Joining a national movement for food safety, restaurant inspectors in Philadelphia have abandoned the "floors, walls, ceilings" focus that experts say catches chipped paint but often misses real public health threats such as undercooked food and chefs' unwashed hands.

Instead, the city is phasing in a more scientific, "risk-based" approach that emphasizes food workers' knowledge and behavior - do they know how contamination is spread and how to prevent it? - and calls for more frequent inspections of eateries that pose greater risks.

Philadelphia is playing catchup in adopting changes that most counties around here have already made, in some cases many years ago. Yet the city's new approach is expected to mean more inspections of the 12,621 establishments that sell or serve food - four times a year at institutional kitchens, for example - than most places.

Still, this region is hardly progressive compared to places like Toronto, which posts red, yellow or green signs in restaurants, or Los Angeles (A-B-Cs), or Denmark (smiley faces). No county in the Philadelphia region requires restaurants to post full inspection reports on location.

It's not clear that food is any safer when there is greater transparency or even more frequent inspections, "but it does get people to think about food safety," said Doug Powell, an associate professor of food safety at Kansas State University who operates BarfBlog.

At the Germantown Home, which prepares three meals a day for the nursing home's 180 residents, a city inspector using the new format found no major violations in June. But the inspector "asked more about personal hygiene, food temperatures, and suggested that I start using test strips daily for the dish machine," said food service director Nicola Burke.

In Center City, an April inspection before the opening of Noble: An American Kitchen found violations in two categories that are considered food-borne-illness risk factors: towels and wash-your-hands reminder signs were not provided at all hand-washing sinks, and the air temperature of an empty walk-in refrigerator was too warm.

Both were corrected and the restaurant passed the next day, said chef-owner Steven Cameron, who had not gone through an inspection under the city's old system but said this one was similar to what he had experienced in three other states.

(To be fair in naming restaurants, The Inquirer asked the city about nine major establishments mentioned in a recent article by restaurant critic Craig LaBan about Restaurant Row. Four had been inspected under the new program; just two were beyond the city's 30-day confidentiality period for reports. Only Noble had risk-factor violations on an initial visit.)

Food safety has been rising on the national agenda ever since an E. coli outbreak linked to undercooked hamburgers sickened 600 people and killed four children in 1993. Big outbreaks seem to be coming more often, but even the 22,000 cases of salmonella from tainted peanut butter last winter amount to merely an asterisk in the estimated 76 million illnesses a year in the United States caused by contaminated food, perhaps half of it consumed in restaurants.

Inspections traditionally have focused as much on appearance as on cooking temperatures. And they often made little distinction between sushi bars that serve raw fish and drug stores that sell prepackaged food.

"What we've learned over time is, not everything is equal," said Don Schaffner, a professor of food microbiology at Rutgers University.

In the past, Philadelphia also failed to keep up with inspections, falling to an average frequency of once every 15.4 months as recently as 2006. An Inquirer investigation that year found the inspection program here was the weakest of the nation's 10 largest cities by some measures, with visits to restaurants far less often.

The interval between inspections improved to once every 12.8 months as of January through March 2009, the latest figures available - slightly worse than the average 11.5 months for the Pennsylvania Department of Agriculture, which conducts most inspections in the state, and less frequent than the once-a-year minimum required by both the city and the state.

Officials say the record has improved since the new inspection program kicked in several months ago, but statistics are not yet available.

A typical surprise visit is different now, said Delores Brokenborough, who supervises inspectors in West and Southwest Philadelphia and also conducts her own.

In the past, "we would see what we saw and write it down," she said. "Now we want to know: What behavior is causing this problem, and do you know how to fix it?"

To protect the public from communicable diseases, inspectors used to look for, say, a gash on a food worker's hand. Now, Brokenborough said, she asks a designated employee what illnesses should prevent someone from working directly with food (hepatitis A, shigella and salmonella, among others).

She still measures temperatures (cold food waiting to be served must be 41 degrees or lower; hot food, 135 or higher; water for hand washing, 110 to 125). But these are now part of 27 points that are considered key to the spread of food-borne illness. Another 27, including several related to appearance, are secondary.

"If you sneeze in the food, you are more likely to make them sick than if you have mouse droppings in a corner somewhere," said Palak Raval-Nelson, chief of the office of food protection since 2007, who is overseeing the transition. Droppings in a salad would be another matter.

Inspectors fill out the forms and make comments on wireless Fujitsu pen tablets that can access a restaurant's history and the city food code, and automatically appear in a searchable database 30 days later. The city says a new restaurant-inspections Web page, with links to full inspection reports, will be up soon.

Inspections in the United States are carried out under a hodgepodge of state and local regulations. Every four years since 1993, the Food and Drug Administration has updated a science-based "model" food code, now well over 500 pages long, but adoption is entirely voluntary.

States and localities "often don't adopt the whole thing, they pick and choose," said Jeffrey C. Lineberry, executive director of the Conference for Food Protection. Inspecting higher-risk eateries more often can cost more, so one barrier to greater adoption, he said, "has been how do you pay for it?"

The Philadelphia Board of Health adopted most of the FDA guidelines in December. "Risk-based" inspections began in February, with institutional kitchens that serve vulnerable populations phased in first; about 3,000 establishments have been inspected one or more times so far.

The frequency of inspections is now determined not just by past compliance records and public complaints but also by the facility's potential to spread food poisoning. The average full-service restaurant will be inspected twice a year - twice the goal in the past.

The changeover is expected to take another year. Meanwhile, city officials say restaurants appear to like the new inspections. Patrick Conway, president and CEO of the Pennsylvania Restaurant Association, says he mainly hears from members who are unhappy, and he has heard almost nothing about this.

But will it matter?

Even quarterly checks provide only snapshots of kitchens that rarely stop a "perfect storm" of events that experts say triggers most outbreaks.

"You need the pathogens present, you need, let's say, [an inadequate] temperature used, you need other steps along the way, the person who washed the lettuce didn't do the job," said Schaffner, the Rutgers microbiologist.

Prevention is really about "the culture of the restaurant," said Ben Chapman, a food-safety extension specialist at North Carolina State University and a contributor to BarfBlog.

Meaning?

"If two workers are from the same restaurant," said Powell, "and one washes his hands, I want one to say to the other: 'Dude, wash your hands!' "