Marijuana in the Workplace

This information was prepared by the National Cannabis Prevention and Information Centre in Australia, and used with permission.  Some information may not be accurate for U.S. readers.

Up to a quarter of all occupational injuries and 20% of fatal injuries in the workplace can be linked to alcohol and other drug use. This has prompted many organisations and companies to implement workplace drug and alcohol education and testing across Australia in a bid to create safer working environments.

According to a 2008 NCETA report, based on a 2004 data set, 13.5% of the workforce had used marijuana. A greater proportion of tradespeople used marijuana than any other occupation. This survey also indicated that 2.5% of the Australian workforce reported going to work under the influence of illicit drugs.

Marijuana affects every user differently and can depend on:

• The person – their mood, personality, size and weight;
• The amount taken and whether it is mixed with anything else;
• The environment where the drug is used.

If marijuana is used in the workplace it can affect the health and safety of the person taking it as well as those around them. It may also have an adverse effect on productivity.

It is also important to remember that marijuana is an illegal drug, which may carry a fine or criminal conviction.

How does marijuana affect work performance?

Marijuana use is known to cause the following:

• Short-term memory problems;
• Impaired thinking;
• Loss of balance and coordination;
• Decreased concentration;
• Changes in sensory perception;
• Impaired ability to perform complex tasks;
• Decreased alertness;
• Decreased reaction time.

The effects of marijuana can last from two to six hours.

These side effects make it dangerous to use marijuana at work, particularly if a person is operating heavy machinery or driving a vehicle. There is also a greater risk of an accident occurring due to the poor performance of even simple manual tasks.

Regular marijuana users may start to exhibit signs of loss of energy and interest in their tasks, causing their performance to suffer. They may also find it difficult to learn new work skills.

What about Workers’ Compensation?

If a disability is incurred as a result of marijuana use this may not be compensated under workers’ compensation rules.

Can marijuana be found in random drug-testing?

While there is much community debate about workplace drug-testing, certain organisations or companies have introduced such initiatives in an attempt to ensure workplace safety and improve worker productivity. Workplace drug-testing can identify a marijuana user.

Once taken, marijuana is stored in the fatty tissues until it is slowly released back into the bloodstream and excreted from the body. Traces of marijuana can be found in urine for 1-5 days after occasional use and up to six weeks (or more) in people who use marijuana regularly (more than three times a week over a number of years). Marijuana can therefore be easily identified by drug testing procedures for a much longer time period compared to most other drugs.

In summary

For the following performance, legal and occupational health and safety reasons, the use of marijuana is not acceptable in the workplace:

• Marijuana is an illegal drug, which may carry a fine or criminal conviction.
• Work performance may be affected.
• The safety of the user and others may be affected.
• Accidents resulting in disability may not be compensated under Workers’ Compensation.

Factsheet information taken with permission from the NCPIC web site.
Coming soon: updates to this page with U.S. data and information.