Class 1 Div 1 Lighting

Class I Division 1 LED Lighting for Hazardous Locations

Class I Division 1, often shortened to Class 1 Div 1 or C1D1, applies to hazardous locations involving flammable gases or vapors where ignitable concentrations may exist during normal operating conditions or under other conditions that meet the Division 1 classification requirements.

Lighting for these areas must be suitable for the documented classification. The Division is only part of the specification; the gas Group, temperature rating, ambient range, environmental exposure, voltage, and installation method can also determine whether a fixture is appropriate.

Explosion-proof Class I equipment is designed so that if gas or vapor enters the enclosure and an internal ignition occurs, the enclosure contains the ignition and prevents it from propagating to the surrounding atmosphere when the equipment is properly selected, installed, and maintained.

Area classification should come from facility documentation, classification drawings, engineering documents, project specifications, the authority having jurisdiction (AHJ), or another qualified source. LED Lighting Supply can help match those established requirements to available fixtures and lighting-performance needs.

Gas Groups A, B, C, and D

Class I locations are divided into gas Groups based on the characteristics of the material present. The fixture must carry markings suitable for the Group identified for the installation area.

Do not treat these Groups as a simple ranking of overall facility risk, and do not assume every C1D1 fixture is approved for every Class I gas Group.

T-Rating and Ambient Temperature

The fixture must also have a T-rating suitable for the gas or vapor present. This rating identifies the maximum surface temperature associated with the equipment under the conditions covered by its listing.

A light can have the correct Class, Division, and Group markings and still be unsuitable if its surface-temperature rating is too high for the hazardous material. The marked ambient-temperature range should be reviewed at the same time.

Toyota Motor Manufacturing Indiana Upgrades to Explosion-Proof LED Lighting Case Study

The Backstory of Toyota Indiana's Relationship With LED Lighting Supply

The project began when Toyota Motor Manufacturing Indiana's (TMMI) Environmental Engineer, Lisa Harmon, reached out to LED Lighting Supply. Lisa needed support in upgrading the company’s Princeton, Indiana auto assembly plant paint booth lights. A contractor working on a separate project at the plant had previously installed our explosion proof fixtures. Their team wanted to order additional replacement fixtures for an area outside of the paint booth. As the project progressed, the purchasing process was handled through Toyota’s distributor, C & E Advanced Technologies. The purchasing channel transferred from Toyota directly to the distributor, while we continued our role as the lighting supplier for the project.

The Challenge of the Hazardous Location Project

The TMMI plant paints vehicle materials, builds automotive bodies, welds panels, and assembles entire vehicles. Heavy-duty work like this creates an environment where flammable vapors may be present during normal operations. Every light fixture in a hazardous area is subject to classification. The legacy fluorescent lighting serving those spaces had reached the end of its useful life and was producing uneven light levels across the work area. The lighting solution needed to raise illumination levels while meeting the safety requirements for high-level assembly work.

Lighting plan metrics:

• Product(s) Used: MLLG-E-LED-EXPLC-150-50-[V]-C1D1

Read the full case study

Barrette Outdoor Living’s Explosion Proof Lighting Case Study

The Backstory

Barrette Outdoor Living, an Oldcastle APG brand, struggled to properly illuminate an existing paint booth with inadequate, exposed fluorescent lighting, leading to a remodel. The Operations Manager, Brandon Hiller, sought LED Lighting Supply's Product Specialist, Joe Hawkins, for expert guidance on the LED lighting upgrade.

The Customer Challenge

The customer needed support in selecting the proper lighting solution for their demanding environment. Barrette Outdoor Living required fixtures for an area that frequently contains flammable paint chemicals and sprays such as lacquers and gelcoat. Additionally, the customer was renovating parts of the booth, including pulling down the ceiling, reframing the walls, and rewiring, while leaving the sprinkler system in place. Due to the intended use of the property, the flammable paint chemical exposure in the environment was not only a concern but also required specialized lighting specifications to comply with local standards. Our team understood that upgrading lighting in hazardous locations involves more complex planning than traditional spaces. The goal was to achieve brighter, safer lighting with minimal shadowing.

