http://ntp-server.niehs.nih.gov/cgi/iH_Indexes/ALL_SRCH/iH_ALL_SRCH_Frames.html

Databases which allow searchs by CAS No., chemical names, or toxicity/tumor site/type, and cover the following topics: carcinogenicity, properties, use, production, exposure, toxicity, regulations, teratogenicity, and handling and emergency procedures. The plug in Chemscape Chime is necessary to visualize 3D structures - available at http://www.mdli.com/cgi/dynamic/welcome.html