An explosion at the ExxonMobil refinery in Torrance was caused by over-pressurization in an air-pollution-control system, according to a report released Monday.
The Wednesday morning blast that injured four contractors was prompted by pressure in an “Electrostatic Precipitator,” which controls particulate matter emissions from a fluid catalytic cracking unit, according to the South Coast Air Quality Management District.
The AQMD noted in a report that the pollution-control mechanism is “a relatively new unit, permitted in December 2008 and has been in operation since 2009/2010.” The catalytic cracking unit was not in operation at the time of the blast and “was not being vented to the ESP at the time of the incident,” according to the report.
“The cause of over pressure and explosion of the ESP is not yet provided and is under investigation,” the report stated.
The AQMD noted that what was originally believed to be ash raining over the plant and nearby neighborhoods was actually spent catalyst. An analysis of samples of the catalyst taken from neighborhoods found only trace amounts of chromium. There was no asbestos in the samples, however, there was fiberglass and glass wool, similar to materials used in commercial insulation, according to AQMD.
The blast occurred shortly before 9 a.m. at the refinery at 3700 W. 190th St.
— City News Service