How IQOS works? Why is it better to heat tobacco without burning? Why tobacco vapor is less harmful than tobacco smoke?
Caravan.kz reporter decided to question Dmitriy Ulupov, Research and Development Manager at Philip Morris International.
- Dmitriy, IQOS is still a new product for people in Kazakhstan. There are things to clear about it. So the first question is about, so to say, physics and chemistry of the process. We know that tobacco smoke contains more than one thousand poisons. Why these substances are not formed when tobacco is heated without burning?
- For a start, why people smoke tobacco. Major active agent in tobacco is nicotine, natural alkaloid. There's no question, nicotine is not a safe substance; it is addictive. But doses of nicotine consumed by a smoker, even a heavy one, pose no toxicological hazard. It's been scientifically proven. Tobacco combustion products are a real threat. It is important to dispel some myths, for example, about assumed safety of cigars. Smokers of cigars, tobacco pipes or hookahs often say something like their way of smoking is risk free, since natural tobacco leaf only is used in cigars or tobacco pipes, and cigarettes contain paper as well. Unfortunately, they are wrong. Think of it like this, if tobacco leaves are replaced, say, with birch or oak leaves, combustion products will be the same. Regardless of what vegetable matter you burn, you’ll get a whole bunch of harmful substances.
Now let's proceed to the tobacco smoking process physics and chemistry. In case of smoldering (non-ﬂaming mode of combustion) the temperature at the burning end of a cigarette is about 750-800 degrees. During puffs it reaches 900-1000 degrees. Smoldering is an oxidation process that burns all organic material. As a result, carbon dioxide, carbon monoxide, nitrogen oxide and a number of other chemical compounds are released. These gases are extremely harmful, though burning and smoldering are relatively “pure” processes if compared to what is going on in the next zone – tobacco layers within a centimeter from the combustion zone that have not start smoldering as yet.
This is a high temperature pyrolysis area. Here the temperature reaches 450-700 degrees, smoldering has not started yet, but as the temperature rises, powerful chemical reactions occur. In fact, high temperature pyrolysis next to the smoldering end of a cigarette is a chemical factory where thousands of substances are synthesized. Lots and lots of the most harmful compounds are formed here rather than elsewhere and this fact is proved by a number of scientific studies. When tobacco temperature exceeds 450 degrees, we can see a snowballing growth of harmful chemicals release.
- What happens in the next, cooler zone?
- Closer to the filter there is a zone of relatively low temperatures known as distillation zone. This is the place where temperatures fall within the interval between 100 and 380 degrees and such substances as various aromatic components, ethers, sugars and nicotine itself evaporate from tobacco. As can be seen from the above, the larger half of the cigarette burns down for nothing, as fuel used to heat the distillation zone with thousands of harmful and poisonous substances released. In fact, smokers smoke for the sake of nicotine and flavors they like in tobacco. Both nicotine and such flavors are released in the distillation zone at the temperatures that are far from temperatures of burning and pyrolysis. In addition, smokers have to inhale whole array of harmful substances released as a result of two latter processes.
- Apparently, IQOS engineering breakthrough is missing burning and pyrolysis zones?
- Exactly. PMI experts obeyed common sense and concluded that it is necessary to cut off, exclude harmful high-temperature part from the process and preserve the temperatures that are just enough for nicotine and aromatic components of tobacco leaf to evaporate. Idea to heat tobacco up to a strictly set temperature – maximum 350 degrees – was obvious and made sense in the context of toxic effects decrease.
As a result, we developed the process which is embodied in IQOS and ensures that most harmful substances found in the cigarette smoke in huge quantities are not detected in IQOS. Some substances are still present, but their concentration is decreased by 95 or more percent. If to take the list of the most dangerous poisons and the harmful substances containing in a tobacco smoke under their maintenance decrease on the average for 95 percent and more is reached. With this in mind, it would be incompatible with logic and science to place burning and heating processes on the same footing (i.e. equate cigarettes to smoke-free tobacco heating systems). These products are completely different both in terms of operating principle and results to be achieved.
- By the way, tobacco aerosol contains neither soot nor resins. Is that right?
