Trucking attorney Jim Mahoney's law practice encompasses trucking and cargo loss litigation, claims management, compliance management, and operations consulting.
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Ready to Roll? Drug Testing and Driver Impairment
As legal marijuana use spreads, detecting driver impairment takes on growing importance and new challenges for trucking companies.
Drug test refusals account for 13% of pre-employment violations in the DOT Drug & Alcohol Clearinghouse. This finding comes from data released in the FMCSA’s Summary Report – the second such report the agency has released since the DOT Clearinghouse went into effect.
For companies engaged in commercial transportation, important considerations include the prevalence of driver impairment (according to University of Central Arkansas study, the total could be as high as 300,000 nationwide), the effectiveness of various testing methods, and how to deal with the moving target of lingering marijuana presence in the human body.
The belief is that most drug test refusals are by drivers trying to avoid a positive test result for marijuana use – something that some drivers have been able to successfully achieve with urinalysis.
Marijuana is usually detectable in bodily fluids for up to 30 days after last use. As with other drugs, it may be detectable in hair for several months (see more on hair follicle testing below). The detection time depends on how much the user smokes or ingests, as well as how often.
The testing methods below seem to belie impairment. An impairment test must be developed that measures the number of legal and medical marijuana users are in the truck driver population. These tests for metabolites, which do nothing to determine impairment, may accomplish little more than triggering a barrage of carrier discrimination lawsuits filed by persons who stopped using long ago or have medical cards.
As the following bullets indicate, higher doses and more frequent use are associated with longer detection times.
Urine Testing
- Occasional users (up to three times a week): 3 days
- Moderate users (four times a week): 5-7 days
- Chronic users (daily): 10-15 days
- Chronic heavy users (multiple times a day): more than 30 days
Blood Testing
- Detectible in blood for 1 to 2 days
Saliva Testing
- Occasional users: 1 to 3 days
- Chronic users: 1 to 29 days
A Case for Hair Testing.
In contrast to the above testing methods, hair follicle tests can reveal drug use for up to 90 days.
Unlike urinalysis, it’s virtually possible to cheat a hair follicle drug test, which also provides a much more thorough look at a driver’s drug use over the previous 90 days. This enables employers to look for patterns of drug abuse that aren’t available through a urine test alone.
While not yet an approved DOT testing method, hair follicle drug testing is used by a few large carriers that want to ensure that, prior to putting them behind the wheel, new drivers don’t have a history of drug use.
Factors Affecting Marijuana Retention
Several factors affect how long marijuana stays in a person’s system. Some of these factors, such as age, gender, and body mass index (BMI), aren’t related to the drug itself, but to how the user’s body processes and metabolizes the drug.
Other factors are related to marijuana and how you use it. As the testing methods described above indicates, factors include how much the person uses at a time and how often. Higher doses and more frequent use tend to increase the amount of time it takes to eliminate marijuana from the system.
More potent marijuana, or extracts, which are higher in THC, may also stay in the system longer. Similarly, ingested marijuana may also remain in the system slightly longer than marijuana that is smoked.
Is there anything to do to metabolize it faster?
There is little that a user can do to shorten the time required for marijuana to leave their system. The body needs time to break it down; exercising, eating healthy, and staying hydrated might help, but not drastically.
Several detox remedies and kits are available on the internet. Many require drinking a lot of water to dilute urine, and then using herbal supplements such as creatinine or vitamin B-12 to mask the dilution. Generally, those kits are not considered to be very reliable.
How long does it take to feel the effects?
Marijuana’s effects appear quickly, usually within 15 to 30 minutes after smoking. After ingestion, it can take one or two hours to feel the effects. Marijuana’s active ingredients produce a short-term “high,” with common effects that include:
- sense of well-being/sense of relaxation
- feeling that time is slowing down
- giggling or chattiness
- altered sensory perception Other short-term effects include:
- inability to focus
- increased appetite
- coordination problems
- sleepiness
- restlessness
- rapid heart rate
- dry mouth and eyes
- confusion
- feeling sick or faint
- anxiety or paranoia
How long does it take for the effects to wear off?
Marijuana’s short-term effects start to taper off after one to three hours. Some effects, like memory problems or sleeplessness, can last a few days. There is no consensus among researchers as to how long the effects of chronic use last, with estimates ranging from a few days to months after marijuana use has ended.
Reliable Testing
As legal marijuana use spreads, detecting driver impairment takes on growing importance and new challenges for companies engaged in commercial transportation.
If your company is focusing heightened attention on drug testing, you would be wise to gain a greater understanding of marijuana detection times and the effectiveness of testing methods available to you.
