May 25 (UPI) -- A malfunctioning 37,000-gallon tank holding toxic chemicals in Orange County, Calif., no longer poses a threat for a catastrophic explosion, local fire officials said Monday. Nearly 50,000 Orange County residents in and around Garden Grove, Calif., have been evacuated since Friday due to a threat of an explosion at the GKN Aerospace facility, located about 33 miles southeast of downtown Los Angeles. The overheated tank holds methyl methacrylate, or MMA, a flammable, toxic and