niche between combustible tobacco smoking and e-cigarettes that aerosolise nicotine. there are different types of htps in the marketplace: some use tobacco sticks like glo and iqos, while others use loose-leaf tobacco such as pax and ploom. firefly vaporizers the firefly developed the firefly 2, which heats loose-leaf plant material and concentrates and is often used to aerosolise cannabis, and is more compact than the original firefly vaporizer. it uses a patented heating technology that heats the device up to the desired temperature (between 200 and 500 °f) with each puff rather than a preset temperature setting from the beginning. glo in 2016, british american tobacco launched a battery-powered heated product called glo in japan before selling it in south korea, switzerland, russia, and ukraine. in france, glo uses tobacco sticks called neostiks. it uses a heating element with a tobacco stick that heats up to 240 °c. glo produces approximately 50% less nicotine emissions than iqos. in may 2017 british american tobacco released i-glo in canada. bonnie herzog, a senior analyst at wells fargo securities, stated that the proposed acquisition of r. j. reynolds by british american tobacco in 2016 would let them catch up with the competition. glo is marketed as being easier to operate than iqos. the glo ifuse debuted in romania in 2015, and is a hybrid of a heated tobacco product and an e-cigarette. it consists of a heating element, a liquid tank (like e-cigarettes), and a tobacco cavity through which the aerosol passes and is infused with tobacco flavour. it uses cartridges called neopods, and heats tobacco to approximately 35 °c. iqos iqos, consisting of a charger, a heater and a small tobacco cigarette. iqos (/ˈaɪkoʊs/ eye-kohs) is a non-combustible reduced risk smoking alternative that was introduced in june 2014 and is marketed by philip morris international (pmi) under the marlboro and parliament brands. although it is marketed as a novel product, it is very similar to the accord released by the same company in 1998; however, the iqos sticks have more nicotine, more tar, and less tobacco. they are heated at a lower temperature. initially launched in 2014 in nagoya, japan, and milan, italy, iqos is being introduced to other countries; as of october 2019, it is available in 49 countries. pmi has projected that when 30 billions units are sold, the iqos would increase profits by $700 million. in october 2018, pmi introduced a less expensive version of iqos called iqos 3 in tokyo, japan. the iqos 3 multi was also launched, and is capable of multiple consecutive uses. the iqos consists of a charger around the size of a mobile phone and a pen-like holder. the disposable tobacco stick, also known as a heatstick, is described as a mini-cigarette. the sticks contain processed tobacco soaked in propylene glycol. the stick is inserted into the holder which then heats it to temperatures up to 350 °c, and the amount of nicotine provided may be a little strong for light cigarette smokers. users have reported less smell and odor on clothing. there is a limited amount of research on the effect of iqos on the user's health. the physical effects on users are not yet known. the emissions of iqos are considered to be smoke by independent researchers, and were called smoke by phillip morris researchers until 2016. the emissions generated by iqos contain the identical harmful constituents as tobacco cigarette smoke, including volatile organic compounds at comparable levels to cigarette smoke, polycyclic aromatic hydrocarbons, and carbon monoxide. each of these substances, on the basis of rigorous research of cigarette smoke, are known to result in significant harms to health. according to netherlands national institute for public health and the environment, iqos is "harmful to health, but probably less harmful than smoking tobacco cigarettes". in 2016, pmi submitted a multi-million page application to the us fda for iqos to be authorized as a modified risk tobacco product. in march 2017, pmi submitted a premarket tobacco product application regarding its iqos product to the us fda. in december 2017, reuters published documents and testimonies of former employees detailing irregularities in the clinical trials conducted by pmi for the approval of the iqos product by the us fda. the advisory panel appointed