DEAR MR. DAD: I’ve been reading more and more that baby bottles and sippy cups are made from harmful plastics. How do I know which ones are safe?

Answer: You’ve probably been hearing about bisphenol A (BPA), which has been making headlines lately. Even if you haven’t heard of it, it’s all over your house – besides baby bottles and sippy cups, it’s in just about anything made of hard, clear plastic, as well as in the lining of food and beverage cans. And if your child’s teeth were sealed by her dentist, there’s a good chance that the coating contains BPA. The problem is that BPA mimics estrogen in the body, and experts suspect that it may cause birth defects, developmental delays, cancer, ADD, early onset puberty, and more. Pretty scary stuff.

In a recent study by the Environmental Health Fund, every baby bottle tested leached BPA into the contents in unsafe levels. That’s at least in part why, in April, Canada banned BPA entirely, saying the health concerns of its citizens outweighed the potential benefits of BPA. In the United States, a number of states are introducing legislation restricting or outlawing BPA in children’s products. The Federal government, however, is still clinging to the idea that it’s safe.

So, as parents, what can we do? First, check the bottom of the bottle, cup, or other product. If you see a triangle with a number 7, put it down and back away slowly. Numbers three and six don’t contain BPA, but have similar chemicals that may make them unsafe. Stick with one, two, four and five.

Baby and discount stores around the country have vowed to phase out baby bottles with BPA by the end of 2008.

Washing plastic bottles and other products in hot water causes higher levels (as much as 55 times higher!) of BPA to come out, as does using a steam sterilizer, running through a dishwasher, and boiling. Stay away from bottle warmers, too. And if you formula feed, use room temperature water and mix the bottles as you need them instead of premixing and heating. And finally, scouring them causes tiny scratches in the plastic’s surface, which can cause BPA to leach out faster than a smooth surface. Instead, wash in lukewarm water and let them drip dry.

Fortunately, not all baby products contain BPA. Safer Sassy bottles and utensils are BPA-free, as are bottles made by BornFree, Gerber’s Clear View, and Playtex’s Drop-in Liners. Other companies, such as PUR, Thermos, Brita, Adiri, and Combi. As more and more data about BPA comes out, more consumer products companies will abandon it. There’s a continually updated list of good products at zrecs.blogspot.com.