U.S. Environmental Protection Agency (EPA)
http://epa.gov/
U.S. EPA Office of Pollution Prevention and Toxics (OPPT)
http://www.epa.gov/oppt/index.html
U.S. EPA Office of Pesticide Programs (OPP)
http://www.epa.gov/pesticides/
U.S. EPA Integrated Risk Information System (IRIS)
http://www.epa.gov/iris/index.html
U.S. EPA Risk Assessment Forum
http://cfpub2.epa.gov/ncea/raf/index.cfm
U.S. EPA Superfund Risk Assessment
http://www.epa.gov/oswer/riskassessment/risk_superfund.htm
Health Canada
http://www.hc-sc.gc.ca/
Entrez PubMed
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=pubmed
Environmental Health Perspectives
http://ehp.niehs.nih.gov/
Society for Risk Analysis
http://sra.org/
Society of Toxicology
http://www.toxicology.org/
World Health Association (WHO)
International Programme on Chemical Safety
http://www.who.int/ipcs/en/
WHO International Agency for Research on Cancer (IARC)
http://www.iarc.fr/