In April 2024, the US Environmental Protection Agency finalised the first ever enforceable limits on PFAS in drinking water. Maximum contaminant levels were set at 4 parts per trillion for PFOA and PFOS, and 10 parts per trillion for PFNA, PFHxS and HFPO-DA (GenX). For context, a part per trillion is equivalent to one drop of water in 20 Olympic swimming pools. The ruling affects around 100 million Americans. It is also, in a very practical sense, relevant to anyone thinking about the PFAS exposure that comes from their kitchen rather than their tap.
What PFAS actually are
PFAS stands for per- and polyfluoroalkyl substances. There are over 12,000 of them. What they share is a carbon-fluorine bond that is among the strongest in organic chemistry. This bond does not break down in the environment, in water treatment plants, or in the human body. The term "forever chemicals" is used because once PFAS accumulate in body tissue, they remain there for years. PFOA, for example, has a half-life in the human body of approximately 3.8 years. That means if you stopped all PFAS exposure today, it would take nearly four years just to halve the amount in your bloodstream.
Health effects linked to PFAS exposure include thyroid disruption, immune suppression, elevated cholesterol, kidney and testicular cancer, reduced fertility, and altered fetal development. The evidence base is extensive: the National Academy of Sciences published a 400-page review in 2022 documenting sufficient evidence for several of these associations at population level.
The cookware problem specifically
Non-stick cookware uses PTFE (polytetrafluoroethylene), marketed under the brand name Teflon. PTFE is technically a PFAS compound. At temperatures above approximately 260 degrees Celsius, the coating begins to degrade and release PFAS gases and particles. A pan left on high heat reaches this temperature within minutes. The fumes produced are lethal to birds at concentrations that are merely toxic to humans.
Beyond overheating, any scratched or worn non-stick coating sheds PTFE particles directly into food. A 2023 study found that a damaged non-stick pan can release over 9,000 plastic particles per use. These particles are ingested. The long-term consequences of ingesting PTFE particles are not fully characterised, which itself represents a meaningful risk given the compound's chemical stability and the demonstrated harms of related PFAS compounds.
“A pan left on high heat reaches 260 degrees Celsius within minutes. The fumes produced are lethal to birds at concentrations that are merely toxic to humans.”
What the EPA ruling changes
The EPA ruling does three things. First, it sets legal maximum contaminant levels that water utilities must comply with by 2029. Second, it requires public water systems to test for these compounds and report results. Third, it creates a legal framework for remediation: utilities that exceed limits must take action to reduce contamination.
What it does not do: it does not address PFAS in food, cookware, packaging, clothing, or any non-drinking-water source. Drinking water is estimated to account for roughly 20-40% of human PFAS exposure in areas with contaminated water supplies. The majority of exposure comes from food, food packaging and consumer products. The ruling is meaningful but partial.
What to do this week
Replace non-stick cookware
Cast iron, carbon steel and stainless steel are the alternatives. Cast iron is the most affordable and available at every price point. Season it with a thin layer of oil and it becomes naturally non-stick over time.
Test or filter your drinking water
If you are on a municipal water supply, your utility is now required to test for the six PFAS compounds covered by the ruling. Check the annual water quality report. If you are on private well water, commission a test. A reverse osmosis filter removes PFAS from drinking water effectively.
Switch from microwave popcorn
Microwave popcorn bags are coated with PFAS on the interior surface. Heating vaporises these compounds into the food. Popcorn made in a stainless steel pot takes two minutes and contains no PFAS.
Check stain-resistant treatments
Furniture, carpet and clothing treated for stain resistance often use PFAS coatings. When purchasing, look for products explicitly labelled PFAS-free. Avoid applying any spray-on water or stain repellent treatments.