If you buy candles, avoid those that are made out of petroleum wax (paraffin). Paraffin is one of the leftover byproduct residue extracts of petroleum (crude) oil. Other extracts of crude oil include gasoline, jet fuel, kerosene, diesel fuel, and asphalt.
When you burn paraffin wax candles in your home, you are essentially poisoning your air. The soot given off by a paraffin wax candle is similar to the soot given off by engines that burn fossil fuels.
Contaminates in the smoke of paraffin wax candles include benzene, methyl ethyl keyton, naphthalene, and toluene, which are also found in lacquer, paint, and varnish removers, and are known to cause cancer, birth defects, and learning disabilities.
If you purchase candles, buy those that contain lead-free wicks (nonmetallic cores), and are made out of such things as hemp oil, soy, vegetable glycerin, and beeswax, palm wax, or vegetable wax. If you are a vegan you may want to avoid beeswax candles.
If the candle says it contains scented oils, find out if the oil is petroleum based, or if it is a plant oil. Some scents used in oils are also toxic and contain hormone-disrupting phthalates. Choose plant-based oils and scents.
Be aware that even some soy candles contain such toxic substances. Solvent extraction using petroleum chemicals is often part of the manufacturing process.
In addition, avoid candles that have leaded wicks. Candle companies use leaded wicks because they are easier to keep straight. Candles with leaded wicks emit lead into the atmosphere, creating a health hazard.