for the Registration Review of 

Oxamyl (PC 103801). The new Part 158 data requirements [40 CFR Part 158 (CFR 40 2007)] specify 

that acute avian oral toxicity data be submitted for a passerine species. A passerine study protocol must be 

submitted for review by the Agency prior to initiation of this study. 

ABC Comment: 

“2) ABC strongly supports oxamyl to be tested under the EDSP, specifically the Tier II avian 2 generation 

tests. We are specifically interested in the embryo and hatchling survival data and chick health, and 

sexual maturation/behavior, which is data that is not gathered from traditional reproductive studies.” 
3 

Oxamyl is among the group of 58 pesticide active ingredients issued test orders under Tier 1 of 

the EDSP between October 2009 and February 2010. This initial list of chemicals was selected 

based on the potential for human exposure through pathways such as food and water, residential 

activity, and certain post-application agricultural scenarios, and should not be construed as a list 

of known or likely endocrine disruptors. 

The Agency has evaluated the "Other Scientifically Relevant Information (OSRI)" submitted in 

response to the Tier 1 test orders for oxamyl and has determined that the Test Order Recipient 

needs to conduct all Tier 1 assays. Once the Agency has received and reviewed all relevant data, 

including Tier 1 results, the Agency will determine which, if any, of the Tier 2 tests are 

necessary. Tier 2 testing is designed to identify potentially adverse estrogen-, androgen-, or 

thyroid-related (E, A, or T) endocrine effects caused by the substance and to establish a doseresponse relationship between the dose and the E, A, or T effect(s). The weight-of-evidence 

analysis is conducted on a case-by-case basis by assessing all individual lines of evidence and 

performing an integrated analysis of the data. For further information on the status of the EDSP, 

the policies and procedures, the test guidelines, and the Tier 1 screening battery, please visit our 

website: http://www.epa.gov/endo/ 

ABC Comment: 

“3) ABC requests an avian reproductive and developmental study using a passerine species. ABC 

recognizes that EPA does not have an official Standard Operation Procedure (SOP) to recommend to 

registrants for passerine reproductive studies, however, we urge EPA to look beyond the lack of SOP and 

investigate the potential toxicity of this compound. Passerine species are altricial birds, and hatch at a 

very difference developmental stage than precocial mallards and bobwhite quail. Altricial hatchlings 

cannot thermoregulate, walk, or see. The differences in embryonic development between altricial and 

precocial birds could potentially lead to differences in sensitively to pesticides. For this reason avian 

reproductive studies should be conducted in both precocial and altricial avian models.” 

EFED is not aware of any data to show that oxamyl is more toxic to passerine species than it is to 

bobwhite quail (Colinus virginianus) or mallard ducks (Anas platyrhynchos) on an acute or 

chronic exposure basis as it relates to reproductive endpoints. EFED is aware of incident data 

for passerine species associated with the use of oxamyl; however, incident data are typically 

associated with acute exposures and are not considered (in and of themselves) to be sufficient 

rationale to support chronic toxicity testing requirements. Therefore, at this time, EFED believes 

that the data from the reproductive studies in the bobwhite quail and mallard duck studies will be 

adequate for assessing potential risks of oxamyl to birds from chronic exposure. As mentioned, 

EFED does not have a validated protocol for a chronic reproduction study in passerines. EFED 

is not prepared at this time to make recommendations regarding such a protocol. Any protocol 

developed would need to go through a process of scientific peer review. Therefore, EFED will 

not recommend requesting a chronic reproductive study using passerines for oxamyl at this time.