Other things being equal, most people facing a drug test probably would prefer handing over a few strands of hair to peeing in a cup on command. The neater, less embarrassing method is easier on the sample recipient as well.
Still, it's not true that hair testing is "less intrusive and less invasive of privacy" than urinalysis, as the Substance Abuse and Mental Health Services Administration (SAMHSA) suggested when it announced new guidelines that will allow federal agencies to use the alternative technique for testing applicants and employees. To the contrary, hair testing, which is apt to become more popular with private employers now that the government has endorsed it, is more intrusive and more invasive; that's the whole point.
Drug traces typically can be detected in urine for a few days after use. (In daily marijuana smokers, the window of detection may be as long as a few weeks.) By contrast, the sort of hair testing approved by SAMHSA can detect drug use up to 90 days after the last dose.
SAMHSA considers the longer detection window a major advantage, especially in pre-employment screening, because it can catch people who otherwise would not be recognized as drug users. A SAMHSA official told the Associated Press that new testing methods will "increase the deterrent value of our program, which is basically the whole bottom line."
But for employers who are genuinely interested in promoting safety and productivity—as opposed to enforcing the nation's drug laws—hair testing makes even less sense than urinalysis. It widens the gap between test results and job performance, ensnaring more people whose drug use has no impact on their work.
As it is, someone who smokes a joint on a Friday night can test positive on Monday morning, long after the drug's effects have worn off. Such a result is no more relevant to an applicant's qualifications or an employee's readiness for work than the knowledge that he drank a beer over the weekend.
With hair testing, employers would in effect be inquiring into the private, off-the job behavior of applicants and workers during the previous three months. Does that sound "less intrusive and less invasive"?
Although urinalysis does not measure employee impairment, it can be defended as a pre-employment screening tool precisely because it's so easy to pass. Since applicants know ahead of time they will be tested and generally can avoid a positive result by abstaining from drugs for a week or two, employers might reasonably question the intelligence, foresight, or discipline of those who nevertheless flunk the test.
Pre-employment urinalysis also can be seen as a way of distinguishing between light or moderate users (who can easily give up drugs until they pass the test) and addicts (who are so attached to their drug that they're willing to risk being passed over rather than stop using it for a while). Once hired, employees usually are free to resume their drug use, since most companies that use urinalysis do not do random testing.
Because it covers such a long period of time, hair testing would impose a much more substantial burden on job applicants, and it would be a less accurate way of identifying problem drug users. Employers therefore would have to worry more about either repelling or rejecting qualified applicants.
According to the government's survey data, something like 35 million Americans use illegal drugs (mainly marijuana) each year. The vast majority of these people are occasional users, who are just as likely to be employed as people who report no illegal drug use. Refusing to hire them makes as much sense as refusing to hire drinkers because some of them are alcoholics.
Many employers recognize this reality, even as they make a show of maintaining "a drug-free workplace." The executive in charge of drug testing at a Philadelphia-based manufacturer told me, "What drives our concern is work performance. If there is such a thing [as] 'recreational use,' we would probably not find that out."
Drug testing consultant J. Michael Walsh told The Washington Post hair testing is not likely to catch on very fast, because "these big corporations are very happy with what they are doing." For the most part, what they're doing is pretending not to hire drug users while in practice welcoming those who are discreet and do their jobs well. Hair testing would make that charade harder to pull off.