Drug detection factors
The length of time that a drug is detectable in the system depends on a variety of factors, including:
- the type of test
- dose
- tolerance
- potency
- metabolism
- the existence of medical conditions
Drug detection in hair
Drugs or their metabolites may be detectable in hair. Hair grows at a rate of approximately 1cm per month so depending on the length of hair it may be possible to determine drug use over recent months.
Dilute means the urine specimen had more water then urine. This basically means that the donor consumed a large quantity of water before providing the urine specimen. Maybe the person drinks a lot of water, maybe they drank a lot of water on purpose in order to try and cheat on the test. A positive dilute is still a positive result. With a negative dilute result there may be suspicion. This is not a positive. Employers should have a provision in the drug free workplace policy for negative dilute results. This policy can state that the negative dilute is accepted as negative or that the employer requires the person to go back for another test. The individual going back for another test should be instructed to not drink any large quantity of water prior to this next test, perhaps even a supervisor should accompany the person for the second test.
There is no exact science for this and may depend on hair testing, oral fluid testing or urine drug testing. For hair testing it takes about a week. For oral fluid drug testing it can be just a few hours. For urine testing it can be from 4-5 to 8-12 hours. The exact time can be different from one individual to another and a lot of other are factors involved including which drug, how strong the drug is, the person’s metabolism, the persons weight and perhaps what the person has eaten or drank. Bottom line is if the individual uses illicit drugs, they will at some point show up in hair, oral fluid or urine.