Marijuana Usage is a Workplace Safety Issue

Let’s clear the smoke on this issue – the expanding societal acceptance and legalization of marijuana usage (medical or recreational) poses a substantial workplace safety issue on construction job sites. Contractors should take immediate action to address this expanding risk.

Regardless of the strength of the arguments for or against medical marijuana usage for what are understandably difficult personal circumstances, none are more compelling than providing a safe construction worksite for employees and the public.
Construction workers must have full use of their skills and faculties while performing all aspects of their jobs. Medical marijuana may have positive medical benefits, but there are also well-documented negative effects. Some negative effects to the central nervous system include changes in sensory perception, altered thought formation and expression, short-term memory problems, and impaired thinking and learning. Negative physical effects include impaired motor performance, loss of balance and coordination, decreased attentiveness and alertness, prolonged response time to stimuli and danger, decreased ability to judge distance and space, and impaired ability to perform complex tasks.
These negative effects could be disastrous on a construction job site. The problem with determining whether an employee is potentially subject to these negative effects on a jobsite is there is currently no reliable metric for determining when a particular level of THC from marijuana usage impairs the user and for how long that user remains impaired. THC and other psychoactive components stay in the body much longer than alcohol. Studies regarding the duration of impairment show the duration of impairment from marijuana use may be longer than previously known and could be up to 24 to 48 hours. Chronic use of marijuana may have long-term brain effects that could impair construction workers even if they are not actively using on the jobsite. A positive drug test does not necessarily indicate a person is currently intoxicated or impaired.

Marijuana usage is broad-based, with no direct connection to age. In a recent survey, 31.6% of people 18-25 used marijuana in 2013. But, the largest growth among marijuana users is in the 55-64 age group with an increase of 455% from 2002 to 2014. Employers should not just be paying attention to this risk with their millennials. Older workers (with growing medical issues related to aging) are increasingly using medical marijuana.
Another problem arises from lagging technology. Use of marijuana and impairment is very often difficult to determine because there is no reliable test that conclusively determines when someone is “high” from marijuana. A positive drug test does not necessarily indicate that the person is currently intoxicated or impaired from the substance.
Marijuana remains illegal under federal law as a Schedule I Narcotic under the Controlled Substances Act of 1970 (CSA). Under the CSA, it is illegal to manufacture, sell, distribute, or possess marijuana and no physician may prescribe marijuana use. However, 30 states have passed laws legalizing the medical use of marijuana under their laws1. Nine states2 and the District of Columbia have also legalized recreational use. These lists seem to grow with every election, so contractors should continue to monitor developments.