Mercaptan identified at site of Lubrizol La Porte chemical leak

HOUSTON (ICIS)–The chemical compound released at the Lubrizol plant in La Porte, Texas, on Sunday night was identified as mercaptan, an organic sulphur material widely used to odourise natural gas because of its distinctive unpleasant smell, according to local authorities.

Earlier, the Harris County Pollution Control Services (PCS) had said in a tweet that the chemical compound released was hydrogen sulfide, but the city of La Porte later confirmed that it was not the primary chemical compound released at the site.

The mercaptan – also known as methanethiol – was released while Lubrizol teams were preparing a railcar for unloading on-site, which included heating the railcar to prepare the stored materials for transfer.

Air monitoring measurements confirm that there is no health risk to the surrounding communities or to employees on the facility.

“We are investigating why the stored material began to break down, resulting in an offsite odour release. Our response team immediately began treating the railcar to minimise the odour, notified local authorities and initiated air monitoring,” said Sarah Arroyo, Global Operations Communications Manager at Lubrizol in a statement to the city’s Office of Emergency Management.

Lubrizol produces additive systems for lubricating oils used in gasoline and diesel engines and marine engines – among others – at its site in Deer Park, according to its website.

La Porte city officials issued an “all clear” for the shelter-in-place order at 23:24 local time on Sunday night.

La Porte is a city on the east side of Harris County, Texas, along Galveston Bay and the Houston Ship Channel.

Additional reporting by Nurluqman Suratman.