Standing Operating Procedure (SOP) for the Development of Provisional Advisory Levels (PALs) for Hazardous Chemicals [open pdf - 856KB]
"The U.S. EPA [Environmental Protection Agency] is responsible for managing accidental and intentional (e.g., terrorist) emergency chemical releases. Decisions following these releases are risk-risk tradeoff decisions, requiring quantitative information. Whether planning for or responding to an unanticipated chemical release, information describing the likelihood and severity (from reversible health impacts to death) of chemical-induced health impact is balanced against the resource requirements and possible unintended consequences of a response activity. EPA has identified toxic industrial chemicals and chemical threat agents that do not have, but do need advisory emergency exposure guideline values. EPA conceived Provisional Advisory Levels (PALs) that characterize risk at three levels of severity; cover both the inhalation and oral routes of exposure; and durations of 1, 30 and 90 days. This peer reviewed document describes the procedures to develop PALs by identifying health effects that increase in severity with increasing exposure, and by organizing them according to exposure durations common during and following an emergency chemical release. PALs developed according to this procedure will enable EPA On Scene Coordinators and their supporting toxicologists in EPA Programs, Offices and Regions; and in the CDC's [Centers for Disease Control and Prevention] Agency for Toxic Substances and Disease Registry to make effective emergency response decisions."
Environmental Protection Agency: https://www.epa.gov