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Persistent Pollutants

US EPA orders first tests of a PFAS chemical

Chemours and DuPont named to conduct safety studies on firefighting foam ingredient

by Cheryl Hogue
June 7, 2022

Chemical structure of 6:2 Fluorotelomer sulfonamide betaine.

Four companies must conduct inhalation toxicity tests on the firefighting foam ingredient 6:2 fluorotelomer sulfonamide betaine (6:2 FTAB), under a June 6 order from the US Environmental Protection Agency (EPA).

Part of the family of per- and polyfluoroalkyl substances (PFAS), 6:2 FTAB may present an unreasonable risk of injury to human health or the environment, the EPA says. Because the chemical is an insoluble solid, the manufacture, processing, or use of 6:2 FTAB may lead to the formation of particles that workers could inhale, the agency says.

This marks the first time the agency has used its authority under the Toxic Substances Control Act (TSCA) to order testing of any PFAS. The synthetic chemicals are resist to breakdown in the environment. Some PFAS are toxic, some are considered inert, and the majority, consisting of thousands of compounds, have never been tested for health effects. Currently, about 600 are made or used commercially.

The EPA order on 6:2 FTAB affects two chemical manufacturers, Chemours and DuPont, as well as two makers of firefighting foams, Johnson Controls and National Foam.

DuPont no longer makes 6:2 FTAB because it spun off its fluorochemical business into Chemours in 2015. But TSCA authorizes the EPA to include any company that made a chemical within the past 10 years in a testing order. In a statement emailed to C&EN, DuPont says it will review the applicability of EPA’s order to the corporation.

A Chemours spokesperson had no comment.

The American Chemistry Council, the largest US association of chemical manufacturers, says in an email it believes much of the information the EPA seeks on 6:2 FTAB already exists. The agency allows companies named in a testing order to form a consortium to share the costs of toxicity studies. This would allow any business that has existing data on 6:2 FTAB to get reimbursement for its testing costs from the other companies before providing the information to the EPA.

More than 11,340 kg of 6:2 FTAB are manufactured in or imported to the US each year and at least 500 workers could be exposed to the chemical annually, according to data that companies reported to the EPA. The substance is used as a surfactant, mainly in firefighting foams that quench blazes involving liquid fuels. It is also used in some floor finishes, according to the agency. There are currently no TSCA restrictions on use of 6:2 FTAB, the order says.

The order is the first of a series the EPA plans as part of implementing its 2021 strategy for identifying toxicity data gaps about PFAS and filling them through testing, the agency says in a statement. The EPA says it will use the data provided from the 6:2 FTAB tests to boost understanding of 503 other PFAS that have similar structures to the chemical.



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