Scotchgard sticks in the environment, study finds 

Margot Higgins / ENN 11apr01

It may help keep the red wine stains out of your carpet, but Scotchgard, a popular water and stain repellant, is leaving its mark on the environment.

A chemical compound known as perfluoro-octanyl sulfonate, or PFOS, found in the product is more prevalent in the environment than previously thought, a recent study finds.

Last May, 3M, which is the sole manufacturer of Scotchgard, decided to reformulate the stain guard due to concerns that PFOS can build up in the tissue of humans and animals.

Now the compound has been found at widespread levels in mammals, fish and birds, even in remote areas of the world that are far from where the product is manufactured.

"What we've done is a global survey that shows you for the first time that this compound is out there," said lead author of the study John Giesy, a chemist at Michigan State University. "We found a good testing method and discovered small amounts of PFOFs in remote areas. That surprised me."

The researchers collected more than 2,000 animal tissue samples, from the Pacific Rim to Antarctica, and analyzed more than 400 for PFOS. Concentrations of the compound in wildlife were 10 times greater in urbanized industrial areas than in less populated coastal areas, according to the results.

Environmental activists have called last year's 3M decision a great victory for the precautionary principle.

Gina Solomon, a senior scientist at the Natural Resources Defense Council applauded 3M for "removing the product before there is absolute scientific proof of harm. . . If companies had taken the same kind of precautionary action with DDT and PCB, then we wouldn't be in the same bad situation we're in now."

While so far there has been no data to suggest adverse health effects in humans, previous research has found that high concentrations of PFOS can cause reproductive problems in rats.

"(At the levels we detected in our research) we have about a four fold level of safety, which is not as great as we would like to see," Giesy said.

PFOS have been difficult to study because the molecules are larger and more difficult for scientific instruments to detect than other known environmental toxins such as PCBs or DDT. Giesy believes it is necessary to conduct more research on the health risks associated with PFOS, although the prospect is unlikely now that Scotchgard containing the compound has been pulled from the shelves.

"I think this is going to change the way we look at chemicals because PFOS were not studied very much and they were not expected to move in the environment," he said. "We don’t know how PFOS might interact with other chemicals. From an academic standpoint it would be useful for this entire class of compounds, to know more about other similar chemicals that might be in the environment or might be made in the future."