When vinyl is first made, it is in powder form. In order to become the flexible, durable material used in vinyl wallcovering, flooring, shower curtains, insulation for wire and cable, upholstery fabrics and other products, plasticizers are mixed with the powder under heat in a process called compounding. The resulting material can be molded, extruded or shaped in other ways into finished products. Because of vinyl’s physical makeup, plasticizers are held tightly within the material. However, under certain unusual conditions, minute quantities may migrate to the surface of a product.
Some of the most commonly used vinyl plasticizers are phthalates, which have the consistency of vegetable oil. Phthalates are used in a wide range of vinyl and non-vinyl products – not only building products, but also food packaging, pharmaceuticals, cosmetics, lotions, detergents and others. Independent scientists, international governmental bodies and phthalate producers have conducted extensive studies on the safety, health and environmental effects of phthalates. In more than 40 years of study and use, phthalates have never been shown to cause harm to humans. Go to the Phthalates Information Center for an exhaustive list of the research that has been conducted.
Perhaps the best evidence of their safety is that certain phthalates have long been accepted for use in products such as blood bags and I.V. tubing, as well as in vinyl food-contact packaging for meat and produce. These products are regulated for safety by the U.S. Food and Drug Administration.
No Evidence of Indoor Air Problems
There is no evidence that use of phthalates in building materials poses a reproductive or developmental toxicity hazard. No scientific basis exists to link the use of phthalates in building materials with asthma or to show that phthalates are responsible for adverse effects in children.
The Institute of Medicine (IOM), established by the National Academy of Sciences, investigated leading causes of childhood asthma and found the strongest correlation with indoor agents such as dust mites, cockroaches and pet dander.1 IOM found insufficient information to link plasticizers in indoor air to childhood asthma. This finding is bolstered by the fact that phthalates have low vapor pressure and thus a low tendency to escape into the air.
Concentrations in indoor air, even in microscopic particles of vinyl attached to dust, are far below levels of concern, according to data from the industry group representing U.S. manufacturers of phthalates, the Phthalate Esters Panel of the American Chemistry Council.
"Clearing the Air: Asthma and Indoor Air Exposures," Institute of Medicine Committee on the Assessment of Asthma and Indoor Air, National Academy of Sciences (2000).