What Does Drug Testing Measure?

The most common forms of workplace drug testing are breath testing for alcohol and urine testing for other drugs

Breath testing results in a measure that is directly related to the amount of alcohol in the blood and there is strong evidence linking a given reading with likely impairment – Australia’s laws about drink driving are based on this evidence.

Urine testing is based on the analysis of the metabolites, or by-products, of drugs. A positive urine test tells us that the individual has been exposed to drugs in the recent past, but there is no evidence indicating that a particular reading is associated with a particular level of use or with performance/impairment.

That is, you can say that someone has been exposed to use, but you cannot say how much of a drug they have used, how intoxicated they are (or even if they are intoxicated) or whether they are impaired.

This is important – many people think urine drug testing detects impairment – it does not.