<Li> Marijuana: 1 - 24h </Li> <P> A disadvantage of saliva based drug testing is that it is not approved by FDA or SAMHSA for use with DOT / Federal Mandated Drug Testing . Oral fluid is not considered a bio-hazard unless there is visible blood; however, it should be treated with care . </P> <P> Sweat patches are attached to the skin to collect sweat over a long period of time (up to 14 days). These are used by child protective services, parole departments, and other government institutions concerned with drug use over long periods, when urine testing is not practical . There are also surface drug tests that test for the metabolite of parent drug groups in the residue of drugs left in sweat . </P> <P> Drug - testing a blood sample measures whether or not a drug or a metabolite is in the body at a particular time . These types of tests are considered to be the most accurate way of telling if a person is intoxicated . Blood drug tests are not used very often because they need specialized equipment and medically trained administrators . </P>

What kind of drug tests do courts use