Per and Polyfluoroalkyl Substances (PFAS) Challenges and Best Practices Taryn McKnight Product Manager

Transcription

1 Per and Polyfluoroalkyl Substances (PFAS) Challenges and Best Practices Taryn McKnight Product Manager Copyright 2018, TestAmerica. All All rights reserved.

2 Briefly - What are PFAS? Synthetic compounds formed from carbon chains with fluorine atoms Persistent The C-F bond is one of the shortest and strongest in nature Toxic Bioaccumul ative

3 Nomenclature PFAS Per- and Polyfluoroalkyl Substances PFCs Perfluorinated Compounds Completely & Incompletely Fluorinated Completely Fluorinated PFSAs Perfluorinated sulfonic acids PFAAs Perfluoroalkyl Acids PFCAs Perfluoroalkylcarboxylic acids Subset of PFCs PFOS PFOA

4 Carbon Chain Nomenclature Acronym Compound Name Chain Length PFDA Perfluorodecanoic acid C10 PFOA Perfluorooctanoic acid C8 PFHxS Perfluorohexanesulfonic acid C6

5 Chemical Structure Chain Length Carbon Backbone Functional Group

6 Chemical Structure Chain Length Carbon backbone Charged Functional Group 8 carbon atom PFCAs 6 carbon atom PFSAs Inert, Persistent & Bioaccumulative Our ability to capitalize on the desirable qualities

7 Properties Fluorocarbon Tail = Hydrophobic/Oleophobic Functional Group Head = Hydrophilic

8 Branched & Linear Isomers

9 PFAS Formation ECF Reaction = B&L & Unintended Byproducts + + = Telomer Reaction: Unintended Byproducts & Precursors

10 Manufacturing Primary Raw Material Industrial Chemicals Secondary Consumer Products Products

11 AFFF DoD Airports Fire Fighting Training & Emergency Response Refineries

12 Consumer Products Manufacturers Landfills POTWs Brownfields GW Monitoring

13 Example Uses Automotive Textiles Carpet/Furniture Paper/Pulp Metal/Surface Finishers Paint Chemicals Semiconductor Mining Car Washes Stone Cutting/Sealing

14 Metal Finishing and PFOS Products used to suppress the mist generated from chromium plating baths contain PFOS

15 Landfill Leachate Complex matrix Wide range of concentrations More short than long chains PFBA/PFBS are dominant Can represent <1% of mass flow from WWTP Can be a minor source to aqueous environment Polyfluoroalkyl compounds in landfill leachates Jan Buschab, Lutz Ahren, Renate Sturma, Ralf Ebinghausa

16 Exposure Pathways Trace chemistry - biotransformation of precursors in the environment

17 Exposure and Toxicity Human exposure is primarily from: food (fish), DW, air Exposure continues: due to persistence Half-lives in humans: 2 to 9 years PFOA/PFOS associated with: kidney and testicular cancer, thyroid disease; toxicology still being studied

18 Regulatory Timeline When Who What Happened 2002 USEPA Initiated voluntary phase out of PFOS 2006 USEPA PFOA Stewardship Program initiated 2008 Canada 2009 UN 2015 USEPA May 2016 USEPA Regulated and prohibited PFOS imports to Canada Stockholm Convention - adds PFOS to Annex B PFOA Stewardship Program completed December 31, 2015 PFOS and PFOA Lifetime Health Advisory Limits 70 ppt combined

19 State Drinking Water Limits State PFOA PFOS ppt ppt Comments North Carolina NA NA GenX 140 ppt Nevada AZ, AL, CO, MD, ME, MA, MI, NY, RI, WV Connecticut Adopted HAL from 2016 Combined limit for: PFNA, PFHxA, PFOA, PFOS, PFHpA Pennsylvania Minnesota Vermont California Interim Notification Levels New Jersey 14 TBD PFNA 13 ppt U.S. EPA Health Advisory Limit = 70 ppt

20 State GW or SW Limits State PFOA ppt PFOS ppt Comments Oregon 24, , 000 North Carolina 2,000 NA Alaska Texas PCLs for 16 PFCs Maine Pennsylvania Rhode Island Minnesota Vermont Sum of PFOA/PFOS, Michigan New Jersey NA NA 10 ppt for PFNA

21 EPA Method 537 A Drinking Water Method Features Method 537 Matrices Drinking Water Sample size 250 mls Holding times 14/28 days Aqueous Extraction SPE SDVB Analysis LCMSMS - no confirmation ion Branched/Linear Isomers Yes Quantitation Internal standard Reporting Limits (2 ppt - 40 ppt) Recovery Correction No LCS recovery limits &searchall=epa%2f600%2fr-08%2f092+

22 Groundwater, Soil, Tissue? What method do we use for non-potable water matrices?

23 537 Modified ISO DoD QSM 5.1 ASTM D7979 EPA 8327 ASTM 7968 EPA 8328

24 Regulatory Challenges Formal Guidance Screening Levels Target Analytes Methods

25 537M - Key Elements Reducing Variability Applicable to all matrices Use available cleanups, rigorous extraction and centrifugation Isotope Dilution Quantitation Use all available labeled analogues w/ recovery correction Branched and Linear Quantitation For all available B/L standards Use of Secondary Ion Transitions

26 PT Study Results - NMI 24 labs submitted 9 Passed Sample Analyte TA Lab Expected Water A PFOA PFOS Water B PFOA PFOS Soil A PFOA PFOS Soil B PFOA PFOS Fish A PFOA ND ND PFOS Fish B PFOA PFOS

27 Sample Containers & Holding Times PFAS can adsorb to filtration equipment Ship on ice; Trizma for DW samples only Field Filtering Preservation HDPE Bottles Hold Times Subsampling more significant than material type 14/28 for 537 Limited HT studies for NPW/SW

28 Managing Artifacts Field Crew: personal care, clothing, food, visitors, books, tarps Sampling Equipment: bailers, pumps, tubing, valves Sample Collection: wash hands, wear gloves, don t filter, include field QC

29 Precursors

30 PFCA Pattern MeFOSA Precursor ppt PFOA PFBA PFPeA PFHxA PFHpA PFOA PFNA

31 What Do the Results Mean? Precursor Pre Post % Oxidation MeFOSA ND 100% MeFOSAA ND 100% EtFOSAA ND 100% 6:2 FTS ND 100% 8:2 FTS ND 100% PFCA Pre Post Total PFBA % PFPeA % PFHxA % PFHpA % PFOA % Total 122 Total 174

32 Replacement Chemicals

33 Legacy Manufacturers Original Chemical PFOA PFOS PFOS Replacement Chemical HFPO-DA GenX ADONA F-53B

34 PFOS-Free Replacements Stockholm Convention Guidance Product Name Fumetrol 21 ANKOR PF1 Netzmittel LF Non Mist-L Ingredient *6:2 FTS based *6:2 FTS based Chemical structure unknown Chemical structure unknown ORGANIC FLUOROSULFONATE *does not contain perfluorinated compounds

35 Thank you for attending Taryn McKnight