On-site drug testing.

Drug testing outside the laboratory environment has become widespread and provides presumptive results within minutes of collection of the specimen. This has become particularly useful for testing of urine and oral fluid. Applications include workplaces where drug use has safety implications, drivers of vehicles at the roadside and situations where drug impairment is suspected. The present article explores the relative advantages of this form of testing for the specimens that can be collected and discusses issues such as cut-offs, the need for laboratory confirmation and safeguards to ensure legal defensibility.