The threat of an explosion in a Southern California suburb from an unstable tank of toxic chemical has been eliminated, the Orange County Fire Authority said in a video statement released Monday. The announcement came after the authorities said that a crack had continued to relieved pressure in the tank and that temperatures inside had dropped.
The threat of an explosion from the chemical was “now off the table,” TJ McGovern, the interim fire chief for the fire authority, said in the video.
Evacuation orders remained in place for more than 40,000 residents around Garden Grove, Calif., where the industrial site is, as local authorities assessed whether it was safe for residents to return home.
“We are cautiously optimistic that the greatest danger may have been eliminated and that we are heading in the right trajectory,” Senator Thomas J. Umberg, a state legislator who represents the area that has been evacuated, said in a statement. “However, we cannot yet assure residents that it is safe to return home. We are asking for a little more patience.”
Firefighters responded on Thursday to an industrial site, belonging to GKN Aerospace, where a tank containing about 7,000 gallons of the chemical methyl methacrylate was becoming pressurized and releasing gas as the tank overheated.
According to the Environmental Protection Agency, exposure to methyl methacrylate can irritate the eyes and skin and make it difficult to breathe, among other symptoms. Birth defects have appeared in exposed animals.
Local authorities issued evacuation orders to thousands on Friday, as the tank’s temperature increased and the tank itself bulged, a sign that it could potentially explode. On Sunday, officials became more optimistic when they found that the tank containing the highly flammable chemical cracked, relieving some of the internal pressure. Internal temperatures also dropped from 100 degrees to 93 degrees.
“The crack is there,” Craig Covey, an incident commander with the fire authority, said on Monday. “We have verified that it’s there, and the tank has released its pressure. That is incredibly positive news as we turn the corner on this incident.”
The Orange County District Attorney’s Office said on Monday that it was investigating GKN, a British manufacturing company that produces jet engine parts, landing gear and other components for military and civilian aircraft.
Shawn Hubler contributed reporting.
