The primary goal of any drug-free workplace policy is to deter substance abuse.
In order to accomplish this end, a combination of education, drug testing, and employee assistance / counseling is required.
Relative to the drug test the following elements must be present:
1. Ability to detect current / on-the-job drug abuse.
2. Convenience for both donor and test administrator.
3. Observed specimen collection.
Only oral fluid / saliva meets all three objectives.
Urine can only detect historical drug abuse and there is no relationship between drug metabolite concentration and impairment and/or time drug was ingested. Observed collection is not possible in most workplace settings.
Hair is the best method for detecting historical drug abuse, and allows for observed collection. However, is only suitable for pre-employment testing as it can not detect drug consumption within the past seven days.
Oral fluid can detect drug consumption within minutes of consumption, up to 2-3 days for many drugs. THC detection is limited to approximately 24 hours, however, the impairment period for marijuana is generally reported to be one hour (two hour maximum).