Review of industry reports on EU priority tobacco additives part B: Methodological limitations.

The Tobacco Products Directive (TPD) defines enhanced reporting obligations applying to 15 priority additives added to cigarettes and roll-your-own tobacco. A consortium of 12 international tobacco companies submitted 14 reports that were reviewed by an independent scientific body within the Joint Action on Tobacco Control (JATC). The reports were evaluated in accordance with the TPD with regard to their comprehensiveness, methodology and conclusions. Here we present their significant identified methodological limitations. The toxicological and chemical evaluation in the industry reports was mainly based on comparative testing, which lacks discriminative power for products with high toxicity and variability, like cigarettes. The literature reviews were biased, the comparative chemical studies did not assess previously identified pyrolysis products, the toxicological evaluation did not include the assessment of inhalation toxicity, and pyrolysis products were not assessed in terms of toxicity, including their genotoxic and carcinogenic potential. For both chemistry and toxicity testing, the statistical approach applied to test the difference between test and additive-free control cigarettes resulted in a high chance of false negatives. The clinical study for inhalation facilitation and nicotine uptake had limitations concerning study design and statistical analysis, while addictiveness was not assessed. Finally, the methodology used to assess characterizing flavors was flawed. In conclusion, there are significant limitations in the methodology applied by the industry. Therefore, the provided reports are of insufficient quality and are clearly not suitable to decide whether a priority additive should be banned in tobacco products according to the TPD.