Primary audience: Specifying engineers
Start with the area's classification, not a product name
A specifying engineer needs the documented hazard before selecting lighting. “Explosion-proof,” “industrial” and “vapor tight” describe very different ideas; none substitutes for the classification of the installation location. The same building can contain areas with different hazards and different equipment requirements.
OSHA 1910.307 bases classification on the substances present and the likelihood of an ignitable concentration. It calls for individual consideration of each room, section or area. Begin with the facility's classification drawing and the responsible engineer's assessment.
Record the process, substances, operating conditions and boundary of the classified area. Include changes such as new storage, altered ventilation or a different cleaning material. A lighting replacement is a poor moment to discover that the drawing describes an earlier process.
If no current classification exists, make that the first design action. A lighting vendor cannot resolve it by selecting the heaviest housing or the highest ingress rating. Hold the equipment selection until the responsible professionals establish the requirements.
Keep class, division, zone and temperature separate
OSHA's definitions distinguish gas or vapor hazards, combustible dust, and ignitable fibers or flyings. Class I concerns gases or vapors; Class II concerns combustible dust; Class III concerns ignitable fibers or flyings. Division and zone designations describe additional conditions within their respective systems.
| Field | Question it resolves | Do not substitute |
|---|---|---|
| Class | What type of hazard is present? | A generic industrial application label |
| Division or zone | What classified conditions apply? | An assumed conversion between systems |
| Substance group | Which ignitable material must the equipment address? | The room's business function |
| Temperature classification | What surface-temperature limitation applies? | The fixture's ambient operating range |
| Ambient conditions | What surrounding temperatures will the equipment experience? | A temperature class alone |
For Class I, Division 1 includes ignitable gas or vapor concentrations during normal operation and certain other defined conditions. Division 2 addresses specified abnormal releases, ventilation failures or adjacent hazards. Gas Zone 0 covers continuous or long-duration presence; Zone 1 includes likely presence during normal operation. Zone 2 includes presence unlikely in normal operation and, if it occurs, lasting only briefly. These are orientation notes, not complete classification rules or a conversion between systems.
Copy the full required designation into the fixture schedule. Do not shorten it to “hazardous rated” during quoting. If two documents use different systems, ask the responsible engineer to reconcile them. Treat that as an engineering decision, not a purchasing abbreviation.
Do not confuse enclosure protection with hazard suitability
OSHA identifies several protection techniques, including explosionproof apparatus, dust ignitionproof construction and intrinsic safety. Each has an application scope. Equipment must address the specific location and substances; a generic enclosure description cannot establish that match.
For a submittal review, compare the required classification with the exact equipment marking and supporting instructions. Then examine the complete installation: entries, fittings, mounting and accessories. A suitable fixture does not make an undocumented attachment suitable.
Ingress protection and corrosion resistance answer additional environmental questions. They are useful inputs, but neither establishes protection against ignition. Likewise, a normal operating-temperature range does not establish the permitted surface temperature for the hazard.
Keep field changes visible. An installer should not improvise a hole, replace a fitting or add an accessory because the part physically fits. Ask for the permitted installation arrangement and route differences through the project designer. Include maintenance restrictions in the turnover package so a later repair does not silently change the reviewed assembly.
Read our published families with the evidence gap visible
Our catalogue separates the explosion-proof drop light, 100–200 W high bay and 30–80 W high bay. It also separates the wall-mount exit sign and pendant-mount exit sign.
The exact hazardous-location classifications, substance groups and temperature classes are not published in these family data. Their catalogue names do not establish suitability for your classified area. This guide does not infer those ratings or assert that the missing approval evidence exists.
Use the published pages to identify a candidate's physical format and the information that needs clarification. Do not release a candidate for a classified installation without matching evidence. A quotation or a general application list cannot replace that review.
Where a family lists variants by wattage rather than an orderable model code, request an unambiguous item identifier. The eventual approval record must identify what purchasing orders and what receiving checks. An incomplete identity can undermine the review even when other documents appear relevant.
Build the hazardous-location submittal checklist
Organize the package around the engineer's required designation, then show the proposed equipment evidence against it. Mark missing evidence as unresolved and retain the hold point in the purchase schedule.
- Current classification drawing with area boundaries, substances, class and division or zone, and responsible review identified.
- Required substance group, temperature classification and ambient limits, including abnormal conditions considered by the designer.
- Exact fixture identity and configuration, with the applicable equipment markings and approval documentation.
- Installation instructions covering entries, fittings, mounting, wiring and all proposed accessories.
- Maintenance instructions and a receiving check that connects delivered equipment to the approved configuration.
Add photographs of the intended mounting location and service access. These help expose conflicts between the documented assembly and the field installation without pretending a photograph establishes the hazard classification.
Record who closes each open item. “Awaiting documents” is incomplete unless the team knows which document, for which configuration, and who decides whether it satisfies the project requirement.
Related guides
- Vapor Tight Lighting: IP Ratings, Wet Areas and Cold Rooms
- Exit Signs and Emergency Lighting: Selection Checklist
- Lighting Spec Sheets and IES Files: Submittal Guide
Request configuration-matched design documents.
Browse all buyer guides or send your fixture schedule for a quote.
Follow NEC/local code and use a licensed electrician.