Emergency Exit Light Requirements: Signs, Luminaires, Battery Duration and Testing

Exit signs and emergency luminaires are different products

Buyers often order "emergency lights" when the design calls for two different items.

Maintained units are lit all the time and stay lit on battery when power fails; exit signs are normally maintained so they are always visible. Non-maintained units light up only when power fails, which is common for emergency luminaires. Units can be self-contained (each with its own battery) or fed from a central battery system.

Battery duration and power

The battery must keep the light working long enough for everyone to evacuate and for firefighters to search the building. NFPA 101 (Life Safety Code) requires emergency illumination to be provided for at least 90 minutes after normal lighting fails. Some other standards and certain occupancies, such as buildings where people sleep, specify longer durations, so follow the duration stated in your design.

Points to check:

• Rated duration on the datasheet, and whether it is achieved by a new battery only or over the battery's life.
• Battery type and expected life; batteries degrade, especially in hot rooms.
• Charging time after a discharge before the unit is ready again.
• Supply circuit: emergency units should be wired from the local lighting circuit so they come on when that circuit fails, not only when the whole building loses power.
• Generators: a generator does not remove the need for battery emergency lighting, because there is a gap before it starts and it can fail.

Placement on escape routes

Place exit signs and emergency luminaires so a person can follow a continuous lit route from any point to a final exit:

• Above every exit door and final exit.
• At each stair, so every flight and landing receives light.
• At every change of direction and intersection of corridors.
• Where the exit is not directly visible, with directional arrows.
• Near fire-fighting equipment and manual call points, so they can be found in the dark.
• At changes in floor level, ramps and steps.
• Outside the final exit, so people can move safely to the assembly point.
• In plant rooms, generator rooms and electrical rooms where staff may need to shut down equipment.
• On large open production floors, at intervals so that aisles towards exits are lit.

Mount signs where they are not hidden by stacked goods, hanging garments, ducting or beams. Low-level signs can help where smoke collects near the ceiling.

Visibility and legibility

• Use a consistent sign style throughout the building. The ISO 7010 running-man pictogram with an arrow is widely recognised; many sites in Bangladesh add "EXIT" or Bangla text.
• Make sure the sign is legible from the distance at which people need to read it; larger signs are needed in large open floors and warehouses.
• Keep signs clean; dust and lint on production floors dim them quickly.
• Avoid placing decorative or advertising lights close to exit signs where they compete for attention.
• Check that the arrow direction is correct after any layout change.

Testing routine

Emergency lights fail silently, so routine testing is essential. NFPA 101 sets out a monthly functional test of at least 30 seconds and an annual test for the full 90-minute duration.

Test outside working hours or zone by zone, because batteries need time to recharge after a full-duration test. Many units have a test button; self-testing units can log results automatically.

Reference prices and what changes them

These are observed Bangladesh retail prices in Oct 2026 — project/bulk prices differ.

The range reflects differences in:

• Sign size and whether it is single- or double-sided.
• Maintained or non-maintained operation and light output.
• Battery type, rated duration and expected battery life.
• Housing material and suitability for dusty or damp areas.
• Self-test features.

For a building, the cost of wiring, fixing and testing should also be included in the budget.

Buying checklist

• Separate the order into exit signs and emergency luminaires, based on a marked-up escape plan.
• Confirm rated duration meets the design and the code your project follows.
• Ask for datasheets showing light output, battery type, charging time and operating temperature.
• Check whether units are listed or tested to a recognised standard, and keep the documents.
• Order spare batteries and units for replacements.
• Plan testing responsibility and a log book from day one.

Common mistakes to avoid: installing exit signs but no emergency luminaires on the stairs; wiring all emergency units from one circuit far from the areas they serve; mounting signs behind hanging garments or ducting; and never replacing batteries until an audit finds dark units.

Exit lighting is part of the wider means-of-escape design; see BNBC 2020 fire safety requirements and the factory fire safety equipment list. Browse emergency exit lights and fire alarm and detection, or send your escape plan through request a quote.

Frequently asked questions

Sources

• National Fire Protection Association (NFPA)
• International Organization for Standardization (ISO)