The Exxon Mobil Corp is not having a super week, as the California Division of Occupational Safety and Health announced they were being charged with multiple citations and fined them after an explosion at their Torrance, CA refinery injured four workers earlier this year.

The company received 19 citations, 18 of which were serious violations that could have potentially harmed workers. Six of the serious violations were also classified as willful, since Exxon knew there were hazardous conditions present and did not try to correct them. They were fined $566,600 in all.

The explosion injured four contracted workers and damaged equipment at the site as well as damaged the surrounding community as ash fell down onto nearby houses. It was caused by a hydrocarbon leak in the fluid catalytic cracker (FCC) unit that leaked into the electrostatic precipitator (ESP) and exploded. Investigators determined that the FCC had been faulty for maybe as long as nine years. This was not the first explosion caused by that piece of machinery; in 2011 a worker lost teeth and fractured his jaw when a motor in a pump on the unit exploded.

The Cal/OSHA investigation team determined that managers knew about the leak and the potential dangers that could have caused yet did not fix the leak. They could not monitor hydrocarbon pressure buildup in the FCC because the unit was faulty. The company is not allowed to use the FCC unit until they can show OSHA that it can operate safely.

There have been other dangerous instances in refineries in other parts of the country, and there have been proposed changes to petroleum refinery safety rules for things like hazard control analysis and damage mechanism reviews (DMRs) to protect workers and keep hazards to a minimum.