The People for the Ethical Treatment of Animals (PETA) and the Humane Society of the United States (HSUS) say the United States Environmental Protection Agency (EPA) Endocrine Disruptor Screening Program is inconsistent when it comes to animal testing.

The Endocrine Disruptor Screening Program (EDSP) is a two-tiered testing program. Tier 1 consists of five in vitro and six in vivo tests that explore the potential of a chemical to interact with the estrogen, androgen, and thyroid hormone systems and uses 595 animals — at minimum— per chemical if the entire battery is performed. Positive chemicals from Tier 1 presumably proceed to Tier 2, consisting of multi-generation reproductive and developmental toxicity studies in mammals, fish, birds, and amphibians, for further testing. 

For Tier 2 animal testing, as an example, the bird assay requires hatching of a minimum of 800 birds while the fish and amphibian assays each use thousands of animals per test. The EPA indicated that, prior to requiring new Tier 1 testing, it would consider Other Scientifically Relevant Information (OSRI) submitted by test order recipients and third parties and determine whether it satisfied data requirements of the EDSP. OSRI is existing data that is either functionally equivalent to information obtained from the Tier 1 assays (i.e., data from assays that perform the same function as EDSP Tier 1 assays) or provides evidence of a potential effect on the endocrine system.

Most of the 52 chemicals in the first round of Tier 1 testing under the EDSP were pesticides for which there is a wealth of existing toxicity data. This data includes results of guideline animal tests conducted under 40 CFR Part 158 data requirements to support pesticide registration as well as research studies published in the peer-reviewed literature. Guideline studies generally include two-generation reproduction toxicity studies in rodents; 28-day, 90-day, and 1-year chronic exposure studies in rodents and dogs; and reproduction and life-cycle studies in fish and birds. With so many of these chemicals already being extensively tested, acceptance of Other Scientifically Relevant Information (OSRI) is a primary means for avoiding duplicative data collection and minimizing further animal use.

The animal advocates declare in their paper (and in lawsuits and on their website) that the EPA lacks enough specific restrictions, guidelines, rules and laws. Navigating and clogging up the Byzantine mechanisms of government-controlled science is one of the ways how they hold back research, and so they declare that OSRI submissions by test order recipients were variable in their length and content - and somehow that is bad. They don't like that some respondents requested waivers based on OSRI for all Tier 1 tests while others did not seek any waivers at all. 

Of the 412 waivers sought, the EPA granted 93 — an overall OSRI acceptance rate of 23 percent. The 49 waivers for in vivo tests and 20 waivers for in vitro assays that use tissues collected from animals spared 3325 animals. However, at least 27,731 animals were estimated to have been used to perform the Tier 1 tests eventually required by the EPA after rejecting OSRI, with additional animals being used by laboratories in preparation for conducting the Tier 1 tests.

The laws creating the EDSP are already arcane and baffling, they provide for the use of OSRI and collect Tier 1 data to the greatest extent possible, but the paper says the EPA applies a narrow and limited approach to acceptance of OSRI - they think the EPA is too scientific, which will surprised no one, though business usually contend the EPA is unscientific against research, not for it.

PETA and the Humane Society find in their analysis that OSRI accepted in lieu of new testing either indicated a positive result or was produced using a study method that was identical or very similar to a Tier 1 or Tier 2 assay, even though the EPA said functionally equivalent studies would be considered. The OSRI analysis shows that results from Part 158 studies were accepted infrequently and that there were cases where literature studies were accepted for one chemical when the results were positive but rejected for another chemical evaluated in the study when the results were negative.

"Even with the EPA's planned integration of 21st -century toxicity-testing tools, such as computational toxicology methods and high throughput in vitro assays, into the EDSP for prioritization and screening purposes, OSRI will continue to play an important role in reducing the number of animals used in testing and in pretesting until such time when we can do away with animal testing completely," notes Patricia Bishop, one of the authors and a research scientist at PETA's Regulatory Testing Division.

Citation: Patricia L. Bishop and Catherine E. Willett, 'The Use and Acceptance of Other Scientifically Relevant Information (OSRI) in the U.S. Environmental Protection Agency (EPA) Endocrine Disruptor Screening Program', Birth Defects Research Part B: Developmental and Reproductive Toxicology 22 October 2013 DOI: 10.1002/bdrb.21077