Table 1.
Aerosol generation parameters of the 41 revised studies using the InExpose. Power tested as declared by authors allegedly from display in the instrument screen of the box mod. Six articles used nicotine concentrations above 30 mg/mL, 14 studies between 20 mg/mL and 30 mg/mL, 9 studies between 10 mg/mL and 20 mg/mL, 12 studies between 3 mg/mL and 10 mg/mL, while 11 studies did not use nicotine. In 20 articles nicotine concentrations above the Tobacco Product Directive requirement of 20 mg/mL were reported.
| Reference | Nicotine (mg/mL) | PG/VG | Device | Coil (Ω) | Power tested (W) | Airflow (L/min) | |
|---|---|---|---|---|---|---|---|
| (27) | 0 and 6 | 50/50 | EVIC | 0.15 | 80 | 2.00 | |
| Certain | (28) | 0 and 18 | 60/30 10% w | EVIC | 0.15 | 112 (4.1 V) | 3 |
| (29) | 30 and 36 | 30/70 and 40/60 | E-Vic and pods | 0.15 | 60 (3 V) | 1.10 | |
| (30) | 50 | 50/50 | 3rd | 0.15 | 70 | 1.05 | |
| (31) | 36 | 50/50 | 3rd | 0.15 | 118 (4.2 V) | 1.10 | |
| Almost | (32) | 20 | 30/70 | EVIC | 0.2 | 70 | 1.40 |
| certain | (33) | 20 | 50/50 | EVIC | 0.2 | 70 | 2.00 |
| (34) | 12 and 18 | Varied | E-Vic and pods | 0.15 | 118 (4.2V) | 1.00 | |
| (35) | 36 | Varied | E-Vic and pods | 0.15; 0.5; 1.5 | 2.8; 3.8; 4.8 V | 1.10 | |
| (36) | NA | 30/70 | Kangertech | 0.15 | 235 °C | 1.27 | |
| (10) | 24 | 55/45 | EVIC | 0.15 | 245 °C | NA | |
| Suspicious | (37) | 0 | 50/50 | NA | NA | 60 | 1.22 |
| (38) | 24 | 50/50 | NA | NA | 70 | 1.05 | |
| (39) | 24 | 50/50 | 3rd | NA | 230 °C | NA (9 s) | |
| (40) | 24 | 50/50 | Subtank | NA | NA | NA (10 s) | |
| (41) | 0 and 18 | NA | KangerTech | NA | NA | 1.10 | |
| (42) | 50 | NA | EVIC | NA | NA | NA | |
| (43) | 50 | NA | EVIC | NA | NA | NA | |
| (44) | 0 and 25 | 100/0 | EVIC | 0.15 | NA | 1.27 | |
| (45) | 18 | 50/50 | EVIC | NA | NA | 1.10 | |
| (46) | 0 and 6 | 70/30 | Subtank | 0.15 | NA | NA | |
| (47) | 0 and 25 | NA | Kangertech | 0.15 | NA | 1.27 | |
| Uncertain | (48) | NA | 100/0 | EVIC | 0.15 | 70 (230 °C) | 1.00 |
| (49) | 0 and 18 | 55/35 10% w | EVIC | NA | NA | NA | |
| (50) | 0 | 50/50 | KangerTech | 0.15 | NA | 1.02 | |
| (51) | 0, 25, 33 | Varied | Kangertech | 0.15 | NA | 1.27 | |
| (52) | NA | 50/50 | EVIC | 0.15 | NA | 3.06 | |
| (53) | 25 | 100/0 | EVIC | 0.15 | NA | 1.4 | |
| (54) | 25 | 50/50 | NA | 0.15 | NA | 1.27 | |
| (55) | 25 | 50/50 | NA | 0.15 | NA | 1.27 | |
| (56) | 12 | 50/50 | EVIC | NA | NA (8V) | NA (3 s) | |
| (57) | 24 | 50/50 | NA | NA | NA | NA | |
| (58) | 6, 14, 18, 24 | 50/50 80/20 | NA | NA | NA | NA | |
| (59) | NA | 30/70 | NA | NA | NA | NA | |
| (60) | 0 | NA | NA | NA | NA | NA | |
| (61) | 0 | 70/30 | NA | NA | NA | 4.20 | |
| Unknown | (62) | 24 | 50/50 | NA | NA | NA | NA |
| (63) | 20 | 50/50 | NA | NA | NA | NA | |
| (64) | 4% of liquid | Varied | NA | NA | NA | 2.00 | |
| (65) | 0 and 4% mass | 50/50 | NA | NA | NA | 1.10 | |
| (66) | 20 | 30/70 | NA | NA | NA | 1.40 |
Figure 1.
