Smoking hemp in France: legal, but not risk-free
Smoking a compliant hemp flower is not an offence in France: the law caps Δ⁹-THC content at 0.30% and says nothing about how the flower is consumed. Three limits remain. Any plant smoke contains the same families of toxic compounds as tobacco smoke. A flower at 0.30% holds up to 3 mg of THC per gram, and that THC may be enough for a positive roadside drug test.
Key takeaways
- On 29 December 2022 the Conseil d'État annulled the provision that banned the "consumption" of hemp flowers.
- The French Public Health Code provides a category of "herbal products for smoking", which must carry a health warning.
- In places for collective use, smoking stays banned whatever the cigarette contains.
- With or without THC, hemp smoke contains ammonia, hydrogen cyanide and known carcinogens.
- Testing positive at the roadside can mean up to 3 years in prison and a €9,000 fine, legal flower or not.
What the law regulates: the plant, not how you use it
Hemp is governed by the decree of 30 December 2021, which authorises Cannabis sativa L. varieties listed in the official catalogues with a Δ⁹-THC content of no more than 0.30%. The first version of the text went further. Paragraph II banned "the sale to consumers of raw flowers or leaves", and also "their possession by consumers and their consumption".
The Conseil d'État annulled that paragraph on 29 December 2022. In the judges' view, a blanket ban was disproportionate because no public health risk had been established below that THC threshold. Buying, holding and consuming a compliant flower has not been prohibited since then, and no text specifies how it should be consumed.
French law even provides for tobacco-free cigarettes. A chapter of the Public Health Code covers herbal products for smoking other than tobacco (articles L3514-1 to L3514-6), defined as tobacco-free plant products "that can be consumed through a combustion process". Their packaging must carry a health warning, and manufacturers must declare the ingredients before putting them on the market.
Many shops still print "not for smoking" or "aromatic use" on their bags. The law does not require that wording; it is how the seller chooses to present the product.
Where you smoke still matters. Article L3512-8 bans "smoking in places for collective use" and on public transport. It targets the act of smoking and makes no exception for a hemp flower.
A flower at 0.30% still contains THC
The legal threshold is above zero. At 0.30% Δ⁹-THC, a flower holds up to 3 mg of THC per gram: 1.5 mg in half a gram, 6 mg in two grams. That threshold covers Δ⁹-THC only. THCA, its acidic form, becomes THC when heated and can raise the total during combustion.
Those milligrams reach the body. Researchers at Johns Hopkins University had six adults vaporise CBD-rich hemp that delivered 100 mg of CBD and 3.7 mg of Δ⁹-THC. Four urine samples came out above the 15 ng/ml confirmation cutoff for the THC metabolite. None did after pure CBD.
For drivers, French law sets no threshold. Article L235-1 of the Highway Code sets three years in prison and a €9,000 fine for driving after drug use detected by a saliva or blood test. The Cour de cassation ruled on 21 June 2023 (no. 22-85.530) that the offence stands "regardless of the dose absorbed", and that CBD being authorised changes nothing. Detection windows are covered in our guide to the saliva test.
What plant smoke contains
Most of the respiratory risk comes from combustion, whatever the THC content. In 2008, Health Canada machine-smoked cannabis and tobacco cigarettes prepared the same way and compared the smoke. Mainstream cannabis smoke held up to 20 times more ammonia than tobacco smoke, and 3 to 5 times more hydrogen cyanide, nitrogen oxides and some aromatic amines. Its polycyclic aromatic hydrocarbons were less concentrated. The authors confirm that both smokes contain known carcinogens.
Burning plant matter produces these compounds, so a low-THC flower yields them too. Adding tobacco to the flower brings in nicotine and its dependence, covered in our article on the differences between tobacco and cannabis.
People often ask whether heat turns CBD into THC. In the laboratory it can. Hungarian chemists heated pure CBD to between 250 and 500 °C and found that 25 to 52% was transformed, mostly into Δ⁹-THC. Closer to real use, the picture changes. A German team machine-smoked six 1 g joints of CBD-rich hemp according to the ISO 4387 standard and could not demonstrate any THC formation.
Vaporising instead of burning: what changes
A vaporiser heats the flower without igniting it, so cannabinoids and terpenes vaporise and the plant matter does not burn. A University of California, San Francisco trial with 18 volunteers compared a cigarette and a vaporiser loaded with the same cannabis. Blood THC levels were similar, and exhaled carbon monoxide was lower with the vaporiser. The trial measured exposure and drew no conclusion about health benefit.
| Method | Temperature | Combustion | What is inhaled |
|---|---|---|---|
| Joint or pipe | Glowing ember | Yes | Smoke: tar, carbon monoxide, irritants |
| Vaporiser | Set, usually between 160 and 210 °C | No | Vapour of cannabinoids and terpenes |
| Mixed with tobacco | Glowing ember | Yes | Smoke, plus nicotine from the tobacco |
Settings for each cannabinoid are in our guide to vaporisation temperatures. When choosing a flower, you will find the aromatic profile of each variety on the pages of our CBD flower selection. The figure that matters is the THC content measured on the batch, which you read on the certificate of analysis.
CBD is not a medicine. Do not use it during pregnancy or breastfeeding, and keep it away from minors.
Frequently asked questions
Yes, provided the flower comes from an authorised variety and contains no more than 0.30% Δ⁹-THC. The Conseil d'État annulled the 2021 ban on consuming flowers on 29 December 2022. Places for collective use remain smoke-free by law.
The seller chooses that wording, and no law requires it. The Public Health Code actually provides a category of herbal products for smoking, with a health warning on the packaging.
Yes. A flower at 0.30% holds up to 3 mg of THC per gram, and the law sets no minimum dose for drivers. In 2023 the Cour de cassation confirmed that CBD being authorised does not rule out the offence.
It contains the same families of toxic compounds, in different proportions. In the Health Canada study, cannabis smoke had more ammonia and hydrogen cyanide and fewer polycyclic aromatic hydrocarbons. Every smoke carries risk.
No. It avoids combustion and reduces the carbon monoxide you inhale, but the vapour still carries the flower's THC, so the risk at the wheel does not change.
Written by the Phytogrammes team
Each journal article draws on cited primary sources: ANSM, EFSA, EUR-Lex and peer-reviewed publications. Product profiles are distinguished from documented laboratory results. Our approach.
Article published on . CBD is not a medicine.