California Governor Gavin Newsom has declared a state of emergency as crews race to contain a toxic chemical leak at a manufacturing facility in Orange County.
A tank containing about 7,000 gallons of methyl methacrylate, a highly volatile and flammable substance used to make plastic, was at risk of failure, officials warned. Thousands of Garden Grove residents are under evacuation orders as a precaution.
Officials said on Saturday that the temperature in the tank was higher than previously thought and it was continuing to rise.
Orange County Fire Authority division chief Craig Covey said they were planning for two scenarios: “Does it rupture and spill, or does it blow up?”
The aerospace facility is about 5 miles (8km) from the Disneyland theme park, which is outside the evacuation zone and is open as normal. The facility is about 35 miles south-east of Los Angeles.
The cause of the failing tank is under investigation and emergency crews have been spraying it with water to try to stabilise the temperature. Officials said an "inoperable valve" had created "additional operational challenges".
Covey said the damaged tank's temperature had risen to 32C (90F) on Saturday and was increasing by about one degree Fahrenheit an hour.
On Friday evening, officials had used drones to measure the external heat levels and believed they had cooled the tank to about 16C (61F).
But when crews were able to get closer and read the tank's gauge, they realised the internal temperature was much higher, Covey said.
He expressed hope that emergency teams could slow the rate of the chemical reactions that were causing the substances to heat up and build pressure inside the tank.
"Letting this thing just fail and blow up is unacceptable to us," Covey said.
Officials were developing "very aggressive plans" for a scenario in which the tank's integrity failed. They were also creating dykes and dams to contain any chemicals if the tank spilled, which Covey said would hopefully prevent any substances reaching storm drains or the ocean.
Local schools have closed as a precaution and the exits of several major roads have been shut to limit access to the area.
Orange County health officer Dr Regina Chinsio-Kwong said anyone who noticed "a fruity and heavy smell" should alert authorities.
"Smelling it doesn't mean you've reached a level that causes symptoms. But we don't want you to smell that," she said.
Chinsio-Kwong said inhaling the vapour could cause respiratory issues, irritation to the eyes and dizziness. She said those outside the one-mile evacuation zone should be safe.
Covey had warned on Friday that there were “literally two options left: the tank fails and spills... or, two, the tank goes into a thermal runaway and blows up.”
He told a news conference on Friday afternoon that if the tank spills, "very bad chemicals" would leak into the parking area surrounding the facility.
“Or two, the tank goes into a thermal runaway and blows up, affecting the tanks that are around it that have fuel or chemicals in them as well.”
"This is not precautionary," he said. “This thing is going to fail, and we don't know when... We're doing our best to figure out when or how we can prevent it.”
"I was woken up by the sirens going across our streets," Mark Olsen, who was evacuated to the Garden Grove Sports and Recreation Center, told NBC LA on Friday.
"Then I was told that they were evacuating, so I grabbed some stuff and got out of there," Olsen said.
But not knowing what would happen to the chemical plant, or when he could return home, was weighing on him.
"It's just frustrating," Olsen said.
The facility is operated by GKN Aerospace, a UK-based company that supplies parts for aircraft.
A spokesperson for the company apologised to local residents and said: “The situation remains ongoing and we are fully focused on working with emergency services, specialised hazardous material teams and the relevant authorities to ensure the safety of the local community, our employees and everyone else involved.”
Source: BBC
– Agencies
