Hair testing can reveal use going back three months or more – some say years, though that would mean really long hair. True, urine testing can only catch substances you have used in the last day or two (or up to a month in some cases like with chronic marijuana use). Presumably, a positive hair test always trumps a negative urine test. They want hair testing to be mandatory, and they don’t want to be bothered with confirmation by a second, different test. But that’s not good enough for Big Trucking. Some carriers use hair testing now along with the required urine tests, and sure enough, hair tests eliminate more applicants than the urine tests. You’ve been indicted, tried, and convicted. When Big Trucking believes they’ve caught you, they want you to stay caught. Big Trucking wants hair to replace urine for mandatory drug testing, and they don’t want to confirm a positive hair test with a urine test.
