The scientific basis of our platform development
Our platform development process follows the principle of “Quality by Design.” This means that the platforms are specifically designed to eliminate or reduce the levels of HPHCs found in the aerosol compared to those found in cigarette smoke.
You can find a summary of our entire product assessment program in the PMI Science Booklet.
Aerosol Science
Particles of very small sizes, such as droplets or fine solid particles, do not settle when surrounded by gas; they instead form a suspended mixture called an aerosol.
Aerosol Science plays a fundamental role in the development of smoke-free products. Chemical characterization of the inhaled aerosol is imperative since the aerosol chemicals are absorbed in the body and have biological effects.
Cigarette smoke is a type of aerosol; in addition to water droplets, it contains over 6000 different chemicals identified to date. Solid carbon-based particles are also present in cigarette smoke, produced as a result of tobacco combustion.
Heated tobacco products and e-vapor products also produce aerosols, but they are very different from cigarette smoke in their composition. Since these products are designed to operate without combustion, carbon-based solid particles are not present in their aerosols, only liquid droplets.
People often use the word “vaping” when referring to the use of e-cigarettes, and the aerosol itself is often called “vapor”.
Aerosol Chemistry: What compounds are found in smoke-free aerosols and cigarette smoke?
At PMI, we have been studying the chemical composition of a variety of aerosols for over a decade.
Based on the guidelines and regulations of health authorities, such as the WHO[1], FDA[2] and HC[3], we have consolidated a list of 58 chemicals that are relevant to the analysis of cigarette smoke and smoke-free aerosols.
The list contains constituents that may pose health risks to humans – which is why our products are specifically designed to reduce them at the lowest possible levels. Through careful monitoring, we are able to determine whether we can effectively reach our aim of eliminating or substantially reducing these constituents.
Besides targeting known constituents, we also perform analyses to identify constituents that may emerge via the evolution of our products. Our scientists have had to overcome analytical challenges to identify and quantify these constituents, due to their chemical diversity.
Indoor air quality
Smoke-free products are also designed to reduce the number of chemicals released into a given space, as compared with the quantities released by cigarette smoke.
Aerosol Physics: Aerosol particle size
The size of droplets in any smoke-free product aerosol plays a key role in inhalation. Droplets in smoke-free aerosols do not all have the same size: they fall in the range of micrometers and most particles need to be smaller than 2.5 micrometers to be respirable.
Measuring the size of smoke-free product aerosol droplets has led to the development of new techniques, as classical methods were not designed for such fine and rapidly changing systems as smoke-free aerosols.
The right size of the particles ensures that nicotine delivery is efficient.Tracking droplet size is not only important for assessing the biological effects of aerosol inhalation. Indeed, it also allows us to understand if our products behave consistently under different conditions.
Products in the lab and products in real life: Stability and robustness
What happens when our products leave the lab? They can stay in storage for a certain period of time and be exposed to large variations in humidity and temperature conditions, and careful thought is given to these parameters.
We also take into account that different people have different puffing behaviors, and that these behaviors may be very different from the conditions that we simulate in the laboratory unless we make sure to use a variety of puffing regimes.
Therefore, to ensure that our measurements hold true in real-life conditions, we test our products in a range of conditions that resemble probable scenarios. We use these results to continuously improve the design of the products. This ensures that when the products are used in real life, the composition of the aerosol will remain within defined and understood parameters.
Developing robust products is only the first step towards a smoke-free future. Toxicity tests, clinical studies and consumer acceptance all provide valuable information that is continuously fed back into our design to achieve our ultimate goal of being able to positively impact population health.
