Reducing PFAS in the Metal-Finishing Industry

What Are PFAS?

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a class of manufactured chemicals invented in the 1930s. One of the first known examples was the invention of non-stick cookware by DuPont in 1946 which features a chemical coating with the brand name of Teflon. Teflon is classified as a PFAS.

Today, PFAS is used in a variety of industries, including firefighting foam, aerospace technologies, consumer products, and electroplating. Electroplating is an industrial process used to apply an anticorrosive “chrome” metal finish.

PFAS are sometimes referred to as “forever chemicals” because they do not dissipate in the environment. PFAS contain very strong carbon-fluorine bonds. These bonds allow these chemicals to last a long period of time within harsh conditions.

The New York State Department of Environmental Conservation (NYSDEC) and United States Environmental Protection Agency (USEPA) have classified PFAS as hazardous substances. Since these substances do not break down in the environment, they are harmful to human beings and wildlife for many years, despite the usefulness of the material in manufacturing and other applications.

Why Reduce PFAS?

Because of their widespread use and persistence in the environment, many PFAS are found in the blood of people all over the world. Consumption of fish and other aquatic animals that were raised in contaminated water is a common way for humans to be exposed to such hazards. Other ways in which humans consume PFAS are through contaminated potable water and food sources that were packaged in PFAS-containing material.

Scientific studies have shown that exposure to some PFAS in the environment may be linked to harmful health effects in humans, including reduced kidney function, thyroid diseases, cancer risk, and high cholesterol.

Use of PFAS in the Metal-Finishing Industry

PFAS are often used in the metal-finishing industry as a fume suppressant during hexavalent chrome-plating, an electroplating process. Hexavalent chrome-plating uses chromium trioxide (CrO₃). During this process, liquid chromium acid becomes airborne in the form of a mist. This mist can be harmful to workers if inhaled, causing irritation to the nose, throat, and lungs.

PFAS-containing fume suppressants are utilized to reduce worker exposure to chromium acid mist. The suppressants work by reducing the surface tension of the chromium acid mist and forming a layer around it.

Ways to Limit the Use of PFAS-Containing Fume Suppressants

Below are 3 ways to reduce the use of suppressants containing PFAS:

• Use an alternative process: Hexavalent chrome-plating can be substituted with processes that do not release a chromium acid mist. A common replacement is called trivalent chrome-plating, which uses chromium chloride (CrCl₃) or chromium sulfate [Cr₂(SO₄)₃] rather than chromium trioxide (CrO₃). The chemicals used in the trivalent chrome-plating process are less toxic to workers than chromium trioxide (CrO₃). One negative to trivalent chrome-plating is the higher cost compared to hexavalent chrome-plating.
• “PFAS-free” fume suppressants: PFAS-based fume suppressants can be substituted with “PFAS-free” fume suppressants. Federal regulations define “PFAS-free” fume suppressants as containing less than one percent PFAS by weight. Using these “PFAS-free” fume suppressants removes PFAS from the electroplating process.
• Air control technologies: Common air control technologies to reduce exposure to PFAS include composite mesh pads (CMPs), packed-bed (or packed-tower) scrubbers, blade mist eliminators, and emission-elimination devices (EEDs).

How Walden Can Help

To learn more about PFAS, visit Walden’s blogs discussing these chemicals here. If you would like more information about how to reduce PFAS in your facility, reach out to our team of experts. Contact us at 516-789-2972.