A First Global Production, Emission, And Environmental Inventory For Perfluorooctane Sulfonate

TLDR

PFOS, with high water solubility, negligible vapor pressure, and limited particle sorption, tends to accumulate in surface waters, with oceanic measurements indicating 235–1,770 t currently present. This study aims to produce the first global historical estimates of POSF production and the corresponding environmental releases of PFOS. The analysis estimates 96,000 t of POSF produced worldwide from 1970–2002 (122,500 t including wastes) and 45,250 t of PFOS released to air and water between 1970–2012, with direct emissions from POSF‑derived products contributing 450–2,700 t of PFOS to wastewater, while indirect sources remain uncertain but likely add via degradation, and monitoring shows rising biota concentrations that have begun to decline since 2002 but still depend on emission routes, transport, and degradation.

Abstract

This study makes a new estimate of the global historical production for perfluorooctane sulfonyl fluoride (POSF), and then focuses on producing a first estimate of the global historical environmental releases of perfluorooctane sulfonate (PFOS). The total historical worldwide production of POSF was estimated to be 96 000 t (or 122 500 t, including unusable wastes) between 1970−2002, with an estimated global release of 45 250 t to air and water between 1970−2012 from direct (manufacture, use, and consumer products) and indirect (PFOS precursors and/or impurities) sources. Estimates indicate that direct emissions from POSF-derived products are the major source to the environment resulting in releases of 450−2700 t PFOS into wastewater streams, primarily through losses from stain repellent treated carpets, waterproof apparel, and aqueous fire fighting foams. Large uncertainties surround indirect sources and have not yet been estimated due to limited information on environmental degradation, although it can be assumed that some POSF-derived chemicals will degrade to PFOS over time. The properties of PFOS (high water solubility, negligible vapor pressure, and limited sorption to particles) imply it will reside in surface waters, predominantly in oceans. Measured oceanic data suggests ∼235−1770 t of PFOS currently reside in ocean surface waters, similar to the estimated PFOS releases. Environmental monitoring from the 1970s onward shows strong upward trends in biota, in broad agreement with the estimates of use and emissions made here. Since cessation of POSF production by 3M in 2002, a reduction in some compartments has been observed, although current and future exposure is dependent on emission routes, subsequent transport and degradation.