Toxicity testing of chemical mixtures: Some general aspects and need of international guidelines

The topics discussed by the Working Group on Toxicity Testing of Chemical Mixtures included the following: (l) the study designs and results from two real-life exposure scenarios as additional information to the various investigations reported at the conference; (2) the need to take into consideration low-level, longterm exposure (i.e. mimicking human exposure conditions) as well as the issue of limited resources in experimental toxicology studies; (3) the importance of exploring alternative and predictive toxicology methodologies to minimize animal use and to conserve resources; (4) the realization that interactive toxicity should include the consideration of physical and biological agents in addition to chemicals. Two specific studies reported at the conference were also discussed. A number of recommendations were made concerning the planning and implementation of toxicology studies on chemical mixtures.