Methods and Protocols

      Procedure for accurately quantify water in mainstream aerosol of the Tobacco Heating System (THS or IQOS) aerosol using the in situ extraction method


      Published on
      Aug 17, 2016

      Because the Tobacco Heating System (THS or IQOS, its commercial name) heats tobacco without burning it (combusting) to generate a nicotine-containing aerosol, the composition of the aerosol is significantly different form the smoke generated by combustible product. Indeed, IQOS aerosol contains about 80% of water. Due to this high content of water, the accurate determination of water in IQOS aerosol is addressed by using a modified (compared to the procedure described in ISO 4387 method) extraction methodology which is based on an in situ extraction. Accurate determination of water is of importance as this parameter is used to calculate the ISO NFDPM (Nicotine Free Dry Particulate Matter). Even though NFDPM can be calculated according to ISO in IQOS aerosol by subtracting the water and nicotine from the total particulate matter, this parameter is not relevant to be reported for this product. Indeed, the NFDPM, also called “Tar” in combustible products, contains mainly glycerol and other tobacco constituents that are transferred by heating the tobacco. In addition as opposed to combustible product we have demonstrated that IQOS aerosol does not contain any solid particles1. It is therefore incorrect to express it as “Tar” for IQOS. However, if for any reason (e.g. regulation) NFDPM must be reported or printed for IQOS, the measurement of water must be done accurately as it has a significant impact on NFDPM.

      This document provides a detailed description of these modifications and step by step instructions for collecting the aerosol of IQOS using an in situ extraction method for the quantification of water, nicotine and glycerol.