Denka Performance Elastomers enters consent agreement with US environment agency

Dallas, Texas - The US Environmental Protection Agency (EPA) has entered into a consent agreement with Denka Performance Elastomers LLC over its handling of likely carcinogenic waste at its production facility in LaPlace, Louisiana.

In a statement 28 Dec 2022, the agency said Denka had “failed to make an appropriate hazardous waste determination” for “poly kettle strainer waste,” a chloroprene waste generated from the manufacturing of polychloroprene rubber.

EPA said it has classified chloroprene as “a likely carcinogen” and that this waste contributed to emissions of chloroprene from the plant.

The consent agreement follows EPA’s on-site inspections of the facility in April and May 2022.

During the visits, EPA said it observed Denka’s process of transferring “poly kettle strainer waste” to an outside, open-air brine pit.

The agency said it is inspectors documented “elevated chloroprene concentrations” in the air in the vicinity of the brine pit during the process.

As part of the consent agreement, beginning 31 Jan, Denka will stop placing this waste stream in its open-air brine pit.

Instead, the Japanese-based supplier will implement hazardous waste regulatory requirements for both storage and ultimate disposal of the waste.

According to EPA, Denka will continue testing additional emissions reductions measures to reduce emissions from the management of this waste

If successful, the emissions reduction projects have the potential to eliminate approximately 2 tonnes of chloroprene emissions per year from poly kettle strainer clean-out, according to Denka’s reported emissions inventory.

Denka manufactures its polychloroprene rubber under the brand name Neoprene.

The elastomer is manufactured in a multi-step process, involving a polymerisation phase, in which chloroprene is mixed with water and other chemicals such as viscosity modifiers and emulsification agents to form an emulsion.

The emulsion is then transferred to "poly kettle" reactors where a free-radical catalysed reaction creates the rubber in a batch polymerisation process.

After adding stabilisers, the emulsion passes through a "poly kettle strainer" to remove undesired solids, or 'poly kettle strainer waste'.