The effects of e-cigarette vapour, relative to tobacco smoke, on oral tissues is an important topic and I welcome research in this area.

Unfortunately the write up of this study has several significant deficiencies that mean any results cannot be given any credence.

Almost all of the key details about how the vapour was produced have been neglected from this paper. For example, even the details about the device used are absent. It would usually be unheard of in any other scientific paper for a researcher to use a device or piece of equipment without providing these details (usually manufacturer name and location). There is not even a mention of whether this was a first, second or third generation product. In addition, all of the parameters normally presented for smoke/vapour exposure systems for toxicological studies are missing e.g. puff duration, puff profile, puff number, product settings, e-liquid strengths used. Indeed, international standards exist for how to conduct this type of study (e.g. ISO) and not even mentioning them is unacceptable.

Within the methods section a paper is cited (reference 11) which may provide some of the missing details. However, this paper is not available as it is not yet published. Unprecedentedly, this paper is only submitted and not even accepted for publication. This is directly against the submission guidance for Plos One which clearly state not to cite ‘manuscripts that have been submitted but not yet accepted’.

One of Plos One’s criteria for publication is that ‘Experiments, statistics, and other analysis are performed to a high technical standard and are described in sufficient detail’. This is obviously not the case for this paper.

Clearly there has been a breakdown of the Plos One ‘Rigorous Peer Review’ process in this case and perhaps naivety by the authors (and editors) to the subject area. The publication should be revised or retracted.

Disclosure: Nil.