Millions of people are subjected to a thc drug test every year! Unfortunately all those marijuana and drug tests are not accurate. Many result in a false drug test. In the U.S. there are two categories of drug testing, federal and private regulation. In 1986 Ronald Reagan signed into law an order making it mandatory for federal employees to avoid abusing illegal drugs.

Several years after that Congress passed the Drug-Free Workplace Act of 1988. This made U.S. government workplace drug testing program guidelines official. The ACT does not include certain semi-governmental agencies like…

  • the Postal Service
  • members of the judicial and legislative branch
  • certain members of the armed forces

A large number of state and local governments use similar guidelines for their drug free workplace programs. Certain federal workers and specific (DOT) Department of Transportation positions are controlled by (SAMHSA) the Substance Abuse and Mental Health Services Administration. SAMHSA took over from (NIDA) the National Institute on Drug Abuse to mandate drug testing for high risk safety sensitive occupations such as…

  • trucking
  • oil and gas pipelines
  • mass transit
  • aviation

The drug testing guidelines of the federal government include uniformed services, companies contracted by the U.S. and executive agencies of the federal government.

thc drug test

THC Drug Tests

THC is one of what’s called the “NIDA-5”. Because of the federal requirement of SAMHSA the majority of drug testing companies recommend tests for these five drug categories.

  • Phencyclidine (PCP)
  • Amphetamines (methamphetamines, speed, amphetamines)
  • Cocaine (crack, benzoylecognine, cocaine)
  • Opiates (opium, heroin, morphine, codeine)
  • Cannabinoids (hashish, marijuana)

A routine urine drug test may detect THC after smoking a single rolled marijuana cigarette or “joint” for up to 6 days. The detection of drug test times would depend on…

  • how much is smoked and how often
  • the cutoff level for a drug test
  • the metabolism rate of the person being drug tested
  • the drug test for THC method used
  • other factors

Cutoff levels for a drug test are the least amounts of a drug or its metabolite that has to be in the drug sample before the drug testing company or lab will report a positive drug test result to the employer. A metabolite is the substance produced and left behind in your body when it processes or metabolizes the original drug.

To learn more about drug test cutoff levels and metabolites follow this link to pre employment drug testing.

thc drug test

Passing A THC Drug Test

The guidelines for deciding what level of drug or metabolite in a drug sample becomes positive is set by (SAMHSA) the Substance Abuse and Mental Health Services Administration. When the test does not meet or exceed this set level the drug test result is not positive.

11-nor-delta9 Tetrahydrocannibinol-9-carboxylic acid the abbreviation for THC is the main metabolite in marijuana. When marijuana is smoked it is metabolized or transformed to become 11-nor-delta9 Tetrahydrocannibinol-9-carboxylic acid in urine. SAMHSA has set the cutoff level for detecting THC in urine in an immunoassay at 50 ng/ml.

This is the standard set for a presumed positive screening test. A test of urine for drug abuse is the most common because it is the major path for drugs and metabolites leaving the body. The ng/ml stands for nanograms per milliliter. A nanogram is one billionth of a gram and a milliliter is fluid volume equal to 1/1000th of a liter, which is slightly larger than a quart.

Now let’s keep this real simple…an immunoassay is the first way to screen test or examine drug samples. When a drug or its metabolite is found and enough is present to be positive, a GC/MS (Gas Chromatography/Mass Spectrometry) confirmation test is performed to prove the screen test is accurate.

If the immunoassay test comes back positive the second gc/ms has to also return positive before a positive drug detection report is passed on to the employer. In the chart below 50 ng/ml (nanograms per milliliter) is the cutoff level for a positive drug test. The “proving” gc/ms (gas chromatography/ mass spectrometry) has a cutoff level of 15 ng/ml.

Cannabis50 ng/ml15 ng/ml

thc drug test

Passing A Drug Test For THC

THC can be dissolved in fat and is packed away in the job applicant or employees fat cells. This is why its hard to get it out of the body. Fat cells produce and discharge fat with THC and the bloodstream collects THC metabolites from fat. The drug users or abusers urine in turn continues to accumulate those THC metabolites from the bloodstream.

The (GC) Gas Chromatography and (MS) Mass Spectrometry process is the most widely accepted means of testing and deciding if drugs or their metabolites are in urine. But this method is very expensive and can have other problems like contamination of urine samples.

NIDA standard drug testing labs are only required when applying for jobs with the federal government. Private companies can use any lab or company drug test that they choose. They will likely use the least expensive as well. Any laboratory can have errors in its drug testing procedures and there can be a high rate of false positives.

It's important for every job seeker and employee to learn more about false positive drug tests and false negative for a drug test. Follow this link to workplace drug testing

Urine drug testing is the first and most commonly used form of drug abuse detection. Urine is so widely used because has the most metabolites of a particular drug in it. Other techniques of drug detection and metabolites are increasingly being used by drug testing companies.

thc drug test

If the job applicant or employee smokes eats or drinks marijuana, passing a drug test for THC may be a challenge. Besides urine the alternative types of drug testing are…

Drug test of blood
Drug testing of blood is the most expensive form of drug testing. It is the most accurate and least used due to cost. A blood drug screen is viewed as the most invasive (cutting or puncturing the skin).

Sweat drug test
Sweat tests can only detect a limited number of drugs. The individual being drug tested wears a patch and there is a concern about possible contamination.

Drug saliva test
Costs more than urine drug screening and not nearly as invasive as blood drug testing. This method is viewed as best for determining if there is current drug use. Learn more about how saliva drug testing works by clicking on this link drug saliva test

Hair drug use testing
Drug in hair info testing is considerably more expensive than drug urine tests. THC hair drug testing will provide a 90 day drug abuse detection time of recent growth hair sample that’s 1.5 inches. Is considered relatively non invasive. This link has more info about hair follicle drug screening. hair strand drug testing

thc drug test

Here are some of the situations and substances that may cause you to have a false positive drug screen.

  • Second hand smoke if it is extreme
  • Ibuprofen (motrin, nuprin, excedrin, advil)
  • Kidney disease
  • Liver disease
  • Naproxen (Aleve)

These are some of the most common but there are others. Research shows that THC drug tests have resulted in a false drug screen almost 30% of the time! There has been a lot of conflict about the cutoff levels for passing a THC drug test is to low. Some experts suggest that you request a higher level of about 65 ng/ml instead of the lab standard of 15 ng/ml to confirm if you test positive.

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