THS

      Tobacco Heating System

      We have developed several variants of the Tobacco Heating System (THS) that are commercialized under the IQOS brand in various markets. Blade and induction devices heat rather than burn tobacco.

      What are heated tobacco products?

      HTPs or heated tobacco products, also known as heat-not-burn products, heat the tobacco just enough to release a nicotine-containing tobacco aerosol but without burning the tobacco. Because tobacco is heated and not burned there is no smoke, and in case of our HTPs the levels of harmful chemicals in the generated aerosols are significantly reduced compared with cigarette smoke. HTPs, though, are not risk free, and provide nicotine, which is addictive.

      THS is the most developed and most thoroughly assessed of our smoke-free products. We have accumulated extensive nonclinical and clinical data to support its potential to reduce the risk of developing smoking-related diseases compared with continued cigarette smoking. 

      Our approach is to develop a range of smoke-free products, so that adult smokers who would otherwise continue to smoke can find a suitable alternative that allows them to fully switch. 

      THS

      Tobacco heating system products

      Initial generations of our heated tobacco products use blade heating technology, and these are designed to be used with specific heated tobacco units commonly known as heatsticks. We later developed the next version of our HTP devices that uses induction to heat tobacco and is commercialized as IQOS ILUMA. These devices also use specifically designed heated tobacco units. Despite the change in heating technology, the aerosol generated by our induction heating device remains comparable to the previous versions of THS. All our HTP devices are supported by the robust scientific evidence generated to date.

      Tobacco heating system product on a table.

      What are heated tobacco units? 

      Heated tobacco units contain a uniquely processed tobacco plug designed for heating. The tobacco plug is made from tobacco leaves, which are ground and reconstituted into tobacco sheets, called cast-leaf. These sheets are then crimped and made into a tobacco plug.

      Both versions of THS use different types of heated tobacco units, specially designed to be used with their corresponding device.  

      How do our blade HTPs work? 

      Our blade HTPs are available in two versions. The first version has three main components—a heated tobacco unit, a holder, and a charger. The second version is an integrated product that combines the holder and charger and allows multiple uses without recharging the battery. Both products contain an electronic system that heats the tobacco within a precisely controlled temperature range to avoid burning the tobacco. The system uses a heating blade, which acts as both a heater and temperature sensor.

      Each of the blade devices heat tobacco in this way. 

      When the heated tobacco unit is inserted into the tobacco holder, the heating blade is embedded in the tobacco. Once turned on, the heating blade heats the tobacco while also monitoring its temperature to ensure consistent taste and avoid burning. 

      The integrated blade version of THS works the same way. It combines the holder and charger into a single unit that must be charged after at least 10 uses. Unlike the original three-part system, the integrated THS design allows for consecutive uses without the need of recharging after each use.

      We have scientifically demonstrated that during the operation of THS, no combustion occurs, and the aerosol generated has on average 90-95% lower levels of harmful and potentially harmful constituents (HPHCs) than found in the smoke of a 3R4F reference cigarette used in tobacco research. Using THS indoors also does not adversely affect overall indoor air quality.

      A number of public health organizations, including the U.S. Food and Drug Administration (FDA) have reviewed our scientific evidence package regarding our HTPs. On July 7, 2020, FDA authorized the marketing of a variant of the IQOS Tobacco Heating System as a Modified Risk Tobacco Product (MRTP) with reduced exposure information in the U.S. The order letters as well as the decision summaries are available on the FDA’s website, and these orders apply to IQOS 2.4 as of July 2020 and IQOS 3 as of March 2022. These orders do not apply to all versions of the IQOS system. 

      You can find a summary of our entire product assessment program in the PMI Science Booklet, and our publications, most of which are open-access, can be found via the publications library.

      How do our induction HTPs work?

      The induction-based THS provides a different way of heating tobacco compared to the original heating blade. With this version, there is no direct contact between the electronics and the heating element. 

      The induction system relies on specially designed heated tobacco units, each with their own internal heating element at their core. When the heated tobacco unit is inside the holder and the system is turned on, an electric current flows through the coil in the holder. This current creates a magnetic field that heats up the heating element inside the tobacco, which in turn heats the surrounding tobacco. 

      Watch the video to see the induction HTP in action:

      "Platform 1" in this video refers to the induction version of the tobacco heating system.

      How our heated tobacco products evolved
      THS

      Over 30 years of innovation

      Explore the 30 years of innovation behind our leading heated tobacco product, THS. Read key information on each iteration, and learn how the user experience, heating technology, and battery technology have evolved over time.

      The Philip Morris International (PMI) approach to substantiate reduced emissions consumer-facing product statement is based on the WHO 9 list. The WHO 9 was selected, because it allows to provide consumers with accurate and non-misleading information while improving the consistency of the messages across product categories and aligning with industry practices. Furthermore, this approach enables consumers to make educated and informed decisions about the products available on the market including product properties, benefits, and risks.

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      PMIScience.com is operated by Philip Morris International for the purpose of publishing and disseminating scientific information about Philip Morris International’s efforts in support of its smoke-free product portfolio. This site is a global site for use by scientists, the public health and regulatory communities, and other stakeholders with an interest in tobacco policy. The purpose of this site is not advertising or marketing, nor is it directed at any specific market. It is not intended for use by consumers. New tobacco products sold in the United States are subject to FDA regulation; therefore the content of this site is not intended to make, and nor should it be construed as making, any product related claims in the United States without proper FDA authorization. ​
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      Reduced Risk Products ("RRPs”) is the term we use to refer to products that present, are likely to present, or have the potential to present less risk of harm to smokers who switch to these products versus continuing smoking. PMI has a range of RRPs in various stages of development, scientific assessment and commercialization. All of our RRPs are smoke-free products that deliver nicotine with far lower quantities of harmful and potentially harmful constituents than found in cigarette smoke.