Threat of Chemical Tank Explosion Eliminated
The threat of a failing chemical tank in Orange County causing a massive explosion has been eliminated following an overnight operation, according to California fire officials.
The tank, containing thousands of gallons of methyl methacrylate—a highly volatile and flammable substance used in plastic manufacturing—had been at risk of a major spillage or explosion in recent days.
Response teams continue to work to mitigate spill potential and address a "very small explosion concern," Orange County Fire Authority Interim Chief TJ McGovern stated on Monday evening.
A new, reduced evacuation zone has been established, with approximately 16,000 residents still unable to return to their homes.
Details on Tank Condition and Evacuation
The damaged chemical tank in southern California cracked over the weekend, and officials had hoped that the pressure built up inside would be gradually released.
The threat of a BLEVE, or Boiling Liquid Expanding Vapor Explosion, has been "eliminated" after an overnight operation, McGovern confirmed on Monday.
"We are happy to report that the threat of a BLEVE is now off the table," McGovern said. "That threat has been eliminated."
Although there is currently no active leak, officials cited the risk of another leak as the reason for maintaining a reduced evacuation zone.
"It's not over yet - we still have work to do," McGovern said when announcing the new evacuation zone, expressing gratitude to residents for their patience.
Covey, who spoke alongside McGovern, shared a video on social media confirming a crack in the tank that led to a pressure release.
The tank's internal temperature has decreased from 100°F (38°C) to 93°F (34°C).
Due to firefighter safety concerns, officials did not provide further updates on the tank's internal temperature over the weekend, Covey explained.
"We were not doing tank temperature checks during the day while the sun was on it in the most extreme conditions for that tank to go the wrong direction," he said. "We were only doing tank temperatures at night."
No chemicals are currently leaking, officials have repeatedly emphasized, and authorities have been working around the clock to ensure this remains the case.
Emergency crews have been spraying the tank with water to stabilize its temperature following rapid heat increases since Thursday.
Evacuations and Emergency Response
Initially, some 50,000 people were affected by precautionary evacuation orders, which included the cities of Garden Grove, Stanton, Anaheim, Cypress, Westminster, and Buena Park. California Governor Gavin Newsom declared a state of emergency in response.
The tank is located at GKN Aerospace Transparency Systems, an aerospace facility in the city of Garden Grove, approximately 35 miles (56 km) southeast of Los Angeles. GKN Aerospace has issued an apology to local residents.
Earlier, officials expressed hope that emergency teams could relieve the pressure by slowing the chemical reactions causing the substances inside the tank to heat up.
"Letting this thing just fail and blow up is unacceptable to us," Covey said.
Officials had also been developing "very aggressive plans" in case the tank's integrity failed, Covey noted. Measures included constructing dykes and dams to contain any chemical spills, aiming to prevent substances from reaching storm drains or the ocean.
Chemical Information and Health Risks
Methyl methacrylate is used in the production of resins and plastics. According to the Environmental Protection Agency, this chemical can irritate the skin, eyes, and mucous membranes in humans and may cause respiratory and neurological symptoms upon exposure.
