Last month Canada announced it would ban the sale of baby bottles made with polycarbonate plastic – the hard, shiny durable plastic used in countless consumer products ranging from baby bottles and refillable water bottles to bike helmets, eye glasses, kitchen appliances, dental sealants, food can liners, and automotive parts. Why? Because scientific studies indicate that its chemical building block, a synthetic called bisphenol A (BPA), has adverse health impacts that include interference with endocrine hormones that regulate reproductive development and metabolism. Days later, Senators Schumer, Kerry, Feinstein, Clinton, Durbin and Menendez introduced a bill that would bar BPA from children’s products. A number of state legislatures have introduced comparable bills – to ban sales of children’s products containing BPA.

No such bills have yet passed but growing concern has prompted major retailers, including Wal-Mart to announce phase-outs of BPA products for children. A well-known manufacturer of refillable plastic bottles has also announced it would replace polycarbonate products with alternative plastics.

BPA plastics have been sold in growing quantities since the 1940s. The FDA has approved them for use in contact with food. The National Toxicology Program is now reviewing BPA – a process that is generating controversy between scientists whose work shows adverse health impacts of BPA and industry that maintains the product’s safety.

My interest in BPA began while researching a related product, a flame retardant called tetrabromobisphenol A that has been widely used in computers, televisions and other consumer electronics. I’ve now read dozens of scientific journal articles about BPA, interviewed numerous scientists studying the substance, and read industry’s pros and cons. Personally inclined to err on the side of caution about what I put into my mouth, I was intrigued to learn of alternatives to polycarbonate water bottles. An investigation of these new plastics revealed the same assurances manufacturers have provided consumers for decades. The material is odor resistant, dishwasher and microwave safe. But it has not been tested for environmental effects and no toxicity data is available.

These new plastics may have absolutely no adverse impacts. But the comparable material safety data sheets for polycarbonates indicate no problems either. Meanwhile, the environmental and health impacts of most chemicals now in common commercial use have not been studied and our system for evaluating new materials’ safety relies on information provided by manufacturers rather than independent assessment. So we launch products onto the market and hope for the best. I wonder if there might be a better way.