Hundreds of thousands of pounds of toxic gas released from the Shell Oil facility in Deer Park, TX, Sunday.
The Texas Commission on Environmental Quality (TCEQ) said 326,166 pounds of butadiene escaped through an open valve on a spherical tank between 10:40 am and 11:35 am.
Butadiene is a known human carcinogen, but its molecular structure allows it to dissipate quickly in the hot summer air, said Neil Carman, a chemist with the Sierra Club of Texas and a former power plant inspector for the TCEQ. The chemical is commonly expelled in car exhaust, but Carman said the quantity in the Shell incident was concerning.
“This release is huge,” he said. “Even 10 percent of 326,000 is big for butadiene.”
Shell is investigating the cause of the release, said company spokesperson Ray Fisher. Meanwhile, data from nearby monitors did not exceed TCEQ odor or health-based screening levels during the incident.
“To the best of our knowledge, there were no adverse impacts on the community,” Fisher said.
Long-term exposure to butadiene linked to an increased likelihood of cardiovascular disease and leukemia, according to the U.S. Environmental Protection Agency.