There has been a number of significant changes in the tobacco industry over the last few years driven by various new legislations. Over the next decade regulations on packaging will almost undoubtedly evolve into outright plain packaging in mature markets and then move on to emerging ones. This will and already is driving innovation in the filter industry to offer consumers more choice, unique taste experiences and visual differentiation lost through plain packaging, with special filters playing a key part in the creation of combustible tobacco products with more favourable smoke constituent profiles. Hollow filter has recently been growing in popularity on a large scale and we therefore would like to focus on this product.

In this study we analysed the influence of hollow tube inner diameter on cigarette smoke parameters. We made four different hollow filter cigarettes with inner tube diameter 2.0 mm, 3.0 mm, 4.0 mm and 5.0 mm, and then compared tar, nicotine, CO, level of triacetin and temperature of smoke in the middle of the hollow tube against a standard monoacetate and dual filter products. Cigarettes with different test filters were made in a standardised way and all confounding factors removed.

Cigarettes with the above described filters were made with 50% ventilation and without ventilation. The smoke was collected on Cambridge filter pads using the ISO and Canada Intense smoking regimes with some machine adjustments to measure smoke temperature. Analyses of smoke composites were made using Agilent 5973N GC-MS.

Our results showed that inner tube diameter and ventilation affects cigarette smoke temperature and triacetin levels. The amount of triacetin in non-ventilated cigarette smoke was higher than in ventilated due to the high concentration of triacetin in the hollow tube.