Indoor air quality risks from candles and incense

Experts and research indicate that burning candles and incense in enclosed spaces can release various pollutants into the air. These substances include fine particulate matter (PM2.5), black carbon, polycyclic aromatic hydrocarbons, nitrogen oxides, and formaldehyde.

The composition of wax and wicks significantly influences emission levels. Specifically, scented candles are noted for posing allergy risks and potential harm to pets, while incense sticks are identified as a potent source of fine particles that may contain known carcinogens. Environmental factors, such as drafts causing unstable flames, can also lead to spikes in particulate matter emissions.

To mitigate health risks, consumer guidance suggests trimming wicks to approximately one centimeter, avoiding drafts, and using a candle snuffer or dipping the wick into liquid wax to prevent smoke. Thorough ventilation after use is also advised. Additionally, users are cautioned against using aluminum foil reflectors that could cause excessive heat buildup and wax fires.