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Chemical Regulation

Olin commits to phasing out asbestos diaphragm cells

Chlor-alkali producer agrees to transition to alternative membranes in 7 years

by Britt E. Erickson
April 6, 2023 | A version of this story appeared in Volume 101, Issue 12


Chrysotile asbestos fibers
Credit: Shutterstock
The chlor-alkali producer Olin has agreed to phase out electrolysis diaphragms that are made from asbestos, shown here.

Olin, the world’s largest chlor-alkali producer, has agreed to immediately stop importing asbestos into the US and to stop installing and replacing asbestos-based diaphragms in 2 years. The firm has also committed to completely phasing out its use of such diaphragms in 7 years.

The firm has yet to officially announce the agreement, but in an April 4 letter to the US Environmental Protection Agency (EPA), Olin CEO Scott Sutton provides details of the plan. The letter was shared by the Asbestos Disease Awareness Organization (ADAO), an advocacy group that is pressuring all chlor-alkali producers to phase out asbestos.

Olin is one of three chlor-alkali producers in the US that still use asbestos diaphragms to separate chlorine from sodium hydroxide in the sodium chloride electrolysis process. The other two producers are OxyChem and Westlake. More than half of the US chlor-alkali industry has transitioned away from asbestos diaphragms to fluoropolymer ion-exchange membranes, according to the EPA.

The American Chemistry Council is not on board with the 7-year timeline advanced by Olin. The industry group’s chlorine panel is calling for a 15-year transition period “to address the time needed for any large capital project, the metal supply disruptions that impact the electrolyzer market and other challenges, including limited contractor resources, supply chain disruptions and regulatory approval cycles.”

In an assessment finalized in December 2020, the EPA identified health risks to chlor-alkali workers from exposure to asbestos fibers. Asbestos causes mesothelioma, a rare cancer of the lining of the lungs and other organs. The EPA proposed to ban US imports of chrysotile asbestos in April 2022. Such imports are used exclusively by the chlor-alkali industry.

The ADAO, which has been pushing Congress and the EPA to ban asbestos for many years, welcomes Olin’s decision. “ADAO has long pointed to the industry’s own efforts to transition away from asbestos-based technology as evidence of the fact that asbestos is not necessary or needed in the United States and Olin’s actions today support that,” Linda Reinstein, cofounder and president of the group, says in a statement.”


This story was updated on April 7, 2023, to correctly describe how C&EN obtained a letter from Olin to the US Environmental Protection Agency. It was posted to a public docket and shared by the Asbestos Disease Awareness Organization, not leaked by that organization.



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