Scientists find a way to say goodbye to PFAS, toxic ‘forever chemicals’ found in non-stick pans, food packaging
- Chemists in the US and China say they have found a breakthrough way to break down these polluting compounds using relatively low temperatures and common reagents
- According to the 2021 report from Hong Kong’s drinking water safety advisory committee, very low concentrations of PFAS have been detected in the city’s water
“Forever chemicals” used in daily items like nonstick pans have long been linked to serious health issues. Photo: AFP“Forever chemicals” are found in daily items such as food packaging, pizza boxes and guitar strings. They have long been linked to serious health issues. This is a result of their toxicity and extreme resistance to being broken down as waste products.
Chemists in the United States and China last month said they had finally found a breakthrough method to break down these polluting compounds, called PFAS, using relatively low temperatures and common reagents.
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Their results were published in the journal Science, and it offers a potential solution to a long-standing source of harm to the environment, livestock and humans.
PFAS, or per- and polyfluoroalkyl substances, were first developed in the 1940s. They are now found in many different products, including non-stick pans, water-resistant textiles and fire suppression foams.
Over time, the pollutants have collected in the environment, entering the air, soil, groundwater and lakes and rivers. This is a result of industrial processes and from leaching through landfills (see graphic).
A study published in August by Stockholm University scientists found rainwater everywhere on the planet is unsafe to drink because of PFAS contamination.
Long-term exposure to even low levels of PFAS has been linked to liver damage, high cholesterol, low birthweight and several kinds of cancer.
Although PFAS chemicals can be filtered out of water, there are not many good solutions for getting rid of them safely once they have been removed. Current methods to destroy PFAS require harsh treatments, such as burning them at extremely high temperatures or irradiating them with ultrasonic waves.
Incineration is not always foolproof. One New York plant was found to still be releasing some of the compounds into the air through smoke.
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PFAS’ indestructibility comes from their carbon-fluoride bonds, one of the strongest types of bonds in organic chemistry. PFAS molecules contain long chains of these bonds, but the research team was able to identify a huge weakness common to a certain type of PFAS.
The solution is a mixture of a soap ingredient and a common solvent. When the solution is boiled, most of the PFAS broke down into harmless by-products in a matter of hours, and the rest broke down within days.
“Once that happens, that provides access to previously unrecognised pathways that cause the entire molecule to fall apart in a cascade of complex reactions,” senior author William Dichtel of Northwestern University told reporters during a news conference.
The current study focused on 10 PFAS chemicals including a major pollutant called GenX, which for example, has contaminated the Cape Fear River in the US state of North Carolina, a water source for 350,000 people.
But it represents just the tip of the iceberg, since the US Environmental Protection Agency has identified more than 12,000 PFAS chemicals.
“There are other classes that do not have the same Achilles’ heel, but each one will have its own weakness,” Dichtel said. “If we can identify it, then we know how to activate it to destroy it.”
Agence France-Presse
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How worried should I be about being exposed to PFAS in Hong Kong?
Drinking water, food, and some consumer products can be contaminated by PFAS. According to the 2021 report from Hong Kong’s drinking water safety advisory committee, very low concentrations of PFAS have been detected in the city’s water.
Also, not all items made with PFAS pose a danger to health. For those approved by the US Food and Drug Administration in the manufacture of non-stick cookware, there is a negligible amount that is capable of migrating to other surfaces.
Still, try minimising contact with these products: takeaway containers, microwave popcorn, waterproof make-up, and household items with PTFE or “perfluor” in the ingredient list.