Studies on the effects of bisphenol A, a chemical commonly used in plastic products, on human health have provided contradicting results, causing uncertainty among consumers. "The fears are irrational," Elizabeth Whelan, of the American Council on Science and Health, said. "People fear what they can't see and don't understand. Some environmental activists emotionally manipulate parents, making them feel that the ones they love the most, their children, are in danger." She said the focus should be on proven health issues, such as cigarettes, obesity and the need for bicycle helmets and other protective equipment.