(Health.com) -- With cheap, chic fare, like arugula pizza, squash empanadas and fish tacos, the country's 15,000-plus food trucks are rolling into virtually every big city and many small towns across the United States.
The burning question: Is it safe to grab a bite to eat from a truck that cooks for hundreds in a space that's a fraction of the size of your kitchen?
For the most part, yes.
"Many of the health inspectors in our office buy lunch from food trucks," says Christie Sweitz, interim supervisor for inspection in Portland, Oregon. "Trucks are required to follow strict guidelines and they are inspected as often as restaurants."
Just as with the fare from their brick-and-mortar peers, though, some meals on wheels are better bets, food safety-wise, than others. Before you line up for that lobster roll, here's what you need to check for:
License. By law, food trucks need one to operate so the local health department can track them for inspections. Why this matters to you: Illegal operators tend to not worry as much about temperature and proper storage as an owner who knows an inspector could drop by at any time.
In Seattle, New York and many other towns, food-truck operators are required to post their license on the window, in a spot where customers can see it. The actual sign looks different from city to city, but in most cases it will have a date, the name of the town and some type of seal. If you don't spot a license, your city (like Phoenix) might not require that it be displayed.
"You can actually ask to see the license," says Sarah Klein, a food-safety expert at the Center for the Science in the Public Interest. "If they can't produce it, find another place to eat and call the local health department."
Good grades. North Carolina, Los Angeles County and a handful of other places require that food trucks post their latest inspection grade on the window. The worse the grade, the greater your chance of getting a food-borne illness.
"I'd feel uneasy about eating at a truck with a B grade because it could have violations like not keeping food at the right temperature or having no soap. And I would never eat at a truck with a C because that's close to being shut down," Klein says.
If your city doesn't post grades, they're likely available on your local health department's website.
Gloves. You might think your biggest worry is that the chicken or beef is undercooked, but you're actually more likely to get sick because a truck (or restaurant) employee has bad hygiene. In fact, one of the leading causes of food-borne illness is contamination from someone's filthy hands.
Ideally, employees should be wearing gloves when handling your food -- and changing them frequently, like after touching raw food -- to avoid transferring bacteria from their fingers to your falafel, says O. Peter Snyder, president of the Hospitality Institute of Technology and Management.
While gloves aren't an absolute deal-breaker -- they aren't legally required everywhere, and an employee without them can handle food safely with utensils and frequent hand-washing -- they're a good sign that food safety is taken seriously at a business.
Even though you can't see every potential problem on a food truck (heck, if you're petite, you can barely reach the window), you still get a closer look at the kitchen than you would in most restaurants. If you spot any of these warning signs, walk away!
Dirty hands. In cities where gloves aren't required, employees have to wash up frequently. You can get a good idea of someone's hand hygiene by looking at their nails, Snyder notes.
"Dirt under nails is a breeding ground for bacteria," he says. "Nails should be clipped short to limit dirt accumulation."
Dangling hair. If employees don't pull back their hair, they'll be constantly moving it out of their eyes, then touching your food, which could get contaminated with bacteria from their face. Untidy hair can also be a sign that a business isn't following the safety rules in general.
Lukewarm food. "Temperature problems are one of the most common violations in food trucks," says Dr. Jonathan Fielding, director of public health for Los Angeles County. Salads and deli sandwiches should feel like they're straight out of the fridge, while soup and burgers should be piping hot.
Messy sink. If you have a chance to peer inside the truck, try to find the sink. Look for soap, towels and a clear place for hand-washing. If the area is stacked up with dishes or there's no soap in sight, where are employees going to wash their hands after coughing, sneezing or touching raw meat?
Copyright Health Magazine 2011