The National Centre for Education and Training on Addiction (NCETA) at Flinders University have produced a rather interesting fact sheet on workplace drug and alcohol testing.

Here is an excerpt:

Does workplace testing improve workplace safety?

Evidence is inconclusive regarding the efficacy of drug testing in reducing workplace accidents and injuries. While some studies suggest that testing can reduce injury and accident rates, more rigorous studies indicate testing has only a small effect or no effect at all. Claims that workplace testing can substantially reduce workplace injuries, accidents and compensation claims are not supported by the available research evidence.

I have a number of concerns about workplace drug testing:

1. That a policy of employee drug testing may unintentionally mark satisfactory employees for punishment. In such cases, urine testing may identify model employees for disciplinary action despite their appearance, performance or behaviour in the workplace being no different to that of other employees.

2. If drug use typically caused employees to perform in a manner that was risky, drug testing would be unnecessary; a negligent worker can be disciplined regardless of their drug use.

3. The mere presence of residual drug metabolites in an employees biological matter in many instances fails to accurately reflect drug related impairment. How does identifying the presence of residual metabolites in unimpaired employees reduce risk in the workplace?

4. The consumption of other substances, such as paint, petrol, glue and gas, may also exacerbate risks in the workplace. Why are alcohol and other specific non-prescription drugs singled out?

The next time your employer asks you to pee in a cup, ask them what evidence they’re using to justify the test. Better yet, print the fact sheet and distribute it among your co-workers.

Note that (as the fact sheet points out) testing can be conducted “only after informed consent is given by the employee”.

A more comprehensive review of the evidence can be found here.