Mark Forster

An experimental method to study emissions from heated tobacco between 100-200°C

BackgroundCigarette smoke emissions are mainly produced by distillation, pyrolysis and combustion reactions when the tobacco is burnt. Some studies have shown that heating tobacco to temperatures below pyrolysis and combustion temperatures has the potential to reduce or eliminate some toxicants found in cigarette smoke. In this study, we designed a bench-top tube furnace that heats tobacco between 100-200°C and systematically studied the effects of heating temperatures on selected gas phase and aerosol phase compounds using an ISO machine-smoking protocol.ResultsAmong a list of target chemical compounds, seven toxicants (nicotine, carbon monoxide, acetaldehyde, crotonaldehyde, formaldehyde, NNN and NNK) were quantifiable but not at all temperatures examined. The levels of the compounds generally displayed an increasing trend with increasing temperatures. The observed carbon monoxide and aldehydes represented the initial thermal breakdown products from the tobacco constituents. Water was the largest measured component in the total aerosol phase collected and appeared to be mainly released by evaporation; nicotine release characteristics were consistent with bond breaking and evaporation. Quantifiable levels of NNK and NNN were thought to be the result of evaporative transfer from the tobacco blend.ConclusionsThese results demonstrate the practical utility of this tool to study low-temperature toxicant formation and emission from heated tobacco. Between 100 to 200°C, nicotine and some cigarette smoke compounds were released as a result of evaporative transfer or initial thermal decomposition from the tobacco blend.

Assessment of tobacco heating product THP1.0. Part 2: Product design, operation and thermophysical characterisation

ABSTRACT A novel tobacco heating product, THP1.0, that heats tobacco below 245 °C is described. It was designed to eliminate tobacco combustion, while heating tobacco to release nicotine, tobacco volatiles and glycerol to form its aerosol. The stewardship assessment approach behind the THP 1.0 design was based on established toxicological principles. Thermophysical studies were conducted to examine the extent of tobacco thermal conversion during operation. Thermogravimetric analysis of the tobacco material revealed the major thermal behaviour in air and nitrogen up to 900 °C. This, combined with the heating temperature profiling of the heater and tobacco rod, verified that the tobacco was not subject to combustion. The levels of tobacco combustion markers (CO, CO2, NO and NOx) in the aerosol of THP1.0 were significantly lower than the levels if there were any significant pyrolysis or combustion. Quantification of other tobacco thermal decomposition and evaporative transfer markers showed that these levels were, on average, reduced by more than 90% in THP1.0 aerosol as compared with cigarette smoke. The physical integrity of the tobacco consumable rod showed no ashing. Taken together, these data establish that the aerosol generated by THP1.0 is produced mainly by evaporation and distillation, and not by combustion or pyrolysis. HighlightsDesign and operation of THP1.0 tobacco heating product is described.A 5‐step thermophysical and thermochemical assessment is conducted on THP1.0.THP1.0 forms its aerosol predominantly through evaporation and distillation.Tobacco in THP1.0 is not subject to combustion.

Assessment of novel tobacco heating product THP1.0. Part 3: Comprehensive chemical characterisation of harmful and potentially harmful aerosol emissions

ABSTRACT For a tobacco heating product (THP), which heats rather than burns tobacco, the emissions of toxicants in the aerosol were compared with those in cigarette smoke under a machine‐puffing regimen of puff volume 55 ml, puff duration 2 s and puff interval 30 s. The list of toxicants included those proposed by Health Canada, the World Health Organization Study Group on Tobacco Product Regulation (TobReg), the US Food and Drug Administration and possible thermal breakdown products. In comparison to the University of Kentucky 3R4F reference cigarette the toxicant levels in the THP1.0 emissions were significantly reduced across all chemical classes. For the nine toxicants proposed by TobReg for mandated reduction in cigarette emissions, the mean reductions in THP1.0 aerosol were 90.6–99.9% per consumable with an overall average reduction of 97.1%. For the abbreviated list of harmful and potentially harmful constituents of smoke specified by the US Food and Drug Administration Tobacco Products Scientific Advisory Committee for reporting in cigarette smoke (excluding nicotine), reductions in the aerosol of THP1.0 were 84.6–99.9% per consumable with an overall average reduction of 97.5%. HighlightsTHP1.0, which heats rather than burns tobacco, was compared with 3R4F cigarette.Harmful and potentially harmful constituents were measured in the aerosols and compared.Toxicants in the aerosol of THP1.0 were substantially lower than in 3R4F smoke.Reduction averaged 96.1 per cent for nine substances prioritised for lowering in cigarettes.Reduction averaged 96.8 per cent for 18 substances prioritised by the US FDA.

