Drug driving in Belgium: saliva test and penalties

For alcohol, the law sets a limit. For drugs, it does not: Belgium applies zero tolerance. If you drive with traces of cannabis, cocaine, amphetamine, ecstasy or heroin in your system, you commit an offence. Even if you feel perfectly able to drive. And even if you used the substance some time ago.

In this article you will find out which substances are banned, who the police can test and how the checklist, the saliva test, the saliva analysis and the blood test work. We also explain the consequences of a positive test, both on the spot and before the police court (tribunal de police). Medication and your defence options are covered too.

Zero tolerance: which substances are banned?

Article 37bis of the Road Traffic Act (loi relative à la police de la circulation routière) makes it an offence to drive with certain substances in your body. Today, this covers five groups:

• THC (cannabis);
• amphetamine (speed);
• MDMA (ecstasy);
• morphine or 6-acetylmorphine (heroin);
• cocaine or benzoylecgonine.

The law does set thresholds (articles 62ter and 63). These are not permitted amounts, as with alcohol. They are there to guarantee scientific certainty and rule out a false positive. Below the threshold, you are not punishable. Once you reach it, you are.

Substance	Saliva analysis (ng/ml)	Blood analysis (ng/ml)
THC	10	1
Amphetamine	25	25
MDMA	25	25
Morphine or 6-acetylmorphine	5	10
Cocaine or benzoylecgonine	10	25

Ketamine is added to the list

In May 2026, the Chamber adopted a bill that explicitly adds ketamine to the list. Saliva tests capable of detecting ketamine are not expected until some time in 2027. Until then, using ketamine at the wheel can already be prosecuted as driving in “a similar state” to drunkenness (article 35), based on what the police observe. We follow the developments in our article on ketamine and driving.

Other substances and medication

Zero tolerance does not apply to synthetic drugs that are not on the list, nor to medication. You can, however, be prosecuted for driving in a state similar to drunkenness (article 35) or for being unfit to drive. More on this below.

Who can be tested?

The rules in article 61bis of the Road Traffic Act follow those for alcohol. The police can test:

• anyone who caused, or may have contributed to causing, a road accident, even if they are the victim. This can also be a passenger or a pedestrian. After an accident, the police can require a saliva test straight away, without going through the checklist first;
• anyone driving a vehicle or riding an animal in a public place, or accompanying a learner driver;
• anyone about to drive or to accompany a learner.

Here too, a public place is not only the public road. It also includes, for example, a hospital car park or a recycling centre.

The checklist: when does a saliva test follow?

Unlike with alcohol, the police cannot require a saliva test at any moment. Outside an accident, the officer must first check, using a standardised checklist, whether there are signs of recent drug use. You cannot refuse this passive observation.

A new checklist has applied since 1 October 2024 (Royal Decree of 3 September 2024, amending the Royal Decree of 17 September 2010). It has two parts:

• Part A lists the classic outward signs, grouped into categories such as the eyes, behaviour and motor skills.
• Part B lists signs that on their own already create a strong presumption: you say yourself that you used recently, the car smells of cannabis, or drugs or drug paraphernalia are found.

A saliva test follows as soon as there are at least three signs in at least two categories of part A, or one sign from part B. The threshold is therefore lower than before.

A positive checklist does not yet prove that you were under the influence. Fatigue, illness or stress can produce the same signs. The checklist only opens the way to the next step. We go through the categories in our article on the drug checklist.

Saliva test, saliva analysis and blood test

The saliva test

The saliva test is a rapid test carried out on the spot. You rub a swab against the inside of your cheek for about 15 seconds. The device shows, per group of substances, whether the result is positive. A control line must be visible, otherwise the test is not valid. If the result stays below the thresholds, the procedure ends there.

The instructions say you should not eat, drink or smoke in the 10 minutes beforehand. Tests show, however, that everyday products such as coffee, cola, toothpaste or mouthwash do not cause a false positive.

The saliva analysis

If the saliva test is positive, a saliva analysis follows. You keep a collector under your tongue until it is saturated, for a maximum of five minutes. The sample is analysed in an accredited laboratory (Royal Decree of 27 November 2015). It is the result of this analysis, not the rapid test, that constitutes the legal evidence.

As a rule, you receive the result within 45 days. You then have 14 days to request a counter-analysis on the same sample. That is a short period: keep an eye on the date the letter arrives.

Because of a shortage of collectors, saliva analyses could not be carried out everywhere between late 2025 and September 2026. The police then more often had a blood sample taken. In those cases it is worth checking which procedure was followed and whether it was applied correctly.

The blood test

A blood test takes place when the saliva test is positive but the saliva analysis cannot be carried out, or when neither is possible. It is performed by a doctor called in by the police. Your own GP may take the blood, but may never fill in the clinical report: that report has to be objective. Here too, you receive the result and can request a counter-analysis within 14 days. For more, read our article on the saliva analysis, the blood test and the counter-analysis.

If the offence is proven, you pay the costs of the test, the analysis and the doctor.

Can you refuse?

Refusing without a legitimate reason to take a saliva test, a saliva analysis or a blood test is an offence in itself (article 37bis, §1, 5°). If you refuse, the police always call in a doctor. The doctor checks whether there is a legitimate reason and takes blood if necessary.

