title: Recommended default methodology for analysis of airborne exposures to mixtures of chemicals in emergencies.
abstract: Emergency planning and hazard assessment of Department of Energy (DOE) facilities require consideration of potential exposures to mixtures of chemicals released to the atmosphere. Exposure to chemical mixtures may lead to additive, synergistic, or antagonistic health effects. In the past, the consequences of exposures to each chemical have been analyzed separately. This approach may not adequately protect the health of persons exposed to mixtures. This article presents default recommendations for use in emergency management and safety analysis within the DOE complex where potential exists for releases of mixtures of chemicals. These recommendations were developed by the DOE Subcommittee on Consequence Assessment and Protective Actions (SCAPA). It is recommended that hazard indices (e.g., HIi = Ci/Limiti, where Ci is the concentration of chemical "i") be calculated for each chemical, and unless sufficient toxicological knowledge is available to indicate otherwise, that they be summed, that is, sigma i(n) = 1HIi = HI1 + HI2 + ... + HIn. A sum of 1.0 or less means the limits have not been exceeded. To facilitate application of these recommendations for analysis of exposures to specific mixtures, chemicals are classified according to their toxic consequences. This is done using health code numbers describing toxic effects by target organ for each chemical. This methodology has been applied to several potential releases of chemicals to compare the resulting hazard indices of a chemical mixture with those obtained when each chemical is treated independently. The methodology used and results obtained from analysis of one mixture are presented in this article. This article also demonstrates how health code numbers can be used to sum hazard indices only for those chemicals that have the same toxic consequence.
authors.affiliation: Westinghouse Safety Management Solutions LLC, Aiken, South Carolina, USA.
authors.forename: D K
authors.initials: DK
authors.lastname: Craig
authors.forename: R L
authors.initials: RL
authors.lastname: Baskett
authors.forename: J S
authors.initials: JS
authors.lastname: Davis
authors.forename: L
authors.initials: L
authors.lastname: Dukes
authors.forename: D J
authors.initials: DJ
authors.lastname: Hansen
authors.forename: A J
authors.initials: AJ
authors.lastname: Petrocchi
authors.forename: T J
authors.initials: TJ
authors.lastname: Powell
authors.forename: P J
authors.initials: PJ
authors.lastname: Sutherland
authors.forename: T E
authors.initials: TE
authors.lastname: Tuccinardi
mesh_terms: D000393:Air Pollutants / Q000032:analysis / Q000145:classification* / Q000506:poisoning; D004189:Disaster Planning / Q000379:methods*; D004784:Environmental Monitoring / Q000379:methods / Q000592:standards*; D017408:Guidelines as Topic; D015386:Hazardous Substances / Q000032:analysis / Q000145:classification* / Q000506:poisoning; D006801:Humans; D012016:Reference Values; D018570:Risk Assessment / Q000379:methods / Q000592:standards*; D014481:United States
chemical_list: D000393:Air Pollutants; D015386:Hazardous Substances