Health & Environmental Research Online (HERO)


Print Feedback Export to File
3860242 
Journal Article 
Perfluorooctanesulfonate (PFOS) Conversion from N-Ethyl-N-(2-hydroxyethyl)-perfluorooctanesulfonamide (EtFOSE) in male Sprague Dawley rats after inhalation exposure 
Chang, S; Mader, BT; Lindstrom, KR; Lange, CC; Hart, JA; Kestner, TA; Schulz, JF; Ehresman, DJ; Butenhoff, JL 
2017 
Yes 
Environmental Research
ISSN: 0013-9351
EISSN: 1096-0953 
155 
307-313 
English 
Ethyl-N-(2-hydroxyethyl)-perfluorooctanesulfonamide (EtFOSE) was one of the key building blocks for many of the perfluorooctanesulfonyl-based chemistry and laboratory studies have shown that EtFOSE can metabolically degrade to perfluorooctanesulfonate (PFOS). Non-occupational contribution sources to PFOS are thought to occur in general population via diets, drinking water, air and dust. For workers, however, the exposure route was mostly airborne and the exposure source was predominantly to precursor compounds such as EtFOSE. We undertook this study to investigate how much EtFOSE was converted to PFOS in the serum for male rats after 6h of exposure to EtFOSE vapor (whole body) at ambient temperature, which simulated a work place exposure scenario. There were no abnormal clinical observations and all rats gained weight during study. Interim tail-vein blood samples, collected up to 21 days after exposure, were analyzed for Et-FOSE and PFOS concentrations by LC-MS/MS. Upon inhalation exposure, the biotransformation of EtFOSE to PFOS in serum in the male rats was rapid and very little EtFOSE was detected in the serum within 24h after EtFOSE exposure. The highest conversion to PFOS in serum after exposure to EtFOSE vapor appeared to occur between Day 8-14 post exposure. Considering the potential surface and fur adsorption of test compound in the whole-body exposure system, our data would support that at least 10% of the inhaled EtFOSE was biotransformed to PFOS in the serum based on the range of lower 95% CI (confidence interval) values. This information is valuable because it quantitatively translates EtFOSE exposure into serum PFOS concentration, which serves as a matrix for internal dosimetry (of PFOS exposure) that can be used as an anchor across species as well as between different exposure routes. 
Perfluorooctanesulfonate; PFOS; N-Ethyl-N-(2-hydroxyethyl)perfluorooctanesulfonamide; EtFOSE; Inhalation 
• ^Per- and Polyfluoroalkyl Substances (PFAS)
     PFOA (335-67-1) and PFOS (1763-23-1)
          Literature Search – Adverse outcome pathway (2015-present)
               Pubmed
               WOS
     PFOSA (754-91-6)
          Literature Search
               Pubmed
               WOS
• PFNA
     Literature Search
          Toxline
     PFNA May 2019 Update
          Toxnet
• PFOA (335-67-1) and PFOS (1763-23-1)
     Literature Search – Adverse outcome pathway (2015-present)
          Pubmed
          WOS
     Screening Results
          Excluded/Not on Topic
     Literature Search Update (2013-2019)
          PubMed
          WOS
• PFOSA
     Literature Search
          Pubmed
          WOS
     Screening Results
          Excluded/Not on Topic