Candle Fumes

Different substances are emitted as gases from scented candles being burned indoors. They vary significantly from those that are potentially carcinogenic, to those with no known health effect. Studies conducted in environmental test chambers proved that the emission of combustion gases such as carbon monoxide or nitrogen oxide would pollute the indoor environment (13). The more significant concern is the presence of measurable amounts of aldehydes, different polycyclic aromatic hydrocarbons including benzene or toluene, dibenzodioxins, and dibenzofurans in candle fumes that are products of wax, aroma substances, or combustion dyes (14). There reports indicating that people who were exposed to scented candles mainly complained about vertigos, headaches, mucosa irritation, respiratory problems, and dry or irritated throat. Concentrations of pollutants [formaldehyde, CO2, CO, PM2.5, PM10, and volatile organic compounds (VOC)] measured indoor during burning of scented candles, exceeded background concentrations indicating that the candles were the source of contamination (15). According to public health authorities, regular burning of several scented candles indoors can expose us to harmful amounts of organic chemicals (16)

https://cancerpreventionresearch.aacrjournals.org/content/12/10/645