There’s nothing that says romance like a candlelit dinner – but scientists say burning certain kinds of candles may actually be hazardous to your health.

In a study presented Wednesday at the annual meeting of the American Chemical Society in Washington, D.C., researchers found fumes from paraffin wax candles — the most popular and cheapest kind of candles — can be poisonous and even cause cancer.

They say the candles, made from petroleum, are an "unrecognized source of exposure to indoor air pollution, including known human carcinogens."

For the study, the researchers burned paraffin candles for up to six hours in a small box and then analyzed the results. What they found was that the candles released toxic chemicals into the air.

"Lighting many paraffin candles every day for years or lighting them frequently in an unventilated bathroom around a tub, for example, may cause problems," said Amid Hamidi, the co-author of the study at South Carolina State University.

However, he said an occasional paraffin candle and its emissions "will not likely affect you."

Hamidi and his colleagues also tested other candles made from beeswax and soy.

“Although more expensive, apparently [they] are healthier," he said. "They do not release potentially harmful amounts of indoor air pollutants while retaining all of the warmth, ambience and fragrance of paraffin candles."

Click here for more information from the American Chemical Society.