Investigators from the U.S. Chemical Safety Board are investigating the cause of the chemical leak which killed four workers and hospitalized a fifth at the DuPont chemical plant in La Porte last Saturday. According to DuPont, a valve on a container of the gas malfunctioned, but the CSB-the federal agency which is charged with investigating chemical accidents-is investigating how the leak was able to kill four people when there was no fire or explosion. In addition, a lawsuit was filed against DuPont today by the daughter of one of the victims.
The chemical released was methyl mercaptan, which is used at the plant to make insecticides and fungicides. Methyl mercaptan, which has a strong “rotten cabbage” smell, is better known as additive used to odorize natural gas. How a leak of a chemical with such a strong odor was able to go undetected long enough to kill four people is unclear. None of the victims appeared to be wearing protective equipment at the plant-the medical examiner who performed the autopsies noted only coveralls being worn by the victims.
This is the fifth investigation of an accident at a DuPont facility by CSB since 2010. In January 2010, a worker died at a DuPont facility in West Virginia after being exposed to phosgene, a gas which was extensively used as a chemical weapon during World War I. In November 2010, a welder was killed and another worker injured at a DuPont plant in Buffalo when a welding torch ignited highly flammable vinyl fluoride vapor.