California's Newsom declares emergency over chemicals tank blast risk

California Governor Gavin Newsom has declared a state of emergency in Orange County in response to the risk of explosion following a leak from a chemicals tank in the Greater Los Angeles area.

The authorities had been mobilized for more than 24 hours and were working to contain the risk, Newsom posted on X late on Saturday.

The move allows California to seek federal assistance from Washington. Tens of thousands of area residents were advised to leave their homes, with some 40,000 heeding the call to spend the night in hotels, in their cars or in the emergency accommodation provided by the authorities.

The tank containing close to 130,000 litres is located on the premises of an aerospace company in Garden Grove, south-east of Los Angeles.

It contains methyl methacrylate, a toxic and flammable chemical used in the production of plastics. The risk of a massive leak or explosion have not been contained yet, according to media reports.

Orange County fire services spokesman Craig Covey said earlier reports that the contents had cooled, reducing the explosion hazard, had turned out to be incorrect, after a drone measured the external temperature.

He added that firefighters had now assessed that the temperature had in fact risen considerably. The team was seeking to prevent the tank exploding, he said.