Fluoride Action Network

Global emission inventories for C4–C14 perfluoroalkyl carboxylic acid (PFCA) homologues from 1951 to 2030, part II: The remaining pieces of the puzzle

Source: Environment International 69:166-176. | Authors: Wanh Z, Cousins IT, Scheringer M, Buck RC, Hungerbuhler K.
Posted on August 1st, 2014
Location: International
Industry type: Perfluorinated chemicals


  • Eleven overlooked but (potentially) significant sources of PFCAs are identified.
  • Substantial emissions may come from historical and current use of C4 and C6 PFCAs.
  • Emissions from substances based on C4, C6 and C10 PASFs may be considerable.
  • Degradation of HFCs, HFEs and polymers may be an abundant and long-lasting source.
  • Critical knowledge and data gaps that prevent quantification are highlighted.


We identify eleven emission sources of perfluoroalkyl carboxylic acids (PFCAs) that have not been discussed in the past. These sources can be divided into three groups: [i] PFCAs released as ingredients or impurities, e.g., historical and current use of perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA) and their derivatives; [ii] PFCAs formed as degradation products, e.g., atmospheric degradation of some hydrofluorocarbons (HFCs) and hydrofluoroethers (HFEs); and [iii] sources from which PFCAs are released as both impurities and degradation products, e.g., historical and current use of perfluorobutane sulfonyl fluoride (PBSF)- and perfluorohexane sulfonyl fluoride (PHxSF)-based products. Available information confirms that these sources were active in the past or are still active today, but due to a lack of information, it is not yet possible to quantify emissions from these sources. However, our review of the available information on these sources shows that some of the sources may have been significant in the past (e.g., the historical use of PFBA-, PFHxA-, PBSF- and PHxSF-based products), whereas others can be significant in the long-term (e.g., (bio)degradation of various side-chain fluorinated polymers where PFCA precursors are chemically bound to the backbone). In addition, we summarize critical knowledge and data gaps regarding these sources as a basis for future research.


Perfluoroalkyl carboxylic acids (PFCAs)
Global emission inventory
Side-chain fluorinated polymers
Substances based on perfluoroalkane sulfonyl fluorides (PASFs)