Menthol and related compounds in waterpipe products.

Introduction: The addition of cooling substances, such as menthol, might be attractive for youth to start smoking waterpipe by reducing the harshness of the smoke, thereby facilitating inhalation. These compounds simultaneously increase the addictiveness of tobacco and related products by stimulating nicotine uptake. Some menthol-like compounds also increase attractiveness by imparting a menthol/mint flavor. We provide an overview of the frequency and quantities of use of menthol-like substances in waterpipe tobacco, herbal molasses and steam stones.

Methods: The primary data source of this study was the European Common Entry Gate (EU-CEG). Product names and ingredients were obtained for 282 waterpipe tobacco products notified to The Netherlands in 2020. Subsequently, gas-chromatography-mass spectrometry (GC-MS) analysis was used to quantify seven menthol-like substances and nicotine in waterpipe tobacco (n=5), herbal molasses (n=1) and steam stones (n=12).

Results: Of the 282 EU-CEG-notified products, 39% have a menthol/mint declared flavor. GC-MS showed that 15 of the 18 investigated waterpipe products contained one or more menthol-like ingredients. GC-MS analysis showed that products termed 'freeze', 'ice' or 'mint' contained higher median menthol concentrations than products without these terms.

Conclusions: Nearly all investigated waterpipe products contained menthol-like compounds, irrespective of their flavor. Such compounds are known to provide flavoring or cooling effects, and some are known to be carcinogenic. Our results can support the regulation of these substances in waterpipe products. Regulators should screen all waterpipe products, not only those with menthol or a similar indicator in product names.