Barbecue aficionados in Prince George's County swear that some of the best barbecued ribs around are sold at the side of the road, fresh off an open grill. But the county Health Department contends the outdoor commercial grills pose a health hazard and has stepped up efforts to drive the illegal vendors out of business.

In the face of this mounting pressure, one family is scrambling to keep the fire stoked under their outdoor grill and keep their thriving business.

"When it comes to ribs, no one wants them pot-boiled," an option some lease vendors use, LeRon Chambliss said, as he flipped a slab of pork ribs on the hot grill, the smell of smoked meat filling the air. "They prefer them cooked on a grill with hickory wood and charcoal."

Chambliss and his family own "Chambliss Texas BBQ," one of several outdoor barbecue vendors that line up on Indian Head Highway in Prince George's County. During the Memorial Day weekend, the Health Department received a phone tip that the Chambliss family was operating a barbecue stand without a permit and ordered LeRon's father, Leonidas Chambliss, to close.

The family promptly hitched its large grill to the back of a van and drove 50 feet west into the District. There they resumed their brisk business.

LeRon Chambliss's mother, Doris Chambliss, said her family now operates out of Prince George's and the District, moving its operation to South Capitol Street in the District "once or twice a week," when business is slow in Prince George's. "You go where the action is," she said, adding, "The D.C. police don't bother us as much there."

The Prince George's Health Department has persisted in what has become a cat-and-mouse chase with the Chamblisses, citing the family again last week.

"It's an ongoing problem that's growing, and we're going to respond to it," Health Departmentsupervisor Debra Freeman said about the outdoor barbecue vendors. Freeman said that on weekends when the weather is nice, about six illegal barbecue vendors operate along Indian Head Highway alone.

The department has had difficulties catching the illegal vendors in the past because of their mobility. Also, the vendors usually operate on weekends and after 4 p.m. on weekdays, times when health inspectors are off duty.

Increasingly, the department has depended on phone complaints to locate the illegal food stands.

"We're getting a growing number of complaints as word gets out that it's wrong," Freeman said.

Maryland and Prince George's health department regulations require food vendors to operate out of enclosed booths, which can include vans, in order to obtain licenses. Barbecue vendors who use outdoor grills do not meet the requirement, and operate their businesses illegally.

In the District, with the exception of enclosed hot dog stands, it is illegal to sell cooked foods on the street.

Only at festivals, where the stands can be monitored by health officials, can vendors legally sell food cooked in the open, including barbecue.

However, police Sgt. Jerome Grey, who works with D.C. health officials to enforce food vending regulations, said illegal vendors are a persistent but "slight problem."

According to Freeman, the Prince George's and state regulations are designed to protect consumers from contaminated food.

An enclosed vehicle, she said, helps shield the meat from airborne particles, such as dust, and are more likely to provide adequate refrigeration.

Freeman said that outdoor barbecue vendors often store large amounts of meat -- LeRon Chambliss estimated 60 pounds of pork ribs each day -- in coolers, which are kept in a parking lot.

That kind of setup increases the chance of food spoilage, according to Freeman.

Doris Chambliss insisted that her food is safe.

Her pork ribs, which are seasoned and marinated overnight, are slowly grilled over charcoal and hickory wood for 40 to 60 minutes, ensuring that they're thoroughly cooked, she explained.

Doris Chambliss contends that her licensed competitors produce an inferior and less popular product by boiling the ribs at home and reheating them on a grill or warming unit inside a van.

"It's all a mystique," countered Curtis Corbett of Fort Washington, who has operated a legal barbecue stand on Indian Head Highway for two years. "People smell the smoke, and they think it's good barbecue."

Corbett said he spent more than $20,000 to bring his van up to code. He equipped it with hot and cold running water, refrigeration and a heating unit. Corbett said he grills his ribs on a rotisserie over hickory wood at his barbecue restaurant in New Carrollton and then transfers the meat to a warming unit in the van.

According to Corbett, because he is registered with the Health Department, he is more likely to be inspected than are the illegal vendors, who operate clandestinely. In addition to biannual inspections, Corbett said, the Health Department has paid at least 10 surprise visits to his business this year.

Despite the concerns of the Prince George's County Health Department about the health hazards posed by the outdoor stands, barbecue enthusiasts continue to flock to the Chambliss grill in the evenings and on weekends.

"There's no comparison to the outdoor grill," said Prentis Carmichael of Mount Vernon. "You get to see what you're eating." He said he stops by "Texas BBQ" on his way home at least three times each week.

Pat Buchanan of Oxon Hill says she has tried the ribs from the indoor grills but prefers the Chambliss family's ribs. "You get more of a smoked-type flavor," she said.