Perfluoroalkyls - ToxFAQs™

What are perfluoroalkyls (PFAs)?

Perfluoroalkyls (PFAs) are a group of man-made chemicals that are not found naturally in the environment. Some chemicals that are in this group PFAs include:

perfluorooctanoic acid (PFOA)
perfluorooctane sulfonic acid (PFOS)
perfluorononanoic acid (PFNA)
perfluorohexane sulfonic acid (PFHxS)
perfluordecanoic acid (PFDeA)

These PFAs were used to protect products like carpet and fabric, and as a coating for paper and cardboard packaging. They can also be found in some fire-fighting foams.

The two PFAs made in the largest amounts in the United States were PFOA and PFOS. However, most companies have stopped making these two chemicals.

Where are PFAs found in the environment?

PFAs can be found in air, soil, and water.
They break down very slowly in air within days or weeks, but then fall to the ground where they can enter water or soil.
PFAs do not break down in water or soil and may be carried over great distances by wind or rain.

How can I be exposed to PFAs?

You may be exposed to PFAs in the air; in indoor dust, food, and water; and in some home products. However, the main sources of exposure to PFAs, such as PFOA and PFOS, are usually from eating food and drinking water that has these chemicals.
Breast feeding infants may be exposed to PFAs since these chemicals have been found in breast milk. The benefits of breastfeeding are well known and almost always outweigh any potential risk, but you can talk with your doctor about concerns.
Children can be exposed to PFAs in carpet since they are closer to the ground and play on the floor.
Workers in facilities that make or use PFAs can be exposed to higher amounts of these chemicals and have higher levels in their blood.
Some communities near factories that made or used PFOA and PFOS or in areas that used certain types of firefighting foam that spread into the environment may have been exposed to high levels of these substances in their drinking water.

How can PFAs affect my health?

A large number of studies have examined possible relationships between levels of PFAs in blood and harmful health effects in people. However, most of these studies analyzed only a small number of chemicals, and not all PFAs have the same health effects. Research suggests that high levels of 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.

At this time, scientists are still learning about the health effects of exposures to mixtures of PFAs.

One way to learn about whether PFAs will harm people is to conduct studies in lab animals. Most of these studies have tested doses of PFOA and PFOS that are higher than levels found in the environment.

These animal studies have found that PFOA and PFOS can cause damage to the liver and the immune system.
PFOA and PFOS have also caused birth defects, delayed development, and newborn deaths in lab animals.

Humans and animals react differently to PFAs, and not all effects observed in animals may occur in humans.

Scientists have ways to estimate how the exposure and effects in animals compare to what they would be in humans.
What they learn from this process helps them decide how to protect people from harm caused by chemical exposure.