(AP) Hundreds of law enforcement officers are raiding Southern California auto parts shops and other businesses suspected of illegally selling nitrous oxide for use as a recreational drug, in one of the largest such raids to date.

Los Angeles County sheriff’s Lt. Rod Armalin says nearly 300 law enforcements officers served 17 simultaneous search warrants Friday.

It’s the result of a year-and-a-half-long joint operation dubbed “No Laughing Matter” by the Food and Drug Administration’s Office of Criminal Investigations and the Los Angeles County Sheriff’s Department.

FDA special agent Lisa Hartsell says the agency has recently focused on the illegal use of nitrous oxide.

The gas is legally used by dentists for anesthesia, to pressurize whipped cream canisters and to speed up race cars. But authorities say its illegal use has spurred fatal car accidents, rapes and teen deaths — all in the name of a temporary high.