Measurements of Aerosol Size Distribution and Particle Number Concentration from a Novel Heated Tobacco Capsule (HTC) Prototype
CHIH-HSIANG CHIEN, Hiral Patel, Matt Melvin, Weiling Li, Yezdi Pithawalla,
Altria Client Services LLC Abstract Number: 710
Working Group: Instrumentation and Methods
AbstractHeated Tobacco Products (HTP) contain a tobacco substrate that is heated to low temperatures (below 350°C), resulting in an inhalable nicotine-containing aerosol. For HTP, test data on aerosol design parameters, such as count medium diameter and particle number concentration are required for regulatory submissions as per the Premarket Tobacco Product Applications and Recordkeeping Requirements Final Rule issued by the Food and Drug Administration in 2021. Currently, there is no defined standardized methodology for HTP aerosol characterization. The objective of this work is 1) to present the measurement methodology we developed, and 2) to compare the results from the analysis of a novel heated tobacco capsule (HTC) prototype to those from the analysis of other HTPs. The HTC prototype consists of a hand-held battery-operated device (BVR 3.2) and a disposable tobacco-containing capsule that is inserted into the device. HTP aerosol was generated under an intense puffing regime (ISO 27088, 55 cc puff volume, 2 s puff duration, 30 s puff interval, and bell-shape puff profile). Due to the high concentration of HTP aerosol, two dilution systems were designed. A scanning mobility particle sizer was used downstream to measure the count medium diameter, while a condensation particle counter was used as the detector for measuring the particle number concentration. The results show the aerosols from different HTPs have count medium diameters in the range of 100 to 200 nm, and particle number concentrations around 10
9 particles/cm
3. Additionally, we developed a low-flow cascade impactor method coupled with a pressure-feedback loop interface for aerosol size measurement. The impactor sampling system was designed to control humidity to minimize aerosol evaporation. The results of measurement using different methodologies will be discussed.