Cannabis in the workplace – the complete Swiss guide

Cannabis and employment: what it is really about legally

In Swiss employment law, there is no provision that explicitly regulates cannabis consumption. Instead, three general principles are decisive, from which almost every dispute can be derived. First, the duty to work under Art. 321 CO: full work performance is owed — anyone who turns up to work impaired breaches this duty, regardless of the substance. Second, the employer's duty of care and protection of personality under Art. 328 CO, which only permits interventions such as drug tests if they are proportionate and objectively justified. Third, the Employment Act with its safety obligations, which justifies stricter standards for safety-sensitive activities.

This leads to the central distinction that is almost always lost in discussions: consumption in one's free time is a private matter, as long as it does not impair work performance. Impairment during working hours, on the other hand, is an employment law issue — with potential consequences ranging from a warning to dismissal, and in serious cases, termination without notice.

These pages are for guidance, not legal advice. In the event of a specific conflict, it is worth seeking legal advice or contacting the relevant trade union before signing any declarations.

• Recreational consumption without impact on performance: fundamentally a private matter
• Impairment during working hours: breach of the duty to work
• Testing: only proportionate, objectively justified and transparently regulated
• Safety-sensitive activities: significantly stricter standard permissible

Drug testing, CBD in the workplace and the special case of driving

A drug test is an infringement on personality rights and therefore cannot be ordered arbitrarily. It is permissible primarily where a safety risk exists — construction sites, machine operation, transport, medical activities — and if it is transparently regulated in a policy. A random test without safety relevance and without regulation is legally contestable.

For employees, what a test actually indicates is also important: the standard procedures measure THC-COOH, an inactive metabolite, and thus prove consumption, not impairment. Even legal CBD consumption can lead to a positive result because products may contain up to 1 % total THC. The decisive factor is always the total THC, i.e. THC plus THCA multiplied by the factor 0.877. A product with 0.4 % delta-9-THC and 0.9 % THCA has around 1.19 % total THC and is therefore a narcotic — even if the packaging says «under 1 %».

Those who drive professionally are subject to the strictest regime: in road traffic, the detection limit of 1.5 µg/L THC in the blood applies, which is effectively a zero-tolerance policy. A driver's license revocation has immediate existential consequences for professional drivers, regardless of whether the THC originates from a legal CBD product.

Guide to the subpages

The cluster covers drug testing in the workplace, the question of dismissal, medical cannabis in the employment relationship, CBD during working hours, as well as safety-sensitive occupations and dealing with superiors.

Those who are acutely affected should first read the page on the admissibility of testing and the one on the consequences of dismissal. Anyone who is prescribed medical cannabis will find the points there that should be clarified before speaking with the employer.

The role of occupational medicine and public authorities

In Swiss working practice, HR departments often reach legal limits in suspected cases. This is where occupational medicine comes into play, acting as a neutral mediator between employer and employees. Since employers do not have direct access to medical data, the assessment of fitness for work in cases of suspected substance use is ideally carried out by specialized occupational physicians. These assess exclusively whether the person concerned is fit for the contractually agreed activity, without passing on confidential diagnoses. This protects the personal rights of employees in accordance with the Code of Obligations while simultaneously ensuring operational safety.

In the event of uncertainty regarding the ingredients of CBD products or acute symptoms of poisoning in the company, Swiss companies rely on established state and medical advisory services. The licensing and monitoring of therapeutic products lies with Swissmedic, while the Federal Office of Public Health (FOPH) sets the legal framework. In the event of suspected overdose or unforeseen interactions in the workplace, Tox Info Suisse provides rapid, professional support for first aiders and supervisors in the company 24/7 under the emergency number 145.

• Involvement of neutral occupational physicians to maintain medical confidentiality vis-à-vis supervisors.
• Assessment of pure fitness for work instead of sharing detailed medical test results.
• Use of Tox Info Suisse via the telephone number 145 in the event of acute medical emergencies in the company.
• Guidance based on the official guidelines of the FOPH (BAG) and Swissmedic when evaluating substances.

Liability risks and financial consequences of occupational accidents

If an employee causes an accident in the workplace under the influence of intoxicating cannabis, this has far-reaching legal and financial consequences. In Switzerland, all employees are compulsorily insured against occupational accidents via accident insurance. However, if there is proven consumption of illegal cannabis with a total THC content of over 1 percent during working hours, insurers generally qualify this as gross negligence. This almost always leads to a massive reduction in daily allowances or to recourse claims, where the insurance company demands the costs back from the person who caused the accident.

In addition to the insurance law aspects, there are also potential criminal consequences for the employee and, under certain circumstances, for the employer. Superiors who ignore an obvious impairment and allow the employee to continue working violate their statutory duty of care under the Labor Act. If an accident occurs as a result, line managers can also be held criminally liable. Financial liability for property damage in the workplace depends on the degree of fault, whereby the liability limits are shifted extremely to the detriment of the employee in the event of proven substance use.

• Reduction of insurance benefits or direct recourse claims in the event of proven gross negligence.
• Joint criminal liability of superiors in the event of disregard of obvious warning signs.
• Civil liability of the employee for self-inflicted property damage in the workplace under the influence of alcohol or THC.
• Increased risk of complete loss of coverage under the private supplementary insurance of the person who caused the accident.

Pilot trials and the impact on the workplace

Switzerland is currently conducting scientific pilot trials with cannabis for recreational purposes in accordance with Article 8b of the Narcotics Act, such as Züri Can, Weed Care in Basel or the SCRIPT project. These time-limited projects enable registered participants to legally purchase cannabis with a total THC content of over 1 percent. However, this lulls many participants into a false sense of security regarding their workplace. Participation in a state-approved pilot trial in no way releases employees from their obligations under employment law or the employer's safety regulations.

Even if purchase and possession are legalized within the framework of these studies, appearing at the workplace under the influence of THC remains a breach of contractual work duties. Employers may continue to strictly prohibit consumption during working hours and sanction violations. Since the pilot trials are strictly scientifically monitored, status as a study participant protects neither against ordinary termination of employment nor against the strict consequences in road traffic, where the strict detection limit of 1.5 micrograms of THC per liter of blood continues to apply.

• No special employment law rights or exceptions for participants in Swiss pilot trials.
• Continued existence of the absolute ban on consumption during working hours in accordance with company policies.
• Unchanged validity of the statutory detection limits in road traffic, also for study participants.
• Possibility of ordinary termination in the event of impaired work performance despite legal participation.

Workplace prevention and substance abuse agreements

To nip conflicts and legal grey areas in the bud, more and more Swiss companies are relying on proactive prevention concepts and written company agreements. A clear substance abuse policy defines unmistakably which substances are tolerated in the workplace and how to proceed in the event of concrete suspicion. Such regulations create legal certainty for both the workforce and management. They prevent arbitrary measures and ensure that, in an emergency, a standardized, fair, and legally sound process is followed that protects personal rights.

An effective prevention concept is based not only on prohibitions, but primarily on education and clearly defined support services. Supervisors should be trained to recognize behavioral changes early and to seek discussion objectively, without making medical diagnoses. By anchoring clear processes—ranging from the first warning and the involvement of occupational medicine to external counseling centers—companies can pave the way to recovery for affected employees before labor law steps or serious accidents occur.

• Establishment of written substance abuse policies for maximum legal certainty of all parties involved in the company.
• Training of managers for the early and objective recognition of behavioral changes.
• Definition of standardized procedures in the event of reasonable suspicion of acute substance use.
• Integration of professional counseling services as a primary measure prior to disciplinary action.

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