A study found that the concentration of volatile organic compounds generated indoors by heated tobacco products is about one-tenth that of conventional cigarettes.
However, harmful compounds such as formaldehyde and acetaldehyde were also detected in heated tobacco products. The concentrations of indoor pollutants varied depending on usage and ventilation.
A research team led by Kim Ki-hyun, a professor in the Department of Civil and Environmental Engineering at Hanyang University, published findings in September 2025 in the international journal "Journal of Hazardous Materials," analyzing the impact of heated tobacco products on indoor air quality.
To compare indoor air pollution from heated tobacco products and conventional cigarettes, the researchers conducted experiments in a 33.8㎥ smoking booth. They used one, three, and six sticks each of heated tobacco products and conventional cigarettes. They measured the concentrations of volatile organic compounds and carbonyl compounds in indoor air with the booth door closed and open. They also examined how the concentrations changed 5, 10, and 20 minutes after smoking.
As a result, the concentration of volatile organic compounds generated by heated tobacco products was lower than that of conventional cigarettes. When six sticks of heated tobacco products were used, the concentration of volatile organic compounds measured in the closed booth was 1,347 ppbC, while conventional cigarettes measured 14,834 ppbC, about 11 times higher. ppbC is a unit that expresses the concentration of organic compounds in air based on carbon content.
With ventilation, heated tobacco products measured 416 ppbC and conventional cigarettes 3,435 ppbC. Heated tobacco products typically heat tobacco at 250–350 degrees Celsius, while conventional cigarettes burn at 800 degrees. The research team said this leads to differences in the concentrations of harmful substances emitted by the two products.
A range of harmful substances was also detected in heated tobacco products. The researchers analyzed 14 types of volatile organic compounds and 10 types of carbonyl compounds. Isoprene, dodecane, and acetaldehyde were identified as major components in heated tobacco products. These can affect the human body.
Indoor pollutant concentrations varied by usage and ventilation conditions. For both heated tobacco products and conventional cigarettes, harmful substances accumulated and concentrations rose as usage increased. Concentrations were lower when the booth door was opened for ventilation than when it was closed.
The researchers compared volatile organic compounds generated by heated tobacco products with indoor cooking activities. They found that heated tobacco products emitted fewer pollutants than some cooking activities. The researchers said, "We analyzed the emission characteristics of harmful substances from heated tobacco products in indoor environments and compared them with conventional cigarettes and cooking activities."
References
Journal of Hazardous Materials (2025), DOI: https://doi.org/10.1016/j.jhazmat.2025.138790