With the potential health hazards of widely used synthetic chemicals coming under increasing scrutiny, and with a growing call from medical and scientific professionals for policies that protect children from such hazards, the question of what takes the place of a threatening chemical has become increasingly important. It also prompts questions about whether it is better to substitute another chemical for the one posing problems or to redesign a product so it can achieve its desired performance, perhaps without such chemicals.
The brominated and chlorinated flame retardants (BFRs and CFRs) found in these children's products offer one cautionary example. Another group of chemicals known as phthalates, used to increase the flexibility of one of the world's most widely used plastics, polyvinyl chloride (PVC), offers another. Together, these compounds account for the vast majority of all plastics additives used worldwide.
In the case of the flame retardants used in upholstery foams, carpet backings, textiles, and hard plastic appliances and other products since the 1970s, new compounds introduced to replace the hazardous ones have in fact resembled their predecessors. The result, despite "early warnings and periodic reminders about the problematic properties of these chemicals" is a "continuing pattern of unfortunate substitution," wrote Linda Birnbaum, director of the National Institute of Environmental Health Sciences and National Toxicology Program, and Ake Bergman, professor of environmental chemistry at Stockholm University, in Environmental Health Perspectives in October. They were introducing a statement of concern about BFRs and CFRs signed by nearly 150 scientists from 22 countries.
While cushions and electronics can function without flame retardants, PVC cannot work without plasticizers. Phthalates—oily, colorless liquids based on benzene chemistry—have been the plasticizers of choice since PVC was commercialized in the early 20th century. Without phthalates, PVC would be brittle and of limited use. In some bendable PVC products, phthalates can make up as much as 40 to 50 percent of the finished plastic—and in 2008, nearly 540 billion pounds of PVC were produced worldwide.
Phthalates are also used in other vinyl-based products, to create thin and flexible films (they've been used in nail polish and other cosmetics), as lubricants (hence their use in lotions), as solvents, and to extend the life of fragrances, among many other applications. They are found in everything from food packaging to insect repellant to bath and teething toys. Some phthalates have been shown in animal studies to cause birth defects, and a number of popular phthalates have been identified as endocrine disrupters that interfere with male reproductive development. Concerned, Europe restricted use of about half a dozen phthalates in 2008, and the U.S. restricted them in products intended for use by children under age 12. Similar regulations exist elsewhere, including Canada, Japan, and Taiwan. On May 4, the French National assembly voted to ban phthalates altogether, based on concerns about endocrine disruption.
