There is evidence of essential oils derived from plants being used by humans since Neanderthal times, with applications ranging from medicinal to food preparation. Traditional application methods for these highly concentrated oils include dermal application and inhalation via vaporisation in large quantities of water via steam diffusion. The increase in popularity of e- cigarettes and vaping in the past several years has led to the development of a novel way of delivering essential oils, which involves suspending them in a carrier liquid (in this case vegetable glycerin) and placing them inside a disposable e-cigarette system for inhalation. MONQ is a market leader in this type of product and to our knowledge no independent laboratory has examined the contents of these pens, or the safety of inhaling aerosolised volatiles such as essential oils. In this study, we analysed liquid from these personal aromatherapy vapes using GC-MS. These samples were compared against pure Essential Oils and the NIST17 database to confirm the presence of terpenes within the liquid. The MONQ company claims their pens contain 80:20 VG: EO blend with each ‘puff’ delivering 0.003 ml of essential oils directly to the user. Based on preliminary liquid analysis of the contents, this appears to be false, with essential oils appearing in the samples in very small amounts and their presence in the vapour unconfirmed. This study suggests that further quantitative analysis of the vapour and liquid is necessary to determine whether there are any potential negative health consequences associated with these products, which remain unregulated.

The vaporization of illicit drugs can be traced back to ancient times, to snuff boxes with traces of psychedelic drugs in Aztec tombs and opium pipes being found in the remains of many great ancient Chinese societies. The advancement of e-cigarette technology has resulted in a new and novel way to vaporize drugs, and while nicotine vaping remains their primary use, meta-analysis of online forums and statistical analysis indicates this is trend which is increasing in popularity. This paper aims to provide an update on the state of e-cigarettes being used as an illicit drug delivery system, the potential public health consequences of this kind of appropriation and a toxicological assessment of the most popular drugs being vaporised. A systematic review of online dark web marketplaces and online drug forums have formed the basis of this review. It can be concluded that this is a growing area of public health concern and one which should be continued to be monitored closely, particularly with respect to Novel Psychoactive Substances due to their continued and abundant proliferation and lack of research with respect to their toxicological profiles.

The use of electronic cigarettes as alternative nicotine delivery devices has seen a dramatic increase in recent years. Regulations (TGO110) have been introduced in an attempt to set out minimum safety and quality requirements for nicotine vaping products. These regulations provide restrictions not only pertaining to the nicotine content but also prohibiting the use of certain flavourings and the addition of any bioactive molecules other than nicotine to these products. However, these regulations do not apply to any e-liquids that do not contain nicotine including nicotine-free vitamin vaping products. The content of 32 samples from five different brands of nicotine-free disposable vaporisers claiming to contain vitamins and other bioactive molecules were examined as part of this study. There was no evidence in the literature of vitamins ever being quantified within this e-liquid matrix. As part of this project a new LC-MS method for the quantification of bioactive molecules in vaporiser e-liquids was developed and validated. Of the 9 targeted bioactive molecules (water soluble vitamins, caffeine and melatonin), very few were able to be quantified or even detected within these e-liquid samples, while some samples contained bioactives in quantifiable concentrations which were not listed in the ingredients. A concurrent degradation study was carried out to monitor the behaviour of targeted bioactive molecules in different mixtures of carrier fluids, which found that many, but especially vitamin B12, were unstable over time and were prone to degradation. To collect additional content information, GC-MS analysis was also carried out on the purchased samples. Tentative content analysis was carried out by library matching to an in house library created from purchased standards of common flavouring molecules and previously synthesised acetals and to a commercially available database (NIST17). GC-MS analysis confirmed the presence of propylene glycol and vegetable glycerin as carrier fluids in all samples. In addition, artificial flavouring molecules, synthetic cooling agents (WS-23) and adduct formation were also observed in a wide range of samples. The findings of this study indicate that the claims made by these companies are demonstrably false and that further investigation is needed into the contents of these vaporisers and their potential toxicity, especially given their lack of regulation.