Off-duty use vs employer: where are the limits?

TL;DR

• Off-duty life is private in principle – protected by personality rights (ZGB Art. 27, OR Art. 328).
• Limit: use that impairs your fitness on the following day.
• Safety-critical jobs: stricter requirements even off-duty.
• Consumption posted on social media can become contractually relevant.

Personality protection and its limits

OR Art. 328 obliges the employer to respect the employee's personality. Questions about leisure are only allowed with a concrete link to work.

The link exists if use impairs performance, safety or company reputation – e.g. a driver with licence loss or a viral consumption video with company logo in the background.

Admissibility and limits of drug testing in the workplace

Drug tests in the workplace represent a significant encroachment on the personal rights and physical integrity of employees. Under Swiss employment law, systematic or suspicionless screenings are generally inadmissible. An employer may not order such measures across the board, even if a corresponding clause is anchored in the employment contract. Conducting a drug test always requires a strict proportionality test. As a rule, it is only justified if there is a concrete danger to the safety of the business, colleagues, or third parties, and no milder means are available.

Even in the event of reasonable suspicion, a test may not be forced against the will of the person concerned. However, if an employee refuses to cooperate, this can be deemed a breach of duty under the contractual duty of loyalty, provided the suspicion was substantial. In practice, this means that companies need clear regulations defining the conditions under which tests may be carried out. Furthermore, sample collection and analysis must be performed by qualified medical personnel to ensure the validity of the results and data protection.

• Systematic drug testing without concrete cause is generally inadmissible in Switzerland.
• The consent of the person concerned is mandatory for carrying out a test.
• Safety-sensitive activities justify targeted monitoring measures under strict conditions.
• Refusing a justified test under reasonable suspicion can have consequences under employment law.

Employer's duty of care and grounds for suspicion

Under the Swiss Code of Obligations, employers bear a comprehensive duty of care for the entire workforce. If there is a reasonable suspicion that an employee is under the influence of substances and thereby endangers themselves or others, the employer must intervene. Ignoring the situation could lead to liability for the company in the event of damage. In such a situation, it is the duty of supervisors to temporarily suspend the person concerned from work or have them accompanied home safely to prevent accidents.

Determining acute impairment is usually based on behavioral abnormalities, as employers cannot make medical diagnoses. Typical indicators include coordination problems, slowed reactions, or noticeable mood swings. Should the suspicion be substantiated that recreational consumption permanently reduces contractually owed work performance or endangers operational safety, measures under employment law can be taken. These range from a formal warning and ordering measures for behavioral change to the ordinary termination of employment in the event of a continued breach of duty.

• The statutory duty of care obliges employers to actively protect operational safety.
• In the event of acute suspicion of impairment, an immediate suspension for the workday must take place.
• Behavioral abnormalities serve supervisors as primary indicators of impaired work capacity.
• Continued impairment of work performance can lead to ordinary termination after a warning.

Mobility, commuting, and the strict limit in road traffic

A critical point of contact between recreational consumption and the employment relationship concerns mobility. In Swiss road traffic, a strict zero-tolerance policy applies to THC, with a statutory detection limit of 1.5 micrograms of THC per litre of blood. Anyone who consumes cannabis in their free time risks exceeding this limit the following day or even days later. Although commuting to work in one's own vehicle is primarily a private matter, the revocation of a driving licence can have direct professional consequences if mobility is strictly required to perform the contractually agreed duties.

For employees who drive vehicles or operate heavy machinery professionally, the consequences of a positive result are particularly severe. If a driver, field representative, or tradesperson loses their driving licence due to recreational consumption, they can no longer perform their contractually owed work. Since proper performance of the contract becomes impossible in these cases, the employer is generally entitled to terminate the employment relationship with regular notice or, in extreme cases, even without notice. The detection of THC in the blood during working hours constitutes a serious breach of duty in driving professions.

• In Swiss road traffic, a strict limit of 1.5 micrograms per litre of blood applies to THC.
• A driving licence revocation endangers employment relationships that are strictly dependent on mobility.
• In driving professions, the detection of THC in the blood almost always leads to immediate employment law sanctions.
• Commuting to work is the individual's own responsibility, but directly affects the ability to work in the event of driving bans.

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