Are soy candles better for my health than conventional wax candles?
No. But there are other good reasons to use soy candles over paraffin: they're cheaper, they burn cleaner, and they're easier on the planet.
Protect the earth: Soy candles are made from soybean oil and beeswax, two renewable resources, whereas paraffin is a by-product of petroleum. Soy candles also produce less soot, although neither kind poses a serious risk to asthma or allergies unless you're standing over the flame.
Use only natural scents: It's best to use candles scented with natural essential oils, especially if you have any respiratory issues. Avoid synthetic scents and clear your home of any strongly scented potpourri or air fresheners.
Protect your skin: When you burn a synthetically scented candle, the oils vaporize; if you're close enough to come into contact with them, you put yourself at risk of developing contact dermatitis, a type of rash.
Read the label: Look for soy candles labeled 100 percent soy. (Some "soy" candles also contain paraffin.) No matter what type of candle you burn, open the windows and air out the room afterward.
—Leonard Bielory, M.D., professor at UMDNJ–New Jersey Medical School, Newark, N.J.