- Yes, recent studies confirmed that another fundamental difference of IQOS tobacco aerosol from tobacco smoke consists in zero content of solid particles. Tobacco smoke contains fine solid particles of carbon that form in the course of burning. You can see them, for example, in the filter of a smoked cigarette. Particles caught by the filter (though far from everyone as such particles are nano-sized) make the filter brownish. Much of such particles find their way to a smoker’s lungs, settle there, and accumulate in alveoles and bronchial tubes for years. Besides, accumulation of solid particles is the very reason why teeth become yellow from smoking. If we analyze physical composition of heated tobacco aerosol, the analysis will not detect any solid particles. Tobacco aerosol contains microscopic liquid matter mostly kept by the special biopolymer filter inside the tobacco stick.
- By the way, your opponents point out that IQOS aerosol contains formaldehyde.
- I’d like to say that formaldehyde is found, for example, in laminated flooring or wall paper in our homes. This is not just presence or absence of any given substance that matters, dose a person can get is also important. Atmosphere of large urban centers also contains dozens of substances, however the real issue is how many are they. Any toxicologist will confirm that a particular substance can be harmful or risk free depending on the dose. Quantitative comparison is of importance here – amount of one and the same substance contained both in the cigarette smoke and IQOS aerosol. All these studies are non-clinical and clinical. Their results are in the public domain.
- Please tell those interested in the matter where they can read more about these studies.
- For example, on FDA (Food and Drug Administration) website. Results of all our non-clinical and clinical studies, chemical composition and physical characteristics of tobacco aerosol in IQOS systems are available at pmiscience.com and in publications of a number of influential scientific magazines. This data is released to the public. Philip Morris International makes all our studies absolutely transparent.
Furthermore, PMI agreed to unprecedented disclosure of information having created online platform – Intervals – that enables all interested scientists and researchers to download for independent analysis so-called “raw”, i.e. primary data – laboratory data of all our non-clinical and clinical studies that are neither processed nor grouped. As a rule, those are data files that may be requested by governmental authorities (such as FDA) to audit trials conducted, for example, by pharmaceutical companies, but such files are usually not published online. We however release this information so that researchers in case of doubts (for example, they suspect that we somehow manipulated the statistical data analysis) could take raw data and check everything by themselves.
- One more technical question. Some public men here in Kazakhstan disassemble IQOS tobacco sticks to the camera, take out biopolymer filter and declare: “This is cellophane, it melts and releases toxic substances.” Let’s discuss more specifically how tobacco stick works and what role biopolymer filter plays therein?
- To begin with, to me is not entirely correct to use the word “filter” when it comes to IQOS tobacco stick for the simple reason that unlike cigarettes there is nothing to filter therein. Biopolymer element inside tobacco sticks (the one that resembles a thin polymer film) is intended to cool aerosol and partially condensate water vapor, i.e. remove excess moisture, rather than filter. In other words, biopolymer element of tobacco stick is designed to make humidity and temperature of inhaled aerosol comfortable for the user. As to the last part of the filter (the end held between user lips when using a tobacco stick), it is made of acetate fiber solely to make the tobacco stick look familiar to the smoker. In fact, no substances remain in this filter.
Now let’s talk about biopolymer filter in more detail. Any allegations that it melts or that it is cellophane fail to comply with the facts. It is not cellophane, but polylactide – a polymer of lactic acid derived from corn starch. Polylactide is widely used in food processing industry and medicine to replace plastic since it is biodegradable and accordingly safe for a human body. Besides, it is biocompatible with human tissue, therefore it is used to manufacture resorbable suture material and coronary stent systems. Polylactide is also used in food-processing industry to make packing materials and casing, for example, edible casing of sausages.
Studies show that polylactide filter of IQOS tobacco stick does not release any harmful substances in normal operation.
- To sum up: whom does the science recommend to use smoke-free products such as IQOS?
- IQOS is not for those who never smoked. Yes, there are a number of scientific studies proving that IQOS is a better alternative for adult smokers as compared to cigarettes. But let's say it again: IQOS is not risk free. It is an alternative reduced risk product for adult smokers and nobody else. Of course, ideal scenario is complete refusal of smoking and any alternative products, whether that be vape, tobacco heating system, nicotine gum, snus, etc. Use of reduced risk products with heat-not-burn technology makes sense only if a smoker does not intent to quit smoking or nicotine consumption as a whole.