All Evacuation Orders Lifted for Residents Near Damaged Chemical Tank

County health officials have said people may notice a chemical smell over a wide area, but insist it is not harmful.

Water is sprayed on a damaged tank at GKN Aerospace after the tank containing a chemical used to make plastic parts overheated, in Garden Grove, Calif., on May 24, 2026. AP Photo/Ethan Swope

Southern California officials lifted all evacuation orders on the night of May 26 for 16,000 residents who live near a damaged chemical tank in Garden Grove, after a crack that formed on the tank relieved enough pressure to help prevent an explosion.

“All residents will go home,” Orange County Fire Authority Division Chief Craig Covey said during a meeting on that night. Authorities said the temperature on the tank remained stable for four hours without intervention, allowing them to lift the evacuation orders.

On May 25, officials reduced the evacuation zone after the tank cooled and the risk of an explosion dropped significantly, allowing 34,000 people to return home. The 16,000 residents remained under orders until the final lift the following night.

Officials began ordering residents to evacuate their homes after a tank containing up to 7,000 gallons of methyl methacrylate overheated, and by the weekend, around 50,000 residents had moved out.

California Gov. Gavin Newsom said on May 24 that he had submitted a request for a federal emergency declaration.

Newsom announced early on May 25 that President Donald Trump had approved the request for a presidential emergency declaration for the incident.

By then, firefighters in Orange County had managed to cool the tank’s interior to 93 degrees F (33.9 degrees C), down from 100 degrees (37.7 degrees C) on May 24.

GKN Aerospace said it had removed external insulation material from the tank to help cool its contents.

Covey said the reduced temperature meant the risk of a large explosion had been “eliminated,” and that 34,000 of the evacuated residents could go home.

‘It’s Not Over Yet’

“It’s not over yet. We still have work to do,” Covey said. “We still have to mitigate a fire and very small explosion concern, and also a spill potential.”

Methyl methacrylate—which is used to make a synthetic polymer used in engineering—is highly flammable and toxic.

The Environmental Protection Agency (EPA) says exposure to methyl methacrylate can cause respiratory symptoms, including “chest tightness, dyspnea, coughing, wheezing, and reduced peak flow.”

A statement on the Orange County website says local law enforcement has reduced the evacuation zone to the area between Orangewood Avenue, Dale Street, Garden Grove Boulevard, and Knott Street.

Orange County Fire Authority (OCFA) posted a map on X showing the new evacuation zone, which came into effect at 6 p.m. local time on May 25.

“We ask that you continue listening to law enforcement and do NOT enter the newly evacuated area,” OCFA said in another post on X.

“Thank you to our community members for your continued support, patience, and cooperation.”

Orange County health director Regina Chinsio-Kwong—who was appointed to the position in 2022—said she wanted to reassure everyone that there is no danger if they return home.

‘There Was No Contamination’

“There was no contamination. There were no fumes. There were not vapors that came from this incident,” she said at a news conference on May 25.

“There was not a leak. So it should be, you should feel comfortable going home even if you’re across the street from that new zone line.”

County health officials have said people may notice a chemical smell over a wide area, but insist it is not harmful.

Orange County Supervisor Janet Nguyen said the South Coast Air Quality Management District would monitor air quality for several months, while the EPA will be checking water in sewer and storm drains.

People tend to their pets outside Freedom Hall, an evacuation center in Fountain Valley, Calif., on May 25, 2026. Ethan Swope/AP

Disneyland’s two theme parks—which were particularly busy due to the Memorial Day weekend—were not evacuated, and park officials said over the weekend they were monitoring the incident and supporting employees impacted by evacuations.

The Garden Grove facility is owned by GKN Aerospace, a British-based multinational corporation.

Cockpit windows, canopies, and windshields for military and commercial aircraft are manufactured at the plant.

Methyl methacrylate is used to make a glass-like polymer, which is used in the manufacturing process.

“We are continuing to work around the clock with the OCFA, the EPA, and all relevant federal, state, and local agencies.” GKN Aerospace said in a statement on May 26.

“We remain extremely grateful for their dedication and hard work and will continue working alongside them and community partners as recovery efforts move forward.

“We apologize for the ongoing disruption this incident is causing, and our priority remains the safety of our neighbors and our community.”

GKN Aerospace employs about 16,000 people across 32 manufacturing sites in 12 countries.

The Associated Press contributed to this report.