The Fairfax County Board of Supervisors launched a new attack yesterday against unsafe construction practices, voting unanimously to do no business with building contractors guilty of serious safety violations in the last three years.

"I don't think this county has any business working with people who have been in flagrant violation of state and local law," commented Supervisor Alan Magazine (D-Mason), who has been in the forefront of the county's recent crusade against construction-related injuries and deaths.

Fourteen persons have died in construction accidents in Northern Virginia in the last year, two of them in Fairfax County.

The supervisors' action is part of their strategy to force state and federal governments, either individually or together, to bring adequate inspection to construction sites in Fairfax. County officials are scheduled to meet today with representatives of the federal Occupational Safety and Health Administration (OSHA) in an effort to drive that point home.

The supervisors voted last month to sue federal and state officials over safety inspection procedures in Virginia's most rapidly developing county.

Under the proposal approved yesterday, Fairfax County will refuse to award any of its estimated $80 million-a-year contracting business to any organization that has been found guilty of a safety violation that could cause death or serious bodily harm.

Acting County Executive J. Hamilton Lambert ackowledged that the decision will add to the county's contracting costs by cutting significantly the number of contractors who could do business with the county. Lambert declined, however, to estimate how much the blacklisting would cost taxpayers or even how many contractors would be affected.

"There's no way we can possibly tell," Lambert said. "We get contract offers from as far away as Baltimore."

Robert Johnson, executive vice president of the Northern Virginia Builders Association, characterized the board's action as a "blunderbuss approach."

"I don't think you can go onto a building site today and not find a violation," Johnson said. "And a lot of the things that are classified as serious violations by the federal government really aren't all that serious if you and I were to look at them."

Johnson said the Fairfax action would have the effect of eliminating "some of the finest" area contractors, who had been cited last month by a federal investigative task force for safety violations.

The supervisors ordered a study of the economic impact of their action.

They also took a new slap at Virginia safety investigators yesterday, directing county investigators to by-pass state officials and instead work directly with OSHA.

Turning to board chairman John F. Herrity (R), retiring supervisor Warren I. Cikins (D-Mt. Vernon) commented, "You've often said that the way to get through to people sometimes is to whack them on the snout.I think this is one of those times."

Only Herrity voted against that measure, saying it would unnecessarily tie the hands of the county team that is negotiating in an attempt to improve safety inspections.