[Mitch]

LA PORTE, Texas –  Four workers were killed and one was injured Saturday during a hazardous chemical leak at a DuPont industrial plant in suburban Houston, company officials said.

Full story here: http://www.foxnews.com/us/2014/11/15/4-workers-killed-after-houston-area-chemical-leak/?intcmp=trending

[curiouscat]

Will be interesting to hear about exactly what went wrong.

With an odor threshold of 1 ppb and a rat LC50 of 675 ppm one would assume one usually gets adequate warning to escape? Unless the discharge was unusually large or you were right around it or got trapped / boxed in.

A quick lookup shows most respirator cartridges being good enough to allow escape at most concentrations.

Somehow all the holes in the cheese just lined up on this one. Sad.

[Mitch]

Looks like a failed valve. From USA Today:

LA PORTE, Texas — Two brothers were among four workers who died Saturday after a chemical leak at a facility here.
Family members said Robert and Gilbert Tisnado worked side by side at the DuPont chemical plant for six years.
When the chemical leak started early Saturday morning, Gilbert rushed in with a gas mask to try and save his brother, relatives said. Tragically, both brothers died. A fifth worker was hospitalized.
DuPont company spokesman Aaron Woods said a valve failed on a container of methyl mercaptan, a chemical used to make insecticide, around 4 a.m. Saturday. Plant officials don't know why the valve failed.

[curiouscat]

Any clue what DuPont was actually using it for? 60 tonnes sounds like a decently big inventory.

There's this incident at AtoFina Michigan from 15 years ago that also started with a methyl mercaptan leak from a valve. Killed 3 people.

http://www.aria.developpement-durable.gouv.fr/wp-content/files_mf/FD_20821_riverview_2001_ang.pdf

I'm wondering if this one's similar.