Marijuana is a plant that has psychoactive effects when ingested by human beings. The active ingredient in marijuana that causes these "mind-altering" effects is delta-9-tetrahydrocannabinol, more commonly referred to as "THC." A saliva THC test is one of the drug tests that can be used to determine if an individual has used marijuana.
The United States government classifies marijuana as a Schedule 1 substance. This means that marijuana is not considered effective for medical use and is considered to be dangerous. Penalties for marijuana possession vary from state to state and depend on the amount of marijuana "in hand." States also have varying penalties for being under the influence of marijuana. Some states have legalized marijuana for medical use, though this conflicts with U.S. federal law.
Many companies require drug screening as a condition of employment. Some companies also require random drug testing. Courts can require drug testing for paroled convicts or as a condition for a plea bargain sentence. In addition, parents may use drug testing to determine if their children are using drugs. Drug rehabilitation programs may also require drug testing to ensure that their participants are clean. Users may also screen themselves in anticipation of having to take an employment drug test.
When a person ingests marijuana, the THC from the marijuana starts to accumulate in fatty tissues in some of the organs in the body. This means that THC can accumulate in the body. A person who is a heavy or long-term user may test positive for marijuana use longer than a "recreational" user who only uses marijuana occasionally because of this.
THC will only show up in a saliva TCH test for a few hours. A saliva THC test, like a blood test, is typically used to determine if marijuana played a part in an "working hours" accident. Unlike taking a blood test, a saliva THC test is will not hurt and is not particularly invasive. In addition, it is much more difficult to switch a saliva sample being used for a saliva THC test than it is for a urine sample as a saliva THC test is typically not handled by the person who is being tested.
The most commonly used form of drug testing is through a urine sample. This is also the least expensive drug screening method. Urine tests may detect THC for three to seven days after usage, although heavy marijuana users may test positive for up to 30 days.
Hair follicles are also used to test for drugs such as marijuana. THC may not be detected in hair follicle testing if the person uses marijuana occasionally. Humidity may also have an effect on hair follicle tests from heavy users resulting in a false negative test.
Blood testing is another form of drug screening. Evidence of marijuana usage only lasts a few hours in blood unless the person being tested is a heavy user. This form of testing is most often used shortly after on-the-job accidents to determine if marijuana played a factor.