When discussing fire safety, flames are often the primary focus. However, in many fire scenarios, smoke presents the greatest risk to life safety. Smoke can spread rapidly through a building, reducing visibility, affecting escape routes, and carrying toxic gases.
This is why smoke performance is an important consideration when specifying access panels and riser doors.
What is a smoke tested access panel?
A smoke tested access panel or riser door is designed to limit the passage of smoke leakage through the door leaf and frame assembly when closed.
This is typically achieved through:
- Smoke seals or gaskets
- Controlled compression between the door and frame
- Precision manufacturing tolerances
- Appropriate locking systems to maintain seal pressure
The aim is to help maintain compartmentation and reduce smoke transfer between areas of a building.
Why smoke leakage matters
Smoke can spread long before structural fire failure occurs.
Controlling smoke leakage helps to:
- Protect escape routes
- Improve visibility during evacuation
- Reduce the spread of toxic gases
- Support compartmentation strategies within the building
Smoke control is particularly important in:
- Corridors and escape routes
- Residential developments
- Healthcare facilities
- Commercial buildings with protected zones
How smoke testing is carried out
Smoke leakage testing is commonly performed in accordance with BS EN 1634-3:2004 — Smoke Control Test for Door and Shutter Assemblies.
This standard measures the amount of smoke leakage passing through a closed doorset or panel under controlled pressure conditions.
During testing:
- The panel assembly is installed into a test rig
- Air pressure is applied to simulate smoke movement
- Leakage rates are measured at different pressures and temperatures
The test assesses how effectively the assembly limits smoke transfer.
Ambient & medium temperature smoke tests
Smoke testing may be carried out at different temperatures depending on the required application.
Ambient smoke testing (Sa)
Ambient smoke testing assesses leakage at room temperature conditions. This is intended to simulate the early stages of a fire before temperatures significantly rise.
Medium temperature smoke testing (S200)
S200 testing is carried out at elevated temperatures, typically around 200°C. This evaluates how the assembly performs when exposed to hotter smoke conditions during a developed fire scenario.
| Test | Temperature | Simulates |
|---|---|---|
| Sa — Ambient | Room temperature | The early stages of a fire, before temperatures rise significantly |
| S200 — Medium temperature | Around 200°C | A developed fire scenario with hotter smoke conditions |
Smoke seals and performance
Smoke performance is heavily influenced by the sealing system used within the panel assembly.
Factors affecting performance include:
- Seal type and quality
- Compression consistency
- Gap tolerances
- Correct installation
Even small gaps can significantly increase smoke leakage, making manufacturing accuracy and installation quality critical.
Smoke testing vs fire resistance
Smoke testing and fire resistance testing are not the same thing.
A product may be:
- Fire rated only
- Smoke tested only
- Or both fire rated and smoke tested
Fire resistance focuses on:
- Integrity (preventing flames and hot gases passing through)
- Insulation (limiting heat transfer)
Smoke testing specifically measures leakage rates through the assembly when closed.
Both characteristics may be required depending on the project specification.
Installation is critical
As with all tested performance, installation plays a major role in real-world results.
To maintain smoke performance:
- Structural openings must be suitable
- Frames must be correctly fixed and sealed
- Approved seals and components must be used
- Installation guidance should always be followed
Key takeaway
Smoke tested access panels help support building safety by:
- Limiting smoke leakage
- Supporting compartmentation
- Protecting escape routes and occupied spaces
Final thoughts
When specifying access panels for fire and smoke applications, it’s important to look beyond headline fire ratings alone.
Ensure products are supported by:
- Recognised smoke leakage testing
- Appropriate seal systems
- Clear installation guidance
- Verified test evidence
This helps ensure the access solution performs correctly when it matters most.
Related reading
- BS EN 1634-1: Fire Resistance Testing Explained — the fire resistance companion test
- Fire Ratings Explained — E and EI ratings explained
- What Is Fire Compartmentation? — why smoke control matters
- Airtight Access Panels — air permeability performance
Ready to specify?
Browse the smoke-rated access panel and riser door ranges, or contact the Technical Service team for BS EN 1634-3 smoke test evidence and installation detail drawings.
FAQs
What is a smoke tested access panel?
A smoke tested access panel or riser door is designed to limit the passage of smoke leakage through the door leaf and frame assembly when closed. This is typically achieved through smoke seals or gaskets, controlled compression between door and frame, precision manufacturing tolerances, and appropriate locking systems to maintain seal pressure.
Why does smoke leakage matter?
In many fire scenarios smoke presents the greatest risk to life safety — it spreads rapidly, reduces visibility, affects escape routes and carries toxic gases. Smoke can spread long before structural fire failure occurs, so controlling smoke leakage helps protect escape routes, improve visibility during evacuation, reduce the spread of toxic gases, and support compartmentation.
How is smoke testing carried out?
Smoke leakage testing is commonly performed to BS EN 1634-3:2004, the smoke control test for door and shutter assemblies. The panel assembly is installed into a test rig, air pressure is applied to simulate smoke movement, and leakage rates are measured at different pressures and temperatures to assess how effectively the assembly limits smoke transfer.
What is the difference between ambient (Sa) and medium-temperature (S200) smoke testing?
Ambient smoke testing (Sa) assesses leakage at room temperature, simulating the early stages of a fire before temperatures rise significantly. Medium-temperature testing (S200) is carried out at elevated temperatures, typically around 200°C, evaluating how the assembly performs when exposed to hotter smoke during a developed fire scenario.
Is smoke testing the same as fire resistance testing?
No. Fire resistance focuses on integrity (preventing flames and hot gases passing through) and insulation (limiting heat transfer). Smoke testing specifically measures leakage rates through the assembly when closed. A product may be fire rated only, smoke tested only, or both — depending on the project specification.
What affects smoke leakage performance?
Smoke performance is heavily influenced by the sealing system used within the panel assembly. Factors include seal type and quality, compression consistency, gap tolerances, and correct installation. Even small gaps can significantly increase smoke leakage, making manufacturing accuracy and installation quality critical.
