Article
At home, most hazardous or harsh conditions we face would be weather 
related. Rain and snow and sleet might be the worst, although 
temperature can be a factor as well.<br><br>However, in the industrial environment, hazards go way beyond that.

Lighting Considerations in Harsh Environments

Steve Maurer, IME
At home, most hazardous or harsh conditions we face would be weather related. Rain and snow and sleet might be the worst, although temperature can be a factor as well.

However, in the industrial environment, hazards go way beyond that.

Sure, you still have moisture to contend with. And in many places, temperature extremes must also be considered.

For example, I've worked in freezers where the temperature fell way below zero degrees. And I've labored in environments where the ambient temperature soared well above what I felt comfortable with.

From freezers to blast furnaces—and everything in between—temperature is just one condition to be factored in when specifying lighting and luminaires.

Of course, along with the temperature of the workplace, you must consider other factors as well. For instance (and contrary to what some would say), water and electricity do mix … often with explosive results.

So you must keep these two separated, just like children fighting over a favorite toy. The cannot … they must not … occupy the same space at the same time. This separation is, of course, made possible by watertight enclosures that keep them isolated from each other.

Proper sealing using gaskets and other methods keep the water demons at bay.

When chemicals are introduced into the working atmosphere, you're faced with an entirely different set of circumstances to cope with. Many are either explosive or flammable and must be separated from any potential source of ignition.

That means that the enclosure must be designed with intrinsically safe properties, and constructed of materials that prevent ignition should a lamp fail and/or explode.

This can be accomplished by proper gasketing and the use of materials and designs that fully enclose the lamp and internal components. When choosing a fixture, be sure to keep the NEC and CEC ratings in mind.

For example, the old "mason jar" configuration isn't suitable for NEC or CEC Class I, Division 2/Zone 2; Class II, Division 1 and 2, or Class III areas. When purchasing lighting for these areas, make sure they meet the stringent requirements.

One last consideration: heat dissipation.

Even with LEDs (which are not light bulbs, per se, but light emitting diodes), the generation of light also generates heat. Whether the heat is spawned by a filament, gas ignition, or ballast/driver operation, it must be dissipated to ensure both luminaire longevity and safe lighting in a hazardous atmosphere.

The method of heat dissipation varies according to the fixture design and the intended use.

When choosing the proper lighting for any harsh or hazardous environment, make sure you take all the variables into account. Once done, you can choose the correct luminaires that will give you safe, efficient, and adequate lighting.
Photo courtesy of Emerson
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