Persistent Organic Pollutants

NINE CHEMICALS, including the widely used chemicals perfluorooctane sulfonate (PFOS) and brominated flame retardants, have been added to the Stockholm Convention on Persistent Organic Pollutants, an international treaty to which the U.S. is not party.

The chemicals are targeted for worldwide elimination or restriction of production and use because they are carcinogens, interfere with reproduction or development, or damage the immune or nervous system, according to a United Nations statement.

PFOS, a substance that imparts stain- and stick-resistance, is listed for restriction. However, treaty partners added a number of exemptions, including the use of PFOS and its related chemicals in textile finishes, fire-fighting foam, and the manufacture of semiconductors.

Other treaty listings essentially call for the phaseout of chemicals. Among those to be eliminated are commercial-grade pentabromodiphenyl ether and octabromodiphenyl ether, which are mixtures of closely related brominated compounds. Uses of these compounds include fire suppression for polyurethane foams and the plastic housing of electronics such as cell phones and computers.

Also newly listed under the Stockholm Convention for elimination are the pesticide lindane, which is also used in some pharmaceuticals, as well as α- and β-hexachlorocyclohexane, both unintentional by-products of the manufacture of lindane.

Another new treaty listing for elimination is pentachlorobenzene, once used in polychlorinated biphenyl ether products and dyestuffs carriers and as a fungicide and a flame retardant.

The two other newly listed substances to be banned are chlordecone, a pesticide, and hexabromobiphenyl, once used as a flame retardant.