URINALYSIS

DETECTION PERIOD: Urinalysis can generally detect drug use for the previous 2-7 days for most drugs.

EVASION: If all standard collection procedures are followed evasion is difficult. At PSI we test for adulterants that could cover up drug use. In addition to testing for adulterants we also test for specimen substitution and dilution.

COLLECTION: A simple urine specimen.

HAIR TESTING

DETECTION PERIOD: Hair analysis can detect drug use for approximately the previous 90 days.

EVASION: Hair testing cannot be evaded, easily since the drug residue remains permanently entrapped in the hair.

COLLECTION: A cosmetically undetectable snip of hair is easily collected without causing embarrassment.

SALIVA TEST

DETECTION PERIOD: Short, when testing for Marijuana, only 8 to 24 hours.

EVASION: A number of researchers argue that oral fluids testing is less susceptible to adulteration than urine.

COLLECTION: A simple non-invasive collection, involving a tube with two sections. The top section holds a small highly absorbent insert. The subject simply puts the insert in their mouth alowing it to absorb as much saliva as possible. The bottom section of the tube collects the saliva as it passes through a small hole in the top section when spun in a centrifuge.
While saliva testing is slightly more expensive than urinalysis, it's advantages in ease of collection, storage and the non-invasive collection process seems to be appealing in the work place.