A legitimate reason is often covered by medical confidentiality. The doctor therefore sends the report to the public prosecutor (parquet) in a sealed envelope. If you genuinely cannot produce enough saliva, you are not refusing. In the end, it is the judge who decides whether a refusal was justified.

What happens right after a positive test?

For drugs too, safety measures apply even before the judge rules:

• a temporary driving prohibition of 12 hours, valid for all vehicles;
• an immediate withdrawal of your driving licence for 15 days, in particular after a positive saliva test, a refusal, or a positive checklist where it is not possible to collect enough saliva.

The public prosecutor can have the withdrawal extended to up to three months. What you can and must do during that period is explained in our article on immediate licence withdrawal.

The data from the checklist and the tests may only be used to punish traffic offences, not for other judicial purposes. A positive test therefore does not automatically lead to prosecution for drug possession.

Foreign drivers

Special rules apply to drivers who have neither a home nor a residence in Belgium. Since early 2025, they also have to pay a deposit (consignation) for drugs: an amount paid as security for the future fine. This applies after a positive saliva test, a refusal of the test, the saliva analysis or the blood test, and after a positive analysis result. Without payment, the vehicle may be held. The case is then handled by the public prosecutor. For the procedure, see our overview of traffic offences, their degrees and the procedure.

What do you risk before the police court?

Driving under the influence of drugs is punishable by a fine and possibly a prison sentence (article 37bis). Since 1 September 2026, the penalty levels of the new Criminal Code apply. The judge can also impose a driving ban (déchéance du droit de conduire) and make getting your licence back conditional on reinstatement exams (examens de réintégration) (article 38). See also our article on reinstatement exams.

For a repeat offence within three years, a ban of at least three, six or nine months is mandatory, together with all four reinstatement exams. See our article on repeat drink or drug driving.

If you have held your category B licence for less than two years, the judge must impose a driving ban on conviction for driving under the influence of drugs. You only get your licence back after passing at least one theory or practical test again (article 38, §5, of the Road Traffic Act).

If you cause a fatal accident under the influence of drugs, the ban is at least three months, and at least one year for a repeat offence, each time with all four reinstatement exams. For an accident with injuries as a repeat offence, it is at least six months (article 38, §2, of the Road Traffic Act). See our article on homicide in the context of road traffic.

If the file shows regular use or dependency, the judge can also declare you unfit to drive (article 42). That ban lasts until you prove you are fit again, in practice through a hair analysis or blood tests. The Court of Cassation has held that a medical expert report is not required for this (Cass. 30 January 2024, P.23.1697.N). The judge must, however, base the decision on concrete evidence. For more, read our article on unfitness to drive.

Medication and driving

Many medicines affect your ability to drive, such as sleeping pills, certain painkillers and sedatives. They do not fall under the zero tolerance of article 37bis. There are still two risks, though.

First, you can be prosecuted for driving in a similar state to drunkenness (article 35) if, because of a medicine, you lose control of your actions.

Second, article 8.3 of the Highway Code (Code de la route) requires every driver to be fit to drive and to have the necessary physical abilities. Annex 6 to the Royal Decree on driving licences sorts medicines into three categories: no influence, a slight to moderate influence, or a serious influence on the ability to drive. Your doctor must inform you about this. A person who is dependent on psychotropic substances, or who regularly uses them in amounts that affect driving, is not fit to drive and must hand in their licence. If they drive anyway, they face a separate penalty (article 30 of the Road Traffic Act). We go into this in more depth in our article on driving on medication.

What defence is possible?

Check the procedure

The drug procedure has more steps than the alcohol procedure, and each step has its own rules. Was the checklist filled in completely and correctly, with the required signs in the required categories? Was there an accident, which allowed the checklist to be skipped? Was a valid saliva test used, and was the saliva analysis correctly collected, packaged and analysed? Was the blood sample taken by the right doctor?

As with alcohol, not every error leads to the evidence being excluded. The judge applies the Antigoon case law, now set out in article 32 of the preliminary title of the Code of Criminal Procedure. A well-built defence can still make the difference, especially if the error affects the reliability of the result. See also our article on errors in the police report.

Use the counter-analysis

If you doubt the result, request a counter-analysis within 14 days of receiving it. Letting that period pass means losing a line of defence.

Sentencing

Many drivers find zero tolerance hard to accept: someone who drives a few days after using cannabis can still test positive without feeling any effect at all. That is not a free pass, but the judge can take it into account when setting the penalty. A hair analysis showing no regular use, a clean record and the importance of your licence for your work all carry weight, including when it comes to avoiding a finding of unfitness to drive.

Conclusion

Drug driving is subject to zero tolerance, with a procedure made up of strict steps. A positive test usually leads to a 12-hour driving prohibition, a 15-day withdrawal and a summons (citation) to the police court. There, a driving ban, reinstatement exams and sometimes a finding of unfitness to drive are at stake.

Have you tested positive or been summoned to court? Our lawyers examine the criminal file in detail, keep track of the deadlines and prepare your defence. Contact us or read more about drug driving. We have a separate article on drink driving.

Frequently asked questions