Recommendations for the conduct of systematic reviews in toxicology and environmental health research (COSTER).

•COSTER is a set of recommendations for conduct of environmental health systematic reviews (EH SRs).•COSTER’s consensus process covered NGOs, academia, industry and government agencies.•COSTER is intended for use by scientists, editors, agencies, and others seeking guidance on EH SRs.•COSTER is put forward to initiate broader discussion of the EH community’s expectations for SRs.•COSTER is a first step in defining robust standards for good practice in conduct of EH SRs.