Cannabis/Marijuana in the Workplace: What Employers Should Know

James Gunter

Cannabis/Marijuana in the Workplace: What Employers Should Know


As Drug Testing Kits UK, is only to aware, the popular use of cannabis/marijuana is creating a very serious situation for all industries, companies, and organisations. This means that employers have to consider various scenarios. These include:


  • How is the illegal use of cannabis/marijuana impacting safety in the workplace?
  • How is the use of this illegal drug affecting the company's bottom line?
  • What sort of issues could the company/organisation face, if there was a serious accident caused by an employee under the influence of cannabis/marijuana?
  • Do we have a strong drug testing policy which incorporates both regular and unexpected drug tests for all employees? If your answer is no, then we invite you to contact our highly experienced, professional Customer Service Team at Drug Testing Kits UK.


The Drugs Testing Kits UK friendly team will be able to advise you on the best types of the latest cutting-edge, highly accurate rapid drug tests, that would be most suitable for your company/organisation. All Drug Testing Kits UK, are fully approved for the UK and Southern Ireland. They test for multiple drugs (including cannabis/marijuana), and over-used prescription drugs. Moreover, they are so user-friendly, that any appointed member of staff can administer them. - There is no need to pay a fortune for a medic to come to your workplace. And another big plus, is that the tests only take a matter of minutes to carry out, so there is minimal work disruption.


How Does the Use of Cannabis/Marijuana Affect Job Safety?


THC (the main psychoactive component in cannabis/marijuana responsible for the high sensation), "affects the user's depth perception, reaction time, coordination, & other motor skills, as well as sensory distortion. Cannabis/marijuana, like alcohol & prescription opioids, can impact judgment, reflexes & cognitive dexterity, thus increasing the risk of injury both behind the wheel and in the workplace" [1, 2]


For someone operating machinery, driving a forklift, or delivering products in a vehicle, these effects can be deadly. Moreover, the effects of cannabis/marijuana can vary greatly & may happen quickly or slowly, depending on how it was consumed & an individual’s body composition. It is difficult to determine how long impairment will last because THC, is stored in body fat, unlike alcohol, which is stored in the blood." [1, 2]


"According to a study reported by the National Institute on Drug Abuse, employees who tested positive for cannabis/marijuana had 55% more industrial accidents, 85% more injuries & 75% greater absenteeism compared to those who tested negative" [1]


In addition to the aforementioned, cannabis/marijuana impacts a company's or organisation's bottom line by decreasing productivity, increasing unemployment compensation and worker compensation claims; and generating legal claims for compensation, which can run into the hundreds of thousands of pounds. The latter of which can ultimately cause bankruptcy, or destroy a company's/organisation's reputation.


Safety-Sensitive Industries


When it comes to creating zero-tolerance policies for illegal drug use, safety-sensitive industry employers are more likely to dedicate the time and effort required to initiate them. However, this means that employers of non-safety-sensitive industries are not always aware of the potential risks and serious consequences of not carrying out regular and unexpected drug tests.


Cannabis/Marijuana (which is an easily grown, naturally occurring plant), is the most frequently used illegal drug of abuse in the UK, & the drug most frequently detected in workplace drug testing. According to Statista: "In 2019/20, 29.6% of people in England & Wales aged between 16 & 59, had used cannabis at least once during their lifetime, compared with 23.6% in 2001/02 [3]


Instituting a Solid Workplace Drug Policy


Keeping the workplace drug-free is absolutely essential for all employers who care about their business/organisation, and reputation.


"Studies show drug testing works; employees are three times less likely to produce a positive test result if they know they will be tested. Moreover, an expanded testing panel that also includes the most commonly misused prescription drugs, may better protect your workforce" [1]

Elements Which Make a Robust Drug Policy


These comprise:


  • Appropriate training to empower managers to enforce the company's/organisation's drug policy
  • Available support for members of staff with drug issues. This can range from referrals to local organisations, to a formal assistance program
  • Regulations to conduct post-accident drug testing
  • Rules on the ways in which the company/organisation will deal with a member of staff's arrest or conviction [1]


As Drugs Testing Kits UK. regularly advises: in order to avoid legal cases brought about by employees, members of the public, and the criminal prosecution service, the company's/organisation's drug policy must be extremely specific, and backed-up by workplace procedures. The latter should be reviewed by a specialist solicitor in the field, in order to make sure that they comply with the current UK/Southern Ireland laws. Moreover, the drug policy should be subject to frequent updates, thereby keeping up-to-date with changing behaviours and laws. Indeed, health and safety in your company's/organisation's workplace (and in some instances outside the workplace) depends on it.


