Global distribution of PFOS and related chemicals

Perfluorinated compounds (PFCs) are synthetic organic chemicals used in a variety of industrial and commercial applications, including surfactants in pesticides, surface protectors in textiles, furnishings, and food packaging. PFCs become emerging chemicals of concern and two of them, namely perfluorooctane sulfonate (PFOS) and perfluorooctane sulfonyl fluoride (POSF) were listed as “restricted use” (Annex B) under the Stockholm Convention in May 2009. PFCs have an anionic functional group and nonpolar perfluoroalkyl chain. This moiety allows them to repel both water and oil, and accounts for their surfaces tension/leveling properties. Additionally, the high-energy carbon-fluorine bond accounts for the chemical and physical stability of these compounds. PFOS and perflurooctanoate (PFOA), having an eight carbon, were the two most well-known PFCs. PFCs have been manufactured and used as surfactant processing aids in the production of fluoropolymers, coatings for clothing, fabrics, upholstery and carpets, in paper products approved for food contact, and in aqueous film-forming foams (AFFF) for the past six decades [1]. PFCs are ubiquitous in the environment, and different governmental agencies have taken corresponding actions to regulate these compounds. The use of PFOS is regulated in the United States; further regulations of PFOS and related compounds have been implemented in the EU (Directive 76/769) from December 2007 in Europe, while the remaining permitted uses will be phased out by 2011 (OJ Directive 2006/122/ECOF). In Japan, according to the Chemical Substance Control Law, PFOS and POSF were listed as class I hazardous chemicals in April 2010. To a certain extent, they were classified as one of the contaminants, similar to polychlorinated biphenyls (PCBs), which can pose the highest risks to human. On the other hand, PFOA was classified as a Class II chemical on the watch list in 2002. PFOA-related chemicals such as perfluorododecanoic acid, perfluorotridecanoic acid, perfluorotetradecanoic acid, perfluoropentadecanoic acid, and perfluorohexadecanoic acid were classified as Class I chemicals on the watch list in 2008. Concern about fluorinated organic compounds, particularly PFCs, has been growing since the late 1990s because of the ubiquitous occurrence of PFCs in the environment, especially since they were found in biota (i.e., polar bear) from remote arctic regions where no PFC-related production facilities existed [1-7].