WASHINGTON (AP) — Eight Senators are calling on the Food and Drug Administration to examine new research suggesting that some electronic cigarettes can produce dangerous carcinogens similar to those from traditional cigarettes.

The lawmakers want regulators to protect e- cigarette users and those nearby from cancer-causing vapors apparently produced by high-powered nicotine devices, known as tank systems. Two studies first reported by the New York Times suggest these devices get hot enough to produce toxic chemicals like formaldehyde, a carcinogen also found in cigarettes.

The findings raise new questions about the safety of e- cigarettes, which some experts have promoted as safer alternatives to cigarettes.

Last month the FDA said it would begin regulating the rapidly expanding e-cigarette field. But the FDA's proposal focuses mainly on e-cigarette ingredients, not the resulting vapors.