Discrepancies in reported versus measured nicotine content of e-cigarette refill liquids across nine European countries before and after the implementation of the EU Tobacco Products Directive.

Introduction:
This text presents the findings of a study that aimed to evaluate the discrepancies between the reported and measured nicotine content of e-cigarette refill liquids in nine European countries before and after the implementation of the EU Tobacco Products Directive (TPD). The study also looked at potential impurities in these products.

Key Points:

* The study analyzed 252 e-cigarette refill liquids for their concentrations of nicotine, nitrosamine, and polycyclic aromatic hydrocarbon (Pah) content using gas chromatography –mass spectrometry and liquid chromatography –mass spectrometry.
* The results showed differences between the measured versus reported nicotine content in both the pre-TPD and post-TPD evaluation, with more than half of the top-selling products in the EU market having a discrepancy in nicotine concentration greater than ±10% of the amount labeled on the product.
* Only one product exceeded the legislated limit of 20 mg·mL−1of nicotine in the post-TPD phase.
* applying the CEN TC437 thresholds, there was an increase in discrepancy for samples with a nicotine concentration <5.99 mg·mL−1, and a slight decrease in discrepancy for samples with a nicotine concentration 6.00 –12.99 mg·mL−1and 13.00 –20.00 mg·mL−1.
* all products in both the pre- and post-TPD phase tested negative for nitrosamines and Pahs, indicating an absence of impurities.
* The study's findings indicate the need for close monitoring of the nicotine concentration of electronic cigarette refills marketed in the EU, as discrepancies exist between the nicotine content in the vial and that stated on the label, even after the implementation of the TPD.
* Improvements in the production process and implementation of quality-control mechanisms for the nicotine content of e-cigarette refill vials in Europe are still needed for the protection of consumer health.

Main Message:
The study found that discrepancies between the reported and measured nicotine content of e-cigarette refill liquids in the EU market still exist, even after the implementation of the TPD. This highlights the need for close monitoring and improvements in the production process and quality-control mechanisms for the nicotine content of e-cigarette refill vials in Europe to protect consumer health. The absence of impurities such as nitrosamines and Pahs in the products indicates that quality control efforts should now focus primarily on nicotine concentrations.

Girvalaki C, Tzatzarakis M, Vardavas a, et al. Discrepancies in reported versus measured nicotine content of e-cigarette refill liquids across nine European countries before and after the implementation of the EU Tobacco Products Directive. The European respiratory journal. 2020;55(2). doi:10.1183/13993003.00941-2019