PORT NECHES — An additive that is intended to stabilize materials for longer-term storage in 11 tanks that store butadiene is not expected to pose another health concern in the wake of the Nov. 27 TPC Group Port Neches Group operations.

Diethyldroxylamine, or DEHA, is being introduced to the tanks using portable equipment. The process to store DEHA takes approximately five days to complete.

TPC has accounted for all 12 storage tanks since the explosions.

TPC recently announced plans to safely transfer all remaining materials from the site. A temporary location for the storage has not yet been determined.

Product removal will take weeks, TPC Houston environmental manager Jason Sanders said.

Air monitoring released at 9:30 p.m. Monday yielded only a 0.05 ppm reading for volatile organic compounds at 100½ E. Port Neches Ave. All other readings for lower explosive limit, hydrogen sulfide, carbon monoxide, sulfur dioxide, benzene, butadiene, hydrogen cyanide and oxygen yielded 0 ppm.

The maximum reading for butadiene in the community through 2:30 p.m. Monday was 0.5 ppm, according to the Environmental Protection Agency.

“Occasional elevated air measurements may continue to register as response teams secure the site,” Unified Command wrote in a Tuesday news release.

UC also announced the Agency for Toxic Substances and Disease Registry, a federal public health agency, remains onsite for reviewing environmental data from UC to assist in making local public health recommendations.

The EPA does not anticipate another management update until Friday.