Guide to EDSP Implementation
The Office of Pesticide Programs (OPP) has established the Endocrine Disruptor Science Policy Council (EDSPOC) in 2022, with Dr. Nicole M. Mokrzan as its head. This council plays a pivotal role in OPP's efforts to implement the 3R's of toxicity testing: reduce, replace, and refine.
EDSPOC serves as OPP's central forum to review hazard and exposure evaluations. It is responsible for the Endocrine Disruptor Screening Program (EDSP), a tiered approach for screening chemicals. The program begins with Tier 1 screening, where data are used to identify substances that have the potential to interact with the endocrine system.
Chemicals that exhibit such potential are further evaluated in Tier 2 testing. Tier 1 screens and Tier 2 tests are designed to evaluate effects on androgen, estrogen, and thyroid hormone systems, as well as steroidogenesis. The results of Tier 2 testing are combined with other hazard information and exposure assessment on a given chemical, resulting in the risk assessment.
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. This information is crucial for informing risk mitigation measures, as necessary, and regulatory decisions concerning chemicals.
EDSPOC also reviews registrant-submitted rebuttals pertaining to required EDSP screening and/or testing data. It may also provide Tier 1 data where necessary. Furthermore, EDSPOC makes recommendations concerning FFDCA section 408(p)(4) exemptions, the use of validated new approach methodologies (NAMs), and the appropriate use of Other Scientifically Relevant Information (OSRI).
The recommendations of EDSPOC are also used for a weight-of-evidence (WoE) analysis. Each type of action (reduce, replace, refine) can be initiated by the request of the EDSP, the OPP Division, or the chemical risk assessment team.
For more detailed information on the study designs, please refer to the provided resources. To understand which hormone systems are interrogated by each screen and test, you can consult the Hormone System Interrogation by Study (pdf) tables, which have a size of 158 KB.
The Agency plans to use the pesticide registration review process as the framework for managing endocrine screening of pesticides. This proactive approach aims to ensure the safety and efficacy of pesticides while minimising their potential impact on the endocrine system.
