Although HTPs are promoted as products with reduced risk compared to conventional cigarettes, still the detection of carbonyls in HTPs emissions is a fact and needs further research. All five HTPs used here and all sticks used emit carbonyls. Carbonyls' concentrations are found to vary significantly among the different brands, the difference of the sticks, and concerning flavor, and to increase when changing to a more intense puffing regime.
Zervas et al. (Wed,) studied this question.