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In a previous post, we talked all about distinguishing between different types of what's often referred to as hazardous location lighting. This included lighting applications such as high abuse, clean room, vandal-resistant, etc.

When lighting is in one of these hazardous locations, technically an area at risk of fire or explosion, the U.S. National Electric Code standards classifying risk levels must be applied so the lighting holds up.

Industry factory lit at night

Below, we'll break down the classifications for you.

First, the standards are separated into three classifications based on the environment the lights will be used in (the types of hazardous conditions):

  • Class I: gases and vapors that are flammable are present in high enough levels to cause ignition
    • Examples: gas station, paint shop, chemical plant, alcohol production facility
  • Class II: combustible dusts are present in high enough levels to cause ignition
    • Examples: candy factory, coal mine, pharmaceutical manufacturing facility
  • Class III: ignitable fibers are present in high enough levels to cause ignition
    • Examples: cotton gins, leather goods work areas (think shoes and handbags)

Next, each of these three classifications is subdivided based on the level of hazardous material present in the area.

  • Division I: ignitable components are present during normal operations, or are easily released if equipment malfunctions or gets cleaned, etc.
  • Division II: ignitable components are present but controlled (perhaps a ventilation system, for instance)

The Occupational Safety and Health Administration (OSHA) further requires that lighting for each classification and division is once again put into one group from A-G. Groups A-G are defined based on all of the characteristics of the hazardous materials present.

  • Class I groups are gases (described above) and are placed in A-D with A gases being the most dangerous (most likely to explode, for example) and D being the least dangerous (think propane)
  • Class II groups are dusts (described above) and are placed in E-G with E containing more dangerous/conductive ingredients, and so on

Based on all of these different classifications, your hazardous location has a minimum requirement for the safety level of its lighting according to OSHA. You may need a Class I, Div I light, for example. There are many permutations.

OSHA provides this example on their website to illustrate all of this at work:

"Let's illustrate our Code "translation" with an example. How would we classify a storage area where LP gas is contained in dosed tanks? LP gas is a Class I substance (gas or vapor). It's Division 2 because it would only be in the atmosphere if an accidental rupture or leakage occurred, and it is Group D material."

Selecting lighting that meets your unique hazardous location's standards could literally save lives, and it's the law! It can also be overwhelming and expensive. If you need help classifying your location, value engineering a lighting package you got that just seems too expensive, retrofitting your current space with LED hazardous location lighting instead of older lighting technologies... Stouch Lighting is here for you.