Mean pH in products purchased in England and the USA
| Overall | N | Mean | Lower CI | Upper CI | Minimum | Maximum | F | P value |
| No nicotine detected | 47 | 4.7 | 4.4 | 5.1 | 3.4 | 9.4 | 784.9 | <0.001 |
| Nicotine detected | 187 | 8.6 | 8.5 | 8.7 | 4.1 | 9.6 | ||
| USA only | ||||||||
| No nicotine detected | 9 | 4.4 | 4.2 | 4.6 | 4.1 | 4.8 | 297.9 | <0.001 |
| Nicotine detected | 45 | 8.5 | 8.3 | 8.8 | 5.9 | 9.4 | ||
| England only | ||||||||
| No nicotine detected | 13 | 5.2 | 4.1 | 6.2 | 3.7 | 9.4 | 185.9 | <0.001 |
| Nicotine detected | 132 | 8.6 | 8.5 | 8.7 | 4.1 | 9.6 | ||
| Overall | ||||||||
| No organic acids detected | 189 | 7.9 | 7.6 | 8.1 | 3.4 | 9.6 | 0.63 | 0.43 |
| Organic acids detected | 45 | 7.6 | 7.2 | 8.1 | 3.8 | 9.1 | ||
| USA only | ||||||||
| No organic acids detected | 52 | 7.8 | 7.4 | 8.3 | 4.1 | 9.4 | 0.33 | 0.57 |
| Organic acids detected | 2 | 8.5 | 3.1 | 13.5 | 8.1 | 8.9 | ||
| England only | ||||||||
| No organic acids detected | 114 | 8.5 | 8.3 | 8.8 | 3.7 | 9.6 | 11.45 | <0.001 |
| Organic acids detected | 41 | 7.6 | 7.3 | 8.2 | 3.8 | 9.1 |