GREENSBORO, N.C. - A 2 Wants to Know viewer called worried about foam take out containers. Jason asked us if they are safe. His concern: the chemicals that could leach out when hot food comes in contact with the foam container.

The expert we used to verify if foam containers leach out dangerous chemicals as Mike Schade from Safer Chemicals Healthy Families and a slew of government research. That includes findings from National Institute of Environmental Health Sciences.

The chemical in question is called styrene. Government research shows styrene is "reasonably anticipated to be a carcinogen" with "increased risks for leukemia and lymphoma and genetic damage in white blood cells." But in food containers levels of Styrene are "very low."

Still the group Safer Chemicals Health Families says there's a hole in the research and we don't know if those "very low" levels build up over time and cause problems. Plus:

"We don't know how it impacts vulnerable populations like pregnant women," Schade said.

So to verify: foam containers do leach out chemicals when they come in contact with hot foods, but there are no immediately health risks. What's questionable are the longer term impacts. Those are still unclear.

However one thing we know for sure: Exerts says the bigger concern with using foam containers is that you're putting the factory workers who make them at risk. Since they deal with the chemical in much higher levels.

"By using foam products we play an important role in contributing to the health problems they face. So consumers can play an important role in driving these products out of commerce," Schade said.

And if you're really concerned about Styrene, stop smoking. Tobacco users take in much more of the chemical than you could ever get from the food containers.