Drug-testing methods and reliability

The methods used by laboratories to analyze urine collected from employees are described. Federally designed procedures designed for analyzing government employee samples have become the highest standard for performing such tests, although at present there are no guidelines that specifically address drug testing in the private sector. Samples and analysis should be handled in a manner that ensures that test results are legally defensible. Enzyme immunoassay is the technique used to perform the initial test on these samples. Positive test samples identified by this method are tested again by gas chromatography-mass spectrometry. Potential problems with these analytical methods, additional safeguards, and data demonstrating the reliability of this approach are presented.