Class O Fire Rating Malaysia: BOMBA Material Classification & Requirements

Every building material installed in a Malaysian premises needs to meet a fire classification standard. Class O is the highest surface fire performance classification under the BS 476 system used in Malaysia, and BOMBA requires a Material Certification Certificate (Sijil Perakuan Bahan) for Class O materials before they can be installed in any premises.

This guide breaks down exactly what Class O means, how it's tested, what BOMBA requires for material certification, and why your choice of building materials directly affects your fire insurance.

We'll cover the BS 476 testing framework, BOMBA's 28-item material certification list, UBBL Eighth Schedule requirements for internal wall and ceiling linings, and the connection between material fire ratings and insurance underwriting.

What Is Class O Fire Rating?

Class O is the highest classification for surface fire performance under the British Standard BS 476 system, which Malaysia adopts through the Uniform Building By-Laws 1984 (UBBL). It is not a test result from a single standard. Class O is a composite classification derived from the results of two separate tests.

A material achieves Class O if it meets either of these two criteria:

• It is composed throughout of materials of limited combustibility (as defined by BS 476: Part 11), or
• It achieves Class 1 surface spread of flame (BS 476: Part 7) AND has a fire propagation index (I) not exceeding 12 with a sub-index (i1) not exceeding 6 (BS 476: Part 6)

The critical point: there is no single test that certifies a product as "Class O." You need test reports from both BS 476: Part 6 and BS 476: Part 7 to establish that a material qualifies.

BS 476 Testing Framework

The BS 476 series is the backbone of fire testing for building materials in Malaysia. Three parts are directly relevant to material classification for surface linings.

Standard	Title	What It Measures	Relevance to Class O
BS 476: Part 4	Non-combustibility test	Whether the material is non-combustible	Non-combustible materials automatically qualify as Class O
BS 476: Part 6	Fire propagation test	Rate and amount of heat released when exposed to standard heating	Must achieve I ≤ 12 and i1 ≤ 6
BS 476: Part 7	Surface spread of flame test	Lateral flame spread across the material surface	Must achieve Class 1 (best rating)

Fire Propagation Index (BS 476: Part 6)

The fire propagation test measures how much heat a material contributes to a fire over a 20-minute test period. The result is expressed as an index of performance (I), which is the sum of three sub-indices.

Sub-Index	Time Period	What It Captures	Class O Limit
i1	First 3 minutes	Early fire growth, ignition characteristics	≤ 6
i2	Minutes 3 to 10	Mid-phase heat contribution	No separate limit
i3	Minutes 10 to 20	Late-phase sustained burning	No separate limit
I (total)	Full 20 minutes	i1 + i2 + i3	≤ 12

The i1 sub-index is particularly important because it reflects early fire behaviour. A material that ignites quickly and releases heat rapidly in the first 3 minutes is dangerous even if it burns out later. That's why Class O imposes a separate cap on i1.

Surface Spread of Flame (BS 476: Part 7)

This test measures how far and how fast flames spread across a material's surface when exposed to radiant heat. Materials are classified into four classes.

Class	Performance	Typical Application
Class 1	Very low flame spread	Required for Class O; escape routes, high-risk areas
Class 2	Low flame spread	General room linings in lower-risk areas
Class 3	Medium flame spread	Rooms of limited size, with restrictions
Class 4	Rapid flame spread	Not acceptable for most building applications

For Class O, the material must achieve Class 1. Classes 2, 3, and 4 don't qualify regardless of their fire propagation index.

Where Class O Materials Are Required

The UBBL 1984 Eighth Schedule specifies which fire classification is required for wall and ceiling linings based on building type and location within the building. By-Laws 204 to 206 govern the classification of interior finish materials.

Class O is typically required in the highest-risk locations: escape routes, stairwells, corridors, and areas with high occupancy loads. The general principle is that the more critical the location for fire escape, the stricter the material classification required.

Location	Typical Minimum Class Required	Reasoning
Escape routes, protected stairways	Class O	Must not contribute to fire during evacuation
Corridors, lobbies, circulation spaces	Class O or Class 1	Critical paths for occupant movement
Rooms and habitable spaces (general)	Class 1 or Class 2	Lower risk but still regulated
Small rooms (limited area)	Class 3 (with restrictions)	Lower occupancy, contained spread

The exact requirements vary by building purpose group under the UBBL. Industrial buildings, assembly buildings, and institutional buildings generally face stricter material requirements than residential properties. Always verify the specific requirements for your building's purpose group under the current UBBL provisions.

