Chemical Storage Tank Leak Triggers Evacuation of Up to 50,000 in Southern California

A chemical storage tank holding approximately 26,500 liters (6,000-7,000 gallons) of methyl methacrylate leaked toxic gases starting May 21 or 22 inside a GKN Aerospace plastic manufacturing facility in Garden Grove, Orange County, California ^{[1, 2, 3, 4]}.

Methyl methacrylate is a flammable industrial chemical used in plastics production that irritates skin, eyes, and respiratory and nervous systems ^{[1, 2, 4]}. Overheating caused the tank to release vapors, with internal temperature reaching about 32.22°C (90°F) by May 23, raising explosion risks ^{[1, 2, 5, 6]}.

California Governor Gavin Newsom declared a state of emergency for Orange County on May 23 as authorities ordered evacuation of about 40,000 to 50,000 residents in Garden Grove and surrounding cities including Cypress, Stanton, Anaheim, Buena Park, and Westminster ^{[1, 2, 3, 4, 5, 6]}. Officials established multiple evacuation centers such as Garden Grove Sports & Recreation Center and Cypress Community Center ^{[5, 6]}.

Craig Covey, Garden Grove Fire Department Chief, said, “This thing will eventually fail, and we don’t know when. We are doing our best to determine the timing or to prevent it.” He also noted concerns about the tank’s temperature rising an average of one degree per hour, up to 90 degrees, calling it "bad news" for the community ^{[3, 5]}.

Experts found a possible crack in the tank between May 23-24 that may relieve internal pressure, but a valve malfunction makes emptying or reinforcing the tank impossible ^{[2, 6]}. Authorities are weighing two outcomes: a controlled release of the chemical into the parking lot or a potential explosion from rising temperature and pressure ^{[6, 7]}.

Efforts to prevent disaster include continuous water spraying and sandbag barriers ^{[1, 3, 4, 5]}. No casualties have been reported so far ^{[3, 4]}. Disneyland, 8 km from the site, remains outside the evacuation zone with no direct impact as of May 24 ^{[2, 3]}.

Some evacuees have expressed frustration, filing a class-action lawsuit against GKN Aerospace ^[2].

U.S. EPA Administrator Michael S. Regan said, "I am told the most likely scenario is a small release that local authorities can monitor, neutralize, and control."

Authorities continue to monitor the situation closely as evacuation and cooling measures remain in place.