Miljøprojekt, 1013 – More environmentally friendly alternatives to PFOS-compounds and PFOA

More environmentally friendly alternatives to PFOS-compounds and PFOA

1 Terminology and definitions

In order to assist the reader of this report, the classes of chemicals discussed and their inter-relationship are defined. More specific terms are provided in Appendix A.

Perfluoroalkylated substance (PFAS)

A general term that describes a substance bearing a perfluorocarbon unit, F(CF₂)_n-R where n is an integer and R is not a halogen, or hydrogen. Examples include F(CF₂)₆CH₂CH₂OH, F(CF₂)₆SO₂N(CH₃)CH₂CH₂OH, and p-F(CF₂)₆-C₆H₄OH.

Perfluorosulfonates

Perfluorooctane sulfonate (PFOS) is a chemical, which is part of the larger perfluorooctyl sulfonyl fluoride (POSF) family. It is believed that many POSF chemicals can degrade to PFOS. The POSF family of chemistry had a wide array of uses. For the purpose of this report "PFOS-related chemicals" are synonymous with the POSF family of chemicals.

Recently, perfluorobutane sulfonate (PFBS) and a family of PFBS –based products have been introduced as alternatives. In this report, the PFBS substances are not considered as a part of the family of "PFOS-related chemicals" (as used in this report), because they have a shorter chain length than PFOS.

Perfluorocarboxylates

Perfluorocarboxylic acids (PFCAs) are a group of chemicals, which have been manufactured as industrial products used principally as processing aids in the manufacture of fluoropolymers such as polytetrafluoroethylene, PTFE. Perfluorooctanoic acid (PFOA) and perfluorononanoic acid (PFNA) are the most commonly used processing aids.

Telomers

Fluorotelomers or "telomers" are a family of speciality chemicals, which have similar function to the PFAS family of chemicals but are chemically different. As a result of their similar uses, they are of interest too. Further, some telomer-based substances can degrade to PFOA. Telomer-based substances are probably the most prevalent alternatives to PFAS-related chemicals.