Sources, Fate and Transport of Perfluorocarboxylates

Abstract

This review describes the sources, fate, and transport of perfluorocarboxylates (PFCAs) in the environment, with a specific focus on perfluorooctanoate (PFO). The global historical industry-wide emissions of total PFCAs from direct (manufacture, use, consumer products) and indirect (PFCA impurities and/or precursors) sources were estimated to be 3200-7300 tonnes. It was estimated that the majority (approximately 80%) of PFCAs have been released to the environment from fluoropolymer manufacture and use. Although indirect sources were estimated to be much less importantthan direct sources, there were larger uncertainties associated with the calculations for indirect sources. The physical-chemical properties of PFO (negligible vapor pressure, high solubility in water, and moderate sorption to solids) suggested that PFO would accumulate in surface waters. Estimated mass inventories of PFO in various environmental compartments confirmed that surface waters, especially oceans, contain the majority of PFO. The only environmental sinks for PFO were identified to be sediment burial and transport to the deep oceans, implying a long environmental residence time. Transport pathways for PFCAs in the environment were reviewed, and it was concluded that, in addition to atmospheric transport/degradation of precursors, atmospheric and ocean water transport of the PFCAs themselves could significantly contribute to their long-range transport. It was estimated that 2-12 tonnes/ year of PFO are transported to the Artic by oceanic transport, which is greater than the amount estimated to result from atmospheric transport/degradation of precursors.

Surface-associated metal catalyst enhances the sorption of perfluorooctanoic acid to multi-walled carbon nanotubes

“…The K OW value of PFOA is unknown [50]. To prepare a stock solution, 1 gram of non-labeled PFOA was weighed into a 1 L volumetric flask and made up to 1 L with Milli-Q water.…”

Trends of polyfluoroalkyl compounds in marine biota and in humans

“…Nevertheless, PFOS, PFOA and a variety of related PFCs are still being produced by other manufacturers in several countries of Europe and Asia and in the USA. [1,2] In the following years stewardship programs and statutory regulations have been discussed and announced to achieve reduction in facility emissions and product contents (see http://www.epa.gov/oppt/pfoa/pubs/stewardship/index.html, accessed 10 December 2010). [3] Regarding the environmental impact of PFCs, the OSPAR commission (an international cooperation on environmental protection in the North-East Atlantic) published a list containing seventeen PFC substances that potentially fulfil the OSPAR criteria.…”

Trace determination of airborne polyfluorinated iodine alkanes using multisorbent thermal desorption/gas chromatography/high resolution mass spectrometry

“…Fluorinated additive materials have a wide range of applications such as in surfactants, lubricants, varnishes, pesticides and vinyl polymerization [1,2]. Regulatory efforts are underway to limit the use of some of these chemicals, mainly the perfluorinated compounds (PFCs), due to concerns over their environmental persistency, bioaccumulation ability and toxicity [3,4].…”

“…They are reaction products synthesized from telomerization process by iodine pentafluoride reacting with unsaturated taxogen molecules such as tetrafluoroethylene and ethylene. PFIs are used as important industrial intermediates for the production of various PFCs, such as fluorotelomer alcohols, olefins and acrylate monomers [2,13]. Since the usage of electrochemical fluorination method has been terminated since 2002 in most countries, the telomerization process has been increasingly popular in the production of PFCs.…”