Per- and Polyfluoroalkyl Substances (PFAS)

firefighting foam (AFFF)

What are PFAS chemicals?

Per- and polyfluoroalkyl substances are a large group of synthetic chemicals not found naturally in the environment.  More than 3,000 fluorinated organic chemcials have been manufactred.  Two common PFAS chemicals are perfluorooctanoic acid, called PFOA, and perfluorooctane sulfonic acid, called PFOS.

What products had or may have PFAS in them?

PFAS are human-made chemicals used since  the 1950s for industrial and consumer uses.  The use of these chemicals is decreasing.  PFAS have been used in stain-resistent carpets and fabrics, water-repellent clothing, non-stick cookware, food packaging, special firefighting foams and other products designed to resist grease, water and oil.

Where can PFAS be found in the environment?

PFAS can be found in air, soil or water.  These chemicals were all manufactured so it is possible to find them near manufacturing sites.  It is also possible to find PFAS where products were used, such as where fires were extinguished with firefigthing foam.  PFAS breakdown down very slowly.  Therefore, PFAS can remain in the environment for a long time.  PFAS can move through soil, seep through groundwater, or be blown and deposited by the wind.

How might I be exposed to PFAS?

PFAS can be in air, soil or water.  You or your family could be exposed to PFAS in air, indoor dust, food, water or by using some products.  The main source of exposure to PFAS would in food or water containing these chemicals.

What are possible health effects of PFAS?

There is a lot of ongoing research into the toxicology of per- and polyfluoroalkyl substances.  Science does not yet know exactly how PFAS affect health.  According to the federal Agengy for Toxic Substances and Disease Registry, research suggests that certain PFAS may:

  • increase cholesterol levels;
  • decrease how well the body responds to vaccines;
  • increase the risk of thyroid disease;
  • decrease fertility in women;
  • increase the risk of serious conditions like high blood pressure or pre-eclampsia in pregnant women;
  • lower infant birth weights; however, the decrease in birth weight is small and may not affect the infant’s health.

ATSDR studied lab animals and learned perfluorooctanoic acid and perfluorooctane sulfonic acid can cause damage to the liver and immune system.  PFOA and PFOS also have caused birth defects, delayed development, and newborn deaths in lab animals.  Humans may react differently than lab animals.  More testing and study is underway to better understand these chemicals.

ATSDR reviewed studies about PFAS and cancer.  These studies do not clearly show whether PFAS cause cancer in people.  People exposed to high levels of PFAS may have increased risk of kidney cancer or testicular cancer.  Animals studies have shown cancer in the liver, testes, pancreas and thyroid.  The International Agency for Research on Cancer has classified PFOA as possibly carcinogenic to humans.

Can a medical test show if I have been exposed to PFAS?

Yes.  A blood test can measure PFAS in your blood.  However, this is not a routine test done in a doctor's office.  While a blood test can show if you've been exposed to PFAS, it cannot determine when or if you will become ill.

What recommendations have been made to protect health?

The U.S. Environmental Protection Agency set a drinking water level for perfluorooctanoic acid and perfluorooctane sulfonic acid of 70 parts per trillion.  You can read more about EPA's Health Advisory on their webpage.  This means municipal, publically-supplied drinking water should meet these criteria.  In Tennessee, people drinking from their own private water wells are responsible for their own water quality and testing.

The Agency for Toxic Substances and Disease Registry has proposed Minimum Risk Levels for the ingestion of perfluorooctanoic acid and perfluorooctane sulfonic acid.  An MRL is an estimate of the amount of a chemical a person can eat, drink, or breathe each day without a detectable risk to health.  These guidance values were calculated for non-cancer medical problems after 15 to 364 days of eating and drinking.   ATSDR's PFAS and Your Health webpage lists the MRL dose at 0.000003 milligrams of PFOA per kilogram per body weight per day.   ATSDR lists a dose of 0.000002 milligrams of PFOS per kilogram body weight per day.  These values suggest it takes only a tiny amount of PFOA or PFOS in food or water on a daily basis to be potential health hazard.

What are good sources for more information?

The State of Tennessee does not independently evaluate the toxicity of chemicals.  The federal government has been working to understand the toxicology of per- and polyfluoroalkyl substances.  Both the ATSDR and the EPA are good sources of information on PFAS and similar chemicals.  There are links to their information below.

Government partners

Agency for Toxic Substances and Disease Registry (ATSDR)
Per- and Polyfluoroalkyl Substances (PFAS) and Your Health

PFAS Continuing Education for Clinicians

Environmental Protection Agency (EPA)
Per- and Polyfluoroalkyl Substances (PFAS)

Food and Drug Administration (FDA)
Packaging & Food Contact Substances

Tennessee Department of Environment and Conservation (TDEC)
Policy - PFAS


Additional resources

American Public Health Association (APHA)
Reducing Human Exposure to Highly Fluorinated Chemicals to Protect Public Health

Interstate Technology Regulatory Council (ITRC)
PFAS -- Per- and Polyfluoroalkyl Substances


Helpful documents

Agency for Toxic Substances and Disease Registry (ATSDR)
ToxFAQs for Perfluoroalkyls
Toxicological Profile for Perfluoroalkyls