Classifications
Class 1 Division 1 LED Lighting
Rated for Continuous Flammable Gas & Vapor Exposure
Filters
What Class 1 Division 1 Means
Fixtures rated Class 1 Div 1 are designed to contain any internal ignition source, preventing it from reaching a hazardous atmosphere that's expected to be present regularly — not just during an equipment malfunction. This is the most stringent classification within Class I, reflecting that the hazardous condition is essentially a normal, ongoing feature of the space rather than an occasional risk.
Fixtures must also be matched to the specific gas group (A, B, C, or D) present at the site, since different gases have different ignition characteristics and require different flame-path tolerances within the fixture housing.
Division 1 vs. Division 2
The division number reflects how often the hazard is present:
- Division 1 applies where a hazardous atmosphere exists continuously, intermittently, or periodically under normal operating conditions.
- Division 2 applies where the hazardous atmosphere is normally contained and only present under abnormal conditions, such as a leak or equipment failure.
This distinction directly affects fixture design requirements — Division 1 fixtures require more robust ignition containment since the hazard is treated as a routine condition rather than an exception.
Where Class 1 Division 1 Is Needed
- LNG and natural gas processing — continuous exposure to flammable vapors during normal operation
- Petrochemical refining and storage — areas where volatile compounds are routinely present
- Areas with continuous flammable vapor presence — process zones where containment isn't the norm
Specifying the Right Fixture
Beyond confirming Division 1, specifiers need to identify the gas group (A–D) present at the site and the appropriate temperature (T) code based on the autoignition point of that substance. A facility hazard assessment, typically conducted by a qualified engineer, determines these specifics for each area of a site.