California Declares Emergency Over Heating Chemical Tank

California Governor Gavin Newsom has declared a state of emergency in Orange County as a faulty 34,000-gallon chemical storage tank at a GKN Aerospace facility in Garden Grove continues to heat up, forcing the evacuation of more than 44,000 residents across six cities. Emergency response teams are racing against time to prevent either a toxic spill or a catastrophic explosion.

The Situation

The crisis began on May 21, 2026, when a storage tank containing approximately 6,000 to 7,000 gallons of methyl methacrylate (MMA) — a toxic, highly flammable chemical used in plastics manufacturing — began overheating and venting vapors at the GKN Aerospace facility located at 12122 Western Ave, Garden Grove, approximately 35 miles southeast of Los Angeles.

According to the Associated Press, the tank’s valves have become “gummed up” or broken, preventing emergency crews from removing the chemical or relieving pressure. Orange County Fire Authority Division Chief Craig Covey, the unified incident commander, described the dire situation: “There are literally two options left remaining. One, the tank fails and spills a total of about 6,000 to 7,000 gallons of very bad chemicals into the parking lot in that area, or two, the tank goes into a thermal runaway and blows up.”

Temperature Rising

Initial efforts to cool the tank with water appeared promising, but crews later discovered a critical error. Drone readings had only measured the exterior temperature of the tank, not the internal chemical temperature. When responders finally accessed an internal gauge on the night of May 22, they found the temperature had reached 90°F (32°C) — far higher than the 77°F (25°C) recorded the previous morning.

Covey confirmed the temperature was rising at approximately 1°F per hour. The liquid chemical has a flashpoint of just 50°F (10°C), meaning it can ignite easily at room temperature. As the MMA converts from liquid to gas under increasing heat, pressure inside the tank continues to build, bringing the facility closer to a potential explosion.

Evacuation and Response

Mandatory evacuation orders now cover a one-mile radius around the facility, affecting parts of Garden Grove, Anaheim, Buena Park, Cypress, Stanton, and Westminster. Several shelters have been established, including at three local high schools. People’s Daily reported that the evacuation zone may expand further, potentially affecting up to 50,000 residents.

Governor Newsom declared a state of emergency on May 23, mobilizing state resources to support local responders. “The safety of Orange County residents is the top priority,” Newsom said. “We are mobilizing every state resource available to support local responders and make sure the community has what they need to stay safe.”

Health Risks and Expert Analysis

Methyl methacrylate is a highly hazardous substance. Dr. Regina Chinsio-Kwong, Orange County Health Officer, warned that exposure can cause “significant irritation in the lungs, the nasal passages, and it can also cause nausea, it can also cause dizziness.” The chemical can also cause neurological problems, severe skin and eye irritation, and unconsciousness at high concentrations.

Purdue University engineering professor Andrew Whelton, who studied the 2023 East Palestine, Ohio train derailment, noted that while the volume of MMA involved is smaller than the vinyl chloride released in that disaster, the risks remain significant. “Many of these are acute, fast-acting effects,” Whelton said. “But the longer somebody stays in contact with it, the more potential for significant damage that occurs.”

Whelton emphasized the need for specific air monitoring for MMA rather than generic volatile organic compound tests, which may fail to detect the chemical. Containment barriers have been set up to prevent any spill from reaching storm drains, creeks, or the Pacific Ocean.

Background and Safety Concerns

The GKN Aerospace facility, which produces military canopies, cockpit windows, and passenger windows, has a documented history of regulatory violations. According to Wikipedia, the company was penalized by California authorities in 2018 for failing to maintain and inspect machinery and improperly cooling tanks. In 2021, GKN paid approximately $900,000 to $1 million to settle environmental violations with the South Coast Air Quality Management District, including failing to keep emission records and operating equipment without permits. As recently as March 2025, the facility received notices to comply regarding operating records and equipment registration.

What Happens Next

Emergency teams from across the country have been consulted, but officials acknowledge that the tank cannot be mechanically secured. The two remaining outcomes — a controlled leak or an explosion — both carry significant risks. A controlled spill would release toxic chemicals into the facility’s parking lot, where containment barriers are ready. An explosion, however, could send shrapnel flying and disperse chemicals over a wide area, causing severe structural damage and potential casualties.

As of May 24, no injuries have been reported, and no timeline has been given for when evacuated residents may return home. Officials continue to monitor the tank’s temperature at 10-minute intervals using drones, while developing scenario maps to predict the path of any potential chemical plume.

The incident has raised broader questions about the storage of hazardous materials near residential areas and whether GKN’s history of regulatory violations should have prompted more stringent oversight. For the 44,000 displaced residents spending their Memorial Day weekend in evacuation shelters, those questions will have to wait — their immediate focus remains on whether the tank will hold.