A special session at the Toxicology and Risk Assessment Conference in Cincinnati, OH, USA in May, 2012 presented approaches expanding upon current uses of in vitro toxicity data for risk assessment. Evaluation of xenobiotics through use of in vitro study methods is increasing exponentially and these methodologies offer a relatively fast and considerably cheaper way to determine toxicities in comparison to traditional approaches. One of the challenges with in vitro data is to effectively use this information for risk assessment purposes. Currently, in vitro studies are used as supportive for hazard characterization and identifying mechanisms associated with toxicity. Being able to effectively correlate in vitro effects to in vivo observations represents a major challenge for risk assessors. The presentations in this special session provided innovative approaches toward effectively using in vitro data for the human health risk assessment process.