Air Regulators: Over Pressurization Led to Exxon Mobil Refinery Blast

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A structure was seriously damaged at the Torrance Refinery after a fire on Feb. 18, 2015. (Credit: Christina Pascucci/KTLA)

Over pressurization caused Wednesday’s large explosion at the Exxon Mobil refinery in Torrance and sent ash into neighborhoods surrounding the plant.

The cause of the over pressurization is still under investigation.

The blast released material into the air that landed on cars and homes. The ash contained fiberglass and glass wool, but no asbestos, according to a South Coast Air Quality Management District report. SCAQMD also found that samples taken from nearby neighborhoods also contained metals used in the refinery’s fluid catalytic cracking unit. The materials are typically found in commercial insulation.

According to the report, samples contained less than 60 parts per billion of hexavalent chromium — a carcinogen — meaning only trace amounts were found.

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