KABC, KCBS, KCAL, CNN
By Taylor Romine, Rebekah Riess, Sarah Dewberry, Alaa Elassar, CNN
(CNN) — Emergency crews are working nonstop to prevent an overheating tank filled with a toxic chemical from leaking or triggering what could be a catastrophic explosion as approximately 50,000 residents in Orange County, California remain under an evacuation order.
Earlier, the Orange County Fire Authority told CNN 79,000 residents were impacted.
Authorities have spent the past two days trying to prevent the tank, which is full of the chemical methyl methacrylate, from exploding after it began to overheat. Evacuation orders were initially issued to those in the 9-square-mile area around the aerospace facility involved, but the evacuation zone was expanded after experts evaluated the volatile situation.
The chemical, also known as MMA, is used to manufacture plastics and can potentially cause respiratory issues if humans are exposed, according to the Environmental Protection Agency.
California Gov. Gavin Newsom declared a state of emergency in Orange County on Saturday as the state ramps up its response to the hazardous chemical incident, including expanding shelter availability for evacuated residents.
Orange County Fire Authority Captain Steve Concialdi told CNN “the air quality is good” and readings were showing safe conditions. However, methyl methacrylate exposure is known to cause serious respiratory effects, and some residents have reported symptoms including throat and nasal irritation, as well as dizziness.
Officials had been using drones to measure the temperature of the tank and had initially believed the tank was cooling off, but Orange County Fire Authority Division Chief and Unified Incident Commander Craig Covey said on Saturday they learned that’s not the case.
“Unfortunately, I do have to report that the temperature was 90 degrees. Yesterday morning it was 77 degrees when we backed out. It’s been averaging about a degree an hour increasing, so that’s the bad news,” Covey said.
The discovery was made after emergency crews were put “in harm’s way” Friday night in an attempt to neutralize a second tank at the facility, Covey said.
Concialdi told CNN on Saturday crews are racing to stabilize the compromised tank by cooling and neutralizing the chemical in hopes it will solidify from the outside inward — a process he compared to an ice cube freezing.
“It basically gets hard from the outside first, and inside there is still liquid in there until it completely ices over, and that’s what we’re hoping will happen,” Concialdi said, but warned the process may not succeed.
“A couple things could happen. … The tank could crack and start spilling out