by the us fda reviewed philip morris international's application in january 2018. the fda granted permission to pmi to sell iqos in the us on 30 april 2019, which also requires the company to follow strict marketing restrictions. iqos formally launched in the us in october 2019. on 7 july 2020, the us fda announced its ruling 456, which granted an "exposure modification" order that allows pmi to market iqos in the united states. ismoke onehitter the ismoke onehitter by ismoke can be used as a loose-leaf tobacco vaporizer or for use with waxy oils. it is described as a "heat, not burn" tobacco vaporizer, and was launched in 2015. it has a chamber that can be filled with up to 800 milligrams of tobacco. iuoc 2 the iuoc 2 is marketed by shenzhen yukan technology co., limited, of china. the htp can use any pack of 20 cigarettes on a single battery charge and does not use tobacco-filled cartridges. it is an updated version over the original iuoc and was formally launched in 2018 at intertabac in germany. lil the lil is an htp that heats a cigarette stick with a circular blade that was launched by the korea tobacco & ginseng corporation on 20 november 2017. according to the company, a two-hour battery charge lasts for up to 20 cigarette sticks, its refills are cheaper than the iqos and glo, and will fit in the iqos product, though they do not recommend doing so for safety reasons. mok in may 2019, china tobacco debuted the mok in korea. according to the company, mok is more compact and weighs less than other products such as glo, iqos, and lil. the coo sticks are longer and wider than tobacco sticks from other companies. pax vaporizers in 2010, the company ploom (later rebranded as pax labs) launched a butane-powered product used to heat tobacco or botanical products. later models replaced the butane heating with an electric system. the pax 2 vaporizer uses loose plant material such as tobacco or cannabis and remains cool to the touch while the oven heats to one of four temperatures (up to 455 °f). the pax 3 takes 15 seconds to heat up and can be used to heat cannabis flowers. ploom vaporizers in january 2016, japan tobacco released ploom, which has been withdrawn from the us. the brand remained with japan tobacco and the product has been replaced with ploom tech, where an aerosol passes through a capsule of granulated tobacco leaves. the ploom brand uses aluminum capsules called vapodes, where tobacco can heat up to 180 °c. because the ploom tech heats up more, it may generate more harmful emissions. in january 2019, japan tobacco introduced ploom tech+ and ploom s in tokyo, japan. sales expanded throughout japan in 2017. japan tobacco intended to spend $500 million to increase their heated tobacco manufacturing capacity by late 2018. studies have not been conducted on japan tobacco international's ploom product as of 2017. pulze in 2018, imperial brands was developing a heated tobacco product named pulze. teeps in december 2017, pmi launched teeps in the dominican republic. it is an htp that looks similar to a traditional cigarette. instead of an electrically controlled heating system, it uses a carbon heat source that, once lit, passes heat to a processed tobacco plug. cigoo in september 2020, yunnan xike science & technology co., ltd. launched cigoo; according to the company, it is a heated herbal product which releases nicotine and aroma aerosol at 300 °c, similar to mainstream htps. instead of using reconstituted tobacco film in the stick, cigoo sticks use patented plant particle as a carrier, added flavourants and additives. teo the teo heats a cigarette stick with a heating blade, and was launched by shenzhen eson technology co. ltd. ("eson") in dec. 2021 after poda. neafs tobacco-free sticks does not use tobacco, but instead a nicotine infused, tea-based organic compound. comparison to mainstream smoke of traditional cigarettes contents of selected analytes in the mainstream aerosol of a heated tobacco product compared to the mainstream smoke of traditional cigarettes. the highest and lowest values in two different types of tobacco sticks and traditional cigarettes were given by mallock et al. and counts et al. respectively. column 5 shows the reduction of the analytes in the mainstream aerosol of the heated tobacco product compared to traditional cigarettes by percentage. tobacco sticks (mallock et al. 2018; ) traditional cigarettes (counts et al. 2005; ) reduction parameterunitmin.