A federal public health agency of the U.S. Department of Health and Human Services. Provides "toxicological profiles" for hundreds of toxic substances.
The Toxic Substances Portal https://www.atsdr.cdc.gov/substances/index.asp gives quick access to toxicological resources by health effect and chemical class.
CAS Registry Number®, chemical names (both formal and common), molecular formulas, and structures or sequences for ~7900 chemicals of widespread general public interest.
