RE: Big Pharma protection ??24 Mar 2016 11:12
This depends on several factors. As a general guide the manufacturers of oral testing kits claim to detect ACTIVE THC for up to 12 hours in the mucosal cavity after smoking/vaporising a single joint/bowl/balloon. However, what's less clear is the cumulative pollution caused by smoking on a regular basis, which leads to a build up of THC in the oral cavity which over time can exceed the limit days after initial ingestion. This means that a regular smoker will always exceed to 2ng/ltr drig driving limit. Other factors include oral hygiene, in that those who use chlorohexydene, mouth washes and brush their teeth more regularly can reduce oral contamination (at least on a temporary basis). These activities stimulate saliva production which temporarily reduces the concentration per litre
Transdermal patches and suppositories bypass the oral cavity, and so wouldn't be detectable in a saliva test at all (because THC isn't soluble in water. Pollution by edibles would vary depending on how long the edible stays in the mouth during mastication, whether it's extracted in butter or coconut oil, or 'bombed' without the contents touching the mouth (concentrated solidified cannacoco oil wrapped in rizzlas for example).
So the answer to your question is if its regularly ingested in such a way that it comes in direct contact with the oral cavity then it will be perpetually polluted and will fail a drug driving test.
So, having a level that exceeds the current drug driving laws does not necessarily mean that you need to have smoked within the preceding 24 hours. With a very heavy smoker the level could exceed the limit for over a week later even with complete abstinence.
The drug driving limit bears no relationship with actual impairment of course. The Wolff review on behalf of the Government recommended 5ng/ltr as a minimum, but the Government overruled Wollf's 'expert' advice and opted for a limit that was well below the agreed impairment level instead (effectively zero tolerance).