14 November 2019
Why our aerosol isn't smoke
The clouds created from our Platforms during use are aerosols that are not smoke, even though they are sometimes wrongly referred to as smoke. There’s often confusion when it comes to differentiating between aerosols that are smoke, and those that aren’t. While smoke is an aerosol, not all aerosols are smoke.
What distinguishes smoke from the aerosols created by our Platforms during use? Smoke is an aerosol containing both liquid and solid particles and is generally formed and emitted during combustion. In a lit cigarette, the tobacco burns at temperatures reaching above 800°C generating smoke. Our portfolio of smoke-free products do not burn tobacco, and produce aerosols that are not smoke; either by heating tobacco (Platform 1/Platform 2), using a nicotine salt (Platform 3), or by heating a nicotine-containing liquid (Platform 4).
Why does this matter? Because during the burning of the tobacco, most of the harmful and potentially harmful constituents (HPHCs) found in cigarette smoke are released, and carbon-based solid particles are generated that can adversely affect your health when inhaled. While not being risk-free, our smoke-free products, which avoid combustion, have the potential to be less harmful alternatives for smokers who won’t quit.
What's in our aerosol?
These are two laboratory filter pads. The left shows collected cigarette smoke, while the right shows collected Platform 1 aerosol. Learn more about how these were created from our Aerosol Demo.
Emphasizing the differences between cigarette smoke and the aerosols generated by our Platforms may seem like semantics, but there are scientifically substantiated differences between them that goes beyond wording.
We created an assessment program to track the scientific developments of all our Platforms, and this program includes testing the composition of our aerosols. Our findings show how our aerosols are compositionally different from cigarette smoke.
A series of studies compared the composition of Platform 1 aerosol against cigarette smoke, covering 54 HPHCs. Platform 1 aerosol produced an average of 95% lower HPHC levels, compared to cigarette smoke.
To investigate whether or not carbon-based solid particles are present in our Platform 1 aerosol, we collected and analyzed mainstream smoke from a cigarette as well as the mainstream aerosol from Platform 1. Scanning electron microscopy confirmed the absence of carbon-based solid particles in our Platform 1 aerosol, whereas over 1 trillion solid particles were detected in cigarette smoke.
Combustion of biomass produces solid carbon particles, whereas their generation is highly unlikely when a biomass is heated instead of being burnt. For instance, in the Tobacco Heating System (THS2.2), the tobacco is heated below 350°C and no combustion takes place. Consequently, at this relatively low temperature, released compounds should form an aerosol consisting of suspended liquid droplets via a homogeneous nucleation process. To verify this assumption, mainstream aerosol generated by the heat-not-burn product, THS2.2, was assessed in comparison with mainstream smoke produced from the 3R4F reference cigarette for which solid particles are likely present. For this purpose, a methodology was developed based on the use of a commercial Dekati thermodenuder operating at 300°C coupled with a two-stage impactor to trap solid particles. If any particles were collected, they were subsequently analyzed by a scanning electron microscope and an electron dispersive X-ray. The setup was first assessed using glycerine-based aerosol as a model system. The removal efficiency of glycerin was determined to be 86 ± 2% using a Trust Science Innovation (TSI) scanning mobility particle sizer, meaning that quantification of solid particles can be achieved as long as their fraction is larger than 14% in number. From experiments conducted using the 3R4F reference cigarette, the methodology showed that approximately 80% in number of the total particulate matter was neither evaporated nor removed by the thermodenuder. This 80% in number was attributed to the presence of solid particles and/or low volatile liquid droplets. The particles collected on the impactor were mainly carbon based. Oxygen, potassium, and chloride traces were also noted. In comparison, solid particles were not detected in the aerosol of THS2.2 after passing through the thermodenuder operated at 300°C. This result is consistent with the fact that no combustion process takes place in THS2.2 and no formation and subsequent transfer of solid carbon particles is expected to occur in the mainstream aerosol.
What does our aerosol do?
Determining what is and isn’t in our aerosol only makes up a part of what we investigate. Knowing how the aerosols might affect the body and environment are also vital pieces of information. We’ve collected a few interesting findings and facts across most of our assessment program:
• Indoor air quality assessment: We tested the air quality in several simulated environments during Platform 1 use or cigarette smoking. In relation to the environmental tobacco smoke emitted during smoking, Platform 1 use showed a vast reduction of the levels of the airborne chemicals measured, even matching background levels in many cases.
• Toxicological assessment: Lower levels of HPHCs in the aerosol of Platform 1 should lead to reduced toxicity, but it's important to quantify. When investigating the toxicity, we found that the mutagentic and cytotoxic effects of the Platform 1 aerosol were reduced by more than 90% compared to cigarette smoke.
• Clinical assessment: Logically, lower levels of HPHCs in the aerosol should lead to reduced exposure for the user and a reduced biological response, but there are actually many factors. Our exposure response study followed over 900 adult smokers who either continued smoking or switched to using Platform 1 for six months. We measured eight biomarkers known to improve upon smoking cessation within this time, corresponding to illnesses such as cancer, respiratory disease, and cardiovascular disease. Our results showed that all eight biomarkers improved in those who switched to Platform 1, with five of the eight showing statistical significance.
We’re always actively working on all of our products, constantly researching and testing everything from early development to post-launch and beyond. Our library contains almost 1000 publications, including research papers, conference posters and presentations, and more. To dig into more information, search through our library here: https://www.pmiscience.com/library.
The impact of the Tobacco Heating System 2.2 (THS 2.2) on indoor air quality was evaluated in an environmentally controlled room using ventilation conditions recommended for simulating “Office”, “Residential” and “Hospitality” environments and was compared with smoking a lit-end cigarette (Marlboro Gold) under identical experimental conditions. The concentrations of eighteen indoor air constituents (respirable suspended particles (RSP)
Reduction of harmful constituents by heating rather than combusting tobacco is a promising new approach to reduce harmful effects associated with cigarette smoking. We investigated the effect from a new candidate modified risk tobacco product, the tobacco heating system (THS) 2.2, on the migratory behavior of monocytes in comparison with combustible 3R4F reference cigarettes. The monocytic cell line (THP-1) and human coronary arterial endothelial cells (HCAECs) were used to analyze chemotaxis and transendothelial migration (TEM). To assess the influence of aerosol extract from THS2.2 and smoke extract from 3R4F on toxicity and inflammation, flow cytometry and ELISA assays were performed. The results show that treatment of THP-1 cells with extract from 3R4F or THS2.2 induced concentration-dependent increases in cytotoxicity and inflammation. The inhibitory effects of THS2.2 extract for chemotaxis and TEM were ∼18 times less effective compared to 3R4F extract. Furthermore, extract from 3R4F or THS2.2 induced concentration-dependent decreases in the integrity of HCAEC monolayer. For all examined endpoints, the extract from 3R4F showed more than one order of magnitude stronger effects than that from THS2.2 extract. These data indicate the potential of a heat not burn tobacco product to reduce the risk for cardiovascular disease compared to combustible cigarettes.