Blood Testing for Cannabis
Q - Can you help? I get my driving licence back next month after a 2-year ban for drink/driving. I no longer drink but I do smoke cannabis occasionally. I have to be blood tested by a doctor before I finally receive my licence - do you know if they also test for cannabis and if so would this invalidate my application. I guess what I'm trying to ask is, how long does cannabis stay in the blood?
A - Cannabis can be detected in blood samples for around few days to a month, depending on what they are looking for (pure drug or metabolites), the sensitivity of the test, how long ago you last used, and how much and for how long you were using.
If your licence is refused on the basis of a positive test for cannabinoids, this should be readily challenged in the courts. There is no evidence that cannabis causes any significant impairment in driving or risk to road safety (except when used with alcohol), and indeed much evidence suggests that it may contribute to safer driving behaviour, particularly among young men otherwise more prone to driving aggressively.
However, I am aware of at least one individual who had his licenced refused in such a way.
IDMU has prepared reports in a number of alleged drug driving cases where test evidence have been successfully challenged in the courts. If you are refused a licence, you should instruct a solicitor to obtain all details of the testing used and seek an estimate for a report from ourselves concerning all relevant aspects of the case. A solicitor should also be able to advise you on how to get your licence back and whether you could seek damages from the DVLC for any losses suffered, or for wilful disregard of scientific evidence regarding drug testing known to the DETR during formulation of policy.