Table 2.
Types of drugged driving legislation and legal Δ9-tetrahydrocannabinol (THC) thresholds for drivers in European countries
| Country | Legislation | Legal THC limit |
|---|---|---|
| Belgium | Two-tier | 1.0 μg/L in blood serum |
| Denmark | Two-tier | 1.0 μg/L in blood |
| Finland | Two-tier | THC: 1.0 μg/L in blood THC-COOH: 5.0 μg/L in blood |
| France | Two-tier | 1.0 μg/L in blood |
| Germany | Two-tier | 1.0 μg/L in blood serum |
| Greece | Impairment | 1.0 μg/L in blood |
| Ireland | Impairment | THC: 2.0 μg/L in blood THC-COOH: 5.0 μg/L in blood |
| Italy | Per se | THC or THC-COOH: 0.5 μg/L in blood |
| Luxembourg | Impairment | 2.0 μg/L in blood serum |
| Netherlands | * | 3.0 μg/L in blood** 5.0 μg/L in blood serum |
| Norway | Impairment | 1.3 μg/L in blood*** |
| Poland | Per se | THC: 2.0 μg/L in blood THC-COOH: 50.0 μg/L in blood |
| Portugal | Per se | THC: 3.0 μg/L in blood THC-COOH: 5.0 μg/L in blood |
| Slovenia | Per se | THC: 0.3 μg/L in blood serum THC-COOH: 5.0 μg/L in blood serum |
| Switzerland | Per se | 1.5 μg/L in blood |
| United Kingdom**** | Impairment | THC: 2.0 μg/L in blood THC-COOH: 10.0 μg/L in blood |
*Impairment as of 2011, but a proposal for a two-tier system has been implemented.
**Recommended by Netherlands Advisory Committee.
***Norway specified THC levels comparable to BAC (with regard to severity of impairment): 3.0 μg/L in blood is comparable to 0.05% BAC; 9.0 μg/L in blood is comparable to 0.12% BAC.
****Initial drug screening is conducted via Drugalyser oral swab tests. A positive test could lead to a blood sample test to quantify THC level.
Abbreviations: THC Δ9-tetrahydrocannabinol, THC-COOH carboxy-Δ9-tetrahydrocannabinol.
Sources: Verstraete A, Knoche A, Jantos R, Skopp G, Gjerde H, Vindenes V et al. Driving under the Influence of Drugs, Alcohol and Medicines (DRUID): Per se limits - Methods of defining cut-off values for zero tolerance. 2011. Accessed July 20 2014; Wolff K, Johnston A. Cannabis use: a perspective in relation to the proposed UK drug-driving legislation. Drug Test Anal. 2014; 6(1–2):143–54.