History of THS: From early development through decades of innovation

A continuing journey

THS was first released commercially 10 years ago, but its development began long before that, with the concept of providing smoke-free alternatives to cigarettes that would reduce the risk of smoking-related disease for adult smokers who switch to them rather than continuing to smoke.

Development began by addressing questions such as what kind of product would best meet consumer needs, how to eliminate combustion and generate an aerosol with far fewer toxicants than cigarette smoke, and what type of heating technology should be used to achieve this. Hundreds of experiments were conducted to address these and other questions. 

Between 1990 and 2011, prototype products were constructed and tested to understand the aerosol chemistry involved, measure the levels of harmful and potentially harmful constituents (HPHCs) in the aerosol, and see if consumers would use the product. The lessons learned were critical to the eventual development and success of THS, which would go on to be commercialized under the IQOS brand.  

Read on to explore the timeline of key developments in the history of THS.

 

From concept to commercialization

Foundations of innovation

The development of a completely new category of product—one which does not burn tobacco or produce smoke can be traced back decades. In the years between 1990 and 1998, PMI developed and commercialized the Electrically Heated Cigarette Smoking System (EHCSS) Series E. This used an array of eight blades, or pins, to heat a specially designed cigarette. Over the next 8 years, the EHCSS was updated to include larger blades, more sensitive puff detection and improved filtration, airflow, and heat control, to reduce the formation of combustion products.

Development and launch of THS

Advances in heating technology made with EHCSS were built on in the following years with the development of THS 2.0. This was a lab prototype that used a single, 3 mm blade to heat a specially designed tobacco stick which was fundamentally different from those used in previous versions. The new stick contained a tobacco plug made from tobacco leaves which had been ground and reconstituted into a tobacco sheet that was then crimpled and folded, combined with a new filter element.

The two-piece design of the THS 2.0 featured a separate holder and charger, making it lighter and less bulky than the EHCSS, and a temperature control for the heating blade. This prototype was not commercialized, but it represented a major advance in heat-not-burn technology. It was followed by the THS 2.1 prototype, designed specifically for consumer research.

The technological and scientific learnings from the prototype research were then incorporated into the development of THS 2.2, which would be commercialized as the first IQOS model ever launched. This featured a 5 mm heating blade, increased battery life, and improved puff-to-puff consistency. In the following years, the design of the THS 2.2 was further refined for large-scale manufacturing and to make the device lighter and easier to hold. 

Expansion and innovation 

In the years following the commercial launch of THS 2.2, PMI continued to update and improve its technology and to substantiate its reduced risk potential with scientific studies. This included the publication, in 2016, of a series of nine peer-reviewed papers supporting PMI’s submission to the U.S. Food and Drug Administration (FDA) of a modified-risk tobacco product (MRTP) application. 

In 2020, the FDA issued its decision, finding that the issuance of exposure modification orders with reduced exposure claims for THS and three variants of our tobacco sticks would be “appropriate to promote the public health and is expected to benefit the health of the population as a whole.”

Technological improvements were made to THS 2.2 over the following years in order to improve key elements of the user experience. This included adding holder vibration, Bluetooth, holder autocleaning, a doubling of the battery lifetime, and greatly improved device robustness and reliability. 

Recent advancements

More recently, PMI has developed an all-new, bladeless SMARTCORE INDUCTION SYSTEM™ (THS 3.0), commercialized as IQOS ILUMA. This system heats tobacco without any direct contact between the electronics and the heating element. 

The THS 3.0 induction system relies on specially designed heated tobacco units (TEREA SMARTCORE STICKS™), each with their own internal heating element at their core. These use a magnetic field to heat the surrounding tobacco, offering improved draw and taste consistency without the need for cleaning. PMI has also developed tobacco-free nicotine-containing sticks, commercialized as LEVIA, which generate a nicotine-containing aerosol when heated in THS 3.0.

This was followed by the development of another new heated tobacco system—the bladeless ROUNDHEAT TOBACCO SYSTEM™ (THS 6.0), commercialized as BONDS by IQOS. This uses a flexible heater that surrounds the tobacco stick and heats its external surface. The all-in-one design focuses on robustness, low maintenance, and ease-of-use. A new tobacco stick was also developed specifically for the system.

In 2023, PMI submitted premarket tobacco product applications (PMTAs) and MRTPAs to the FDA for IQOS ILUMA. The following year, PMI launched the IQOS ILUMA i series, with advanced features such as a touch screen, FlexPuff, and pause mode. PMI also published a clinical study demonstrating that product acceptance is similar between IQOS ILUMA and the previous IQOS version and a pharmacokinetic study showing that the reduction of exposure to toxicants is similar between the two versions of IQOS.

 

What’s next for THS?

In the decade since its launch, research studies have demonstrated that, for adults who do not quit, switching completely to THS can potentially reduce the risk of smoking related harm compared with continued smoking. However, quitting tobacco and nicotine products altogether is the best way to reduce the risk from smoking.  

Scientifically substantiated harm reduction is only part of the equation, however. To reduce harm at a population level, adult smokers who do not quit need to switch to using smoke-free products such as PMI’s THS. Many of the technological advances made in the development of THS are designed to make it easier for adult smokers to switch and to provide a variety of options to choose from.

There is also independent research suggesting that THS may be having an impact. In Japan, cigarette sales began declining after the introduction of THS. Data from the 2022 Japan National Health and Nutrition Survey indicated that 86% of consumers who use heated tobacco products like IQOS do so exclusively, and do not smoke cigarettes. 

By 2030, PMI aims to be a substantially smoke-free business, replacing cigarettes with smoke-free products that are scientifically substantiated to be less harmful than smoking. THS will continue to be a cornerstone of this commitment to advancing smoke-free technology and improving public health outcomes.