Article
Recently, I was in a processing plant where they were upgrading the alarm system. This was a major overhaul that included more than just a fire alarm array. In fact, they were installing systems for fire, weather, and chemical emergencies. Letting employees and other people know about impending danger is vitally important in today's work environment. You need to give them adequate warning to get to a safe place of refuge.

Hazard Communication Lighting and More

Steve Maurer, IME
Recently, I was in a processing plant where they were upgrading the alarm system. This was a major overhaul that included more than just a fire alarm array. In fact, they were installing systems for fire, weather, and chemical emergencies.

Letting employees and other people know about impending danger is vitally important in today's work environment. You need to give them adequate warning to get to a safe place of refuge.

While audible warnings are often used, the most prevalent are visual signals in the form of colored warning lights.

In the case listed above, both were used—a common practice for industry. Hearing a warning sound is sometimes difficult when noisy machinery is present. Often the noise is perceptible, however, drawing attention to the visual indicators.

This particular system used three different colors for flashing, visual indicators: blue, yellow, and white. Each signified a different hazard event. The employees were trained on the meaning of each color so that they recognized the hazard immediately.

The annunciator caused them to look at the beacons … and the color of the light told them what to do. That's important as two of the warnings signified that they should leave the building (fire and chemical release) and congregate at designated zoned evacuation stations.

The other (weather) let them know to take shelter inside the building at specified safe locations.

Hazard Warnings of All Kinds
Fire, weather, and other emergency conditions aren't the only types of hazards. In a manufacturing plant, warning lights inform workers of machine state as well. That may vary for each equipment manufacturer, but warning lights can let a team member know if a machine is in operation, stopped, or malfunctioning.

Of course, you've probably looked up into the night sky and seen the flashing beacons on tall buildings and communications towers, warning low flying aircraft of their location. Approach and boundary luminaires are used on airport runways to direct planes during takeoff and landing.

I've even seen warning lights to remind people to be careful when ascending and descending stairs. A word of caution, though. Certain flashing sequences can cause seizures when a person with epilepsy is exposed to them. I've seen the warnings on installation manuals myself. Make sure that the warning light you use doesn't create additional hazards as well.

Other Considerations
It should be obvious, but make sure the warning light enclosure and installation is matched to the location. For example, in the instance I mentioned at the top of the article, the warning lights installed out in the processing area were designed for the damp and wet atmospheres. However, the lights installed in office areas didn't need to be quite as robust.

And when warning lights are installed in potentially flammable or explosive atmosphere, make sure the fixture is rated for the hazard classification.

Finally, you'll see an increasing use of LEDs in hazard or warning lights. You also see them used a lot for emergency lighting. I like LEDs in these situations as they drain less power from battery backups when in use.

The most common standard is that an emergency evacuation light or exit light must stay light for 90 minutes. I've seen LED exit and emergency lights burn for hours longer than that, lasting way beyond the required time.

In any case, I'd recommend talking with a lighting professional when specifying lighting and fixtures for your warning needs. They will know the right light to use for your application.
Photo courtesy of Emerson
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