Improper cooking techniques have resulted in "dangerously undercooked" hamburger patties being served at Burger King restaurants across Washington state, and health officials are concerned the problem could be happening in franchises nationwide.

The Tacoma-Pierce County Health Department first reported the problem on July 29 after a routine health inspection resulted in a "potentially hazardous" violation at a Burger King in Puyallup. The inspector expressed concern to her supervisors that the undercooked meat was due to a glitch with equipment, and the incident might not be isolated.

"So we went ahead and proactively inspected all 13 of their outlets in Pierce County," said Dr. Anthony Chen, Director of Health for the Tacoma-Pierce County Health Department. The inspector was right; roughly half of Pierce County locations were serving undercooked meat.

"We spoke to the Department of Health and turned it over to them," Chen said.

After discovering similar violations across at least 10 counties statewide, the State Health Department sent Burger King a letter on September 1, with their findings.

"We are deeply concerned about reports relating to undercooking hamburgers at many Burger Kings in our state," read the letter, obtained by KIRO Radio. "Inspection reports from several of our local health jurisdictions show a disturbing trend."

Among the potential dangers detailed in the letter was a concern with the "Duke Flamebroiler," the piece of equipment that is meant to give Burger King hamburgers their signature flame broil. Products coming off the broiler were sometimes undercooked as "broken ceramic tiles" inside the units reduced the cook temperatures and allowed insulation to fall onto the food.

There were also several concerns with employee error. For instance, employees "did not know how to take final cook temperatures of burgers." Some workers "did not know that undercooked patties should be discarded," and believed a brief microwave step would "remedy" any issues with undercooking.

State health officials say they are not aware of similar systemic problems with undercooked meat at other chain restaurants and are concerned the problem presents a serious safety concern to consumers if not addressed.

"We wanted to make sure we took care of business immediately," said Dave Gifford, Food Safety Program Coordinator for the Washington State Department of Health. "Obviously we're sensitive to these issues because of the Jack in the Box outbreak from about 20 years ago. We know about the concerns with undercooked hamburgers here in Washington state and we want to avoid that."

Just hearing the phrase "Jack in the Box outbreak" is enough to make some people in the Northwest cringe. The 1993 E. Coli outbreak sickened more than 700 people, most of those in Washington state. Four people were killed in the ordeal, which was the direct result of undercooked hamburgers.

"What Burger King doesn't want to see happen is another Jack in the Box case and that certainly could happen," said Bill Marler, a Seattle food safety attorney who handled some of the high-profile cases related to the Jack in the Box outbreak. "It's likely that if there is an ongoing problem with these grills, it's not just in one restaurant or in a handful of restaurants. It may be in literally dozens or hundreds of these restaurants. If they're not doing something about it and you've got an outbreak that occurs, I wouldn't want to be Burger King."

Listen to Bill Marler, food safety attorney

While there have been no reports of people sickened by undercooked patties, the company has said it is taking proactive steps to ensure that doesn't happen.

"Burger King Corp. has recently been made aware of the findings from the Tacoma-Pierce County Health Department and is investigating the matter to determine if all proper cooking protocols were followed," Denise Wilson, Global Communications Manager for Burger King, wrote in an email to KIRO Radio. "Additionally, BKC has been in contact with the local franchisees and they are taking immediate corrective measures to ensure that their restaurants are meeting the company's stringent food safety standards."

After KIRO Radio initially aired this story, Burger King Corp. sent a revised statement saying they would conduct retraining sessions today with franchise owners in Washington state, calling it an "abundance of caution."

"These franchise operators are now taking immediate action to ensure that their restaurants are meeting the company's stringent food preparation procedures, which include cooking hamburger patties to a target temperature of 165 degrees, as well as, verifying cooking temperatures at least four times a day."

The State Department of Health has said local officials will conduct follow-up inspections to ensure the Burger King restaurants have made necessary changes to cooking time and temperatures. The Tacoma-Pierce County health Department said they did not believe the initial violations were enough to notify the public about a potential health hazard.

"As far as we know, they are taking care of it and addressing it," Dr. Chen said. "We should feel confident that the food in these restaurants is safe to eat."

But Marler believes the danger to the public is imminent if the problem is not addressed immediately at locations across the country.

"Just undercooking things by 10 degrees can cause a significant public health concern. It could allow E. coli or salmonella to remain in the hamburger," he said. "A child might be ingesting literally hundreds of these bacteria. It's the reason why cook temps are 160 degrees for hamburgers; slight variations in temperature can mean the difference between life and death."

Brandi Kruse, 97.3 KIRO FM

You might also be interested in:

• Washington State Department of Health's inspection findings
• Statement from Burger King Corp.