Candles and Incense sources of Indoor Air Pollution

Candles and Incense sources of Indoor Air Pollution

They look nice and they smell even better, but unfortunately most of them are made of toxic ingredients and when you light them, they diffuse all these toxic ingredients inside your house.

Harmful VOCs

Most commercial candles are full of toxic ingredients that many times they don’t even write on the package like Paraffin, Acetone, Trichlorofluoromethane, Carbon Disulfide, 2-Butanone, Trichloroethane, Trichloroethene, Carbon Tetrachloride, Tetrachloroethene, Chlorobenzene, Ethylbenzene, Styrene, Xylene, Phenol, Cresol and Cyclopentene. Most of them are VOCs and the majority of the AQI monitors with VOC sensor will recognize the toxins in the air. Now, when paraffin burned releases toluene and benzene which are highly toxic and carcinogens (these fumes are the same as when diesel is burnt).

A 3% of the candles that are sold in US contain lead wicks which have the potential to generate indoor airborne lead concentrations of health concern.

Particulate Matter

Burning an incense was found to generate large quantities of particulate matter. It is estimated the median diameter of particulates in aerosols to be between 0.24 and 0.40 μm, and the diameter of candle flame particles have been measured between 20 and 100 nm and 100 and 800 nm depending on the mode of burning that particles could deposit in the respiratory tract.

“Safer options”

Candles made of 100% Pure beeswax. This kind of candles are unscented, but you can buy or add your personal scents like cinnamon or cloves which work perfect in winter seasons and give a warmness in the room especially when we don’t ventilate the room often due to cold outside. The scents have to be 100% pure organic essential oils.

There are also some claims that beeswax candles emit negative ions, which reduce positively charged ions in the air. The air inside the house has a higher concentration of positive ions which make dust/pollen/mold move around the house easier and the positive ions are created by the electrical devices or by friction or by the A/C systems.


Conventional or beeswax candles will reduce the amount of Oxygen O2 inside a room in case your house is tidy closed like in winter season and will increase the amount of Carbon Dioxide CO2, so I wouldn’t recommend burning candles. Find alternative and healthy options to aromatise a room like boiling water with cinnamon, cloves, orange and lemon peels.

On the next post I will conduct and experiment to see how much CO2 is produced by burning some candles inside a room.


5 thoughts on “Candles and Incense sources of Indoor Air Pollution

    • Hi, the ultrasonic diffusers are safe, they just add a small amount of moisture in the room plus the scent of the essential oil. Make sure the water is clean and you use 100% pure organic essential oil because some people confuse them with fragrances.


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