MARTINEZ, Calif. -- It's been more than a month since the massive fire at the Martinez Refining Company, and we're learning more about how it sparked.
Martinez Refining Company said 170 barrels (7,140 gallons) of hydrocarbon materials were released during the February fire, most of which they said were consumed by the flames.
MRC--which is owned by PBF Energy Inc.--submitted its required 30-day report to Contra Costa Health (CCH) on Feb. 28.
An explosion and fire were reported at approximately 1:30 p.m. Feb. 1, when two workers opened equipment while preparing for planned maintenance on a process unit.
MRC said hydrocarbon material started leaking, prompting workers to flee. The material caught fire, which spread. Massive amounts of smoke prompted the county to issued a shelter-in-place alert at 4:49 p.m. for neighborhoods near the refinery, which was lifted about 9 p.m. The fire burned for three days.
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Both workers were transported for medical evaluation and released. Four other workers were also injured, though none seriously.
The company said it believes hydrocarbon materials that burned during the fire, producing smoke, included light cat cracked naphtha, light cat cracked distillates, intermediate cat cracked distillates, light thermal cracked naphtha, and isobutane-rich C3-C4.
Hydrocarbons can cause cancer, according to the National Cancer Institute.
MRC's report said its "best estimate" breakdown of the 170 barrels of hydrocarbons burned is 30 combined barrels (1,260 gallons) of light thermal cracked naphtha and isobutane-rich C3 C4; 20 combined barrels (840 gallons) of light cat cracked naphtha and light cat cracked distillates and 120 barrels (5,040 gallons) of intermediate cat cracked distillates.
MRC said it believes diethanolamine was likely released during the incident because of a ruptured pipe in the CFH area due to the fire.
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The U.S. Environmental Protection Agency says on its website diethanolamine is used in consumer products like shampoo, cosmetics and pharmaceuticals. It said there's limited information on its health effects.
When asked about the potential health effects of the released chemicals, a PBF spokesperson on Tuesday referred to a Feb. 11 CCH statement, which said MRC told health officials chemicals and combustion byproducts from the fire included chemicals that can cause cancer, as well as heart and lung disease.
The statement included a quote from Dr. Ori Tzvieli, the county's health officer, saying the community was fortunate the wind blew most of the toxic smoke north of the refinery, away from populated areas. It also said air-quality measurements taken by CCH during the incident showed concentrations of chemicals in the air during the event were mostly below the threshold considered dangerous.
A CCH spokesperson said Tuesday the agency "is still working with our toxicologist to fully understand any potential impacts on health. We will share that information with the public once we have it."
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The 30-day report said, because of flaring arising from the unplanned shut down of refinery operating units to respond to the incident, more than 500 pounds of sulfur dioxide was released.
The refinery said its personnel continues monitoring the scene of the fire, assessing equipment damage, and ensuring the safety of the area. Refinery operating units remain shut down while damage assessment continues, exception for required utility and environmental systems.
MRC said it doesn't have an estimate as to when the units will be running again. The Bay Area Air District cited MRC for visible emissions and odor caused by the fire, for visible emissions and fallout exceeding standards, and for not operating equipment as needed.
CCH said Bay Area Air District samples taken during the fire were consistent with its findings: that cancer-causing chemicals in the air north of the refinery were above "historical background levels."
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The air district took three samples on Feb. 1-2 -- the first two days of the three-day fire -- at two locations: at the Marina Vista Avenue/Waterfront Road off-ramp from northbound Interstate Highway 680 and Waterfront Road near the I-680 off-ramp.
CCH analyzed the air district's findings and found above normal levels of benzine (a known carcinogen) and 1,2,4-Trimethylbenzene, also known as pseudocumene.
The report said MRC expects to be done investigating the fire by April 30.
More information can be found here.