LOS ANGELES, May 25 (Xinhua) -- The threat of an explosion due to pressure buildup inside a toxic chemical tank at an aerospace manufacturing facility in Garden Grove, Southern California, has been eliminated, local fire authorities said early Monday.
Interim Fire Chief of the Orange County Fire Authority (OCFA) TJ McGovern said the risk of a Boiling Liquid Expanding Vapor Explosion, known as a BLEVE, was "off the table" following a hazardous materials emergency response launched Thursday.
Fire officials said temperatures and pressure levels inside the tank had stabilized and were continuing to decline.
OCFA Incident Commander Craig Covey said firefighters entered the exclusion zone overnight to assess conditions around the tank and confirmed that a crack had formed, allowing pressure to escape safely.
"The tank has released its pressure," Covey said, adding that the tank's temperature had dropped to 93 degrees Fahrenheit (33.9 degrees Celsius) from about 100 degrees Fahrenheit (37.8 degrees Celsius) previously. He described the development as "incredibly positive news" as responders began to gain control of the incident.
Officials said firefighters had limited close-range inspections of the tank to nighttime operations to reduce risks to personnel. Temperature checks were not conducted during daytime hours, when direct sunlight could have created more hazardous conditions around the tank.
Meanwhile, authorities stressed that evacuation zones around the facility remain in effect and urged residents to continue complying with evacuation orders as response efforts continue.
The emergency began Thursday after a toxic chemical storage tank at the facility started overheating and building pressure, raising concerns that it could explode and release hazardous materials into the surrounding area.
Around 50,000 residents in portions of six Southern California cities remain under evacuation orders due to the emergency.
