EPA http://www.epa.gov/ – which includes information on asbestos, Lead, Mold, etc.
Consumer Safety & Recalls http://www.cpsc.gov/ from swimming pools to items in the home
Polybutylene plumbing in homes http://www.polybutylene.com/poly.html
Federal Pacific Panels http://www.inspect-ny.com/fpe/fpe.html. Fires waiting to happen, debate waiting to be ended