Puffing Topography, Mouth Level Exposure, Average Daily Consumption and Machine Emissions of Three Variants of glo™ Heated Tobacco Products Among UK Smokers

Adam Gray; Lauren Edward; Krishna Prasad

doi:10.2478/cttr-2026-0006

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Puffing Topography, Mouth Level Exposure, Average Daily Consumption and Machine Emissions of Three Variants of glo™ Heated Tobacco Products Among UK Smokers

Contributions to Tobacco & Nicotine Research

Volume 35 (2026): Issue 2 (April 2026)

By: Adam Gray, Lauren Edward and Krishna Prasad

Open Access

|Jun 2026

Figures & Tables

Diagram of glo™ HTP with a tobacco consumable.

Image of glo™ attached to the SA7 topography device.

Comparison of ADC and MLE among the three consumable variants_a

Parameter	Variant 1 comparison				Variant 2 comparison
Parameter	Base	Variant	Difference (variant - base)	Statistical equivalence^b	Base	Variant	Difference (variant - base)	Statistical equivalence^b
ADC study product (sticks/day)^c	4.5 ± 3.8	4.6 ± 3.8	0.10	–	4.5 ± 3.8	4.6 ± 4.0	0.07	–
Total ADC (sticks/day)^d	12.6 ± 6.0	12.7 ± 6.0	0.03	–	12.6 ± 6.0	12.0 ± 5.5	−0.69	–
MLE to NFDPM (mg/stick)	4.71 ± 1.86	5.30 ± 2.52	0.59	–	4.71 ± 1.86	4.59 ± 3.14	−0.12	–
MLE to nicotine (mg/stick)	0.30 ± 0.12	0.30 ± 0.14	0.007	–	0.30 ± 0.12	0.41 ± 0.28	0.112	Not equivalent (90% CI: 1.05, 1.34)
MLE to NFDPM (mg/day)	22.2 ± 21.5	27.2 ± 33.1	5.00	Equivalent (90% CI: 0.93, 1.23)	22.2 ± 21.5	22.4 ± 28.7	0.21	–
MLE to nicotine (mg/day)	1.40 ± 1.36	1.56 ± 1.91	0,159	–	1.40 ± 1.36	2.00 ± 2.57	0.597	Not equivalent (90% CI: 1.03, 1.48)

Study design_

Study day	Study stage
Study day	1	2	3	4	5	6	7	8	9	10	11	12	13
Visit 1: product/consumption diary allocation
Home placement 1
Visit 2: puffing topography & product allocation
Home placement 2
Visit 3: puffing topography & product allocation
Home placement 3
Visit 4: puffing topography measurements

Percentage reduction in nine toxicants relative to cigarette smoke_a

TobReg toxicant	Base product	Variant 1	Variant 2
CO	99.76	99.55	99.90
Formaldehyde	93.92	95.60	96.32
Acetaldehyde	94.96	94.16	96.37
Acrolein	98.59	98.92	98.66
1,3-Butadiene	99.99	99.99	99.99
Benzene	99.95	99.90	99.95
Benzo[a]pyrene	97.72	98.00	98.92
NNN	90.61	93.74	93.72
NNK	97.65	98.17	98.24
Overall reduction	97.02	97.56	97.93

Comparison of puffing topography data among the three consumable variants_a

Parameter	Variant 1 comparison				Variant 2 comparison
Parameter	Base	Variant	Difference (variant - base)	Statistical equivalence^b	Base	Variant	Difference (variant - base)	Statistical equivalence^b
Puff number	15.9 ± 8.4	16.4 ± 8.5	0.53	–	15.9 ± 8.4	14.8 ± 8.3	−1.05	Equivalent (90% CI: 0.86, 0.98)
Puff volume (mL)	58.9 ± 31.7	63.4 ± 31.9	4.45	Equivalent (90% CI: 1.01, 1.12)	58.9 ± 31.7	58.8 ± 22.9	−0.15	–
Puff duration (s)	2.0 ± 0.9	2.0 ± 0.9	0.08	–	2.0 ± 0.9	1.8 ± 0.7	−0.21	Equivalent (90% CI: 0.86, 0.93)
Puff interval (s)	10.0 ± 4.8	9.7 ± 5.0	−0.37	–	10.0 ± 4.8	10.0 ± 5.6	−0.03	–
Effort (mm WGs)	500 ± 329	526 ± 314	26.2	Equivalent (90% CI: 0.99, 1.15)	500 ± 329	437 ± 279	−63.4	Not equivalent (90% CI: 0.80, 0.94)

Comparison of other aerosol constituents among the study products_a

Smoke constituent	Base product	Variant 1	Variant 2
Nicotine (mg/stick)	0.46 ± 0.04	0.38 ± 0.03	0.55 ± 0.03
NFDPM (mg/stick)	13.50 ± 1.20	11.00 ± 0.50	11.10 ± 0.40
Water (mg/stick)	12.10 ± 1.00	15.74 ± 0.44	12.80 ± 0.40
Glycerol (mg/stick)	3.02 ± 0.25	1.94 ± 0.35	2.74 ± 0.19

Comparison of ADC and MLE for the base product among three different studies_a

Country	MLE to NFDPM (mg/stick)	MLE to nicotine (mg/stick)	ADC study product (sticks/day)^b	Total ADC (sticks/day)^c	Reference
Japan
Smokers (n = 52)	5.2 ± 3.4	0.3 ± 0.2	10.3 ± 5.5	12.1 ± 5.5	(23)
HTP users (n = 52)	5.0 ± 3.1	0.3 ± 0.1	8.6 ± 4.6	11.2 ± 6.2
Italy
Smokers (n = 52)	4.7 ± 2.9	0.3 ± 0.2	7.0 ± 5.5	11.6 ± 5.7	(24)
UK
Smokers (n = 70)	4.7 ± 1.9	0.3 ± 0.1	4.5 ± 3.8	12.6 ± 6.0	This study

Articles in this issue

DOI: https://doi.org/10.2478/cttr-2026-0006 | Journal eISSN: 2719-9509

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Language: English

Page range: 77 - 89

Submitted on: Nov 26, 2025

Accepted on: Apr 29, 2026

Published on: Jun 20, 2026

Published by: Beiträge zur Tabakforschung GmbH

In partnership with: Paradigm Publishing Services

Publication frequency: 4 issues per year

Keywords:

Average daily consumption,

ADC,

puffing topography,

tobacco heating product,

THP,

heated tobacco product,

HTP,

glo™,

mouth level exposure,

MLE,

use behaviour

Related subjects:

General interest,

Life sciences,

Life sciences, other,

Physics,

Physics, other

© 2026 Adam Gray, Lauren Edward, Krishna Prasad, published by Beiträge zur Tabakforschung GmbH
This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License.

Volume 35 (2026): Issue 2 (April 2026)

Puffing Topography, Mouth Level Exposure, Average Daily Consumption and Machine Emissions of Three Variants of glo™ Heated Tobacco Products Among UK Smokers

Figures & Tables

Figure 1.

Figure 2.

Comparison of ADC and MLE among the three consumable variants_a

Study design_

Percentage reduction in nine toxicants relative to cigarette smoke_a

Comparison of puffing topography data among the three consumable variants_a

Comparison of other aerosol constituents among the study products_a

Comparison of ADC and MLE for the base product among three different studies_a

Paradigm

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