Free resources for searching the toxicological literature

I thought I´d add a post about some great resources available in the USA and Canada for searching toxicological literature. TOXNET is a great "cluster of databases" that can be searched together using a very simple interface. You can search HSBD (see the fact sheet on Hazardous Substances Data Bank), IRIS (see the fact sheet on Integrated Risk Information System), ITER (see the fact sheet on International Toxicity Estimates for Risk), Gene-Tox (see the fact sheet), CCRIS (see the fact sheet on Chemical Carcinogenesis Research Information System), TOXLINE (see the fact sheet), DART/ETIC (see the fact sheet on Developmental and Reproductive Toxicology/Environmental Teratology Information Center Database), TRI (see the fact sheet on EPA's Toxic Chemical Release Inventory), and ChemIDplus (see the fact sheet). It's a good idea to read the fact sheets if you're really interested in toxicological research because you'd be surprised at the usefulness and relevance of these databases.