Explosion threat at southern California chemical tank eliminated, firefighters say | California
Firefighters battling the overheating of a tank filled with hazardous chemicals in southern California eliminated the danger of the tank exploding with a night operation, Orange County fire officials said Monday.
The damaged chemical tank in Southern California cracked over the weekend; officials hoped this would relieve pressure and reduce the risk of an explosion.
Crews conduct tank temperature checks at night to reduce risks to firefighters, avoiding daytime operations when heat from the tank makes conditions around it the most dangerous, officials said.
The overnight mission allowed crews to verify the crack and confirm that temperatures had dropped, Orange County Fire Marshal Craig Covey said Monday morning. Covey said the results of the tank’s overnight assessment – in which the temperature inside dropped and pressure was released – were “incredibly positive news”.
In Garden Grove, a city of about 170,000 people about 40 miles (60 km) south of downtown Los Angeles, about 50,000 residents have been evacuated and await a resolution.
The tank overheated and began expelling vapors on Thursday, leaving local and state officials scrambling to avoid the worst-case scenario at the aerospace company’s site.
No injuries have been reported yet.
Donald Trump declared federal emergency Statement at the request of California governor Gavin Newsom. The declaration provides for federal assistance to emergency responders through the Federal Emergency Management Agency (Fema).
Firefighters sprayed water into the tank several times to cool the methyl methacrylate chemical used to make plastic parts. The inside of the tank reached 100F (37.7C) on Sunday.
The tank from GKN Aerospace Transparency Systems, which makes parts for commercial and military aircraft, contains 6,000 to 7,000 gallons (22,700 to 26,500 liters) of methyl methacrylate, which is used to make plastic parts.
State and federal environmental officials said Saturday that monitoring tests found that air pollution around the evacuation zone was within normal limits and that special equipment was used to ensure the gas was not released.
The firefighters’ first goal is to cool the chemical inside the tank to prevent leakage or explosion.
Drones were monitoring temperatures at 10-minute intervals to watch for any spikes. Containment barriers are installed to prevent the chemical from entering storm drains or reaching streams or the nearby ocean in the event of a spill, Covey said on social media.
As internal temperature increases, methyl methacrylate turns from liquid to gas, increasing the pressure, according to Purdue University engineering professor Andrew Whelton. A crack could mean product or pressure has been released, reducing the likelihood of an explosion, Whelton said.
“Think of a soda can. If you leave it in a hot car, it could explode,” Whelton said. “But if you poke a hole in the can, the product will be released and the can itself won’t explode.”
Whelton added that the tank could eventually cool enough for the crew to safely stabilize and dump the remaining material without triggering any sparks or ignitions. He warned that there was still some risk of explosion as the chemical inside the tank remained hot and reactive.
Temperatures need to approach ambient levels — about 60 to 70F (15.6 to 21.1C) — before conditions are considered significantly safer, he said.
Aerial photos taken by The Associated Press showed empty streets in the area Sunday, while many evacuation shelters were open. At a high school in neighboring La Palma, people slept in cars or on mats and sleeping bags on the asphalt.
Garden Grove is located next to Anaheim, which is home to Disneyland’s two theme parks that are not under evacuation orders. Park officials said they are monitoring the situation.
Exposure to methyl methacrylate can cause serious respiratory problems, neurological problems and irritation to the skin, eyes and throat, according to fact sheets on the chemical.
GKN Aerospace Transparency Systems employs approximately 16,000 people at 32 manufacturing facilities in 12 countries, according to its website. The company agreed to pay state regulators more than $900,000 in 2025 to resolve violations related to recordkeeping, permitting issues and nitrogen oxide emissions, according to a report on the South Coast Air Quality Management District website.
Some Garden Grove residents filed a federal class-action lawsuit Saturday against GKN Aerospace Transparency Systems, which operates the facility where the tank is located. Lawyers for residents argued that property values in the surrounding community would be affected no matter what.
GKN Aerospace did not comment on the lawsuit but apologized to residents and businesses who were forced to evacuate. It said Sunday it was “working around the clock to reduce the risk of leaks.”
Associated Press and Reuters contributed to this report
