Next generation tobacco and nicotine products (NGPs) such as electronic cigarettes (EC) and tobacco heating products (THP) have reduced toxicity and hold great potential for reducing the risks associated with cigarette smoking. NGPs may also have hygiene benefits for consumers that switch to these products. In this study, the level of skin staining was assessed following exposure to a scientific reference cigarette (3R4F) and NGPs across the risk continuum; a prototype EC or a commercial THP (glo™).
Test articles (TAs) were prepared by capturing cigarette smoke or EC/THP aerosol on Cambridge filter pads followed by elution with Dimethyl Sulfoxide (DMSO). Abattoir-obtained porcine skin (ø 0.5) samples were incubated at 37°C with each TA or DMSO control for 0, 0.25, 0.5, 1, 4 and 6h. Colour readings (L*, a*, b*) were measured for individual skin samples using a Konica Minolta CM-700d Spectrophotometer and mean colour change (ΔE) for each TA compared.
The reference cigarette 3R4F TA showed the greatest colour change, which was significantly higher than the EC and THP TAs, both of which showed relatively little colour change. The mean ΔE values at 6 hrs were: 21.78 ± 2.80, 8.38 ± 2.93, 10.01 ± 2.53 and 9.23 ± 2.87 for 3R4F, a prototype EC, glo™ or DMSO respectively.
The cigarette smoke extract significantly increased the level of staining of the skin samples whereas EC or the THP TAs induced little or no staining with values comparable to the DMSO control. For the first time, diverse NGPs across the risk continuum have been assessed in vitro for their impact on skin staining. Further studies are required to assess the long-term impact on skin staining of NGP aerosols.