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Per - and Polyfluoroalkyl Substances (PFAS)

Per- and Polyfluoroalkyl Substances (PFAS)


Per- and polyfluoroalkyl substances (PFAS) are a group of thousands of different chemicals that have been manufactured and used in a variety of commercial products since the 1940s – from everyday household items to food packaging – due to their heat, moisture, stain resistance, and non-stick qualities.  PFOS and PFOA have been the most extensively produced and studied of these chemicals, followed by PFHxS and PFNA.  These chemicals do not break down in the environment or human body and can accumulate over time.  There is evidence that exposure to certain PFAS can lead to adverse human health effects.  For more information, see the OHA Environmental Public Health PFAS webpage.

PFAS Drinking Water Health Advisory Levels
OHA has established drinking water health advisory levels (HALs) for four PFAS compounds most commonly found in humans.  These health advisory levels for PFOS, PFOA, PFNA, and PFHxS are based on adverse liver, developmental, immune, and thyroid effects and are set at levels meant to protect all persons, including sensitive populations, from both short and long-term exposures in drinking water.

PFAS
Compound
Oregon Drinking Water Health Advisory Levels (HALs)*
parts per trillion (ppt) or nanograms per liter (ng/L)
PFOS
30 ppt
PFOA
30 ppt
PFNA
30 ppt
PFHxS
30 ppt


*Because these chemicals may have cumulative health effects, OHA will also calculate the sum of detections of the four PFAS chemicals with HALs in the table above. The HAL is exceeded when any of these four PFAS chemicals with results showing detections exceeds 30 ppt, or when the sum of these four PFAS chemicals with results showing detections exceeds 30 ppt. PFAS chemicals with a HAL that are not detected and other PFAS chemicals that do not have a HAL would not be included in the calculation.

Oregon’s drinking water PFAS HALs are non-regulatory and do not mandate a required action; rather they provide information on health risks of certain PFAS compounds so that drinking water system operators and health officials can take the appropriate steps to protect drinking water consumers.  OHA's expectation is that public water systems will notify their customers if a health advisory level is exceeded.

PFAS Monitoring by Public Water Systems in Oregon
Six PFAS compounds (PFOS, PFOA, PFNA, PFHxS, PFHpA, and PFBS ) were among the list of contaminants that public water systems were required to monitor for under the third Unregulated Contaminant Monitoring Rule (UCMR3).  All public water systems nationwide serving more than 10,000 people and 800 representative systems serving 10,000 or fewer people monitored for these and other unregulated contaminants during a 12-month period from January 2013 through December 2015.  In Oregon, 65 public water systems monitored for these PFAS contaminants and there were no detections reported.


OHA is conducting a PFAS drinking water monitoring project in 2021 at public water systems in Oregon identified as at risk due to their proximity to a known or suspected PFAS use or contamination site.  The purpose of this sampling project is to make sure customers are not being exposed to potentially harmful PFAS chemicals in their drinking water.  The analysis is being paid for through an EPA grant and will be done at no cost to the water system.  The Oregon Department of Environmental Quality lab will be analyzing drinking water samples from select public water systems for 25 PFAS compounds using EPA method 533. A list of the 25 PFAS compounds can be found here under the “Method 533” column.   


For more information:

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