What is a hair drug test?
Hair drug testing is utilized by collecting a sample of an individual hair at a minimum length of 1.5 inches from the crown (back center) portion of the head. The minimum amount that must be collected is approximately 120 strands of hair (diameter of a #2 pencil), which must be cut from the area closest to the scalp at a length of 1.5 inches. Hair drug testing is becoming more widely utilized by employers and individuals because of its longer window of detection which is will provide accurate results of approximately 10 – 90 days of drug use.
Oftentimes many clients as the Question:
Can products and treatments affect hair drug test results?
When we receive inquiries regarding hair drug testing from employers and individuals who have questions, they typically wonder if hair products (shampoos, sprays, gels, coloring, bleaching, and perming), can have an impact on their test results?
Typically laboratories would prefer the hair sample be not manipulated in any way such as dye’s, bleaches, coloring etc., but we found through research that when shampoos, sprays or gels were applied to cut hair samples analyzed at Quest Diagnostics, they had little or no effect on positive or negative hair specimens. Click here to read Quest Diagnostics White Paper Regarding Hair Drug Testing.
The finding also went on to mention that when normal hair treatments, including bleaching or dyeing, were applied to cut hair samples, they typically did not interfere with test results.
Hair drug testing for drugs of abuse is the only drug testing method available that provides up to a 90-day drug use history. The major differences when compared to urine testing, is that hair drug testing typically provides a greater number of positive test results due to its longer detection window.
Hair drug testing requires a small sample of hair that is collected under direct supervision and observed supervised collections make hair testing a tamper-resistant screening method limiting the opportunities for a donor to cheat.