"As the public has learned of health risks tied to chemicals in everyday products, many companies have responded by eliminating, one by one, the suspected cancer causers, brain damagers and hormone disruptors. But even prompt action doesn't entirely appease some health experts, who warn of a problematic pattern.
'We're playing toxic whack-a-mole,' said Arlene Blum, a chemist at the University of California, Berkeley, and executive director of the nonprofit Green Science Policy Institute. 'When after a great deal of research and testing, a chemical is found to be harmful, then the tendency is to replace it with as similar a chemical as possible. That's the easiest thing to do.'
History has shown, however, that the substitutes may prove equally harmful. Take, for example, the widespread replacement of bisphenol A with bisphenol S in products such as hard plastic water bottles and cash register receipts. New research suggests the latter chemical may be just as harmful to human health."