Blast zones identified as Garden Grove chemical tank inches toward explosion

Fire officials have released a clear and haunting view of what damage could look like if the toxic Garden Grove tank explodes, with its temperature increasing with each passing hour.

OCFA Division Chief Nick Freeman said Friday that blast zones would be divided into severe, moderate, and light blast zones in a radius around the tank.

The most severe blast zone will cause “severe structural damage and significant harm,” while the moderate zone will see structural damage and some harm. The lightest zone will see just some structural damage.

In addition, an oblong circle above the tank is divided into three zones representing further hazards caused by the chemicals: a red, orange, and yellow zone.

The red zone is the most lethal, representing a flammable area that could see fire or flash fires. Orange is still threatening and could cause injury to anyone who inhales the chemicals. The yellow area represents spots where residents could smell the vapors, but they would not be dangerous.

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Dr. Regina Chinsio-Kwong was also at the news conference and said anyone smelling the chemicals will get notes of a strong fruity odor. But she said smelling the odor doesn’t mean you will have symptoms.

“We actually do know that when you smell it, you don’t typically have symptoms, and when you actually measure the levels in the air, it doesn’t mean it’s dangerous,” she said. She also urged people to evacuate and said a precautionary mask is unnecessary outside the evacuation zone.

She previously said the chemical involved, methyl methacrylate, can cause “significant irritation in the lungs, the nasal passages,” along with nausea and dizziness. Heavy doses of the substance could “cause severe respiratory distress and hospitalization.”

About 40,000 people have evacuated, though about 15% of residents contacted by local officials refused to leave. Shelter systems have been strained as people flood in.

Orange County fire officials gave a grim update earlier Saturday morning, saying the tank had only increased in temperature despite their efforts.

Orange County Fire Authority Division Chief Craig Covey gave an update Saturday morning, saying the tank had increased from 77 degrees to 90 degrees in temperature after they incorrectly measured the outside of the tank with a drone instead of the actual liquid temperature.

“Yesterday afternoon I did report that we had some positive intel and that the tanks were stable, and we were keeping the temperature cool. And actually we thought we were reducing it a little bit,” Covey said.

“Unfortunately, I have to say those temperatures we are doing is via drone, doing readings on the external of the vessel. It’s not covering the interior temperatures inside of what actually [is in the] liquid,” he added.

He said the liquid is increasing by a degree an hour on average.

The tank will explode if it enters a “thermal runaway,” but it’s unclear when that would be.

Gov. Gavin Newsom has a state of emergency in place for Orange County, and officials urge anyone in the area to evacuate.