Any doubt about the skyrocketing popularity of a new anticrime device ended Sunday aboard Delta Airlines' Flight 268, the scene of the first aerial face-off in America's great tear-gas war.

Shortly after takeoff from Seattle, an emotionally disturbed passenger began yelling at a flight attendant and suddenly pulled out a small tear-gas spray canister and threatened her with it.

A married couple immediately rose, held up their own unauthorized canisters and faced down the passengers, airline and FBI officials say.

No one fired, no one was hurt and the instigator was escorted off the plane when the pilot made an unscheduled stop at Salt Lake City. But law enforcement officials in California, where as many as 1 million tear-gas canisters may be sold this year, say they expect to hear many more stories like that involving Flight 268.

The canisters, which are five inches tall and one-inch wide and sell for between $6 and $12, have become an attractive compromise as Americans before more concerned about crime yet maintain a widespread fear of firearms.

Joel Wine of Los Angeles, an instructor in use of the canisters, said demands for classes in the first two months of this year were "incredible" and included requests from many companies organizing classes for employes.

Use of the devices has grown so fast that police departments, legislatures and even the Federal Aviation Administration have been struggling to cope.

"We've had guys in fender-benders on the highway get mad and fire their canister at the other driver," said Los Angeles police officer Pat Connelly, who also teaches a class on use of the canister.

The aerosol irritant inside has been standard equipment for police officers for several years but only recently has been permitted in some jurisdictions for civilian use. Such canisters are illegal in the District of Columbia and Virginia but may be carried in Maryland if they are not concealed, police said.

Throughout the country, instructors and police officers say, there are reports about use of tear gas in family disputes and in some crimes.

Robert Boxer, president of a Wisconsin company that makes a popular brand of canister, said several men were arrested in Milwaukee recently for using canisters -- not his brand -- against women and stealing their purses.

The sprayed irritant causes an intense burning sensation and can blind a person temporarily and cause incapacitation for several minutes. Two of the Milwaukee victims were hospitalized for concussions suffered when they fell during the attacks.

Boxer, president of Aero/Chem Corp. of Milwaukee, said a majority of states allow private use of canisters in self-defense. But controls sometimes are lax.

A Los Angeles journalist who recently took a required two-hour course for her certificate to buy a canister said the final test was administered by a fellow student. The course supervisor never checked her answers.

"Policemen are making a lot of money teaching these courses [which charge about $25-$35 per person]," said Jim Fraser, a sales manager at Cheshire and Perez, a leading police equipment outlet in Monrovia, Calif."Some are making more on the classes than at their jobs."

All of the canisters aboard Flight 268 were there illegally, and FAA officials in Seattle say they are investigating how the devices got on board.

The disturbed passenger on Flight 268 is to be sent to a mental health clinic, and no criminal charges will be filed against him, the FBI said. Charges may be filed against the couple who subdued the passenger, the FBI said.