Author's response to: "Harmful effects form one puff of shisha-pen vapor: methodological and interpretational problems in the risk assessment analysis"

We thank Dr. Farsalinos and Dr. Baeyens for their comments in their letter to the editor on our publication: “Potential harmful health effects of inhaling nicotine-free shisha-pen vapor: a chemical risk assessment of the main components propylene glycol and glycerol” [1]. Apparently some issues discussed in our publication were not sufficiently clear and we thank the editor of Tobacco Induced Diseases for the opportunity to respond to these comments and clarify the issues raised