What is PFAS?

PFAS is the abbreviation for per- and polyfluoroalkyl substances, which is a collective term for synthetic chemicals containing fluorine. Read more about the properties and consequences of PFAS in this article.

What defines PFAS and what types exist?

PFAS is the abbreviation for per- and polyfluoroalkyl substances (per- and poly•fluoro•alkyl substances), which is a collective term for synthetic chemicals containing fluorine with strong carbon bonds. PFAS are harmful to the environment and health in higher concentrations for humans, animals, and nature.

PFAS are also called forever chemicals because they are difficult to break down organically. They make everything from rainwear to pizza boxes more durable and resistant, as PFAS-treated surfaces make products resistant to, for example, water, grease, oil, and other liquids that would otherwise degrade materials over time through repeated exposure.

Under the PFAS designation, there are many other related abbreviations of chemicals that are fluorine-containing, such as:

• PFOS (perfluorooctane sulfonic acid)
• PFOA (perfluorooctanoic acid)
• PFNA (perfluorononanoic acid)
• PFHxS (perfluorohexane sulfonic acid)
• PAPS (polyfluoroalkyl phosphate esters)

What is the difference between perfluoroalkyl substances and polyfluoroalkyl substances?

The chemical composition of PFAS is primarily fluorine-containing. The difference between perfluoroalkyl substances and polyfluoroalkyl substances depends on how many hydrogen atoms in the carbon chain are replaced with fluorine.

In perfluoroalkyl substances, all hydrogen atoms are thus replaced with fluorine, while polyfluoroalkyl substances are characterized by still having hydrogen atoms left in the carbon chain.

Where does PFAS come from?

PFAS are man-made chemicals containing fluorine, which have been used in industry since the 1950s to create more durable products. With a strong chemical bond to carbon, fluorine-containing substances are difficult to break down.

PFAS are also called forever chemicals, which due to their properties are suitable for solving difficult tasks and extending the durability of products for many applications. This is because PFAS are liquid-, oil-, and grease-resistant and can withstand very high temperatures, making products more durable.

PFAS are found in many consumer goods and materials such as:

• Food packaging made of plastic and paper
• Adhesives
• Paint, varnish, and impregnation
• Cleaning agents
• Cosmetics
• Kitchen utensils with Teflon coating (polytetrafluoroethylene) such as pots, pans, baking molds, and baking paper

Why is PFAS harmful to health?

PFAS are harmful to health in higher concentrations for humans, animals, and nature. Exactly how great a health risk PFAS poses is still difficult to conclude unequivocally. However, research points to potential human risks, where exposure to PFAS has a potential effect on the immune system and people’s general health.

This includes elevated cholesterol, slight harmful effects on the liver, and reduced birth weight, while PFAS is still suspected of a slightly increased risk of certain types of cancer when exposed to higher concentrations of PFAS. High exposure to PFAS can, for example, be due to the intake of heavily contaminated drinking water and food or through handling and production of PFAS-containing chemicals.

How is PFAS combated?

In water treatment plants and wastewater treatment plants, PFAS can, for example, be removed using carbon filters. The strong carbon bond that PFAS has due to fluorine adheres to the carbon. The carbon with PFAS is then filtered out in the water treatment process. Hans Buch’s customer Split Water Nordic has found a more effective purification of PFAS and pesticides using a special filter with activated carbon.

Hans Buch has contributed to Split Water Nordic’s unique and scalable application with technical sparring and delivery of components. Here we have, among other things, delivered pumps and stainless steel valves, as well as instrumentation in the form of flow and level meters, transmitters and switches, as well as meters for pressure, pH, temperature, and turbidity.

Read the entire Hans Buch customer case: “Effective water purification with Hans Buch’s wide quality selection“

What does the legislation say about limit values for PFAS?

The limit values are continuously adjusted for how high a concentration of PFAS may occur in a given environment or element. In Denmark, the limit values are set in, for example, the Drinking Water Directive and the Environmental Protection Act § 14.

The limit values constitute the quality criteria for human health to protect against pollution from the chemicals we are exposed to in everyday life via air, soil, sludge, and groundwater, drinking water, and bathing water. In addition, there are quality criteria for the aquatic environment, which with its limit values are set according to the PFAS effect on animals and plants in and around lakes, streams, and the sea.

The limit values are defined based on “4 PFAS”, which covers a total limit value of the occurrence of PFOA, PFOS, PFNA, and PFHxS. “22 PFAS” describes the total allowed value from a larger palette of identified fluorine-containing substances under the PFAS designation.

Examples of limit values for PFAS

• Soil – milligrams per kilogram dry matter (mg/kg DM) – last updated in 2019:
  Total sum of “4 PFAS” occurrence at a maximum of 0.01 mg
  Total sum of “22 PFAS” occurrence at a maximum of 0.4 mg
• Groundwater and sludge – micrograms per liter (µg/L) – last updated in 2021:
  Total sum of “4 PFAS” occurrence at a maximum of 0.002 µg/L
  Total sum of “22 PFAS” occurrence at a maximum of 0.1 µg/L

Sources

• Safe Chemistry, Quality Criteria and Limit Values, Environmental Protection Agency:
  https://mst.dk/erhverv/sikker-kemi/kemikalier/graensevaerdier-og-kvalitetskriterier
• Thomas Hebsgaard, Zetland, February 2023; “There is PFAS everywhere. How dangerous is it really?”:
  https://www.zetland.dk/historie/serDX7a7-ae6XddK5-e078c
• “Reduction of PFAS”, Split Water Nordic:
  https://splitwaternordic.dk/pfas
• “Facts about PFAS (fluorine substances)”, Danish Veterinary and Food Administration:
  https://foedevarestyrelsen.dk/kost-og-foedevarer/foedevaresikkerhed/kemiske-stoffer-og-toksiner/miljoeforureninger-i-foedevarer/pfas
• “Information about PFAS and health”, Danish Health Authority (2023):
  https://sst.dk/-/media/Udgivelser/2023/PFAS/Information-om-PFAS-og-Sundhed.ashx