HPHC levels in heated tobacco aerosol

Comparing HPHC levels using the PMI 58 list

The PMI 58 is an internal list of HPHCs, which prioritizes 58 constituents and analytes representing all major toxicologically relevant chemical classes of compounds present in both the particulate and gas-vapor phases of cigarette smoke. This list was established to enable the comparison of HPHC levels between THS aerosol and cigarette smoke. It also helps us monitor how effectively we are reducing or eliminating HPHCs emitted by THS, while also meeting regulatory requirements worldwide.

The PMI 58 list of HPHCs is presented in the table below, which also includes comparisons of constituents in THS aerosol with lists of priority smoke constituents proposed by the World Health Organization (WHO) Study Group on Tobacco Product Regulation (TobReg) (WHO, 2007; WHO, 2008; WHO, 2015), Health Canada (Health Canada, 2000), and the U.S. Food and Drug Administration (FDA) (U.S. FDA, 2012a and b).

The PMI 58 list covers:

• Smoke constituents determined by the International Organization for Standardization (ISO) standard methods (carbon monoxide [CO], nicotine, nicotine-free dry particulate matter [NFDPM], total particulate matter [TPM], and water)
• Chemical constituents representative of all major toxicologically relevant chemical classes of compounds, present in both the particulate phase and gas/vapor phase of cigarette smoke; and
• Compounds reported in cigarette smoke which have been classified as either known or probable human carcinogens by the International Agency for Research on Cancer (IARC, 1985). 

Laboratory studies have shown that THS aerosol contains significantly lower levels of HPHCs compared with the smoke of a standard reference cigarette (3R4F), with an observed average reduction of 90–95%.

Analyses were conducted by Labstat International ULC, an independent ISO 17025 accredited laboratory in Kitchener, Ontario, Canada. All aerosol and smoke collections were performed according to the Health Canada Intense (HCI) machine-smoking protocol.

Results for THS 2.2 (commercialized as IQOS 3 or IQOS ORIGINALS) and THS 3.0 (commercialized as IQOS ILUMA) are showcased below:

Comparing HPHC levels using the FDA 93 list

In 2012, the U.S. Food and Drug Administration (FDA) published a list of HPHCs found in tobacco products and tobacco smoke. This is known as the FDA 93 list, as it comprises 93 compounds or classes of compounds. The FDA 93 is the most comprehensive list to date. It covers toxicants linked to diseases such as cancer and cardiovascular disease, among others.

Below, we’ve listed the levels of those HPHCs (with the exception of nicotine) measured in the smoke of a standard reference cigarette (3R4F) and the aerosols of two versions of THS 2.2—regular and smooth menthol. In all cases where a comparison could be made, we found that HPHC levels in THS aerosol were significantly lower compared with 3R4F smoke, with an average reduction of more than 90.5% on a per stick basis for THS 2.2 Regular and more than 91.0% on a per stick basis for THS 2.2 Smooth Menthol.

Reductions shown in this table are consistent with reduction ranges observed using the PMI 58 list. The similarity of the results between THS regular and THS menthol also show that the reduction in levels of HPHCs is not impacted by the nature of the flavor system.

Aerosol and smoke collections were performed using the HCI machine-smoking protocol, with measurements conducted by Labstat International ULC.