title: Setting exposure standards: a decision process.
abstract: Increased emphasis on routine screening of chemicals for potential neurotoxicity has resulted in the development of testing guidelines and standardized procedures. A multiphased, tiered-testing strategy has been proposed by numerous expert panels to evaluate large numbers of chemicals. In a regulatory context, however, a formal tiered-testing approach is not used, mostly because of the constraints of differing regulatory authorities and the potential cost of such a testing strategy. Instead, current regulatory decision making utilizes all available animal and human data to identify a critical adverse effect which is then used for setting standards. Although the current decision-making process does not use a formal tiered-testing approach, it appears to identify chemicals with neurotoxic effects. An analysis of U.S. Environmental Protection Agency integrated risk information system (IRIS) indicates that about 20% of the chemicals having standards or health advisories are based on neurotoxicity.
authors.affiliation: National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA. tilson@herl4S.herl.epa.gov
authors.forename: H A
authors.initials: HA
authors.lastname: Tilson
authors.forename: R C
authors.initials: RC
authors.lastname: MacPhail
authors.forename: K M
authors.initials: KM
authors.lastname: Crofton
mesh_terms: D000465:Algorithms; D004781:Environmental Exposure; D006801:Humans; D009498:Neurotoxins / Q000009:adverse effects*; D012015:Reference Standards; D018570:Risk Assessment; D018675:Toxicity Tests / Q000592:standards*; D014481:United States; D014484:United States Environmental Protection Agency; D014486:United States Food and Drug Administration
chemical_list: D009498:Neurotoxins