Lighting Plan We Created for the Customer

Lighting Plan Metrics:

• Mounting Height: 10 ft
• Fixture Used: 50 Watt Round Explosion Proof LED Light
• Average Foot Candles Achieved: 53
• Product(s) Used: MLLG-E-EXPLS2-150-50-C1D1

Read the full case study

Choosing a C1D1 Fixture

Common Class I Division 1 Lighting Applications

Class I Division 1 lighting is used in specific areas where flammable gases or vapors may be present under conditions that require Division 1 equipment. A facility can contain Division 1, Division 2, and unclassified areas, so use the documented classification for the exact fixture location rather than the industry name alone.

• Oil, gas, and fuel operations: C1D1 areas may occur around drilling, production, processing, storage, transfer, and related equipment. See application-specific guidance for oil and gas facilities, refineries, oil fields, offshore oil rigs, and pipeline facilities.
• Chemical and flammable-vapor processes: Classified locations may also occur in chemical plants, paint booths and finishing areas, distilleries, hydrogen facilities, biofuel facilities, and hazardous material storage areas.
• Utilities, marine, and process facilities: Certain areas within water and wastewater treatment plants, ship engine rooms, and power generation facilities may also require Class I Division 1 lighting where the established classification calls for it.

For any of these applications, confirm the required gas Group, T-rating, ambient range, environmental conditions, voltage, mounting, and fixture listing for the specific installation area.

Installation, Listings, and Certifications

A hazardous-location luminaire is only one part of the electrical system. Wiring methods, conduit or approved cable systems, boxes, fittings, seals where required, switches, grounding, bonding, and other components must also be suitable for the classified area.

Installation should be performed by qualified electrical professionals experienced with hazardous locations and in accordance with applicable codes, product listings, manufacturer instructions, and local requirements. Listed equipment should not be altered by drilling unapproved openings, modifying flame paths, or substituting unauthorized components.

Safety and Performance Certifications: Certifications and markings are model-specific. Depending on the product and project, fixtures may carry UL, ETL, CSA, or other applicable listings. Review the exact model for its Class, Division, Group, T-rating, ambient range, voltage, environmental ratings, mounting, and controls.

Warranty and Lighting Support

Many Class I Division 1 LED fixtures include a 5-year warranty unless otherwise specified, with warranty support based in the USA. Check the warranty terms for the exact product selected.

LED Lighting Supply can help match an established hazardous-area classification to fixture options and provide a hazardous-area lighting design for fixture placement, quantity, foot-candles, and uniformity.

If the documented area is Division 2 rather than Division 1, see our Class I Division 2 LED Lighting options.

Class 1 Div 1 Lighting FAQs

Is A Class I Division 1 Rating Alone Enough To Select A Fixture?

No. The fixture must also be suitable for the documented gas Group, T-rating, ambient-temperature range, environmental exposure, voltage, mounting method, and installation requirements for the exact location.

Can Any C1D1 Fixture Be Used For Any Class I Gas Group?

No. A C1D1 fixture must carry markings suitable for the gas Group identified for the installation area. Do not assume every Class I Division 1 fixture is approved for Groups A, B, C, and D.

Why Does T-Rating Matter For Class I Division 1 Lighting?

The T-rating must be suitable for the gas or vapor present because it identifies the maximum equipment surface temperature under its listed conditions. A fixture can have the correct Class, Division, and Group markings but still be unsuitable if its T-rating is too high for the hazardous material.

What Should Be Confirmed Before Ordering C1D1 Lighting?

Confirm the documented classification, gas Group, T-rating, ambient range, environmental conditions, voltage, mounting, and fixture listing for the specific installation area. Lighting performance factors such as lumens, optics, mounting height, spacing, foot-candles, and uniformity should also be considered for the final layout.

Can A Hazardous-Area Lighting Design Help Determine Fixture Quantity And Placement?

Yes. A hazardous-area lighting design can help plan fixture placement, quantity, foot-candles, and uniformity while matching available fixture options to established hazardous-area requirements.