Trends of Perfluoroalkyl Acid Content in Articles of Commerce-Market Monitoring from 2007 through 2011.

摘要

The U.S. Environmental Protection Agency (EPA) has established an ongoing effort to quantify possible changes in levels of perfluorinated chemicals (PFCs) in articles of commerce (AOCs). Temporal trends in the concentrations of selected PFCs, including perfluorooctanoic acid (PFOA) and other perfluorocarboxylic acids (PFCAs), in 35 AOCs were measured from the year of 2007 through 2011. The AOC samples that were collected included carpet, commercial carpet-care liquids, household carpet/fabric-care liquids, treated apparel, treated home textiles, treated nonwoven medical garments, floor waxes, food-contact paper, membranes for apparel, and thread-sealant tapes. They were purchased from retail outlets in the United States between March 2007 and September 2011. Two to five AOCs from each of the ten categories were monitored. Depending on the market availability, products were collected for two to four data points in a span of four years. The perfluorocarboxylic acid (PFCA) contents in AOCs have shown an overall downward trend as portion of the fluorochemical industry has reformulated their PFC products. However, PFOA (C8) could still be detected in many AOCs that we had monitored. No obvious tendencies for change over the monitored period for short-chain PFCA (sum of C4 to C7) versus long-chain PFCA (sum of C8 to C12) were observed. A longer and wider range of monitoring will be required to confirm an observed trend. In addition to monitoring PFCA contents in AOCs, fourteen AOC samples were analyzed to determine the amounts of perfluoroalkyl sulfonates (PFAS) they contained. The limited data show the pronounced increase of perfluoro-butane sulfonate (PFBS-C4), an alternative to perfluorooctanoic sulfonate (PFOS), in the samples.