News broke today that two cases, brought under the Psychoactive Substances Act 2016, collapsed in respect of “nitrous oxide” contained in small cartridges of the kind intended to be used in dispensers for (e.g.) whipping cream (see The Metro [link] and the BBC [Link]). It was reported that in one case, prosecuting counsel informed the Crown Court that its own expert witness….is “expressing the firm view that nitrous oxide, as the legislation is currently worded, is an exempt substance”. The PSA does indeed exempt from the legislation “medicinal products” as defined by reg.2 of the Human Medicines Regulations 2012 (S.I. 2012/1916).
The main problem here, I suggest, is in the definition of “medicinal product”, which is ambiguous, but which has been the subject several decisions of the ECJ. The solution might be to give that definition a purposive meaning. Reg. 2 broadly mirrors the wording of art.1(2) of Council Directive 2001/83 (as amended). In the ECJ decision of D and G, (C-358/13) EU:C:2014:2060;  P.T.S.R. 1217, the Court said: “… the answer to the question referred is that article 1(2)(b) of Directive 2001/83 must be interpreted as not covering substances, such as those at issue in the main proceedings, which produce effects that merely modify physiological functions but which are not such as to have any beneficial effects, either immediately or in the long term, on human health, are consumed solely to induce a state of intoxication and are, as such, harmful to human health.”
The test, perhaps, of whether a product is a “medicinal product” or not, is whether it was designed or intended for medicinal or therapeutic use. It is surely inconceivable that those who produced or supplied cartridges of N2O for food use, have produced/supplied “medicinal products”!
For a detailed article on the PSA 2016, see “The Psychoactive Substances Act 2016“, R. Fortson, Criminal Law Review  Crim L R 303.
On a wider note, this commentator warned more than once that the PSA 2016 was flawed in its drafting (not least in relation to the exemptions) and liable to give rise to definitional and scientific problems.
An interesting article regarding the two cases appears in “The Independent” (by Lizzie Dearden, Home Affairs Correspondent, 30.8.17) [Link]
[Addendum to the Post]: As to whether these cases represent a drug policy that is working or failing, see a cogent discussion by Professor Harry Sumnall (Substance use, the Public Health Institute, Liverpool John Moores University) -“The laughing gas verdicts represent a failure of Britain’s drug policy“, Guardian, 1st September 2017 [Link]. In an unrelated piece, in the Islington Tribune (1.9.17), another N2O case has come to light, but where the jury convicted [Link].