Hair Drug Test Procedures

Most hair drugs tests require about sixty hair strands at the length of 1 ½ inches. They clip the hair, which are grown since last ninety days. Some labs will not test for new hair, grown in last one month. They may acquire body hair, if necessary. Examiners clip those hair strands, which are close to the back of head. They then wash it with solutions to eliminate external contamination. Later, they place those strands in an organic solvent and implement testing methods as specified by DOT and FDA. They use GC/MS (gas chromatography / mass spectrometry) method to perform drug analysis on every single molecular level to find out specific metabolites of drug in the hair sample. At this stage, drug metabolites separate out and testers can easily locate the specific type of drug. The intensity of drug molecules show whether you take drugs frequently or not. It also detects as when you took drugs. The cut-off levels in GC/MS hair drug test is as per the cut-off levels determined by the FDA. If the levels of drugs in your hair strands are equal to or above the cut-off levels, it means the outcome of hair drug test is positive, and if levels of drug are less than the cut-off levels, the outcome of the test is negative.