Article 20 of the European Tobacco Products Directive (EU-TPD) limits the nicotine level in e-liquids to 20 mg/mL. After this regulation went into effect, many vapers were forced to switch to lower concentrations of nicotine which equates to more intensive puffing, and hence increased inhalation of harmful compounds.
The study titled Compensatory Puffing With Lower Nicotine Concentration E-liquids Increases Carbonyl Exposure in E-cigarette Aerosols, published on Nicotine and Tobacco Research, Oxford Academic, looked into whether this more intensive puffing leads to inhaling higher levels of carbonyl compounds, namely formaldehyde, acetaldehyde, acetone, and acrolein.
The above compounds were measured in liquids and aerosols from nicotine solutions of 24 and 6 mg/mL. Aerosols were produced by using a smoking machine which was configured to replicate the puffing patterns obtained from 12 seasoned e-cig users.
Sadly, the Carbonyl levels in aerosols from the puffing regimen from the nicotine solution of 6 mg/mL were significantly higher (p < .05 ) than those in 24 mg/mL nicotine solution. “For the 6 and 24 mg/mL nicotine aerosols respectively, means ± SD for formaldehyde levels were 3.41 ± 0.94, and 1.49 ± 0.30 µg per hour (µg/h) of e-cigarette use. Means ± SD for acetaldehyde levels were 2.17 ± 0.36 and 1.04 ± 0.13 µg/h. Means ± SD for acetone levels were 0.73 ± 0.20 and 0.28 ± 0.14 µg/h. Acrolein was not detected.” read the study results.
Lowered nicotine does not equate to minimized harm
This study clearly indicates, that limiting the amount of nicotine in e-cigarettes (and other tobacco products for that matter), does not equate to harm reduction. Nicotine addicts who are looking to satisfy their addiction, will just increase the frequency with which they use their devices in order to match up the nicotine levels they are used to, leading to an increase in consumption of any other risky substances that the vapor may contain.
“Higher levels of carbonyls associated with more intensive puffing suggest that vapers switching to lower nicotine concentrations (either due to the EU-TPD implementation or personal choice), may increase their exposure to these compounds. Based on real human puffing topography data, this study suggests that limiting nicotine concentrations to 20 mg/mL may not result in the desired harm minimization effect.” concluded the study.
When vaping patterns matter
Scientists such as Konstantinos Farsalinos, Riccardo Polosa or Jacques Le Houezecoften explain in their public statements that it is preferable to increase or keep nicotine levels high and vape less, than to reduce nic level at any cost but increase the volume of vapor inhaled daily.
Some economic data, however, clearly show that e-liquids in 6 mg / ml have gained the upper hand over liquids with more nicotine. This trend is accompanied by atomizers oriented towards vapor production, very low resistances and mods with increased powers, which consequently deliver more nicotine per puff.
The popularization of direct lung inhalation (DLI) is also of concern to researchers, because if vaping offers a significant tobacco harm reduction, vapor is not completely free of polluants. Increasing the volume of vapor with very large puffs, exposes the user to more toxins, especially aldehydes.