Harmful Chemicals Measured

      Which harmful chemicals does PMI measure for its smoke-free products and why?

      With an ever-increasing range of smoke-free products in our product portfolio, it is essential that we, Philip Morris International (PMI), ensure uniformity in our consumer-facing messaging to provide adult smokers who would otherwise continue to smoke a better understanding of the properties and risks inherent to these products. This includes how we communicate the science behind our smoke-free products. We review below what chemicals we measure for monitoring and regulatory reporting and why we use a single list of nine harmful chemicals for our consumer-facing messaging.

      Assessing our smoke-free products

      Cigarette smoke has been well characterized, with more than 6,000 constituents identified. Within this complex mixture, about 100 constituents have been associated with smoking-related disease by public health authorities and are known as harmful and potentially harmful constituents (HPHCs). Scientifically substantiated smoke-free products have a potentially valuable role to play because they emit or release much lower levels of HPHCs than cigarettes. Our aim at PMI is to reduce and, if possible, completely eliminate the presence of HPHCs emitted or released by our smoke-free products.

      We conduct a robust approach when assessing our smoke-free products. At each step of our assessment program, scientific rigor is applied. As such, we follow recognized scientific standards, guidelines, and practices. We also prioritize transparency and openly share our research and findings in peer-reviewed journals.

      When it comes to our aerosol studies, we use HPHC lists to measure our progress of eliminating or reducing the presence of toxicants emitted by our smoke-free products, as well as to satisfy regulatory requirements worldwide. Some of the lists we use include the U.S. Food and Drug Administration (FDA)’s 2012 list which comprises of HPHCs to be measured and reported in either cigarette smoke, smokeless tobacco, or roll-your-own tobacco and cigarette filler, or the Health Canada list, currently the most extensive active regulatory reporting list for cigarette smoke constituents worldwide. We have also developed an internal list, the PMI-58 list, where we prioritize 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.

      For consumer-facing reduced emission statements, what HPHC list do we use? 

      We believe that adult smokers should receive accurate information about smoke-free products so that they can make informed decisions about the product properties, benefits, and risks. For communicating the extent of HPHCs emitted by our smoke-free products, we use reduced emission statements which are the relative reductions of a number of toxicants in emissions of smoke-free products compared with cigarettes. Our consumer-facing smoke-free product reduced emissions statements are based on the World Health Organization (WHO)’s list of nine HPHCs, the WHO 9 list.  

      These nine HPHCs were proposed by the WHO Study Group on Tobacco Product Regulation (TobReg) for mandated lowering in cigarette smoke, and the list comprises of the following toxicants: acetaldehyde, acrolein, benzene, benzo[a]pyrene, 1,3-butadiene, carbon monoxide, formaldehyde, NNK (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone), and NNN (N-nitrosonornicotine). 
      We have selected to base our consumer-facing smoke-free product reduced emissions statements on the WHO 9 list to ensure the consistency of the messages across product categories as well as aligning with industry practices. In addition, because these nine toxicants have been recommended for reporting, standardized analytical methods exist for their measurement in smoke, making comparison between results more meaningful.

      Although there are many more toxicants in cigarette smoke than the nine chemicals in this list, it is clear that the most important criterion for selecting compounds for regulation was evidence of toxicity. As our smoke-free product portfolio continues to grow, the use of the WHO 9 list as the single list of HPHCs for reporting to consumers the reduced emissions compared with cigarettes will ensure uniformity in our messaging across all our smoke-free products.


      How does our leading smoke-free product perform against the WHO 9 list?

      Below is the reduction per individual WHO 9 toxicant seen in the aerosol of our leading smoke-free product, the Tobacco Heating System (THS) version 2.2, versus smoke of the reference cigarette 3R4F. It is such reductions, and others, that are used as evidence to support our statement that THS emits on average 95% lower levels of harmful chemicals compared with cigarettes. The toxicant classification seen in this chart is based on the established FDA list focusing on chemicals that are linked to the most serious health effects of smoking. 

      Why measuring the chemicals emitted or released by smoke-free products is not enough

      The HPHC lists have become central for many health bodies and regulatory agencies worldwide in assessing claims of reduced toxicants emissions made by manufacturers of smoke-free products. It is important to remember though, that while a reduction in HPHCs emissions can be an indicator of reduced toxicity as compared with cigarette smoke, it does not alone prove harm reduction. Nevertheless, such a reduction is a good predictor that harm reduction can be confirmed through further studies such as toxicological assessments, product use studies, clinical trials, and the long-term assessment. For more information, you will find all the scientific studies across our assessment program in our publications library.