Estimation of potential health effects from acute exposure to hydrogen fluoride using a "benchmark dose" approach.
Communities across the United States are examining the manufacture, use, transport, and storage of hydrogen fluoride (HF) near residential areas as a consequence of a major release of HF in Texas in 1987. Reference exposure levels for routine and accidental HF emissions are calculated using existing animal and human data. The approach employs a log-probit extrapolation of concentration-response data to the 95% lower confidence limit on the toxic concentration producing a "benchmark dose" of 1% response (TC01), called a practical threshold. Species-specific and chemical-specific adjustment factors are applied to develop exposure levels applicable to the general public. Using this method, the 1-hr reference exposure level to protect the public against any irritation from a routine emission (REL-1) is 0.7 ppm and the level to protect against severe irritation from a once-in-a-lifetime (REL-2) release is 2 ppm. This approach is compared to a modified "uncertainty factor" approach.
Alexeeff
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GV
Office of Environmental Health Hazard Assessment, California Environmental Protection Agency, Berkeley 94704.
Lewis
D C
DC
Ragle
N L
NL
D000393:Air Pollutants / Q000008:administration & dosage / Q000009:adverse effects*; D000818:Animals; D006801:Humans; D006858:Hydrofluoric Acid / Q000008:administration & dosage / Q000009:adverse effects*; D008452:Maximum Allowable Concentration; D008954:Models, Biological; D012307:Risk Factors; D013045:Species Specificity
D000393:Air Pollutants; D006858:Hydrofluoric Acid