BOMBA Material Certification (Sijil Perakuan Bahan)

BOMBA requires that all fire safety installations and construction materials with fire performance claims carry a Material Certification Certificate (Sijil Perakuan Bahan) issued by the Malaysian Fire and Rescue Department (JBPM). Class O materials fall within this requirement.

The BOMBA material certification covers 28 categories of fire safety items. This isn't just about surface linings. It includes fire doors, fire dampers, firestop materials, and active fire protection components.

Category	Items Requiring Certification
Passive fire protection	Fire resistance door, fire damper, fire roller shutter, Class O materials, firestop, drywall construction, hollow concrete block, fire rated lift landing door, fire rated duct, smoke curtain
Detection and alarm	Smoke detector, heat detector, manual fire alarm, alarm bell, fire alarm panel
Emergency lighting	Exit sign light, emergency light
Suppression and firefighting	Fire hose reel, sprinkler head, fire suppression system (halon alternative), smoke extraction system
Fire resistant services	Fire resistant cable, bricks

How to Apply for Material Certification

The application is submitted to BOMBA's Material Certification Division. You'll need the following documents:

Document	Details
Application form	BKK-PKK 1 (available from BOMBA)
Distributor appointment letter	Copy of official appointment letter from manufacturer. If from overseas, must be certified by a local Commissioner for Oaths
Test report	Latest test report from accredited laboratory. For Class O: must include BS 476 Part 6 and Part 7 results. If from overseas lab, must be certified
Company profile	Applicant company information
Product brochure and documentation	Technical data sheets, installation guides, supporting literature
Material sample	Mini sample with company label and material name

The processing timeline depends on the completeness of your application and BOMBA's schedule. Don't assume a fixed processing period. Submit well ahead of your project deadline.

How Material Fire Ratings Affect Fire Insurance

In Malaysia, fire insurance operates under the PIAM Revised Fire Tariff (RFT). One of the first things an underwriter assesses is the construction class of your building, which is determined by the materials used in walls, floors, and roof.

Construction Class	Description	Flame Spread Index (FSI)	Fire Rating (FR)
C1A (best)	Concrete and brick walls	FSI = 0	≥ 1 hour
C1B	Metal cladding (e.g., factory walls)	FSI = 0	Less than 1 hour
C2	Timber frame or combustible construction	Higher FSI	Limited
C3 (worst)	Makeshift, temporary, or highly combustible	High FSI	Minimal to none

Buildings with better construction classes (C1A) attract lower fire insurance premiums. A factory with concrete walls and Class O interior linings presents a fundamentally different risk profile from one with metal cladding and no fire-rated linings.

Fire engineering surveys conducted during underwriting evaluate the material construction alongside other factors like sprinkler systems, fire separation distances, and occupancy type. The materials you choose during construction or renovation have long-term cost implications for your annual insurance premiums.

Common Materials and Their Fire Classifications

Not all building materials are created equal when it comes to fire performance. Here's how common materials typically perform under BS 476 testing. Note that actual test results vary by manufacturer and product formulation.

Material	Typical Classification	Notes
Concrete, brick, stone	Non-combustible (Class O eligible)	Automatically qualifies as limited combustibility
Plasterboard (standard)	Typically Class O	Gypsum core with paper facing; verify specific product test reports
Glass	Non-combustible	Standard glass is non-combustible; fire-rated glass is a separate category
Metal cladding (steel, aluminium)	Non-combustible surface	The metal itself is non-combustible; check insulation core material separately
Fire-retardant treated timber	Class 1 (varies by treatment)	May achieve Class O if fire propagation index is also controlled
Untreated timber	Class 3 or 4	Not suitable for areas requiring Class O or Class 1
Composite/sandwich panels	Varies widely	Depends on core material (mineral wool core is better than polyurethane/EPS core)
Polycarbonate, acrylic sheets	Class 3 or lower	Thermoplastics generally perform poorly in flame spread tests

The catch with composite panels is that the surface material and core material can have very different fire properties. A steel-faced sandwich panel might have a non-combustible surface but a combustible polyurethane core. BOMBA and insurers assess the entire assembly, not just the face material.

