Authorities in southern California ordered the evacuation of 40,000 people on Friday after a huge storage tank began leaking a hazardous chemical used to make plastic parts, posing the risk of an explosion.

About 40,000 people are under evacuation orders and schools have shut down in Southern California due to a hazardous chemical leak.

Authorities in Orange County say they’re unable to control the valves on a tank that contains methyl methacrylate, a chemical used in the manufacture of plexiglass.

El tanque químico contiene 26 mil litros de metacrilato de metilo, un líquido inflamable y volátil utilizado para hacer plástico.