Read the full article by Cheryl Hogue and Craig Bettenhausen (C&EN)

“Analytical reference standards are not known for attracting intrigue and drama. Standards—compounds of known purity and concentration—are pivotal to investigating pollution because they allow researchers to determine the levels of contaminants in water, soil, or tissue samples. Recently, though, the specter of patent infringement lawsuits has prevented researchers from quantifying environmental contamination by a perfluorinated ‘forever chemical.’

This complicated situation involves the Brussels-based chemical maker Solvay, a Canadian analytical standards company, pollution by per- and polyfluoroalkyl substances (PFAS) in Italy, and the complexities of patent law.

Earlier this year, Solvay told the analytical standards firm Wellington Laboratories to cease making and selling a standard for C6O4, a chemical used as a processing aid for making commercial PFAS compounds. Solvay, which makes and uses C6O4 in Italy but does not sell it, holds patents on the compound and its synthesis in several countries.

The use of patent infringement claims to take an analytical reference standard off the market is a new idea to the experts on patent law and reference standards consulted by C&EN. Analytical chemists are concerned that the maneuver could have a chilling effect on efforts to trace the sources of pollution.

The Background of C604

C6O4 is the nickname for a monocyclic perfluorinated ether. It is a substitute for an older chemical in the PFAS group that was used for decades: the toxic and environmentally persistent perfluoro­octanoic acid (PFOA).

Solvay registered C6O4 in 2011 under the European Union’s Registration, Evaluation, Authorisation, and Restriction of Chemicals (REACH) law. In the registration documents, Solvay identifies the chemical as a production intermediate that isn’t intended for environmental release.

The company employs the ammonium salt of C6O4 to manufacture fluoropolymers such as polytetrafluoroethylene, which are used as nonstick coatings on cooking utensils and other food-contact articles, according to a 2014 scientific opinion from the European Food Safety Authority. The opinion concludes ‘There is no safety concern for the consumer if the substance is only to be used as a polymer production aid during the manufacture of fluoropolymers which are produced under high temperature conditions of at least 370 °C’ (EFSA J. 2014, DOI: 10.2903/j.efsa.2014.3718).

But even though C6O4 was supposed to remain within industrial processing equipment, officials from Italy’s Veneto region in 2019 found the compound in the Pothe country’s longest river. Upstream of Veneto, the area that drains into the river includes part of Italy’s Piedmont region where a Solvay fluoropolymer plant operates in the town of Spinetta Marengo, near Alessandria. The river empties into the Adriatic Sea in Italy’s northeast.

In addition to the Solvay plant, landfills in the Piedmont region that accepted industrial waste are also contributing C6O4 to the Po River, says Sara Valsecchi, a researcher at the Italian National Research Council. ‘We found significant concentrations of this compound in landfill leachates,’ she says.

Solvay wasn’t the only company that registered C6O4 in the EU. Another business in Italy did too.

That was Miteni, whose facility in Trissino, Italy, reclaimed fluoroethers from industrial waste. For years, the plant processed materials from the Chemours plant in Dordrecht, the Netherlands. In 2017, officials in the Veneto region announced they’d found hexafluoropropylene oxide dimer acid (HFPO-DA), a perfluorinated compound, in wells near the Miteni facility. That chemical is the product of hydrolysis of Chemours’s substitute for PFOA, a fluoroether called GenX...”