CBD and work: what an employer may lawfully check

The reference decision dates from 5 December 2016. Ruling on a challenge to a set of workplace rules, the Conseil d'État held that no rule or principle reserves the collection of a saliva sample to a medical profession. An immediate-detection saliva test is not a medical biology examination: it only reveals recent use through an instant reading.

That decision is often summed up as "the employer may test". That is a simplification. The decision set precise conditions, and the lawfulness of a check depends on them.

As the INRS summarises them from that decision, there are four conditions.

The test may be carried out by the employer or a line manager only if it is written into the workplace rules. It must be reserved for those posts alone where being under the influence of drugs constitutes a particularly high danger, the so-called hypersensitive posts. An employee who tests positive must be able to obtain a second medical opinion, at the employer's expense. Finally, the employer and the line manager are bound by professional secrecy as to the result.

If any one of these conditions is missing, the check falls outside the validated framework.

Article L1321-1 of the Labour Code states that the workplace rules set out "exclusively" three categories of rule, among them the measures implementing health and safety regulations. A screening clause is lawful only because it attaches to that safety purpose.

It is also subject to the general proportionality test of article L1121-1. Under that article, no one may impose on personal rights and individual freedoms any restriction that is not justified by the nature of the task to be performed nor proportionate to the aim pursued.

The workplace rules must also have been submitted for the opinion of the social and economic committee and communicated to the labour inspector. A check based on an improvised internal memo does not meet those requirements.

The saliva test does not look for cannabidiol. As Drogues Info Service, a Santé publique France scheme, points out, the test reacts to the presence of delta-9-tetrahydrocannabinol, and where users have screened positive, it is because the CBD they consume contains THC.

Buying a product that complies with the 0.30% threshold is therefore no protection against a positive result, since that threshold caps THC content and does not require its absence. We set out this mechanism in our article on CBD and drug screening, and the detection windows in the one devoted to how long CBD stays in the body.

That Drogues Info Service page deals with roadside checks. We have found no official French source quantifying the positive rate of the saliva devices used in the workplace. The mechanism is the same; the roadside figures cannot be transposed.

On the roadside front, the Cour de cassation ruled on 21 June 2023 that the authorisation to market cannabis derivatives below 0.30% THC has no bearing on the offence of driving after using narcotics. The offence is made out as soon as use is established, whatever the dose absorbed. The regulatory thresholds are detection thresholds, not thresholds of criminal liability. We return to this point in our article on CBD behind the wheel.

That logic does not transfer automatically to employment law, which follows its own proportionality rules. It does, however, show how the courts reason: a lawfully purchased product does not cancel out the presence of the substance being tested for. On the distinction between the two molecules, our article on CBD and THC covers the basics.