3M is still on track to stop making PFAS by the end of the year.

But it's probably going to take longer to stop using or selling the toxic "forever chemicals" completely.

The Maplewood-based manufacturer disclosed last week a number of key inputs from outside suppliers — including batteries, circuit boards and gaskets — might still contain PFAS next year.

Some of those PFAS uses are "required by regulatory or industry standards," 3M wrote in a Securities and Exchange Commission filing, while in other cases, there simply aren't PFAS-free alternatives.

"The company continues to evaluate the availability and feasibility of third-party products that do not contain PFAS," the filing said.

But 3M is bracing for a reality in which "the use of PFAS-containing products manufactured by third parties ... may or are expected to, depending on applications, continue beyond 2025."

3M pioneered many uses of PFAS and has paid billions to settle lawsuits about their legacy of environmental contamination. In December 2022, 3M announced it would phase out the manufacture and use of per- and polyfluoroalkyl substances (PFAS) through three years.

Not all manufacturers have been so willing to walk away from the chemicals, embedded as they are in manufacturing processes, parts and finished products throughout global supply chains. More than 80% of manufacturers supply chain company Assent surveyed have reported at least one use of PFAS in their parts.

So it's no surprise 3M might be running behind its self-imposed deadline, said PFAS legal expert Allison Lange Garrison, a product liability attorney with Nilan Johnson Lewis in Minneapolis.

"You usually can't just hot-swap compounds in a product without affecting product safety and efficacy that are hugely important to consumer safety and satisfaction," she said. "If a PFAS-free alternative results in a leaky seal or gasket, that's a problem."

3M originally hedged that while it would "exit" PFAS manufacturing, it would "work to discontinue use of PFAS across our product portfolio by the end of 2025."

"The company intends to continue to evaluate beyond the end of 2025 the adoption of third-party products that do not contain PFAS to the extent such products are available and such adoption is feasible," 3M's filing said.

PFAS are so widespread because they are so useful at making things waterproof, grease-proof and heat resistant.

The strong chemical bonds that endow these properties also make PFAS build up in the environment and human bodies because they do not readily break down, hence the moniker "forever chemicals." Some PFAS have been linked to cancer and other health problems.

Yet even Minnesota's nation-leading ban on PFAS in consumer products that went into effect this year recognizes there are "unavoidable uses" for PFAS in medical devices and other areas.

"Regulators pushed hard to reduce PFAS use, hoping industry would quickly find safe and effective substitutes — but that's much easier said than done," said Lange Garrison. "No one wants industry to hastily introduce 'regrettable substitutions' to PFAS that may pose similar or greater risks to consumers or the environment."

3M has slowly wound down the manufacturing of more than 22,000 products containing PFAS by reformulating or discontinuing them. 3M sold $345 million of PFAS-containing products during the first three months of 2023, according to financial reports.

During the first quarter of this year, PFAS sales had dropped to $174 million.

"The company remains focused on completing the exit in a timely and orderly fashion," the SEC filing said.

3M declined to further comment on its phase-out.