Back in 2009 researchers at South Carolina State University examined indoor air quality of petroleum-based (paraffin) and vegetable-source (soy) candles to determine if the stream of smoke they emitted posed a danger to the indoor inhabitants. They found that paraffin-based candles emitted toxic chemicals. Soybean candles did not.
The undesired chemicals of the paraffin candles were emitted because the candles are by-products of oil refineries – they put polycyclic aromatic hydrocarbons, one of the most widespread organic pollutants into the air. Soy candles are by-products of vegetables which generally are not harmful to people. So in this research – you need to use soy candles. But…
More recently, scientists writing in the medical journal Regulatory toxicology and pharmacology examined the particulate emissions from petroleum-based wax based scented candles to see if they did indeed provide a health risk. The reason for this research was that it was speculated that “lower quality wax” may burn off polycyclic aromatic hydrocarbons, higher grade wax (vegetable) did not.
In their summary abstract the scientists noted that airborne compounds in the indoor environment arise from a wide variety of sources, not just candles. Regardless of the wax, the candle burn off material maybe safe by itself but when combined with other indoor elements and chemicals it could become harmful.
So they did some tests. After testing the scientists concluded: “On the basis of this investigation it was concluded that under normal conditions of use scented candles do not pose known health risks to the consumer.”1
So in this research, regardless of the wax, if your indoor air is not polluted already the candles are okay, if your indoor air is filled with tobacco smoke or heavy chemicals from cleaners, then the candles can add to the poor air quality. So under good air quality – candles okay – bad air quality – candles no good.
However some were not convinced. In another study researchers suggested that the quality of wax was indeed a heavy influence. All waxes are not the same. Writing in the industry journal Environmental science and pollution research international, Scientists found that there is an expectation that candle composition (the quality of wax) will negatively influence the air pollutants emissions, possibly leading to important differences in the emissions of volatile organic compounds and polycyclic aromatic hydrocarbons.
In this regard, the purity of the raw materials and additives used can play a key role as it has been found that wax quality strongly influences the air pollutant emissions. 2
Now of course there are not scientific papers without money involved – so depending on who you believe you can find that: There are no problems at all with any quality of wax candles by themselves – that from the National Candle Association (link to citation)
So what is the answer then? Let’s ask the scientists of Iowa State University who you would think would be very partial to vegetable based candles:
“Partially hydrogenated soybean oil, referred to as soywax, is gaining attention as a renewable and biodegradable alternative to paraffin wax for use in candles. However, current soywax candles suffer from several problems, especially poor melting and solidification properties. (Note: Partially hydrogenated soybean oil has been documented as one of the most harmful ingredients in processed foods.)
Fully hydrogenated soybean oil exhibits improved melting properties but owing to its fragile texture, it is not yet acceptable in most candle applications. The scientists found that adding cottonseed oil and paraffin made for a better burning candle and maybe a little less harmful.3 Seems like a solution but for those who want pollution free candles Green America says:
Buy 100 percent beeswax candles with cotton wicks, which are free of toxins. Beeswax can cost as much as six times the price of paraffin, so many candle manufacturers blend paraffin with their beeswax to cut costs. Be sure your candles say 100 percent beeswax on the label.
The reality of it all – if you have people in the home who have respiratory problems – it is probably a good idea to get as toxic free as possible. If you like candles with your bath – no matter the quaility of the candle – if your bathroom smells like lemon fresh industrial cleaner – it probably wont matter what candle you burn.
References
1. Petry T, Vitale D, Joachim FJ, Smith B, Cruse L, Mascarenhas R, Schneider S, Singal M2. Human health risk evaluation of selected VOC, SVOC and particulate emissions from scented candles. Regul Toxicol Pharmacol. 2014 Jun;69(1):55-70. doi: 10.1016/j.yrtph.2014.02.010. Epub 2014 Feb 26.
2. Derudi M, Gelosa S, Sliepcevich A, Cattaneo A, Cavallo D, Rota R, Nano G. Emission of air pollutants from burning candles with different composition in indoor environments. Environ Sci Pollut Res Int. 2014 Mar;21(6):4320-30. doi: 10.1007/s11356-013-2394-2. Epub 2013 Dec 7.
3. Journal of the American Oil Chemists’ Society. December 2002, Volume 79, Issue 12, pp 1241-1247
Barry Weiner is a medical ghost writer who is trying to get his own byline going after all these years. Don’t use this information other than as a guide to doing your own research – research is fun – everyone should be a scientist.