Common Mistakes with Fire-Rated Materials in Malaysia

Mistake	Consequence	How to Avoid
Assuming "Class 1" equals "Class O"	Class 1 is only the flame spread component. Without meeting the fire propagation index limits, it's not Class O.	Always check both BS 476 Part 6 AND Part 7 reports
Using overseas test reports without BOMBA certification	Material may have valid BS 476 reports but BOMBA still requires its own Sijil Perakuan Bahan	Apply for BOMBA material certification before installation
Testing the surface material but ignoring the substrate or core	The assembly as installed may not meet the classification	Request test reports for the complete assembly, not just individual components
Renovating with non-rated materials in rated areas	BOMBA inspection failure; fire certificate refusal; insurance implications	Check UBBL requirements before specifying renovation materials
Not checking material certification expiry	Expired Sijil Perakuan Bahan means the material is technically not certified	Track certification validity and request updated certificates from suppliers

Class O Compliance Checklist

Item	Status
Identified all areas requiring Class O linings per UBBL Eighth Schedule	☐
Obtained BS 476 Part 7 test report (Class 1 surface spread of flame)	☐
Obtained BS 476 Part 6 test report (I ≤ 12, i1 ≤ 6)	☐
Confirmed test reports cover the complete assembly (not just surface material)	☐
Supplier holds valid BOMBA Sijil Perakuan Bahan for this product	☐
Material certification is current (not expired)	☐
Installation follows manufacturer specifications and test conditions	☐
Documentation filed for BOMBA inspection and insurance records	☐

FAQ

What is the difference between Class O and Class 1 fire rating?

Class 1 refers only to surface spread of flame performance under BS 476: Part 7. Class O is a higher composite classification that requires Class 1 flame spread AND a fire propagation index of I ≤ 12 with sub-index i1 ≤ 6 under BS 476: Part 6. A material can be Class 1 without being Class O.

Is there a single test for Class O certification?

No. There is no single test standard that produces a "Class O" result. You need separate test reports from BS 476: Part 6 (fire propagation) and BS 476: Part 7 (surface spread of flame). The Class O designation is derived from combining both results.

Do all building materials in Malaysia need BOMBA material certification?

Not all building materials, but all fire safety installations and materials with fire performance claims need a Material Certification Certificate (Sijil Perakuan Bahan) from BOMBA. This covers 28 categories of items including Class O materials, fire doors, fire dampers, detectors, and suppression system components.

How does Class O fire rating affect my fire insurance premium?

Your building's construction materials determine its construction class under the PIAM Revised Fire Tariff. Buildings with non-combustible or Class O rated materials typically achieve better construction classes (C1A or C1B), which attract lower base rates. Poor material choices can push you into higher-cost construction classes.

Can I use imported materials with overseas BS 476 test reports?

The test reports themselves may be valid, but BOMBA still requires its own Material Certification Certificate for materials installed in Malaysian premises. You'll need to apply through the Sijil Perakuan Bahan process with certified copies of the overseas test reports.

What happens if BOMBA finds non-rated materials during inspection?

BOMBA can refuse to issue or renew your fire certificate (Perakuan Bomba). Without a valid fire certificate, your premises may not be legally permitted to operate, and your fire insurance policy may be affected if the insurer identifies non-compliance during a survey or at the time of a claim.

Are composite sandwich panels acceptable as Class O?

It depends entirely on the core material. A steel-faced panel with a mineral wool core can achieve Class O or non-combustible status. The same panel with a polyurethane or expanded polystyrene core will not. Always check the test reports for the complete panel assembly, not just the metal face.

Foundation Conclusion

Class O fire rating is about more than passing a BOMBA inspection. It's the measurable standard that separates buildings designed to resist fire spread from those that accelerate it. Every material choice you make during construction or renovation, from wall linings to ceiling panels, feeds into both your regulatory compliance and your insurance risk profile.

If you're building, renovating, or renewing insurance on industrial or commercial premises, the fire classification of your materials matters. Foundation works with factory owners, developers, and facility managers to connect construction decisions with the right fire insurance and IAR coverage.

Talk to our risk specialists about fire insurance for your premises

Disclaimer: This article provides general guidance based on BS 476 standards, the Uniform Building By-Laws 1984, and official BOMBA (JBPM) information as of March 2026. Standards and regulations may be amended. Always verify current requirements with BOMBA, your local authority, or qualified fire safety professionals before making compliance decisions.