WASHINGTON – A panel of scientists has recommended that all forms of per- and polyfluoroalkyl substances (PFAS) used in waterproofing, nonstick cookware, firefighting foams and other heat- and stain-resistant uses be classified collectively as problematic and restricted in uses.

PFAS — made by many companies including DuPont and Maplewood-based 3M — have been linked to environmental issues and also potential health problems. Known as "forever chemicals," they have become a source of multiple pollution lawsuits and injury claims because they build up in humans and take years to clear from the body.

Thousands of PFAS exist and hundreds are used commercially. In an article in the latest issue of the journal Environmental Science & Technology Letters, a broad range of scientists, including university researchers and a former high-ranking government official, called for government regulators and businesses to consider all PFAS as potentially toxic and curb their use accordingly.

Currently, only a few specific PFAS have been banned or limited in use.

The journal article "Scientific Basis for Managing PFAS as a Chemical Class" argues that the piecemeal approach has not worked to protect public health and that all PFAS should be placed in a class of problem compounds.

The potential human health issues associated with PFAS justify a new approach, the scientists said in the article.

The journal article stresses "the importance of eliminating nonessential uses of PFAS, and further developing safer alternatives and methods to remove existing PFAS from the environment."

Industries that use PFAS have taken the position that each individual type should be tested for adverse effects before being regulated or removed from the market.

Contamination by two specific kinds of PFAS — or PFOA and PFOS — are the source of water and soil pollution litigation by states and localities across the country.

3M settled a pollution claim with the state of Minnesota for $850 million in 2018. Thousands of personal injury claims against a DuPont Teflon plant in West Virginia settled for $671 million in 2017. The movie "Dark Waters" was based on those cases.

Attempts to describe PFAS as a class of hazardous substances broke down in Congress, with many Republicans saying the classification was too broad. Most Democrats and some Republicans whose districts suffered from PFAS pollution favored the designation.

The journal article laid out the scientists' concerns for a piecemeal approach: "Limiting the entire class of PFAS, including fluorinated polymers, to essential uses is critical, given that currently, remediating PFAS, once released to the environment, is at best extremely costly and, in some cases, impossible."