–max.min.–max. % puff countpuff/stick125.5–13.6– tpmmg/stick51.2–52.627.5–60.9– nicotinemg/stick1.11.07–2.70– watermg/stick28.0–31.79.8–21.4– nfdpmmg/stick19.8–21.616.3–37.6– acetaldehydeµg/stick179.4–183.5930–154080.5–88.2 acroleinµg/stick8.9–9.989.2–154.189.5–93.9 formaldehydeµg/stick4.7–5.329.3–130.382.9–96.2 crotonaldehydeµg/stick<3.032.7–70.8– 1.3-butadieneµg/stick0.20–0.277.0–116.799.7–99.8 benzineµg/stick0.5–0.649.7–98.398.8–99.4 isopreneµg/stick1.8–2.1509–116099.6–99.8 styreneµg/stick0.515.4–33.396.9–98.6 tolueneµg/stick2.0–2.286.2–176.297.6–98.8 tobacco stick, d. h. for heated tobacco products: a tobacco stick; for traditional cigarette: a cigarette.all values were generated using the health canada intense (hci) puffing conditions.tpm = total particulate matter, and nfdpm = nicotine-free dried particulate matter. prevalence rapid fall in cigarette sales associated with the rise of htp sales in japan: from burning issues: the global state of tobacco harm reduction as of 2017, htps are being introduced in markets around the world, and since october 2019, they have been sold in at least 49 countries. they are not as globally popular as the e-cigarette, which has an estimated global user count of 20 million. as of 2018, the iqos is the most popular product, and was authorised for marketing by the fda in the us on 30 april 2019. as of january 2018, the industry has been rapidly introducing new heated tobacco products. htps were first sold in japan, and several brands have been marketed there since 2014. since the introduction of htp in japan there has been a 32% drop in the sale of tobacco cigarettes. the share of the market in south korea for heated tobacco products has surged at least five-fold during the last two years leading up to 2019. as of early 2018, these products are not sold in france. tobacco industry leaders predicted that htps may displace traditional cigarette smoking and, by extension, tobacco control strategies typically framed around cigarettes. since the introduction of pmi's iqos brand in select japanese cities in november 2014, web searches in japan for "heat-not-burn products" (a marketing name for htps) increased substantially; average monthly searches rose 1,426% (95% ci: 746–3,574) during 2015–2016, and they continued to grow an additional 100% (95% ci: 60–173) between 2016 and 2017; in practical terms, there are now between 5.9 and 7.5 million heat-not-burn related google searches in japan each month based on the latest search estimates for september 2017. moreover, forecasts relying on the historical trend suggest heat-not-burn searches would increase an additional 32% (95%ci: -4 to 79) during 2018, compared to current estimates for 2017 (january–september), with further growth expected. queries for heat-not-burn in japan occur more frequently than queries for e-cigarettes in the united states, with the japanese heat-not-burn queries first eclipsing e-cigarette queries in april 2016. further, the change in average monthly queries for heat-not-burn in japan between 2015 and 2017 was 399 (95% ci: 184–1,490) times larger than the change in average monthly queries for e-cigarettes in the united states over the same time period, increasing by 2,956% (95% ci: 1,729–7,304) compared to only 7% (95% ci: 3–13), which indicate that interest in heat-not-burn may outpace interest in e-cigarettes in the future. google searches for heat-not-burn tobacco (heated tobacco) outpace rise of electronic cigarettes. the above figure shows the relative search volume (scaled from 0–100 and adjusted for number of total google search volumes per month in japan and the usa) for heat-not-burn and e-cigarette products. htp demand presents a host of tobacco control challenges similar to e-cigarettes and new challenges specific to these products. they have been advertised as reduced-risk tobacco products in their japanese test market. marketing temporary smoking room and a sales promotion of glo at the 2016 sendai pageant of starlight in kōtōdai-kōen park. the term "heat-not-burn" refers to tobacco heated (at ~350 °c) by an electrically powered element or carbon instead of being fully combusted (at ~800 °c). terms used in marketing for cigarette-like products that "heat rather than