It is not recommended to drive after having taken drugs as your driving might be affected, but it is now also illegal to drive with specified levels of certain drugs in your blood, if you have not been prescribed them or have not followed the advice given to you about how to take them. If you have been prescribed the drugs and followed the advice, even if you have higher than the allowed amount in your blood you can still drive as long as your driving is not affected (impaired).
If you are convicted of this offence you will be banned from driving for at least 1 year, and may also be fined an unlimited amount of money and/or face up to 6 months in prison.
The table below sets out the levels and addresses potential timeframes for elimination from the body/detection in blood (only blood is referred to as this is what will be tested). **THESE ARE APPROXIMATE TIMES ONLY AS ELIMINATION AND DETECTION TIMES ARE DEPENDENT ON A WIDE RANGE OF FACTORS, INCLUDING BUT NOT LIMITED TO: GENDER; AGE; BUILD/BODY COMPOSITION; DOSAGE; HISTORY AND FREQUENCY OF USE.
The law about levels of drugs in the body is used as well as the law about being unfit to drive through drugs – it DOES NOT REPLACE IT. Your fitness to drive is assessed by a police officer at the side if the road by asking you to do certain activities. Drugs in your system might be used as evidence to support the charge. It is still illegal to drive if your driving is affected (impaired) after using drugs, even if you are below the set limit.
Below is a table of the set limits with some information about how long they might last in your system. If you have a specific question please contact our expert drugs and legal advisers on 0207 324 2989 or ask@release.org.uk
Controlled drug |
Limit (mcg/L blood) |
Comments |
Elimination/detection times (other factors apply) |
Benzoylecgonine (BZE) |
50 |
|
|
Clonazepam |
50 |
|
|
Cocaine |
10 |
|
|
Delta-9-Tetrahydrocannabinol |
2 |
|
|
Diazepam |
550 |
|
|
Flunitrazepam |
300 |
|
|
Ketamine |
20 |
|
|
Lorazepam |
100 |
|
|
Lysergic Acid Diethylamide |
1 |
|
|
Methadone |
500 |
|
|
Methylamphetamine |
10 |
|
|
Methylenedioxymethamphetamine |
10 |
|
|
6-Monoacetylmorphine |
5 |
|
|
Morphine |
80 |
|
|
Oxazepam |
300 |
|
|
Temazepam |
1000 |
|
|
Glossary
Absorption (absorbed):
The process by which a substance is assimilated (taken up) by an organism, in this case the human body
Concentration:
The amount of a substance (e.g. a drug) divided by the volume of the liquid it is in (e.g. blood)
Detectable (time):
The length of time it is possible to find a substance in a liquid, usually to a set level
Elimination (time):
The length of time it takes for a substance to be entirely removed from the body (or to below a minimum level that it is possible to detect), usually through excretion (e.g. urine, faeces, sweat, etc.)
Metabolite:
A product that is left over after a drug is metabolised (broken down) by the body; these can sometimes be used as evidence that a particular drug is likely to have been taken
Psychoactive (drug):
A chemical substance that works on the brain to alter functions and perceptions, i.e. makes the user feel and experience things differently, and can affect their ability to perform certain tasks