Selecting hazardous location lighting correctly requires matching four technical parameters to both the installation environment and applicable standards. This six-step selection process covers everything from obtaining the area classification drawing through verifying fixture certifications, ensuring every luminaire specified meets the exact requirements of its installation location.
Step 1: Obtain the Current Area Classification Drawing
The area classification drawing is the authoritative document for fixture selection. It shows the Class, Division, Group, and T-code for every classified zone and the extent dimensions of each zone. Before specifying a single fixture, obtain the current revision. If the drawing is outdated or doesn’t exist, a qualified engineer must perform the classification per NFPA 497 (flammable liquids and gases) or API RP 505 (petroleum facilities) before proceeding.
Step 2: Identify All Flammable Substances and Their Gas Groups
The area classification drawing identifies the Group, but verify it covers all substances present. Key rules for multi-substance areas:
- A Group D fixture covers Group D areas only
- A Group C fixture covers Group C and D areas
- A Group B fixture covers Group B, C, and D areas
- The T-code must be below the AIT of the most restrictive substance present — not just the primary process material
Verify auto-ignition temperatures against NFPA 497 Table B.1 or IEC 60079-20-1 for the substances present in each area.
Step 3: Determine IP Rating Requirements
| Environment | Minimum IP Rating |
|---|---|
| Indoor, dry, no washdown | IP54 |
| Indoor industrial with occasional water | IP65 |
| Outdoor or indoor with washdown | IP66 |
| High-pressure washdown or driving rain | IP66 or IP67 |
| Marine/offshore with salt spray | IP66 minimum + corrosion-resistant housing |
Step 4: Calculate Required Lumen Output
Minimum footcandle requirements by area type (ANSI/IES RP-7):
- General storage, inactive areas: 5 fc
- General processing areas, infrequent visual tasks: 10 fc
- Processing areas with frequent visual tasks: 20–30 fc
- Fine work, instrument panels, precision tasks: 50–100 fc
- Emergency egress paths (NFPA 101): 1.0 fc minimum
Simplified lumen calculation: Required lumens per fixture = (Required fc × Coverage area per fixture in sq ft) / Coefficient of Utilization. At 30-ft mounting height with a CU of 0.7, achieving 20 fc over a 400 sq ft area requires approximately 11,400 delivered lumens — select a fixture with at least 14,000 initial lumens to account for depreciation.
Step 5: Select Fixture Type and Configuration
| Application | Fixture Type | Typical Wattage |
|---|---|---|
| Process units, warehouses (high ceiling) | High-bay LED | 100W–200W |
| Outdoor areas, tank farms, yards | Floodlight LED | 100W–300W |
| Walkways, aisles, pipe racks | Linear LED | 40W–80W |
| Pump rooms, small enclosed spaces | Bay/drum LED | 50W–100W |
| Facility roads, perimeters | Street/area light | 80W–150W |
| Emergency egress in classified areas | Emergency LED with battery | 10W–30W |
Step 6: Verify the Certification Before Ordering
Verify the exact fixture model number and configuration in the authoritative certification database:
- UL 844 (North America): UL Product iQ at iq.ul.com — search “Luminaires for Hazardous Locations” and verify exact model number
- ATEX (EU/UK): Verify certificate number with the issuing Notified Body — DEKRA, SGS, Bureau Veritas, DNV, or equivalent
- IECEx: IECEx Equipment Certification database at iecex.iec.ch
Verify that suffix variations (lens type, mounting configuration, conduit entry size) are all covered under the same certificate listing. Do not assume that a different configuration of a certified fixture family is automatically covered.
See: Explosion-Proof Lighting Solutions Guide | Hazardous Area Classification Glossary | Explosion-Proof Lighting Products
Frequently Asked Questions
What are the key factors in selecting hazardous location lighting?
Four non-negotiable parameters: (1) area classification match — Class/Division/Group or Zone/Category/Gas Group; (2) T-code below the AIT of all substances present; (3) IP rating appropriate for the environment; (4) lumen output sufficient for required footcandle levels at mounting height.
What information do I need before specifying explosion-proof lights?
Current area classification drawing, list of flammable substances with gas groups and auto-ignition temperatures, mounting heights and coverage areas, environmental conditions (IP, temperature, corrosion), applicable certification system, and required footcandle standards by area type.
How do I verify a light fixture is certified for my hazardous area?
Verify in the authoritative database: UL Product iQ (iq.ul.com) for UL 844; Notified Body records for ATEX; iecex.iec.ch for IECEx. Verify the exact model number and configuration — not just the manufacturer or fixture family name.
What happens if I install an incorrectly rated light in a hazardous area?
OSHA violation up to $15,625 per violation per day, voided insurance coverage, and an unmitigated ignition risk in a classified area. An incorrectly rated fixture can ignite a flammable atmosphere that properly certified equipment is designed to prevent.
Browse explosion-proof lighting products: Explosion-Proof LED Lighting Shop | LED High Bay Lights | Linear LED Lights
Related technical guides: Class 1 Division 1 vs Division 2 | ATEX/IECEx/UL Certification Guide | CCTV System Design Guide
Get a certified lighting quote for your facility: Request an Industrial Quote — Veilux responds within 1 business day with full ATEX/UL certification documentation.
Key Takeaways: Hazardous Location Lighting Selection
Hazardous Location Lighting Selection is essential equipment in hazardous classified environments where flammable gases, vapors, or dust may be present. Facilities relying on Hazardous Location Lighting Selection benefit from enhanced safety and regulatory compliance with ATEX, IECEx, and UL certifications. When specifying Hazardous Location Lighting Selection for your site, match the certification to your area classification — Zone 0/1/2 or Class I Division 1/2. Hazardous Location Lighting Selection from Veilux is available in fixed and PTZ configurations to suit perimeter, process, and critical-area coverage needs. Properly maintained Hazardous Location Lighting Selection extends system life and upholds certification validity per NFPA 70E inspection requirements.