Experts guesstimate that about 50,000 chemicals are used in U.S. consumer products and industrial processes. Why the uncertainty? The 1976 Toxic Substances Control Act does not require chemicals to be registered or proven safe before use. Because the Environmental Protection Agency must show, after the fact, that a substance is dangerous, it has managed to require testing of only about 300 substances that have been in circulation for decades. It has restricted applications of five.



The House Toxic Chemicals Safety Act of 2010 and the Senate Safe Chemicals Act of 2010 would require manufacturers to prove that existing and new chemicals meet specific safety criteria. Stricter scrutiny in Europe and Canada suggests that “10 to 30 percent of U.S. chemicals would need some additional level of control,” says Richard Denison, a molecular biochemist at the Environmental Defense Fund. That would be 5,000 to 15,000 chemicals, not five.