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Ground-level Ozone Pollution

Revision to the Regulatory Definition of Volatile Organic Compounds – Exclusion of cis-1,1,1,4,4,4-hexafluorobut-2-ene

November 16, 2018 - EPA added HFO-1336mzz-Z to the list of compounds excluded from the regulatory definition of volatile organic compounds or VOC. Some VOC contribute significantly to the formation of ground-level ozone which can cause serious respiratory illnesses. Evidence shows that HFO 1336mzz-Z is negligibly reactive in forming ground-level ozone. This action will allow states to remove regulatory controls on HFO-1336mzz-Z that are part of State Implementation Plans designed to help meet the ground-level ozone standards. HFO-1336mzz-Z is used in a variety of applications as a replacement for foam expansion or blowing agents.

Read the proposal and summary fact sheet.

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