A task of federal inspectors has been dispatched to Norhtern Virginia to investigate complaints of safety hazards at commercial and industrial construction sites in the rapidly developing Washington suburbs.

The investigation was prompted by complaints from leaders of building trade unions that state inspectors were failing to enforce safety regulations.

"Workers out there are getting hurt, and they can't get any justice out of Virginia," said George Taylor, director of the AFL-CIO's occupational safety and health office.

"It's true we're responding to complaints," said Patricia Clark, acting administrator of the federal Occupational Safety and Health Administration's regional office in Philadelphia. "That's normal working practice."

The question of whether Virginia's inspectors are adequately enforcing job safety rules has been the subject of a prolonged debate between state and federal authorities.

Several Northern Virginia politicians have maintained that local governments should use their own building inspectors to enforce the safety regulations in the suburbs, citing a paucity of state inspectors.

State officials have rejected this as improper and have said that the state inspectors alone are empowered to enforce the rules under an agreement with the federal government.

"We're trying to get the Virginia plan withdrawn," said the AFL-CIO's Taylor yesterday. "There's not enough inspection, and there is a very poor law. You've got a shambles in that state."

State officials could not be reached for comment yesterday, but one construction industry executive claimed the federal intervention was aimed at aiding unionism. "I think it's politically motivated," said Thomas G. Tranter, executive director of the Associated Builders and Contractors Inc., which has 300 members in Northern Virginia. "I'd be curious to know how many federal imspectors hold or held union cards," he said. The federal inspection team, operating out of the Falls Church Inn, will investigate major nonresidential construction in Northern Virginia, with most of it in Arlington and Fairfax counties.

Under its agreement with Virginia, the federal government has the right to send its inspectors into the state if the Labor Department believes Virginia is not living up to terms of the agreement. In the past two years, at least 12 persons have died in construction-related accidents in Northern Virginia. Five of those deaths involved cave-ins at building sites.

Taylor said part of the problem is that in Virginia, many of the construction sites have nonunion workers "who may be afraid to make complaints of safety problems. In a union climate, you get a good safety committtee."

Federal occupational safety and health inspectors are not allowed to cover residential construction, which accounts for a good deal of the building activity in Fairfax and Prince William counties. However, Fairfax is in the midst of a boom in office and commercial construction, especially around Tysons Corner.

Gilbert Esparaza, Washington area director of the federal Occupational Safety and Health Administration, said, "I don't see any special problems in one area. I see problems all over."

He said that up to three members of his inspection staff have been detailed to the Northern Virginia task force, which also is composed of inspectors from throughout the country.