In oil & gas facilities, egress lighting must do two things at once: meet emergency performance requirements and avoid becoming an ignition source. This guide shows facility managers and electrical contractors how to specify and deploy explosion‑proof emergency lights, hazardous‑location exit signs, and combo units across refineries, terminals, platforms, and compressor stations—using plain English and field‑ready checklists.
Last updated: October 2025
Where Oil & Gas Differs (Risk & Use Areas)
- Atmospheres: Flammable gases/vapors (e.g., methane, H2S) → typically Class I Div 1/2 areas; some dust handling can introduce Class II pockets.
- Locations: Process units, loading racks, tank farms, compressor buildings, blending/metering skids, offshore modules, and jetties.
- Conditions: Corrosive salt spray, washdown, UV exposure, wide temperature swings, and persistent vibration from rotating equipment.
Codes, Listings & Nameplates (UL 844 / UL 924)
- UL 844 (hazardous‑location): Nameplate must show Class/Division/Group and T‑code (or max surface °C) that match your classified area and ambient (Ta).
- UL 924 (egress): For emergency lights/EXIT signs—automatic transfer and ~90‑minute runtime; maintain EXIT legibility and 90‑minute photometrics.
- NEC 500–516: Follow classification and wiring rules; use listed sealing fittings/compounds in classified runs; preserve flame‑path joints.
- NFPA 101/OSHA: Egress visibility and testing/logs apply in hazardous areas just like ordinary spaces.
Code context: Hazardous‑Location Code Checklist
Fixture Types (Lights • Exit Signs • Combos)
- Hazardous‑Location Emergency Lights: Dual LED heads for egress; select Class I Div 1 or Div 2 models per zone and ambient.
- Hazardous‑Location Exit Signs: LED EXIT legends in sealed housings; verify letter height and sightlines across piping racks and skids.
- Combos (Exit + Lights): One enclosure at doors/junctions; add separate hazardous‑location lights for large bays or obstructed paths.
Environmental Hardening (NEMA/IP, Corrosion, Temperature, Vibration)
- NEMA/IP: Use NEMA 4X / IP66 for washdown, rain, or salt spray—in addition to UL 844.
- Materials/finish: Copper‑free aluminum or FRP enclosures; marine‑grade powder coat/epoxy; 316 stainless hardware; sealed optics & gaskets.
- Ambient limits: Confirm the listed T‑code at your Ta; consider battery heaters for cold exposure and thermal shields in hot modules.
- Vibration: Use locking hardware; re‑torque cover bolts per OEM; plan inspection intervals on compressor skids.
Compare terms: Explosion‑Proof vs Wet‑Location vs Outdoor
Quick Reference: Class I Gas Groups & Examples
| Group | Common in O&G | Egress Notes |
|---|---|---|
| IIA | Propane/propane mix, n‑butane, gasoline vapors | Verify adequate T‑code margin vs auto‑ignition; standard for many transfer areas. |
| IIB | Ethylene, ethyl ether | More stringent than IIA; maintain gasket/flame‑path integrity to hold rating. |
| IIC | Hydrogen, acetylene | Most stringent; expect heavier housings and lower surface temperature limits. |
Temperature ratings: T‑Codes for Explosion‑Proof Fixtures
Placement & Photometric Tips by Area
- Process units: Use combos over exits; add lights to clear tanks, racks, and ladders; check shadows under overhead piping and cable trays.
- Loading racks/tank farms: Mount for long throws across platforms; add fills near stair towers, valves, and hose bays; verify coverage for the full 90 minutes.
- Compressor buildings: Control vibration with secure mounting and lock‑washers; keep heads clear of acoustic enclosures; re‑aim after maintenance.
- Offshore modules: Prioritize corrosion resistance and gasket integrity; verify legend sightlines in tight corridors and around blast‑walls.
Install how‑to: Installing Explosion‑Proof Lighting
Installation Notes (Seals, Hubs, Vibration)
- Sealing fittings: Use listed explosion‑proof seals/compounds at required distances; no ordinary hubs in classified conduit.
- Flame‑paths: Keep mating surfaces pristine; torque cover bolts to spec; re‑torque after vibratory exposure; document with photos for the AHJ.
- Labeling & circuits: Identify emergency circuits; separate where required; include nameplate photos (Class/Div/Group, T‑code, Ta) in the packet.
Testing, Logs & AHJ Packet
- Monthly: 30‑second functional test; visual for gaskets, corrosion, seals, and lens cleanliness.
- Annual: Full 90‑minute discharge; confirm floor illumination throughout; re‑aim heads as needed.
- Records: Maintain test logs, cut sheets (UL 844/UL 924), as‑builts, and nameplate photos for AHJ review.
Documentation & inspections: What Inspectors Check
Common Pitfalls in O&G Sites
- Specifying NEMA/IP‑only devices without a UL 844 hazardous‑location listing.
- Incorrect T‑code for the process stream or ambient; battery runtime drops in extreme heat/cold.
- Missing sealing fittings; contaminated/over‑torqued flame‑paths after service.
- Insufficient coverage around racks, stairs, and hose bays; heads not re‑aimed after process changes.
Printable Spec Checklist (Oil & Gas)
- Area classification map confirms Class/Division/Group and required T‑code (or °C limit)
- Fixtures labeled UL 844 (haz‑loc) and UL 924 (egress), as applicable
- NEMA 4X/IP66 specified where washdown, rain, or salt spray exist
- Sealing fittings installed/compounded per NEC; flame‑paths clean and torqued
- Photometrics verified at doors/stairs/turns for the full 90‑minute test
- Commissioning packet: cut sheets, nameplates, as‑builts, test logs ready for AHJ
This guide is informational and not a substitute for professional engineering judgment or the authority of your AHJ.