Thousands of Americans are at risk of false arrest because of this shortcoming. The State of California keeps records on more people in its criminal information system than there are people in California. When some librarians blew the whistle on the program, the FBI investigated them. As mandatory drug testing grips the world of corporate and government employment, methods to fool the standard urine test detection method have become well-known. To combat this trend, some companies have turned to the more reliable method of hair testing.
Hair maintains a permanent and unalterable record of all drugs an individual ingests.
While urine tests catch only those drugs in a subjects system at the time of urination, missing those consumed any time prior to a few days before the test, hair grows at the rate of about one-half inch per month. A person's history of drug indulgence is therefore as easy to read as his or her hair is long. But head hair is far from the only source for that information. Body hair and fingernails also do the trick. In other words, don't shave in the company men's room.