Drug Driving Legal Limits

What are the drug driving limits?

Unlike drink driving offences, it’s difficult – if not impossible – to work out what the new drug driving limits actually mean, making it much easier to break the law. Please remember that you can still be found guilty even if you did not intend to be over the limit. We may be able to take advantage of these confusing limits to help win your case.


The legal drug driving limits are as follows:

Illegal DrugLegal Limit (Blood)
Delta – 9 -Tetrahydrocannibinol (Cannabis)2µg/L
Lysergic Acid Diethylamide1µg/L
6 – Monoacetylmorphine (Heroin)10µg/L

(‘µg/L’ means ‘micrograms per litre of blood)

Prescription DrugLegal Limit (Blood)

In drug driving cases the legal limits are relatively meaningless. This is because guidance issued by the Magistrates’ Courts Sentencing Council in November 2016 advised all magistrates to impose a 12 month driving disqualification for a first time offender, even if the result was two or three times the legal limit. If the offender has a previous drink or drug driving conviction within the last ten-years, the minimum disqualification will be three years. If the magistrates feel as though the circumstances are more serious because of aggravating factors (such as a collision, poor driving etc…) then this will increase the disqualification period.

Of course, if you avoid a conviction then you cannot be disqualified. To chat in confidence about your case, fill in the contact form below and a member of our team will be in touch.

Please don’t make the mistake of accepting the accuracy of the blood test results without checking the prosecution’s analytical data. This data, often in excess of 300 pages, contains;

  • Calibration checks
  • Quality control & quality assurance
  • Sample preservation
  • Storage
  • Method of analysis

Technical Defences

Most labs get it wrong. No analytical method is 100% accurate.

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