Clint Eastwood/Harry Callahan's pithy question rings in my head, every time I read the chemical lobby's defense of bisphenol A(BPA), a high-volume industrial plastics chemical.

Many experiments have shown that BPA, a synthetic estrogen as well as a plastics hardener, disrupts the endocrine system and causes a growing list of chronic, often permanent disorders in lab animals.

To which industry routinely responds: 1) animals aren't people; 2) in people, BPA is, as one industry spokesman put it, "efficiently...