Toxic chemical leak at Garden Grove aerospace plant prompts evacuations

A 34,000-gallon tank at GKN Aerospace's Western Avenue facility released methyl methacrylate into the air Thursday, prompting Orange County authorities to issue evacuation orders for areas near the Garden Grove plant.

The incident underscores the chemical exposure risks facing residential communities near industrial facilities along the Garden Grove–Stanton corridor, one of Orange County's densest mixed-use zones.

Orange County Fire Authority crews responded to the GKN Aerospace plant on Western Avenue after a tank containing methyl methacrylate (MMA) — a colorless liquid used in the manufacturing of acrylic plastics — began leaking. Aerial observation confirmed the hazardous material had been released into the atmosphere from the 34,000-gallon tank, according to ABC7 Los Angeles.

A faulty valve complicated containment efforts. "An inoperable valve on the tank has created additional operational challenges, preventing complete mitigation at this time," the Orange County Fire Authority said, according to ABC7 Los Angeles.

As site conditions shifted during the afternoon, authorities expanded protective measures. "Due to changing conditions, evacuation orders are being reissued as a precautionary measure while mitigation operations continue," the agency said, according to ABC7 Los Angeles.

Officials established an evacuation center at Stanton City Hall and Community Center, at 7800 Katella Ave. in Stanton, to accommodate displaced residents. No injuries were immediately reported as of Thursday afternoon.

The cause of the initial spill remained unknown. GKN Aerospace, a manufacturer of aerospace structural components, operates the Western Avenue plant in Garden Grove.

Hazmat crews remained on scene Thursday evening as mitigation efforts continued. Residents near the facility were urged to comply with evacuation orders and avoid the area until authorities declared it safe.