Newsletters Criminal Defence 7th Dec 2017

Nitrous Oxide – No Laughing Matter

In R v Chapman and others, the Court of Appeal dismissed four applications for permission to appeal on the grounds that Nitrous Oxide, commonly known as laughing gas, was not covered by criminal offences in the Psychoactive Substances Act 2016 (‘the PSA’). The Court dismissed the appeal on the arguments advanced by the defendants but the unanimous judgment makes for interesting reading for practitioners involved in a developing area of jurisprudence.

Psychoactive substances

 The PSA essentially criminalises the supply, production and possession with intent to supply of psychoactive substances. Simple possession remains legal. Whilst the Misuse of Drugs Act 1971 lists prohibited substances, the PSA, aimed as it is at ‘legal highs’, adopts an extremely wide definition of psychoactive substances, and then exempts many of the things which would otherwise be caught, such as food, alcohol, nicotine and tobacco.

A psychoactive substance is defined as any substance capable of affecting a person’s mental functioning or emotional state by stimulating or depressing a person’s central nervous system (PSA section 2). However, a substance is not a psychoactive substance if it is exempted in Schedule 1.

The definition of psychoactive substances is both unhelpfully vague and overly inclusive. It was the subject of much criticism throughout the legislative consultation process. Many of those criticisms have been substantiated by the PSA’s use in court. The appeals under consideration were prompted by widespread publicity about cases where trial judges had ruled nitrous oxide not to be a psychoactive substance, despite it being a substance clearly contemplated as included by legislators when considering and passing the legislation.

The primary argument on behalf of the appellants was that Nitrous Oxide was an exempted substance because it was a medicinal product. However, on the eve of the hearing for permission to appeal the appellants produced a report from Professor David Nutt, seeking to argue in addition that Nitrous Oxide was not caught by the definition in section 2, largely because it only produced an indirect effect on the central nervous system. The Court of Appeal declined to admit the expert evidence, but in any event made it clear that they gave Professor Nutt’s argument relatively short shrift. There was no distinction in the legislation between a direct and indirect effect, and Professor Nutt’s report did not deal in any detail with the prosecution expert’s conclusion that Nitrous Oxide was caught by the section 2 definition, merely asserting that such a conclusion had not been proved beyond doubt.

Medicinal products

 One category of substances exempted under Schedule 1 are ‘medicinal products’ as defined in Regulation 2 of the Human Medicines Regulations 2012, which implement Directive 2001/83/EC. The Lord Chief Justice recognised that it is only when “interpreted in conformity with its meaning in European law” that the definition in the Regulations did not catch Nitrous Oxide in the particular circumstances of the appeals under consideration. So interpreted, a medicinal product is either something presented as having properties for treating or preventing disease in human beings (the presentation limb), or which may be used with a view to restoring, correcting, or modifying physiological functions by exerting a pharmacological immunological or metabolic action, or to making a medical diagnosis (the function limb).

While Nitrous Oxide still appears to be caught by the function limb, in D&G (C-358/13, C-181/4), the Luxembourg Court found that the requirement in the presentation limb, that the substance be presented as having properties to treat or prevent disease, must also be included in the function limb, which “implies that a beneficial effect should be secured for human health”. The manner in which a substance is used is relevant. A substance which is merely used to modify physiological function without immediate or long-term beneficial effects for human health will not be caught.

In the particular circumstances of each of the four cases before the Court, the nitrous oxide was not a medicinal product. It had in each case been manufactured originally for use in catering, ruling out the presentation limb. In any case:

“the purpose for which it was intended to supply the canisters was purely recreational with nothing whatsoever to do with health. This last feature coupled with the fact that the gas was intended to be used in circumstances which were not beneficial to health, indeed import some risk to health [sic], was sufficient to take it outside the definition of medicinal product whatever label may have been on the boxes in which the canisters were originally packed.” (paragraph [32]).

A dead end?

R v Chapman and others is unlikely to be the end of the argument in two respects. Firstly, in respect of the section 2 definition of psychoactive substances the Court explicitly left open the possibility that:

“Were Professor Nutt to have set out a clear explanation of how each of the well-recognised effects of nitrous oxide are caused, supported by such academic and research material as is available, with a clear conclusion that it does not stimulate or depress a person’s central nervous system and thereby affect the person’s mental functioning or emotional state, the position might have been different.” (paragraph [42]).

Secondly, the Court also explicitly recognised that “products with precisely the same chemical composition may fall within or outside the definition of medicinal products depending on the circumstances” (paragraph [23]). It would therefore remain open to a defendant to argue that in the particular circumstances the nitrous oxide he or she was producing/supplying was presented, or for use, for benefiting human health within the definition of the Regulations.

A defendant charged under the PSA thus retains a number of options:

  • The usual factual defences are available; either that the psychoactive substance in question was for personal use, or was not intended for supply for its psychoactive effects (Chapman himself argued at trial that his gas canisters were for use in his catering business. The jury were unpersuaded).
  • The factual defence that in the particular circumstances the psychoactive substance was exempted, most likely because it was a medicinal product. It is of note that the marketing and presentation of the product may be relevant to this defence.
  • Seek to present expert opinion as to whether the substance in question is caught by section 2 of the PSA at all. Such arguments might focus on the effect on the central nervous system.

Lewis MacDonald

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