MARTINEZ (CBS SF) – A health advisory issued because of flaring at the Shell refinery in Martinez Tuesday afternoon has been canceled.

A problem occurred at the refinery at about 12:40 p.m., said Randy Sawyer, the agency’s chief environmental health and hazardous materials officer.

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Sawyer said a vessel at the refinery somehow became “overpressurized,” which activated a safety mechanism that releases pressure through flaring.

The flaring is visible to those in the area, he said.

“About every minute or so you get a big puff of black smoke,” Sawyer said.

He said the smoke contains sulfur dioxide and other combustible products.

The flaring, which comes a day after a small fire at the same refinery,  is considered a “Level 2” incident, meaning residents with respiratory problems or other health conditions are being advised to stay indoors, but there was no mandatory shelter-in-place warning.

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No community warning sirens were being activated and no automated phone calls are going out, he said.

The flaring stopped about 2:45 p.m. and the health advisory was lifted, Contra Costa Health Services spokeswoman Maria Duazo said.

The agency downgraded the incident from “Level 2” to “Level 0,” meaning that everything has been controlled by refinery personnel, with no threat to the public, Duazo said.

The flaring has stopped and there is no expectation of any more odors coming from the refinery, Duazo said.

Last week’s massive fire at the Chevron refinery in Richmond was considered a “Level 3,” incident—the highest level in the agency’s classification system.

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