For pre-employment hair follicle drugscreens, is there a threshold the level must be over for a posi

Say a person did something once in the past 90 days. Is that enough to show up on a hair drug screen, and if so does it have to be above a certain level to become positive and therefore deny employment? Thanks

For pre-employment hair follicle drugscreens, is there a threshold the level must be over for a positive?

If it is present, it is positive. If it is positive, no employment. Shave your head.

For pre-employment hair follicle drugscreens, is there a threshold the level must be over for a positive?

Marijuana (for example) will show up in your hair for up to six months. Like the above, if it's there, it's positive.

For pre-employment hair follicle drugscreens, is there a threshold the level must be over for a positive?

Hair follicle tests can show drug use for over a year. Stop using drugs. You are killing yourself slowly and ruining your chance to get a decent job.