Threat of massive chemical tank explosion is ‘eliminated’, California officials say

The threat of a faulty chemical tank exploding in Orange County was eliminated following an overnight operation, California fire officials said.

Division Chief Craig Covey said Monday that the tank’s temperature had dropped, leading to “positive news.”

The tank, which contains thousands of gallons of methyl methacrylate (a highly volatile and flammable substance used to make plastics), was at risk of a major spill or explosion in recent days.

There is currently no active leak, but teams have been working to assess the risk since Sunday. Officials said the spill was a possible outcome as an evacuation order for the area remains in effect.

A damaged chemical tank in Southern California ruptured over the weekend, and officials were hopeful that the pressure built up inside the tank would gradually release.

The threat of a BLEVE, or Boiling Liquid Expanding Vapor Explosion, was “eliminated” following an overnight operation, Orange County Fire Authority Interim Chief TJ McGovern said Monday.

“We are happy to report that the BLEVE threat is now off the table,” McGovern said. “This threat has been eliminated.”

Speaking alongside McGovern, Covey said in a video shared on social media that the crew confirmed there was a crack in the tank, allowing pressure to be released.

The internal temperature of the tank dropped from 100F (38C) to 93F (34C).

Covey said the safety of firefighters on site prevented officials from providing further updates on the tank’s internal temperature over the weekend.

“We were not doing tank temperature checks during the day when the sun was on it so that in the most extreme conditions the tank would go in the wrong direction,” he said. “We were only measuring tank temperatures at night.”

Officials said no chemicals are currently leaking and officials are working around the clock to ensure it stays that way.

Emergency crews are spraying water into the tank to stabilize the temperature after some rapid temperature increases since Thursday.

Approximately 50,000 people are under precautionary evacuation orders and a state of emergency has been declared by California Governor Gavin Newsom.

The cities of Garden Grove, Stanton, Anaheim, Cypress, Westminster and Buena Park are all affected by evacuation orders.

The tank at GKN Aerospace Transparency Systems, an aerospace facility, is located in the city of Garden Grove, about 35 miles (56 km) southeast of Los Angeles. GKN Aerospace apologized to local residents.

At an earlier stage, officials expressed hope that emergency crews could relieve the pressure problem by slowing the rate of chemical reactions that cause substances to heat up inside the tank.

“It’s unacceptable for us to let this thing fail and implode,” Covey said.

Covey said officials are also developing “very aggressive plans” for a scenario in which the tank’s integrity would be compromised. They create levees and dams to hold back any chemicals in case the tank spills, to prevent any from reaching storm drains or the ocean.

Methyl methacrylate is used to make resins and plastics. The chemical irritates skin, eyes and mucous membranes in humans and can cause respiratory and neurological symptoms upon exposure, according to the Environmental Protection Agency.