Assessment of tobacco heating product THP1.0. Part 4: Characterisation of indoor air quality and odour

ABSTRACT The tobacco heating product THP1.0, which heats but does not burn tobacco, was tested as part of a modified‐risk tobacco product assessment framework for its impacts on indoor air quality and residual tobacco smoke odour. THP1.0 heats the tobacco to less than 240 °C ± 5 °C during puffs. An environmentally controlled room was used to simulate ventilation conditions corresponding to residential, office and hospitality environments. An analysis of known tobacco smoke constituents, included CO, CO2, NO, NO2, nicotine, glycerol, 3‐ethenyl pyridine, sixteen polycyclic aromatic hydrocarbons, eight volatile organic compounds, four carbonyls, four tobacco‐specific nitrosamines and total aerosol particulate matter. Significant emissions reductions in comparison to conventional cigarettes were measured for THP1.0. Levels of nicotine, acetaldehyde, formaldehyde and particulate matter emitted from THP1.0 exceeded ambient air measurements, but were more than 90% reduced relative to cigarette smoke emissions within the laboratory conditions defined Residual tobacco smoke odour was assessed by trained sensory panels after exposure of cloth, hair and skin to both mainstream and environmental emissions from the test products. Residual tobacco smoke odour was significantly lower from THP1.0 than from a conventional cigarette. These data show that using THP1.0 has the potential to result in considerably reduced environmental emissions that affect indoor air quality relative to conventional cigarettes. HighlightsTHP emissions are reduced in indoor air versus conventional cigarettes.Tobacco combustion markers were not observed for THP emissions.Residual tobacco odour post THP exposure was less than cigarettes.First reported high‐resolution time‐resolved particle size and mass measurements.

Evaluation of flavourings potentially used in a heated tobacco product: Chemical analysis, in vitro mutagenicity, genotoxicity, cytotoxicity and in vitro tumour promoting activity

We designed a novel tobacco-heating product (THP) that heats tobacco to release nicotine and aerosolised components, such as glycerol and tobacco volatiles from a tobacco rod (Neostik). Heating tobacco significantly reduces levels of combustion-derived toxicants in the aerosol compared to cigarette smoke. This study was conducted to determine whether the inclusion of potential flavourings in the THP would add to the levels of toxicants in the emissions or alter in vitro responses. Levels of measured toxicants were similar in the flavoured and unflavoured Neostik emissions and significantly less than emissions from the reference cigarette, 3R4F. No mutagenicity was observed with the Neostiks in the Ames test or in the mouse lymphoma assay. There was evidence of a weak genotoxic response in the in vitro micronucleus test using V79 cells from both Neostiks and these responses were less than 3R4F. They did not show tumour-promoting potential in the Bhas 42 cell transformation assay and were not cytotoxic in the Neutral Red uptake assay. 3R4F elicited toxic responses in all assays at significantly lower concentrations. The addition of flavourings to the Neostik tested did not alter the chemical profile of THP emissions or change in vitro responses relative to the unflavoured Neostik.

The effect of tobacco ingredients on the in vitro mutagenicity, cytotoxicity and cell transformation potential of a novel heated tobacco product

Figure 2. THP ingredient and material risk assessment approach. • Recently, tobacco-heating products (THPs) have been developed (Figure 1) to heat rather than burn tobacco. The toxicant emissions of THPs have been shown to be considerably lower than the standard University of Kentucky reference cigarette, 3R4F[1]. • BAT has established an approach (Figure 2) to assess the toxicological risk of a novel THP device and the consumable tobacco rod (Neostik) that is heated to 240°C to release nicotine, glycerol, tobacco volatiles and any added flavour compounds. • One of the key steps in the risk assessment paradigm is to compare the in vitro toxicity of the emissions from a THP relative to that of 3R4F. • This reports the study conducted to compare the in vitro toxicity of both an unflavoured Neostik and a Neostik containing typical tobacco flavourings[2] to that of 3R4F.