Selection of endpoints for acute effects due to exposure to toxic chemicals in Sri Lanka

Abstract

This article considers the challenge of setting threshold values or end points for toxic gas exposure from Major Accident Hazards (MAH) to third parties or the public in the Sri Lankan context. Two different categories of endpoints are considered; fixed and probit based. Setting probit based end points are considered in detail for three toxic chemicals H2S, Ch and NH3. End points are selected corresponding to the onset of fatality or 1% fatality of an exposed population due to a potential toxic gas release event. The selected end points are applied in a CI2 gas release accident scenario and the related threat zones are identified.