Many people, including myself 5 years back, did not know what regular candles are made from. They are made from paraffin wax, which is made from petroleum, which is refined to produce diesel fuel. When you light those candles, you are breathing these toxins that are known to cause health hazards to humans! Those black rings you see on your candles during and after you burn them is what is in the air. Some people even say the black soot from paraffin candles stains their walls!