EDSP Approach
The EDSP uses a tiered approach for screening chemicals. Under the tiered approach:
- Tier 1 screening data are used to identify substances that have the potential to interact with the endocrine system. Chemicals that go through Tier 1 screening and are found to exhibit the potential to interact with the estrogen, androgen, or thyroid hormone systems will proceed to Tier 2 for testing.
- Tier 2 testing data identify any adverse endocrine-related effects caused by the substance, and establish a quantitative relationship between the dose and that adverse effect. The results of Tier 2 testing will be combined with other hazard information and exposure assessment on a given chemical resulting in the risk assessment. Risk assessments are used to inform risk mitigation measures, as necessary, and regulatory decisions concerning chemicals.
Tier 1 screens and Tier 2 tests are designed to evaluate effects on androgen, estrogen, and thyroid hormone systems, as well as steroidogenesis. Details on the study on the study designs are found here. To see which hormone systems are interrogated by each screen and test, see the Hormone System Interrogation by Study (pdf) tables.
As the EDSP screening and testing requirements mature into routine evaluations, the Agency intends to utilize the pesticide registration review process as the framework for managing its responsibilities regarding the endocrine screening of pesticides, and intends to eventually incorporate these requirements routinely into the pesticide registration review process.
The Office of Pesticide Programs (OPP) established the Endocrine Disruptor Science Policy Council (EDSPOC) in 2022. One of EDSPOC’s primary functions is to serve as OPP’s central forum to review hazard and exposure evaluations to the extent relevant for making recommendations concerning 1) FFDCA section 408(p)(4) exemptions, 2) when the use of validated new approach methodologies (NAMs) as alternatives is acceptable to provide Tier 1 data, or 3) appropriate use of Other Scientifically Relevant Information (OSRI) to satisfy specific EDSP data requirements and for use in a weight-of-evidence (WoE) analysis.
In addition to the primary functions listed above, EDSPOC may also assist in reviewing registrant-submitted rebuttals pertaining to required EDSP screening and/or testing data. EDSPOC plays a key role in OPP’s effort to implement the 3R’s-of toxicity testing (reduce, replace, refine). Each of these three types of actions can be initiated by the request of the EDSP, the OPP Division, or the chemical risk assessment team.