Six employes of the Fairfax County Emergency Operations Center went to the hospital during the weekend after lingering fumes from an insecticide sprayed last week made them dizzy and nauseous. The center continued to operate yesterday from two mobile units.

After four months of unsuccessfully fighting fleas, county officials had the center -- which takes the county's 911 calls and dispatches police, fire and ambulance personnel -- sprayed on Thursday.

Although some employes were affected by the fumes on Friday, the problem was thought to be solved by late Friday afternoon. However, during the weekend more employes became sick.

"We set the mobile units back up," said Larry Spaine, director of the county's Department of Facilities Management, which oversaw the spraying operation.

"We think we put too much insecticide down," he said.

The insecticide, Diffusion Spray Concentrate, which is kerosene-based and contains the chemical pyretherin, is a commonly used chemical for ridding areas of fleas.

Keith Rhodes, a laboratory manager with Puritan/Churchill, the manufacturer, said that although it is a safe insecticide, "that doesn't mean you're going to feel great smelling it."

Rose Ann Soloway, of the National Cap-ital Poison Center at Georgetown University Hospital, agreed. "It is one of the least hazardous insecticides," she said.

"I would imagine that breathing kerosene fumes would cause the problems."

The entire carpet in the center was sprayed for fleas Thursday because the infestation was so great, according to Officer David Russell, a police spokesman.

Usually, only the perimeter of an area is sprayed. Yesterday, the carpet was steam-cleaned in an effort to salvage it, he said.

The six workers, who complained of headaches, dizziness and nausea, were treated at Commonwealth Hospital's emergency room Sunday and released, according to a hospital spokesman.

Three were granted short leaves and the others were back on the job yesterday, Russell said.

The EOC continued to take calls on Friday from its offices in the Massey Building at 4100 Chain Bridge Rd., but rotated the workers every 30 minutes.

Outside, they were given blood pressure checks and then assigned to the buses where the calls were dispatched, Russell said.

About 30 minutes later they would go back inside for another stint, he said.

Russell said that the center was continuing the rotation and that the ability to handle calls had not been impaired. He said he did not know when the displaced dispatchers would be able to resume work in the center.

And Spaine wasn't sure about the fleas. One thing was certain: "The smell is gone," he said.