Fairfax County officials are not quite ready to "thank heaven for 7-Eleven."

To the county's way of thinking, the stores with their red, white and green signs, frozen ice Slurpees, and "hot to go" foods are in the same category as slaughter houses, vinegar and glue factories, fish canneries, iron smelters, garbage incinerators and "any other" business that "might be injurious or noxious by reason of odor, fumes, dust, smoke, vibration, noise or other cause."

As a result the county's supervisors have declared that 7-Elevens and similar convenience food stores must get a special-use permit from them before they can be built -- even if the store already has the proper commercial zoning.

To the Dallas-based Southland Corp., which owns and operates 7-Elevens and has turned their convenience into a multi-million-dollar empire, the county's arguments are infuriating. The firm challenged the county's reasoning and won a fair ruling from a Fairfax Circuit Court judge overturning the permit requirement.

Neither the High's Dairy chain nor other businesses affected by the permit rule have challenged it in court.

7-Eleven argued -- and Judge Lewis Hall Griffith agreed -- that "there are no substantial differences" between a convenience food store, which needs the permit and a supermarket, which doesn't. Furthermore, he dealt the county's case a serious blow, folding that Fairfax's lawyers had failed to produce "credible evidence" that convenience stores are more detrimental to the public's health, safety and welfare than the unregulated supermarkets.

Southland has argued that the Fairfax classification is discriminatory, and violates not only state zoning law, but "the equal protection" clause of the 14th Amendment of the U.S. Constitution.

"If a supermarket were planned for the same site as a quick-service food store," it would not need a special-use permit," said the firm's attorney, Michael R. Vanderpool.

The Virginia Supreme Court, which in the past has been less than sympathetic to Fairfax's efforts to place controls on developers, has agreed to hear the county's appeal. Fairfax lawyers had argued that "there is clearly reasonable basis for singling out" convenience stores and not applying the same restrictions to other food stores such as supermarkets.

Assistant County Attorney Karen J. Harwood said convenience stores can create "adverse traffic impact." She said most of their business occurs during the morning and evening rush hours, when the roads already are crowded with cars going to and from work.

"What's good for business might not be good for land use," she said. "Just because you can make a profit off the operation doesn't mean it's a good idea."

Fairfax County has a long history of trying to impose controls on both residential and commercial growth. The special-use permit is an outgrowth of pressures from suburban residents who object to certain businesses which they feel will disrupt their neighborhoods.

County officials say they fear if the lower-court decision against them is upheld, the county could find itself forced to defend its entire permit process.