The 405 Freeway has been fully reopened through Redondo Beach on Thursday afternoon after it was temporarily closed amid fears of a hazardous chemical leak, officials said.
The closure began shortly before noon over concerns that boxes that had fallen from a vehicle had possibly leaked the potentially deadly chemical compound hydrogen cyanide onto the 405, according to the Los Angeles County Fire Department.
All northbound lanes were closed at Hawthorne Boulevard while the southbound side was shut down at Rosecrans Avenue, Caltrans officials said. A hazardous materials team was called out to the scene
Aerial video from Sky5 showed a pickup truck carrying cardboard boxes, some of them toppled over, stopped on the freeway as firefighters responded.
County Supervisor Janice Hahn later said the department found that there was no leak and determined it was safe to reopen the freeway.
The Fire Department tweeted that a small amount of the chemical was found in lanes, but confirmed it was not hydrogen cyanide.
Hydrogen cyanide is an asphyxiant classified as a chemical warfare agent and exposure can be “rapidly fatal,” according to the U.S. Centers for Disease Control and Prevention. The substance is used commercially for fumigation, electroplating, mining, and for producing of synthetic fibers, plastics, dyes and pesticides.
It was later determined the substance in the dropped packages was actually "Thioglycolid Acid," a statement from the California Highway Patrol said. Thioglycolic acid is used to make permanent wave solutions and depilatories, according to the National Institute of Health. It is corrosive to metal and and tissue, and has acute toxicity.
No injuries were reported.
Both sides of the freeway were reopened by 3 p.m.