Hair drug testing is a method that can detect drug use over a much longer period of time, and is often used for highly safety-critical positions where there is zero tolerance of illegal drug use. Standard hair follicle screen covers a period of 30 to 90 days. The growth of hair is usually at the rate of 0.5 inches per month. The hair sample is cut close to the scalp. In the absence of hair on the head, body hair can be used as an acceptable substitute. This includes facial hair, the underarms, arms, and legs or even pubic hair. Because body hair grows at a different rate than head hair, the timeframe changes, with scientists estimating that drug use can be detected in body hair for up to 12 months. Currently, most entities that use hair testing have prescribed consequences for individuals removing hair to avoid a hair drug test.
Laihe's hair drug rapid trace analyzer is quantitative test and only need 3 minutes to detect the drug in people hair or body hair. And its minimum detection limit is 0.1 ng/mg.