[QUOTE="steve"] You must have had a different test to me then , i got flagged twice on a full blood hair piss test and i have never used the stuff .[/QUOTE] I've never had a test but I've represented a lot of people who have failed. Your test must have been fucked up - not entirely sure why they'd test hair, blood /and/ piss. The norm is either urine or swab and in the case of the railway, breath as well. In the case of a suspected fuck up there's always a second sample. [QUOTE] The Doctor administering the test said passive smokeing can leave you with traces in your system for a week although at low levels[/QUOTE] Unusual for a Doctor to conduct the test. Passive smoking, even in an enclosed space (say a car) with a couple of people smoking will not result in a positive. To get a positive in those circumstances the enclosed space must be so thick with smoke you'd need to be wearing goggles. Even if you smoked a joint (for the very first time) it's unlikely you'll test positive in normal circumstances after a week. The much vaunted 36 days detection is for regular users. IIRC, it's because canabis byproducts (the things I've forgotten the name of) that the test looks for end up in the body's fatty tissue and is processed more slowly and dependent on how regular usage is - hence the extended detection times.