It's a burning (sorry) issue among candle makers - Paraffin (otherwise known as mineral Wax) or Soy.
We use soy, and this is why:-
Soy Wax is Natural, derived from 100% renewable soybeans while paraffin is a crude-oil by-product
Soy Wax is 100% biodegradable while paraffin wax is not
Soy Wax candles burn cooler and slower than paraffin candles, which means they typically last 30-50% longer than a paraffin candle
Soy Wax releases fragrance easier than paraffin candles to give a richer fragrance throw and 'Pot Pourri' effect when not lit
Soy Wax is cleaner burning with no toxins, carcinogens or pollutants which means it's less likely to trigger allergies