ProTip: When dealing with hazardous locations, always verify the unit’s hazard classification rating. Class I Div 2 covers most volatile vapor conditions.
Highlight: Explosion-proof combo signs serve two life-safety functions in one — marking exits and providing emergency lighting, all within a rugged enclosure.
Learn more about compliance requirements in our UL 924 Compliance Guide or explore Hazardous Location Exit Sign / Light Combos.
What Are Explosion-Proof Combo Units?
Explosion-proof exit & emergency light combo units are specialized devices designed for hazardous environments. These fixtures combine an illuminated EXIT sign and emergency lighting in one compact, sealed, and ruggedized housing built to contain sparks, arcs, or heat from igniting a potentially explosive atmosphere.
They’re commonly rated for Class I Division 2 hazardous areas, where flammable gases or vapors may exist during abnormal conditions. These units meet stringent standards such as UL 924 (for emergency lighting) and UL 844 (for hazardous locations). Most feature LED illumination, battery backup, and 90-minute runtime for code compliance.
Use Cases for Hazardous Location Combos
Explosion-proof exit/light combos are required in environments where combustible gases, vapors, dust, or fibers may be present. These include:
- Oil & Gas Facilities: Refineries, offshore rigs, and tank farms.
- Chemical Plants: Locations handling flammable liquids, solvents, or vapors.
- Food & Grain Processing: Areas with airborne combustible dust.
- Wastewater Treatment: Methane exposure in pump rooms and digesters.
- Paint Booths & Manufacturing: Industrial zones using volatile sprays or coatings.
See our related guide: Designing Explosion Proof Emergency Lights
Compliance: Codes and Regulations
These combo units must meet multiple overlapping regulations. Key compliance points include:
- UL 924 – Emergency Lighting standard for EXIT signage and battery backup.
- UL 844 – Covers fixtures used in Class I, II, III hazardous locations.
- NFPA 101 – Life Safety Code requiring emergency egress lighting.
- OSHA 1910.37/38 – Mandates safe egress and clear EXIT marking.
- NEC Articles 500–516 – Hazardous classification and wiring methods.
Also see: Hazardous Location Emergency Lights & Exit Signs – Complete Guide
Testing & Maintenance Requirements
Explosion-proof combos must be tested regularly:
- Monthly: 30-second functional test using a built-in push button or remote control.
- Annually: 90-minute full-duration test simulating a power outage.
Some models support self-testing and diagnostics with LED indicators for battery faults or lamp failures.
ProTip: Use self-testing units to simplify inspection logs and reduce lift truck use in tall installations.
Key Features to Look For
- UL 924 & UL 844 Certification
- Class Rating for hazardous zones
- LED Illumination & long-life batteries
- NEMA/IP Ratings like NEMA 4X, IP66
- Self-Testing Circuitry
- Mounting Flexibility
- Battery Runtime ≥ 90 min
Price Range and Cost Considerations
- Basic Class I Div 2: $850–$950
- Mid-Tier w/ diagnostics: $1000–$1200
- Heavy-duty/Div 1: $1400+
Highlight: One explosion-proof combo can replace 2–3 separate fixtures and streamline installation.
Combo Unit vs Separate Exit Sign and Light
Combo Units
- Single device covers code for signage and lighting
- Fewer parts, simpler maintenance
- Best for doorways or compact egress zones
Separate Fixtures
- More flexibility for high-ceiling installs
- Useful where high lumen output is needed
- Best when signs and lights need independent aiming
Conclusion
Explosion-proof combo units are essential in many industries. They ensure building occupants can safely exit in emergencies without risking ignition in hazardous atmospheres. Always choose certified products that meet your facility’s class and division requirements.
Also see: Special Use Emergency Lights – For the Most Demanding Environments
Highlight: Don’t cut corners in hazardous environments—explosion-proof combo units are engineered for safety, longevity, and code compliance.
Questions? Contact our support team or browse all Hazardous Location Exit Sign Combos.