Some Facts about a Hair Drug Test
A hair drug test is one of the most reliable drug testing methods these days. Oftentimes, an FDA-cleared hair follicle drug testing system is used to detect the presence or absence of drugs in the body because it can reveal drug use for the past 90 days. Typically, hair testing can reveal the presence or absence of cocaine, marijuana, methamphetamine (including amphetamines and Ecstasy), opiates, and phencyclidine or PCP.
The results of a hair drug test are usually defensible through the help of forensic principles. This kind of drug test also requires an observed collection process – this simply means there are less chances of adulteration. As have been mentioned, hair drug testing can reveal drug use for the past 90 days, depending on the length of the hair sample. Hair drug testing usually requires at least an inch and a half of hair to represent growth for the past three months. While a hair drug test can tell much about the history of drug use for the past three months, it cannot reveal drugs used seven days prior to the collection of the samples.
There are some prescription drugs that contain the same kind of components found in illicit drugs. Not many hair drug tests can distinguish the difference between the two forms of the drug (prescription and illicit). Nevertheless, this does not pose quite a big issue because there is rarely a legal use for cocaine or PCP, although cocaine can be used in a medical setting on extremely rare cases (like controlling bleeding in the eye or nose). And should it be used, it should be properly documented in that person?s medical file.
When someone tests positive for drug use, a confirmation test would be needed. This is necessary because there are drugs that can interfere with screening and these might cause false positive results. Presently, the accepted method for confirming a drug test result is through GC/MS or gas chromatography/mass spectrometry. When someone tests positive for methamphetamine, his or her hair samples should contain methamphetamine and its metabolites (like amphetamine) and should later on be confirmed through GC/MS.
While there are those who believe in the reliability of hair drug tests, there are still some who are apprehensive about the accuracy of their results. Unlike what most people believe, a hair drug test will not reveal any drug use if you were merely n a room with someone who uses drugs. There are also those that speculate hair drug testing can be dodged by masking the hair. Masking the hair is possible through the use of hair products but remember: drugs and their metabolites stay inside the hair and not on it.