ECE R118 — Burning Behaviour of Materials in Motor Vehicles

Introduction to ECE R118

UNECE Regulation No. 118 (ECE R118) establishes uniform provisions concerning the burning behaviour of materials used in the interior construction of certain categories of motor vehicles. Its purpose is to reduce the risk of fire spreading within the passenger compartment, giving occupants sufficient time to evacuate in the event of a fire.

ECE R118 is mandatory for type approval of vehicles in categories M2 and M3 (buses carrying more than eight passengers) and certain categories of N vehicles (commercial vehicles) in all contracting parties to the UNECE 1958 Agreement. The regulation also applies to specific components and materials used in these vehicles, regardless of where in the world they are manufactured.

Scope of the Regulation

ECE R118 covers the flammability characteristics of interior materials including:

• Seat upholstery fabrics and foams
• Headlining and roof panel materials
• Wall panels and partitions
• Floor coverings and mats
• Luggage rack and shelf materials
• Curtains and blinds
• Insulation materials in contact with the interior
• Any other material within the passenger compartment that could contribute to fire spread

The regulation does not apply to exterior body panels, structural metalwork, glass, or engine compartment components. It is specifically focused on materials within the zones accessible to passengers and the driver.

Material Flammability Tests

ECE R118 defines multiple test methods depending on the material type and its location in the vehicle. The primary tests are:

Horizontal Burning Rate Test (Annex 6)

This is the most widely applied test. A material specimen measuring 356 mm by 100 mm is mounted horizontally in a U-shaped holder and exposed to a small Bunsen burner flame at one end for 15 seconds. The test measures:

• Whether the material ignites
• The rate at which the flame front advances across the specimen

Pass criteria: The horizontal burning rate must not exceed 100 mm per minute for most materials. If the flame extinguishes before reaching the first timing mark (38 mm from the flame application point), the material is classified as self-extinguishing and passes.

Melting Behaviour Test (Annex 7)

For materials that melt and drip when exposed to flame, this test evaluates whether molten droplets can ignite underlying materials. A specimen is positioned above a layer of cotton wool and exposed to a flame. The test assesses whether falling droplets ignite the cotton below.

Vertical Burning Test (Annex 8)

Applied to curtains, blinds, and other vertically oriented materials. The specimen is mounted vertically and a flame is applied at the bottom edge. The test measures the upward flame spread rate and the time for the flame to travel a defined distance.

Resistance to Flame Spread for Horizontal Surfaces (Annex 9)

This test applies to floor coverings and horizontal surfaces. A larger flame source is used, and the test evaluates whether the flame spreads beyond a defined boundary.

Summary of Test Requirements

Test (Annex)	Applies To	Key Criterion
Annex 6 — Horizontal burning	General interior trim, seat materials	Burning rate max 100 mm/min
Annex 7 — Melting behaviour	Materials prone to melting and dripping	No ignition of cotton substrate
Annex 8 — Vertical burning	Curtains, blinds, hanging fabrics	Limited flame spread rate
Annex 9 — Horizontal flame spread	Floor coverings	No flame spread beyond boundary

E-Mark Requirements

When a component manufacturer seeks separate approval for an interior material or component, the approved item must carry an E-mark. The marking includes:

• The letter “E” inside a circle, followed by the country code number of the approving authority
• The regulation number (R118) and the approval sequence number
• Placement on the component or its packaging where it is clearly visible

Vehicle manufacturers who integrate approved materials into their vehicles can reference the component E-mark approvals in the vehicle type-approval documentation.

Affected Components

In practice, the following components typically require ECE R118 testing:

• Bus and coach seating (fabric, leather, foam, and composite)
• Overhead luggage bins and rack systems
• Dashboard and instrument panel coverings
• Door trim panels
• Pillar trim and garnish moldings
• Headlining materials and adhesive layers
• Thermal and acoustic insulation products
• Privacy curtains and driver partition screens

Suppliers of these components to bus and coach manufacturers must ensure that their materials have been tested and approved before delivery.

Compliance Process

The path to ECE R118 compliance involves:

1. Material identification: Catalog all interior materials in the vehicle or component that fall within the scope of ECE R118.
2. Sample preparation: Prepare test specimens from production-representative materials according to the conditioning requirements in the regulation (typically 24 hours at 23 degrees Celsius and 50% relative humidity).
3. Laboratory testing: Submit specimens to an accredited test laboratory for the applicable burning tests. At least five specimens per material per test method are typically required.
4. Test report: The laboratory issues a test report confirming pass or fail for each material.
5. Type-approval application: Submit the test reports along with the technical documentation to the relevant Type Approval Authority.
6. Approval and marking: Upon approval, apply the E-mark to components and include the approval references in the vehicle documentation.

Relationship to Other Standards

ECE R118 coexists with other flammability standards in the automotive sector:

• FMVSS 302 (USA) specifies a similar horizontal burning rate test with a 102 mm/min limit. Many materials that pass FMVSS 302 will also pass ECE R118 Annex 6, but the test procedures and specimen preparation differ in detail.
• ISO 3795 is the international equivalent of the horizontal burning test and is technically aligned with both ECE R118 Annex 6 and FMVSS 302.

Manufacturers targeting both European and North American markets should plan testing to cover all applicable standards simultaneously.

How TESTUPS Can Help

TESTUPS offers complete ECE R118 flammability testing services, covering all annexes from horizontal and vertical burning to melting behaviour assessment. Our material testing laboratory is equipped with the standardized test apparatus specified in ECE R118, and our team guides material suppliers and vehicle manufacturers through sample preparation, testing, and type-approval documentation. We also coordinate ECE R118 testing with other vehicle-level approvals to streamline the overall certification timeline.

For related automotive certifications, see our articles on ECE R122 heating systems and UNECE regulations.