Orange County braces for toxic plume as aerospace tank nears failure

An unprecedented risk is unfolding at a Garden Grove aerospace facility where a large tank of methyl methacrylate (MMA) could fail, potentially releasing toxic vapors and triggering a BLEVE. About 40,000 residents are under a 1–3 mile evacuation zone across parts of Garden Grove, Anaheim, Buena Park, Cypress, Stanton and Westminster, with Disneyland outside the area. One tank contains roughly 7,000 gallons and is most at risk; valves are broken and stabilized agents can’t be added, complicating efforts to depressurize or drain it. Crews have cooled the tank with sprinklers and are monitoring with drones, while authorities search for alternative mitigation methods. MMA exposure can irritate the lungs and, at high levels, cause severe respiratory distress; long-term effects are a concern, though the chemical is not deemed likely to be carcinogenic. Some residents are refusing to evacuate, and officials stress this could last days as they work to prevent a toxic vapor plume from reaching other areas.