UC Berkeley licenses the ChemKnowledge System from Thomson Micromedex, a suite of databases and resources that together, provide a huge amount of information on chemical hazards. 
Anyone working in toxicology, hazardous waste, or occupational health should check this out.
Databases included in our subscription are:
- HAZARDTEXT, which provides information needed for the initial response to incidents such as spills, leaks, fires, or explosions involving hazardous materials
- INFOTEXT Documents offer general health and safety data on nonchemical-specific topics such as ergonomics and human health risk assessments
- HSDB (Hazardous Substance Data Bank) addresses the impact of thousands of hazardous chemical substances on health and the environment. Specific data on health effects, environmental fate, animal studies, chemical handling and manufacturer is presented
- RTECS (Registry of Toxic Effects of Chemical Substances) offers toxicity data on more than 135,000 substances, including specifics on mutagenicity, carcinogenicity, reproductive hazards, and acute and chronic toxicity of hazardous substances
- REPRORISK® System, the single most comprehensive compilation of reproductive risks information databases available, helps evaluate reproductive risks of drugs, chemicals and physical & environmental agents on females, males and unborn children
- Dolphin MSDS Collection, a vendor-rich collection of Material Safety Data Sheets for thousands of workplace chemicals. More the 330,000 MSDS from over 19,050 vendors is presented, with 5,000 new and revised MSDS added each month
and more!
Search help is available online. Databases may be searched individually, or in any combination.