The document was recommended by the U.S. EPA's Science Advisory Board as a means of providing the broad technical background for the principles and procedures described in the 'Guidelines for Health Risk Assessment of Chemical Mixtures'. Unique sections include an overview of available toxicity data on complex mixtures and binary exposures, an estimate of the maximum synergistic effect observed for environmental chemicals, an evaluation of quantitative methods (statistics and models) that have been used in characterizing interaction data base, and recommendations for Guidelines revisions and future research relevant to risk assessment. The two most significant conclusions in the document are (1) that the available literature is extremely poor for use in quantifying the extent of synergism expected from environmental exposures, and (2) that validation of in vitro and short-term in vivo studies seems to be the most promising approach for assessment of complex mixtures.

"EPA/600/8-90/064." "November 1988."