Methodological flow diagram.
Figure 2.
Calibration curve of the E-Vic VTC modes using the OCC 0.15 Ω coil and an airflow rate of 1.1 L/min (a) power-controlled mode and b) temperature-controlled mode). Gray boxes illustrate the range of conditions reported in the literature we listed in Table 1 and reviewed in Section 4.
Figure 3.
Calibration curve of the E-Vic VTC modes using the OCC 0.15 Ω coil and an airflow rate of 1.1L/min (a) power-controlled mode and b) temperature-controlled mode).
Figure 5.
Functioning curves of the OCC 0.15 Ω coil applying 1.1 L/min and 10 L/min.
Figure 6
a) Functioning curve of the OCC 0.15 Ω coil and b) the resulting aldehydes released. The green rectangles mark the power range of the Optimal Regime.
Figure 7.
Prisma chart associated with our literature search (see Section 3).
Figure 4.
Calibration curve of the E-Vic VTC modes using a 0.20 Ω coil (left y-axis) voltage calibration and (right y-axis) resulting wattage supplied in wattage mode. Gray boxes mark the voltages (4.1 V and 4.2 V) reported by three studies listed in Table 1.
Table 2.
Summary of the aldehydes quantified in the five articles reviewed. Values were graphically determined. Numbers in parentheses denote number of tests per flavor.
| Reference | Conditions | Aldehyde [μg] / puff | ||
|---|---|---|---|---|
| Acrolein | Acetaldehyde | Formaldehyde | ||
| But(1) (2.8 V) | 0.05 | 0.05 | 0.08 | |
| But(1) (3.8 V) | 3.5 | 15 | 3.5 | |
| (35) | But(1) (4.8 V) | 9.5 | 16 | 8 |
| Cin(2) (2.8 V) | NA | 0.17 | 0.10 | |
| Cin(2) (3.8 V) | NA | 0.33 | 0.18 | |
| Cin(2) (4.8 V) | NA | 0.39 | 0.02 | |
| (31) | Cin(2) (4.2 V) | NA | 0.386 | 0.021 |
| (29) | Men(3) (3 V) | 0.02 | 0.1 | 2.5 |
| CB(4) (3 V) | 10 | 4 | 13 | |
| (27) | Tob(5) (80 W) | 3.5 | 3.1 | NA |
| Men(3) (80 W) | 150 | 150 | NA | |
| 30/70 (4.2 V) | 0.8 | 0.7 | 3 | |
| 50/50 (4.2 V) | 0.15 | 3 | 7 | |
| 70/30 (4.2 V) | 0.9 | 2 | 7 | |
| Str(6.12) (4.2 V) | 0.01 | 0.6 | NA | |
| (34) | Str(6.18) (4.2 V) | 0.01 | 0.7 | NA |
| Van(7.12) (4.2 V) | 1.3 | 0.8 | 3.5 | |
| Van(7.18) (4.2 V) | 0.1 | 0.1 | 0.05 | |
| Cat(8.12) (4.2 V) | 0.2 | 0.2 | NA | |
| Cat(8.18) (4.2V) | 0.5 | 2 | 7 | |