Many people prefer soy wax candles over paraffin candles due to their clean burn and eco-friendliness. But, what happens to the burnt wax and are they safe to use? The answer is yes, soy wax candles burn clean and do not emit harmful chemicals into the air. The wax tends to evaporate as it burns, leaving behind no carbon residue. Additionally, soy wax candles can be used safely in AC compartments, but it’s always best to use a smaller sized candle and avoid leaving it unattended in a closed room.