Robustness of HPHC Reduction for THS 2.2 Aerosol Compared with 3R4F Reference Cigarette Smoke Under High Intensity Puffing Conditions
Bibliographic record
Abstract
Summary In the absence of standards specific for testing the reduction robustness of the levels of harmful and potentially harmful constituents (HPHCs), the aerosol from the THS 2.2, a heated tobacco product, was compared with the mainstream smoke of the 3R4F reference cigarette over a broad range of machine-smoking regimes. The average reduction and the introduced concept of threshold limits of robust reduction were derived from HPHC concentrations, in mass per tobacco-stick normalized per total puff volume, to propose an alternative for the assessment of products where nicotine-adjusted yields would be inappropriate. In addition, this study explores the influence of 3R4F reference cigarette filter ventilation, and discusses the roles of temperature and precursors in the present context of robustness of HPHC reduction. Fifty-four HPHCs were analyzed under multiple regimes in THS 2.2 aerosol and 3R4F cigarette smoke. The average reduction of HPHC concentrations compared across all regimes characterized the robustness. Threshold limits of reduction of individual HPHCs were statistically determined across all regimes. The results observed under Health Canada Intense (HCI) and more intense regimes indicated that on average the reductions in HPHCs levels investigated in THS 2.2 aerosol were more than 90% and that the majority of the 54 HPHCs investigated in THS 2.2 aerosol showed more than 90% reduction. The robustness of THS 2.2 in maintaining the levels of reduction of representative HPHCs, whatever the puffing regime, can be quantified. The mass of HPHC per tobacco-stick normalized per total puff volume is a valuable approach to compare the robustness of the performance of a product over a large range of puffing conditions. Our findings will greatly complement the assessment for robustness of current and future similar products where classical approaches would present limitations.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".