Drug testing is a very common part of many companies’ standard procedures. Although many people think of drug tests as an almost unavoidable part of the hiring process, these tests are also sometimes used as part of a random testing program. In addition to being used by corporations, law enforcement agencies, government agencies, sporting teams and other organizations also frequently utilize drug testing.
Today, urine tests seem to be the most frequently used test. But, there are other tests that are also used, such as saliva tests, hair tests, blood tests and sweat patch tests. Although these tests work in different ways, they are all designed to look for designated concentrations of detectable substances, which remain in the body after drug use. The timeframe during which these tests can detect usage varies, depending on the drug, the test being used, and how heavy of a user the person being tested is.
Understanding the Marijuana Testing Process
When a person smokes or ingests marijuana, the active ingredient, commonly referred to as THC, enters the body’s bloodstream. After a few hours, the THC is metabolized into metabolites, which are then stored in the body’s fat. Over time, these metabolites leave the body through its natural elimination processes. However, until the metabolites have been eliminated, they can be detected by drug tests.
Because the urine test is commonly used to test for marijuana, it’s important to understand what the test is actually looking for. Instead of looking for THC, which is marijuana’s psychoactive component, they are actually looking for the metabolite, which is non-psychoactive. While these metabolites can remain in the body for days or even weeks, they do not cause any kind of impairment for the individual. So, a person could test positive for marijuana even though they used marijuana weeks ago and are currently not impaired in any way.
On the other hand, blood tests are designed to look for THC in the blood itself, which is a sign of recent marijuana use. Saliva tests are also designed to look for recent marijuana usage. These tests are frequently used when investigating an accident or DUI, since the presence of THC in the bloodstream can be a sign that the person is actually under the influence. This is why saliva or blood tests are frequently used in the case of driving tests.
Hair testing is designed to look for long-term usage, sometimes going back months. These tests are better at detecting regular marijuana usage as compared to occasional or one-time usage. Many people particularly object to the hair test because a person could test positive, even if they have not used marijuana for a long period of time.
How Long Can Marijuana Be Detected?
There are a number of different factors that can determine how long marijuana usage can be detected by the tests. There are many different kinds of metabolites, and they are not all eliminated from the body at the same rate. Because the metabolites are stored in body fat, the amount of fat a person has can also dramatically alter the detection timeframe.
In the case of a urine test, occasional marijuana usage can usually be detected for approximately 2 to 7 days. However, in the case of regular marijuana usage, this timeframe is expanded to 30 days or even more. If a person is a heavy marijuana user, they could test positive even after 90 days or more. If the person being tested has a high amount of body fat, this could also drastically increase the length of the detection period.
It’s also important to note that metabolites require a certain amount of time to make their way to the urine. In most cases, it takes approximately 1 to 4 hours after using marijuana before it can be detected in the urine. Metabolite levels can also fluctuate throughout the day. This fluctuation can mean that a person could test negative, then turn around and test positive later in the day. This natural fluctuation in metabolite levels is one reason why people often try to make sure that their first urine of the day is not tested, because concentrations of detectable substances can be higher.
In the case of a blood test, occasional usage is generally only detectable for 2 to 3 days. For heavy marijuana users, this timeframe can extend up to 2 weeks. Although saliva tests are similar to blood tests in regards to detection timeframes for many drugs, they do vary in the case of marijuana. In most cases, marijuana usage is only detectable by a saliva test for 2 to 24 hours.
Hair testing is designed to look at long-term drug usage. As such, hair sample testing can often detect usage that occurred up to 90 days prior, or sometimes even longer.
Marijuana Test Controversies
As is the case with most kinds of drug and alcohol testing, there are a number of controversies that surround testing for marijuana usage. Since urine and hair testing are both designed to look for metabolites, they are clearly intended to merely prove past usage. If the THC has already metabolized, then this is an indication that the person is not actually under the influence of marijuana. Although these tests may indicate that a person used marijuana in the past, it is argued that past usage should not factor into a company’s employment practices.
Saliva tests are one of the newer tests, and as such many people feel that their reliability has not been fully proven. As such, even though they are designed to detect THC, meaning the person may be actually under the influence of the drug, many feel these tests are unreliable and should not be used.
Blood tests are also designed to show that a person may be under the influence of the drug. However, these test are not a good indication of a particular person’s level of impairment. Regardless of the test results, a person may not be actually impaired, and could potentially pass a performance-based sobriety test. Additionally, there have been numerous accident studies conducted which indicate that marijuana is not a primary risk factor when it comes to driving fatalities.