Fairfax City Police Chief Loyd W. Smith has ordered his department to stop using Boy Scouts to attempt to make illegal beer purchases after being notified that the national scout organization disapproves of the practice.

His was the first such action by police in several area jurisdictions, including Fairfax, Montgomery and Howard counties, that have used Explorer scouts to test whether merchants will sell alcoholic beverages to underage youths.

All the area police departments have termed the scout operations successful. "There's no other way we can do it," Chief Smith said yesterday. "All our officers are over 21."

Brian Archimbaud, national director of Law Enforcement Exploring, a branch of the Boy Scouts of America that works with police agencies, said that he contacted the National Capital Area Scout organization in Washington last week after reading news reports of police-scout operations in the area.

He cited a three-year-old policy by the national organization advising "against the use of youth members in illegal or hazardous operations" and saying specifically "that the use of underage Explorers to make illegal purchases of alcoholic beverages is clearly a violation" of that policy.

Montgomery and Fairfax County police say they have not received notification of the policy, but Fairfax County police spokesman Warren Carmichael said: "I'm not sure what that would have to do with what we're doing."

"It was not an Explorer activity," he said. "We were soliciting volunteers, people known to be reliable, between the ages of 16 and 18, and they responded. They just happened to be Explorers."

"I don't think it's hazardous," said Fairfax City police dispatcher Anita Colvard, a former Explorer and consultant to a scout post. "And if it's run by police officers, I don't see why it's illegal. I know they're doing it in Florida a lot. But the BSA is somewhat conservative."