Response Training & Impairment Recognition for Supervisors/Managers


"Cannabis/Marijuana can have a major impact on safety at work, & this creates serious challenges for employers" [2]


One research survey showed that:


  • More than 50% of employers who stopped THC (the primary psychoactive component in testing for cannabis/marijuana), documented a rise in concerns about employee performance, or incidents in the workplace
    The majority of employers thought that most members of staff would tell their supervisor/manager, if they were too impaired to do their job; while under 50% of staff stated that they would be comfortable doing so
    Under 50% of organisations have a written cannabis/marijuana policy [2]


Recommendations For Employers


As the use of cannabis/marijuana flourishes, and is always in great supply across the UK and Southern Ireland, employers have legal duty to ensure safety in the workplace. In order to empower employers to address the risks of cannabis/marijuana in the workplace, leaders of companies and organisations should (in addition to other points already discussed earlier in this article): "build a safety-focused, trusting culture for employees to report cannabis/marijuana use; train

supervisors to recognise and respond to impairment in the workplace; and educate company drivers about cannabis impairment" [2].


Drug-Impaired Driving


"Driving while using cannabis is dangerous. According to the National Institutes of Health, cannabis significantly impairs judgement, motor coordination & reaction time, & studies have found a direct relationship between blood THC concentration & impaired driving ability,

And while multiple substances can increase driving risks, cannabis/marijuana alone can also create dangerous driving conditions." [2]


The National Health Service's Overview


"According to the NHS, Cannabis can make some existing mental health symptoms worse, & has been linked with the possible development of mental health issues.

The risk factors include an underlying vulnerability to mental health issues such as family history, heavy cannabis use from a young age over a long period of time, or use of high potency cannabis" [4]


When it comes to employees' dependency and long-term use of cannabis (marijuana); if they use it on a daily basis over an extended period of time, they might acquire a tolerance towards its impact. To that end, such employees will have to consume even more, in order to attain the desired effects that they have been accustomed to. However, when such employees cannot afford to purchase a higher quantity of cannabis/marijuana, they are likely to display certain symptoms, due to its reduced effect [4]. A few of the symptoms to spot, comprise:


  • Having trouble concentrating on their work task/s
  • Displaying a low mood
  • Being irritable
  • Exhibiting cravings [4]


Being Aware of Employees Selling Cannabis/Marijuana to Others


"In the UK: selling cannabis/marijuana to others can result in serious consequences. Moreover, the law doesn’t distinguish between dealing cannabis & sharing or giving it to fellow employees/friends, it all can be counted as supplying the drug" [5]


Employees Who Take Cannabis/Marijuana During Their Lunch Break


While it goes without saying that when someone smokes this drug, it can easily be smelt on the breath, employees can be very good at covering this odour up, by using a strong peppermint mouth spray, etc. And this is why it is important for senior members of staff, such as supervisors and managers, to be mindful of the symptoms of being under the influence of cannabis (marijuana).


Moreover, this is also why it is crucial to have unannounced, random drug tests, and to incorporate the right to administer them, in work contracts. Furthermore, if an employee is reported, or seen to be under the influence of cannabis/marijuana, the member/s of staff concerned should be given an immediate drug test, using a top-of-the-range, legally approved, drug testing kit, such as one supplied to countless companies and organisations across the UK and Southern Ireland, by Drug Testing Kits UK.





[1]. National Safety Council (2022). "Marijuana at Work: What Employers Need to Know.",Decreased%20productivity


[2]. National Safety Council (2022).  "Cannabis and Safety: It's Complicated."



[3]. Statista (2022). "Proportion of 16 to 59 year old's in England and Wales reporting use of cannabis ever in their lifetime from 2001/02 to 2019/20."



[4]. NHS Inform (2022). "Cannabis."


[5]. Drug Science (2022). "Cannabis."