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Cannabis abuse in the workplace

Cannabis is the world’s most used illicit drug, with cannabis use in Australia and New Zealand significantly higher than the global average.

Why should this high-ranking raise alarm bells for CEOs, HR, and safety officers? Because it suggests that some of your workers could be among the many Australians who are using cannabis at work.

In this article, we provide you with an overview of cannabis, its effects, the impact of cannabis in the workplace, and how to manage cannabis abuse at work.

What is cannabis?

Cannabis, or marijuana, is a depressant drug that slows down the activities of the central nervous system when consumed.

Illicit drug makers derive cannabis from Indian hemp plants. They’ve also given the drug different names to avoid detection by law enforcement. Some people refer to it as marijuana, ganja, grass, hashish, pot, dope, herb, weed, and reefer.

Cannabis is the most widely used illegal drug in Australia. According to the National Drug Household Survey in 2019, 36% of the Australian population have used cannabis at some point in their life.

Medicinal cannabis

Medicinal cannabis is a special form of cannabis meant to relieve the symptoms of conditions like epilepsy, fibromyalgia, and cancer.

In places where medical cannabis is legal, doctors prescribe it to sufferers of chronic pain or terminal illnesses who don’t respond well to pharmaceutical drugs. In other cases, they may also give them to patients who use conventional treatment but need relief from its debilitating side effects.

The main difference between medical cannabis and recreational cannabis is that the effects depend on the category of the medicine being used: Category 1 medication which contain only CBD will not make you high, but as you rise from Category 2 (low THC content) to Category 5 (nearly pure THC preparation) the level of impairment will increase.

To learn more about medicinal cannabis, watch our Medicinal Cannabis in the Workplace webinar held 9 August 2023.

Taking a closer look at cannabis

Cannabis contains an active ingredient known as delta-9 tetrahydrocannabinol or THC. This is the part of the plant that provides users with the “high” they’re looking for. 

There are several ways that people can use marijuana.

The most common way is to smoke it in hand-rolled cigarettes popularly referred to as joints. Some smoke them in pipes or even water pipes called bongs. Other people use marijuana by stuffing the drug in emptied cigars. This results in the cannabis product popularly known as ‘blunts’.

There are also marijuana users who like to take the drug as a beverage. They brew the cannabis leaves just like traditional tea leaves. Meanwhile, other users mix it with food such as brownies, cookies, or candy.

Effects of cannabis on the body

Depending on the dose, method of consumption, and combination with other drugs, cannabis can bring varied effects to the body.

Short-term effects of cannabis include:

  • Altered state of consciousness, where the user can feel very happy, relaxed, and euphoric
  • Distorted perceptions of time and space
  • Increased appetite, dilated pupils, bloodshot eyes, and increased pulse and heart rate
  • Impaired concentration and body coordination, making activities such as driving a car or operating machinery very challenging and dangerous.

Long-term effects of cannabis include:

  • Increased risk of respiratory diseases, including sore throat, asthma, and bronchitis, greater than the risk associated with the use of tobacco alone
  • Decreased brain function and learning abilities
  • Decreased motivation in areas such as work, concentration, and everyday activities
  • Lowered sex drive, and irregular menstrual cycle for females
  • Hallucinations when the drug is taken in high doses and, among vulnerable individuals, some risk of paranoia and toxic psychosis.

Duration of cannabis impairment 

Impairment from recreational marijuana use is most marked for at least the first 5 to 7 hours after use (it can be longer with higher doses) but is still present up to 12 hours after use.

Synthetic cannabis

Using traditional cannabis already carries certain health risks. However, there is an even more dangerous variant of the drug that’s gained popularity in recent years. Many people refer to it as synthetic cannabis, synthetic marijuana or SynCan. 

Illicit drug makers combine dried plant material with chopped-up herbs to produce the designer drug. They then add the synthetic chemical compound by spraying it on the mixture.

On a per-weight basis, synthetic cannabis is between 60 to 800 times more potent than natural cannabis and can induce serious, body-wide effects like a rapid heart rate (120-150 beats a minute) and a sharp rise in blood pressure which may occasionally require hospitalisation. 

While it is impossible to physically poison yourself with a cannabis overdose, several deaths have occurred in Australia due to toxic doses of synthetic cannabis. 

Cannabis isn’t addictive but synthetic cannabis is, and withdrawal from this drug is associated with marked insomnia, paranoia, and panic attacks. Cannabis, by itself, rarely induces psychosis, except among the ~ 1% of the population with an underlying predisposition to schizophrenia. By contrast, synthetic cannabis can easily induce psychosis, often associated with suicidal thinking. 

What makes synthetic cannabis even more dangerous is that no one really knows what chemicals it contains. 

Synthetic cannabis is often sold under different names including spice, kronic, k2, blueberry haze, and blaze.

The impact of cannabis at work

Marijuana appears in urine and blood 3 – 5 times more frequently in fatal driving & workplace accidents than in the general population (Substance Abuse and Mental Health Services Administration, 1999).

Marijuana abuse can have a significant impact on the workplace.

An employee who uses marijuana at work is likely to suffer from short-term memory problems, impaired thinking, and an impaired ability to perform more complex tasks. 

Using marijuana at work can lead to loss of balance and coordination, decreased concentration, alertness, and reaction time, all of which can be highly dangerous if the impaired worker is tasked with operating heavy equipment or driving vehicles for the company. 

There could also be financial and legal ramifications for the business.

Signs of cannabis abuse 

Signs that can help determine if a worker is under the influence of the drug include the dilation of the blood vessels in the eyes, increased heart rate, memory impairment, and difficulty in paying attention to one’s surroundings.

What to do about marijuana abuse at work

The first step to protect your business from cannabis is to develop a drug and alcohol policy and procedure. This provides a solid foundation from which to combat the problem.

For the policy to be effective, it must contain provisions for drug and alcohol awareness and education programmes as well as drug and alcohol testing regimens.

Testing for cannabis 

Testing for cannabis in the workplace is one of the best ways to keep your employees safe, healthy, and productive. 

The most common cannabis testing methods are:

  • Urine drug testing – This is the most common method used by employers. A cannabis urine test provides a window of detection that usually ranges from two to 30 days. However, certain factors like method and frequency of use, THC content, diet and body type can affect how long marijuana remains detectable in the body. Urine cannabis tests show that a worker is using marijuana, but don’t correlate well with impairment at the time of testing. 
  • Hair follicle drug testing – Compared to a urine test, a hair test for cannabis use has a longer window of detection. It can detect cannabis use for the past two to three months, and sometimes even longer. This longer window of detection makes it popular for use in pre-employment cannabis testing.
  • Oral fluid drug testing – This is the least common method for cannabis testing. Less invasive than a urine or hair test, oral fluid testing or saliva testing has an approximate window of detection for cannabis of 12 to 36 hours and gives a reasonable match with the period of impairment associated with cannabis use.

Learn more

Safework Health can help you keep your workplace safe from drugs and alcohol.

Contact us today for a confidential discussion.


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