You can determine which plastics contain bisphenol-A by checking the recycling code on the bottom. Avoid #3 (polyvinyl chloride) and #6 (polystyrene) for food and liquid storage, and it's not a bad idea to avoid #7 (which includes polycarbonate but other plastics) as well. Not all plastic is labeled so if it's made of clear, rigid plastic, it's probably made of polycarbonate. Products made of polypropylene are easy to identify because the BPA-free plastic is slightly cloudy and more flexible than polycarbonate.

Bisphenol-A has been shown to stimulate estrogen receptors which causes effects similar to estrogen in the body. In men, this may cause lowered sperm count and infertile sperm. It should be noted that most major bottle makers stand behind their products and it has been proven that the amount of BPA that's leached is below the recommended daily intake limit. Additionally, the studies that have been done have only focused on animals and results do not always correlate to humans. However, it is recommended by doctors that we avoid BPA - just in case. And because there are choices, why not make the safest one?