Citing regulatory restrictions that have made the business “unsustainable,” US chemical producer Chemtura said it plans to end production of hexabromocyclododecane (HBCD)-based flame retardant products by the end of this year.

Sale of the products will continue until inventories are depleted, the company said.

In 2011, the European Commission placed HBCD on the list of substances requiring registration in Annex XIV of REACh regulation due to its non-biodegradability. Its use in polystyrene-based insulation foam projects was banned from August of this year, by which time most foam producers had already phased it out.

Chemtura has also developed a substitute product for flame retardants, which it markets under the trademark Emerald Innovation 3000.