Introduction:
Dry herb vaping has become quite popular especially among young users. This could be attributed mainly to the opinion that herbs are natural products and, because of that, their vapors do not contain any harmful substances. Thus, herb’s vaping is suggested as a healthy alternative to tobacco products. This opinion is strengthened due to the already known pharmaceutical properties of a variety of herbs. However, the published works about the emissions during herbs vaporizing is very limited today. The objective of the current study is to examine the emissions of Particulate Matter (PM) and Black Carbon (BC) during chamomile vaping.

Material and Methods:
Organic chamomile was vaporized using a temperature-controlled, electrically-driven commercial vaporizer. In average 0,085g of chamomile was used to load the device before heated until evaporation at 195, 210 and 225oC. A peristaltic pump is connected to the vaporizer to collect the emissions. Pump flow rate was set to 35ml per minute and puff interval at 30 seconds. Τhe puff duration was 2 and 5 seconds and every session lasted for 7 puffs. PM and BC emissions were measured in real-time using a Light-Scattering Laser Photometer and an Aethalometer, respectively.

Results:
During the first two puffs, a very small concentration of particles is emitted, which increased to reach a maximum at the 4th puff and decrease at the next puffs. Particles emission per session increase with temperature and with puff duration.PM emissions can reach almost 100,000 mg/m3 at the maximum values. BC corresponds to 0.04% of PM emissions for 2 secs puff and 0.05-0.07% for 5 secs puff.

Conclusions:
Chamomile used in an herb vaping device produces a non-negligible concentration of PMs. The production of PMs depends strongly on the vaping conditions. These findings highlight the necessity for future research in the field of dried herb vaping.