US conglomerate 3M (St. Paul, Minnesota; www.3m.com) reached an agreement to pay up to USD 12.5 bn (EUR 11.5 bn) in settlement to a class action lawsuit over contaminated water supplies. The settlement notice was issued by the United States District Court for the District of South Carolina Charleston division.

The suit claims that firefighting foam made with poly- and per-fluorinated alkyl substances (PFAS) – also known as “forever chemicals” – polluted drinking water in hundreds of municipalities, posing severe health risks.

3M manufactured perfluoro octane sulfonic acid (PFOS) since the 1940s, and the chemicals were used in firefighting foam for decades starting in the 1960s.

Related: EPA proposes limits to PFAS in drinking water

The chemical group has agreed to a payment of no less than USD 10.5 bn and no more than USD 12.5 bn, payable over 13 years, as remediation to public water suppliers to install PFAS water treatment technologies. The settlement amount also provides funding for eligible public water suppliers that may detect PFAS in the future.

The agreement is subject to approval by the plaintiffs and the presiding judge.

3M CEO and chairman Mike Roman said the settlement is not an admission of liability, but is instead “an important step forward for 3M, which builds on our actions that include our announced exit of PFOA (perfluorooctanoic acid) and PFOS manufacturing more than twenty years ago”.

While the company maintains that PFAS can be safely made and used and is critical in the manufacture of many products, including medical technologies, semiconductors, and airplanes, it said it plans to cease all PFAS manufacturing by the end of 2025. 3M expects to record a pre-tax charge of approximately USD 10.5 bn in the second quarter of 2023.

In February, Plasteurope.com reported that in Europe, the US group had to shell out EUR 571 mn to fund remediation efforts mandated by Belgium’s Flemish regional government for discharges from its plant at Zwijndrecht in the Netherlands.

Related: What the PFAS ban proposed by the ECHA means for the plastics industry

PFAS are slow-to-degrade chemicals used to make coatings that repel water, grease, and oil.

The firefighting foam, known as Aqueous Film-Forming Foam or AFFF, is said to have been widely used by the military and fire departments since the 1960s, where the chemicals resist heat and effectively smother liquid-fuel fires. The lawsuits allege that the AFFF seeped into public water systems, according to a report by the Wall Street Journal.

3M is still subject to lawsuits relating to PFAS contamination in cases unrelated to AFFF firefighting foam.

Earlier in June 2023, three US-based chemical companies, DuPont, Chemours, and Corteva, reached an agreement in principle to pay nearly USD 1.2 bn to settle claims of US public water system contamination with PFAS.

Chemours is set to contribute 50% of the settlement, with USD 400 mn coming from DuPont and Corteva paying the remaining USD 193 mn.

The definitive agreement is expected by the end of June, subject to approval by the United States District Court for the District of South Carolina Charleston division.