Evaluation of 10% minimum elicitation threshold for Cr(VI)‐Induced allergic contact dermatitis using benchmark dose methods

Historical patch test data have been used to propose health‐based soil cleanup levels for Cr(VI) that are protective of eliciting allergic contact dermatitis (ACD) among previously sensitized individuals. Shortcomings regarding the use of these historical studies in the risk assessment of Cr(VI) have been identified and include the use of concentration as the dosimetric for ACD eiicitation rather than the mass per surface area. Information on the surface areas of the patches used by the authors of three of the historical studies have been made available recently, and their dose levels have been converted from units of concentration to mass per surface area. For this study, benchmark dose methods were used to estimate the 10% minimum eiicitation threshold (MET) based on the converted patch test data from these historical studies and from the data presented in a more recent patch test study by Nethercott et ah (1994). A truncated lognonmal model was fitted to the historical data from each individual histori...