The saliva tests the government plans to introduce to allow the police to check motorists for drugs are unreliable and have a wide margin of error, the AD reports on Tuesday.

Although the manufacturers promise 95% reliability, research by the French Académie Nationale de Pharmacie show that in 16% of cases, users wrongly test positive, the paper says. And in 19% of tests, drug use is not identified at all.
The justice ministry defends its plans, saying the test is ‘sufficiently trustworthy’ and pointing out that a blood test will be needed to prove drugs use. The saliva test is simply a means of selection, a spokesman told the paper.
Roel Kerssemakers of the Jellinek addiction clinic said cannabis users will be unfairly hit by the saliva test. ‘It shows drugs use but not when the drug was taken. If you smoke a joint in the evening and then drive the next day it will have no affect whatsoever on your driving,’ he said. ‘But you will test positive and be taken to the police station.’