How Spotless Carpet Gets Into Your Blood

Stain-blocking products, not just factories, spread PFOA.

Mary Joyce Dinglasan-Panlilio

Researchers have discovered that a wide variety of stain-resistant products contain volatile compounds that can escape and break down into perfluorooctanoic acid (PFOA). This indestructible chemical has been accumulating in humans and wildlife, and it has been shown to harm laboratory animals. In related news, the Environmental Protection Agency yesterday asked major manufacturers of these compounds to cut their use by 95% over the next 4 years.

PFOA is used in the process of manufacturing polymers that can repel stains, keep grease on the inside of fast food wrappers, and improve the properties of polishes, paints, and hair-care products. Environmental scientists and regulators are worried because PFOA and related chemicals don't break down, and they cause cancer and developmental effects in lab animals. The environmental puzzle is that PFOA itself is not found in consumer products.

However, some PFOA is inadvertently released from factories that make the stain-resistant polymers. (DuPont says it has already substantially reduced such emissions.) PFOA also comes from the breakdown of other chemicals--including volatile fluorotelomer alcohols--that escape from the manufacturing process.

It turns out that those emissions are not the only source of fluorotelomers. In a study published online 24 January in Environmental Science and Technology, University of Toronto chemists Scott Mabury and Mary Joyce Dinglasan-Panlilio show that consumer products contain these volatile alcohols as residuals of the manufacturing process. They found these alcohols in seven materials including paint and polish additives, consumer carpet protector sprays, and windshield wiper fluid. Moreover, they are released from these products at part-per-hundred concentrations. "Our work shows that the indirect pathway could be the significant path to humans and the environment," says Mabury. He estimates that this could explain the measured concentrations of these chemicals in the atmosphere.

Other experts welcome the new findings. "We know about the global distribution of these chemicals and their levels in biota and the air," says Environment Canada research scientist Tom Harner. "It's about time someone looked at sources."

On 25 January, the EPA asked eight companies to reduce their emissions of PFOA and chemicals that break down to PFOA by 95% by 2010. Removing residuals is not insurmountable, according to chemical engineers familiar with fluorochemical polymers and other plastics. They note that familiar plastics such as soda drink bottles and PVC pipe all had problems with troublesome residuals at one time, the engineers say.

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