Although workers are often exposed to contaminant mixtures, exposure regulations do not take into account the effects of the various types of contaminant interactions capable of modifying toxicity. To remedy this situation, the scientific literature will be critically reviewed and a database of the toxicity of mixtures developed and made accessible. The database will be used to produce French-language data sheets (including information on the primary target organs of substances listed in Appendix A of the Regulation Concerning the Quality of the Work Environment) which will be available on the Internet. With this information, health and safety specialists will be able to quantify contaminant interactions for any given situation.