National Institutes of Health
National Institutes of Health: Household Products Database
Everything you ever wanted to know about every household product available, from battery disposal to detergent and glue.
Encyclopedia of Earth
Encyclopedia of Earth: Human Health: Carcinogen
Gives definition of a carcinogen, examples, and the two categories of carcinogens - those known to cause cancer in humans, and those 'anticipated' to cause it.
Centers for Disease Control and Prevention
Centers for Disease Control: Atsdr: Superfund Hazardous Waste Sites
Extremely detailed look at the dangers associated with the hazardous and solid waste sites in the U.S.