As an engineer for an infant car seat company, I realize the tremendous pressure of designing safe products for babies and the world. That begins with understanding of what materials to use (or not).
PVC, or polyvinyl chloride, is one such material that has gotten a bad rap. It is a polymer of vinyl chloride, a known human carcinogen. Although, just because the monomer is dangerous, it should not necessarily mean that the polymer is dangerous? However, PVC factories raise vinyl chloride emissions and exposes workers and neighboring areas to the dangers. Other emissions from the manufacture of PVC are dioxins, which are a group of chlorinated hydrocarbons. Dioxins affect the growth regulation of cells, with some causing cancer in animals and increasing the cancer incidence in all sites for humans. Dioxins were used in Agent Orange, a powerful herbicide used in the Vietnam War. Incineration of PVC also releases dioxins, as well as hydrogen chloride gas (which forms hydrochloric acid when inhaled).
Most parents, however, are thinking mainly of the effects of PVC on their children. Rightly so, because PVC is known to have other additives that tend to leach out over the lifetime, including lead, cadmium, mercury. Some additives called plasticizers help make flexible PVC more durable. The most highly publicized plasticizers are phthalates. The most common phthalate in PVC (up to 40%) is DEHP, which is possibly carcinogenic to humans. DEHP cannot be taken up easily through the skin, but children are exposed by mouthing on PVC or through contaminated breast milk. Since DEHP does not easily disappear from the environment, bioaccumulation is a concern. The easy solution to limit children's exposure to DEHP is by avoiding PVC.
What about food safe PVC? That typically refers to PVC with a low phthalate content, so heating food carries a lower potential of chemicals leaching out. Considering that the lifecycle of PVC is so chemical intensive, it is easy to see why the food industry has been slowly switching to other plastics.
And the medical industry? Rigid PVC carries less of a chemical risk because of the lack of plasticizers, but there has been a move to replace PVC tubing with other flexible materials.
Bottom line: there are healthier alternatives than using PVC, so we have no excuse not to explore them.
