Garden Grove's chemical crisis: Thousands flee as conditions worsen at damaged tank

Fire officials responded to a worsening emergency at GKN Aerospace in Garden Grove involving a tank holding about 7,000 liquid gallons of methyl methacrylate (MMA). Temperatures inside the compromised tank rose to 90 degrees Celsius by 10 a.m. Saturday, increasing from 77 degrees the previous day. An internal sprinkler system and unmanned ground sprinklers helped stabilize temperatures around 90 degrees despite round-the-clock firefighting. Officials said the two most likely outcomes remained a massive explosion of the pressurized tank or a rupture releasing thousands of gallons of a highly toxic chemical. MMA boils at 101 degrees Celsius, and the tank gauge detects temperatures only up to 100 degrees, leaving uncertainty about the threshold for imminent explosion.

"Fire officials spent Saturday in an increasingly dire race against the clock at Garden Grove's GKN Aerospace, with temperatures in a compromised tank of toxic chemicals creeping perilously upward and evacuated residents increasingly worried for their homes and health."

"By Saturday morning, it was clear that conditions had worsened inside the failing tank holding an estimated 7,000 liquid gallons of methyl methacrylate, or MMA, making the possibility of a massive explosion or toxic chemical leak at the aircraft and spacecraft manufacturer significantly more likely."

"Despite firefighters' round-the-clock efforts, by Saturday afternoon, Freeman said the two most likely outcomes remained dire ones: a massive explosion of the pressurized tank, or a rupture that releases thousands of gallons of a highly toxic chemical. "We have all of our folks, and you name it, working on what our other options could be," Freeman said."

"MMA's boiling point is 101 degrees Celsius, and the tank's gauge only detects temperatures up to 100 degrees. Officials haven't disclosed what temperature they believe would indicate an imminent explosion. It's not necessarily the case that the tank would explode at 101 degrees, said Elias Picazo, assistant professor of chemistry at USC."

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