When we talk about the safety risks posed by drug use in the workplace, we’re usually talking about illegal drugs, such as marijuana, cocaine, and heroin. But workers may be on perfectly legal drugs, such as over-the-counter (OTC) allergy or pain medicine while working. And these OTC drugs can pose safety risks, too.

But many workplaces don’t seem very worried about legal drug use. In fact, when we recently asked if you have rules on the use of OTC drugs in the workplace:

• Only 44% said yes
• 38% said no
• Another 13% said no, but they should have such rules
• 13% weren’t sure.

Why should safety professionals be concerned about the use of OTC drugs by workers’ Because many of these drugs come with safety warnings, such as don’t operate heavy machinery while on this medication. So it’s a bad idea for a worker on this drug to be, say, operating a crane or forklift.

If you think we’re being alarmist, consider a fatal train crash in NY.

On Dec. 1, 2013, a Metro North train derailed, killing four people and injuring 59 others. The National Transportation Safety Board investigated and conducted toxicology tests on the train’s engineer.

Tests revealed that the engineer had taken an OTC cold/allergy medicine containing the ‘sedating antihistamine’ chlorpheniramine. The medicine carried a warning that chlorpheniramine ‘may impair mental and/or physical ability required for the performance of potentially hazardous tasks (e.g., driving, operating heavy machinery).’

And the engineer had, in fact, reported feeling drowsy and being ‘hypnotized’ by the tracks.

So how should employers address OTC’and prescription’drug use by workers’

Make workers aware that certain legal drugs can impact their ability to safely perform their jobs. Advise them to ask their healthcare providers about the side effects of any such drugs and any possible ‘safer’ alternatives. You should also ask workers to let their supervisor know if they’re on cold, allergy or similar medication that could affect their job performance.