Types of testing for validation of marijuana consumption include urine, blood, hair follicle and saliva. The most accurate test for validating current cannabis (the chemical name) intoxication is the blood test. Urine analysis can determine use within approximately 20 days. Hair follicle testing for marijuana use is difficult because the chemicals present in cannabis do not bind as well to hair. Saliva testing is used in Australia as an immediate roadside test with notable results.
Types
Specific types of testing venues include urine analysis, blood testing, saliva and hair follicle testing. According to Forensic Toxicology Specialists, detection times in urine are greater than detection times in blood, which is also more expensive. However, the presence of drugs in urine does not give sufficient information regarding the person's actual level of current influence. In addition, urine analysis does not determine the amount of the dose of cannabis or the time of the dose. Marijuana testing exists to determine the level of chemical compounds known as cannabinoids in the body. THC is the mood-altering active chemical in cannabis.
Testing Procedures
Drug Detection Laboratories Inc. explains that there are two types of testing procedures: the cut-off test and limit of detection test. A cut-off type test has a limit set to report a positive result. If the drug is identified, but is below the limit, it is reported as not detected. The limit of detection test reports any amount present in the bloodstream or body tissues. This test is generally below the cut-off test limits. However, Forensic Toxicology Experts note that the most reliable test results are determined by a zero tolerance testing process. Most laboratories are required to use the cut-off test results. The zero tolerance test would be positive if any cannabis existed in the test sample.
Efficacy
The National Organization for the Reformation of Marijuana Laws states that despite the prevalence of workplace drug testing programs in the United States, there is little scientific evidence demonstrating the efficacy of drug testing procedures. A review by the National Academy of Sciences notes "... there is as of yet no conclusive scientific evidence from properly controlled studies that employment drug testing programs widely discourage drug use or encourage drug rehabilitation."
Psychoactive Ingredients
The U.S. Drug Enforcement Administration indicates that cannabis contains cannabinoids that are synthesized by the marijuana plant. Some of these chemical compounds include cannabinol, cannabinolidic acids and several forms of tetrahydrocannabinol, or THC. THC is responsible for the chemical residue found in cannabis testing results. A brand name medication has been developed that chemically extracts THC and reformulates this compound in pill form. It is legally prescribed for symptoms of nausea and vomiting caused by cancer treatment medications. The synthesized THC is also prescribed as an appetite stimulant for AIDS patients, but it is a medically controlled class III substance, according to the Drug Enforcement Administration.
Expert Insight
The Drug War Facts website notes that the federal government gives individual states and employers the authority to drug test its employees. Two federal agencies, the Department of Transportation and Department of Defense, require random drug testing for contractors and employees holding certain jobs. In addition, the Omnibus Transportation Employee Testing Act requires testing for transit operators. Random testing may be prohibited or required for jobs such as school-bus drivers in some states. In addition, other states have confidentiality laws regarding test results as well as policies and procedures for conducting such tests.
References
- Drug Policy Alliance: Myths and Facts About Marijuana
- The National Organization for the Reform of Marijuana Laws, NORML: The ABC's of Marijuana and Drug Testing
- U.S. Drug Enforcement Administration: Chapter 7 Cannabis
- Drug Detection Laboratory Inc.: General Information on Drugs of Abuse and Drug Detection Testing
- National Highway Traffic Safety Administration: Drugs and Human Performance Fact Sheet
