Colour me sceptical:
It hopes the so-called “drugalyser” will make it easier to catch and prosecute offenders and help reduce accidents. The drug testers will be able to screen for an array of illegal substances, including cocaine and ecstasy.
A positive result would mean that police would no longer have to wait for permission from a doctor before a blood test could be taken to be used as evidence in court.
No, not about the desirability of such a test. People spaced out on drugs are as bad as those drunk, dangerous to other road users and thus righteously to be prosecuted.
No, rather, it\’s the technology that worries. Here\’s the detection times that such oral based testing has:
Detection in saliva tests begins almost immediately upon use of the following substances, and lasts for approximately the following times:
- Alcohol: 6–12 h
- Marijuana and hashish (THC): 12–24 h
- Cocaine (including crack): 1 day
- Opiates: Up to 2–3 days
- Methamphetamine (\”Tweak,\” \”crank,\” \”ice\”) and ecstasy (MDMA,) : Up to 5 to 13 days.
- Benzodiazepines: From time of ingestion up to 2 to 3 days
- Amphetamines 3 days
- Phencyclidine (PCP) 3 days
NOTE: Saliva tests are highly sensitive and detection times can vary considerably based on the cutoffs used.
So, the presence of such drugs, or their metabolytes, in such a sample does not in fact show being under the influence of said drugs. For someone is not driving (or any other way) impaired two days after taking smack, nor several days after taking meth etc.
And yes, poppy seed pastries can indeed give a false positive for opiates.
The test are good for checking whether someone has been taking drugs. They\’re not good for checking whether someone was actually under their influence at the time of driving.