The settlement involving DuPont, the Chemours Co. and Corteva Inc. resolves Ohio’s claims relating to releases of manmade, fluorinated compounds known as PFAS. It also resolves claims relating to the manufacture and sale of PFAS-containing products and claims related to firefighting foam containing PFAS.

The compounds, which are associated with an increased risk of certain cancers and other health problems, are often referred to as “forever chemicals” because of their longevity in the environment. They have been used in the production of nonstick coatings such as Teflon, firefighting foam, water- and stain-resistant textiles, food packaging and many other household and personal items.

According to the companies, Ohio will allocate 80% of the settlement to the restoration of natural resources related to the operation of the Washington Works facility near Parkersburg, West Virginia, on the eastern shore of the Ohio River. The other 20% will be used to address PFAS claims statewide, including the use of firefighting foam. The settlement is subject to court approval.

Under a 2021 agreement with the state of Delaware, the Ohio settlement means the companies also are obligated to pay $25 million to Delaware for environmental initiatives. As part of the 2021 settlement, the companies agreed to pay $50 million to Delaware and to fund up to an additional $25 million if they settled similar claims with other states for more than $50 million.

Ohio began litigation against DuPont and Chemours in February 2018 regarding historical emissions of perfluorooctanoic acid, known as PFOA, from the Washington Works site. PFOA was once widely used in a variety of products, including nonstick cookware. Ohio alleged damage to natural resources from the use of the compound, and impropriety in the 2015 spinoff by DuPont that created Chemours.

DuPont will contribute about $39 million to the settlement. Chemours, the former performance chemicals unit of DuPont, will pay about $55 million, with the rest owed by Corteva. Chemours was spun off as a stand-alone company in 2015. Corteva, the former agriculture division of DowDuPont, became a separate company in 2019.

Under a 2021 cost-sharing arrangement that resolved legal disputes over PFAS liabilities arising out of pre-2015 conduct, DuPont and Corteva, on one hand, and Chemours, on the other, agreed to a 50-50 split of certain expenses incurred over a term of up to 20 years, or an aggregate $4 billion.

DuPont began using PFOA in products at the Washington Works facility in the 1950s. Chemical releases from the site have been blamed for a variety of health problems among local residents and have resulted in multiple lawsuits.

In April, the U.S. Environmental Protection Agency ordered Chemours to address PFAS pollution in stormwater and effluent from the Washington Works facility. The EPA said it was the first Clean Water Act enforcement action to hold polluters accountable for discharging PFAS into the environment.

According to the EPA, PFAS levels in the discharges from Washington Works have exceeded levels set in the facility’s Clean Water Act permit.