3M billboard
© Dave Thompson/PADenise Rutherford, senior vice-president of corporate affairs for 3M, argued the chemicals pose no human health threats at current levels and have no victims, conflicting with a large body of research and 3M’s own internal documents.
The 3M Company, the Chemours Company and DuPont appeared before lawmakers over PFAS

Chemical company executives have denied responsibility for a category of toxic fluorinated chemicals that have contaminated water supplies around the US and are now found in the bodies of nearly all Americans.

Three companies - the 3M Company, the Chemours Company and DuPont - appeared before US lawmakers in a Tuesday hearing reminiscent of those with tobacco companies in the 1990s.

Democrat lawmakers on a subcommittee of the House oversight panel questioned who would pay for medical bills and massive clean-up programs, if not the corporations.

The California representative Harley Rouda, who chairs the subcommittee, accused the companies of obscuring and suppressing evidence in what he called a "seismic event" that "shakes the foundation of democratic capitalism" by "violating the trust of the American people".

The class of chemicals, called PFAS, are in non-stick pans, water-resistant clothes, food packaging and firefighting foam. Nicknamed "forever chemicals", they do not break down in the environment and accumulate in the human body. Numerous studies link PFAS exposure with cancer, thyroid problems and developmental issues in children.

The chemicals have been found in high levels in groundwater near industrial facilities and near military installations and airports that have used PFAS-based firefighting foam.

Congress is seeking to address the chemicals as part of negotiations on a 2020 defense bill, and the chemical industry broadly has opposed stringent regulation. Republicans on the subcommittee largely defended the companies.

Denise Rutherford, senior vice-president of corporate affairs for 3M, argued the chemicals pose no human health threats at current levels and have no victims, conflicting with a large body of research and 3M's own internal documents. The company's records - made public in lawsuits in West Virginia and Minnesota - underscore decades-long knowledge of the risk associated with the chemicals and an effort to avoid disclosing those dangers to the public.

DuPont's chief operating and engineering officer, Daryl Roberts, however, said his company endorses regulation of two specific types of the chemicals - PFOA and PFOS. He said the Environmental Protection Agency (EPA) should deem the chemicals hazardous substances and set a drinking water standard for them within two years.

DuPont both used PFOA in its Teflon products and then manufactured the chemical before spinning off that part of the business into a new company, Chemours.

Chemours is now challenging DuPont in court as the company denies liability over the chemicals.

The Michigan representative Dan Kildee called the companies' defenses "ridiculous", and said they have "made millions and billions of dollars by selling these chemicals", but don't want to take responsibility.

Debbie Wasserman Schultz, a representative from Florida, told the companies: "You have sickened our first responders and our members of our military, and I don't know how you sleep at night."

As far back as 1950, a 3M study of mice showed PFAS building up in the animals' blood. In 1961, a DuPont toxicologist warned the chemicals enlarge rat and rabbit livers. In 1963, a 3M technical manual deemed PFAS toxic. The evidence continued to build for years, as outlined by health advocacy organization the Environmental Working Group. At 3M and DuPont, female workers were for a time reassigned from working with the chemicals for fear of the risks to any developing fetus.

Lori Swanson, the former Minnesota attorney general who sued 3M for contamination of her state, said the company "knew about the risks of the chemicals to the drinking water, the environment and human health for decades but concealed its knowledge, subverted the science and kept pushing the chemicals out the door".

The Environmental Working Group has documented PFAS contamination in hundreds of communities. This week the group published data from the Pentagon showing an additional 90 army and national guard installations are contaminated with the chemicals, bringing the total number of military installations with known contamination to 297.

Rob Bilott, a lawyer for people who say they were made sick by PFAS chemicals, said: "The public may only now be realizing the scope of this problem, but the companies that manufactured these chemicals have been aware of the risks for decades and failed to alert the rest of us."