Summary Response to UCSF on Reduced Exposure

Response to the article entitled “IQOS: examination of Philip Morris International claim of reduced exposure”

by Gideon St. Helen1,2, Peyton Jacob III1,2, Natalie Nardone1, Neal L. Benowitz1,2,3


1 Division of Clinical Pharmacology, Department of Medicine, University of California San Francisco, San Francisco, California, USA

2 Center for Tobacco Control Research and Education, University of California, San Francisco, California, USA

3 Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, USA

by Gizelle Baker, Cédric Gubelmann, Serge Maeder, Patrick Picavet, Maurice Smith, and Manuel C. Peitsch1

1 PMI Research and Development, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland. Authors are listed in alphabetical order.


Philip Morris International R&D







The Division of Clinical Pharmacology, Department of Medicine, University of California San Francisco, California, USA, has recently published a research paper in Tobacco Control (St Helen, 2018) claiming that “PMI’s data […] show significantly higher levels of several substances that are not recognised as HPHCs by the FDA in IQOS emissions compared with combustible cigarette smoke. The impact of these substances on the overall toxicity or harm of IQOS is not known. We examined PMI’s MRTP application, specifically sections on aerosol chemistry and human exposure assessment, to assess the validity of PMI’s claims of reduced exposure and risk.”

In summary, we have assessed these claims based on a careful review of our scientific data (PMI’s Modified Risk Tobacco Product Application (MRTPA) for IQOS) submitted to the U.S. Food and Drug Administration (FDA). The scientific data is in the FDA submission and requires knowledge of the design and conduct of aerosol chemistry and clinical studies, together with a careful and detailed review of the resulting data, to reach accurate, science-based conclusions. While we welcome scientific review and discussion of our results, the authors of this paper failed to consider the totality of the available evidence and therefore led to conclusions that are incorrect and misleading.

We have prepared a point-by-point assessment of the claims made by the authors, and this detailed analysis can be found here.

In conclusion, based on an analysis of our aerosol chemistry and human exposure studies performed according to international standards of good practice, the totality of evidence supports the claim of Philip Morris International (PMI) that the Tobacco Heating System (THS) emits significantly lower levels of harmful and potentially harmful constituents (HPHC) that are emitted in cigarette smoke and, consequently, leads to significant reduction in exposure to HPHCs in smokers who completely switch to THS.

Although THS is not risk-free, the totality of evidence available for THS clearly demonstrates that switching completely to THS significantly reduces the exposure to harmful compounds contained in cigarette smoke and presents less risk of harm compared with continuing to smoke.