Plastics make our lives easier in many respects, but the chemicals used to manufacture plastic are having a significant impact on human health in ways that many people may not realize.
Chemical additives are used to make plastic products softer or more flexible or to stabilize their components. The additives may include lead, cadmium, phthalates ("thay-lates"), bisphenol A (BPA) and fungicides. Studies have shown that exposure to these chemicals may be linked to health problems, including reduced sperm counts and fertility, damage to the heart, liver, kidneys, immune and endocrine systems and increases in breast, testicular and prostate cancers.
There is currently no way for a consumer to be absolutely sure of the safety of any plastic product. Looking for recycling codes (which appear in a triangle on the bottom of most food containers) can help you steer clear of plastics which are known to present health risks. Polyvinyl chloride (PVC), bearing the #3 recycling code, is the most toxic plastic from both an environmental and human health standpoint. Other plastics to avoid are polystyrene (styrofoam®) (recycling code #6) and polycarbonate (recycling code #7).
One more thing. Keep in mind that a microwavable-label on a plastic container only means it will not break or melt in the microwave. It does not address the fact that certain chemicals will leach more readily from plastic when heated. Foods with a high fat content present the greatest risk, as many chemicals used in plastic are lipophilic (fat-loving). To avoid this risk, never use plastic containers to heat food, especially for babies. For heating or storage, use glass or lead-free ceramic containers.