Marijuana for medical uses can still impair

An incident last week where a worker in Michigan was fired for testing positive for use of medical marijuana has focused attention on a ballot initiative that may appear on Arizona's ballot this fall.

The worker in Michigan had been legally prescribed marijuana as part of treatment of pain from sinus cancer and a brain tumor. The fact that it was a medical issue did not stop Wal-Mart Inc., from firing him, however, under its anti-drug policy, which does not differentiate between whether marijuana is used for medical purposes or not.

Supporters of the Arizona medical marijuana initiation say that probably could not happen here if the proposal is approved by voters because there are specific provisions in it to prevent medical users from being fired.

Although it is possible that companies with anti-drug policies might be able to fire a marijuana user that was too impaired to work, observers say it would be difficult and costly to prove in court because tests only reveal whether the drug was used in the past 30 days, not necessarily currently.

The presents a real dilemma for employers. The rules many of them have against drug use are not based just on the fact they are illegal, but also on the need to ensure they have a safe workplace. Workers who are impaired due to substance abuse can be a danger not only to themselves but to their fellow workers and even to the public.

This is especially true where equipment is used or where employees must drive. If something were to happen, the employer could be held liable for the harm that resulted if they knew a worker was potentially impaired and did nothing about it.

Even if the marijuana is for medical purposes, it could impair the worker. Employers need to have some way to deal with this potential problem so they can maintain safe workplaces if the use of medical marijuana is allowed.