What Is Horizontal Flame?
Horizontal flame test: Flame is applied to the sample held horizontally for a defined period of time; It is an experiment in which the speed of progress of the flame between the marking lines is measured in mm/minute. ISO 3795 / FMVSS 302 applies to automotive interior materials.
Purpose of Horizontal Flame
The purpose is to verify that the flame propagation speed of the material in a horizontal position remains below the permissible limit.
Which Products Is Horizontal Flame Applied To?
- Automotive interior trim and trim materials
- Electrical product plastic parts
- Insulation and filling materials
- Ceiling and seat coverings
In Which Sectors Is Horizontal Flame Used?
Standards Related to Horizontal Flame
- ISO 3795
- FMVSS 302
- UL 94 HB
- IEC 60695-11-10 Method A
- GB 8410
- UL 94flammability class in plastic materials test
- EN 13501Fire classification of building products test
- ASTM E84flame spread on the surface test
- ASTM E119Fire resistance in building elements test
Horizontal Flame Conditions
- Flame application
- Standard defined burner and 15 seconds application (ISO 3795)
- Measurement
- Burning speed is calculated from the progress time between the marking lines
- Border
- Maximum burning rate defined in ISO 3795 / FMVSS 302
- Conditioning
- In the environment defined in the standard; typically 23 °C and 50% relative humidity
Equipment for Horizontal Flame
- Yatay alev test kabini
- Calibrated burner and sample holder
- Timer
- Conditioning room
Sample Requirements for Horizontal Flame
- Sample size and thickness must comply with the standard
- Layered materials should be tested with their actual structure
- Conditioning must be completed
- The number of specimens is defined in the standard
Duration of Horizontal Flame
Typically 1–2 weeks.
Horizontal Flame Procedure
- 1Samples are cut and marked.
- 2Conditioning is completed.
- 3The burner is calibrated.
- 4The sample is placed in the horizontal holder and a flame is applied.
- 5The time between the marking lines is measured.
- 6The burning rate is calculated and compared to the limit.
Horizontal Flame Acceptance Criteria
The acceptance criterion is the maximum burning rate given in ISO 3795 / FMVSS 302; In some samples, the flame not reaching the first marking line is also a passing criterion.
Evaluation of Results
The horizontal experiment is significantly less challenging than the vertical experiment; UL 94 HB class does not replace V classes. If layered materials are tested as a single layer, the result does not represent the actual product.
Horizontal Flame Report
- Standard applied
- Sample structure and thickness
- Conditioning conditions
- Measured burning rate
- Assessment
Accreditation
EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.
Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.
Scope and authorisationsRelated Regulations
- Automotive interior materials legislation (ISO 3795 / FMVSS 302)
- Electrical product standards
Fire Testing — What Does This Testing Field Cover?
The section below describes the field that the Horizontal Flame test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.
Fire testing measures two different concepts, and confusing them is the most common mistake in the field. REACTION to fire describes how much a material contributes to the start and growth of a fire. RESISTANCE to fire is the ability of a building element to hold a fire back for a defined period. One is a material property, the other a property of an element.
On the reaction side, ignitability, flame spread, heat release, smoke production, flaming droplets and toxic gas release are measured. The result is translated into an EN 13501-1 class in Europe, ASTM E84 indices in North America and a UL 94 class for appliance plastics. These three systems cannot be converted into one another; their scales and set-ups differ.
On the resistance side, furnace tests are carried out. The element is exposed to a defined temperature-time curve and it is measured how long it maintains three functions: load bearing (R), integrity (E) and insulation (I). For a fire door, the designation EI 60 says the element maintains its integrity and insulating function for sixty minutes.
SCALE is decisive in this family and directly affects cost. Small flame tests are suitable for screening materials and are fast and inexpensive. But real fire behaviour changes with scale: a material that self-extinguishes on a small specimen may sustain a flame over a large surface. Large-scale set-ups such as the room corner test and full-scale facade tests are therefore indispensable in critical applications.
Facade systems have become the most sensitive subject in the field in recent years. The rapid spread of facade fires in tall buildings has led national regulations to require large-scale facade testing. What is assessed here is not a single material but the SYSTEM: insulation, cladding, air cavity, fixings and fire barriers are tested together.
Smoke and toxicity form a separate body of work, because most deaths in a fire are caused by smoke rather than flame. In rail systems and on ships, smoke density and gas toxicity measurements are mandatory items; in an enclosed space the time available for evacuation depends on these values.
Cables have a sub-body of their own. A cable bundle inside a building can form a serious path for fire to spread between floors; flame spread, smoke production, halogen content and circuit integrity are therefore assessed for cables under separate standards, and in Europe the EN 13501-6 classification is used.
Method groups in this field
Non-combustibility and calorific value
The EN ISO 1182 non-combustibility furnace and EN ISO 1716 gross calorific value; the determinants of classes A1 and A2.
Single burning item (SBI)
EN 13823; heat release, flame spread and smoke production are measured together in a medium-scale corner set-up.
Small flame
Ignitability with a single flame source to EN ISO 11925-2; UL 94 horizontal and vertical burning; needle flame and glow wire.
Cone calorimeter
ISO 5660 / ASTM E1354; heat release rate, total heat release and smoke production are measured. The most informative test in material development.
Fire resistance
Furnace tests with the standard temperature-time curve; separate set-ups for doors, walls, floors, glazing and service penetrations.
Large scale
Room corner test (ISO 9705, NFPA 286), facade fire tests and vertical flame spread tests on cable bundles.
Smoke and toxicity
Optical smoke density, smoke gas analysis and toxicity indices; mandatory in rail systems and marine.
Commonly confused in this field
- Reaction to fire and resistance to fire are different concepts; the specification must be explicit about which is required.
- UL 94, ASTM E84 and EN 13501-1 results cannot be converted into one another.
- A small-scale result is not evidence of large-scale behaviour; large-scale testing is required in critical applications.
- A class is valid together with the end-use installation of the product; a different substrate or air cavity changes the result.
- For facade systems a result for a single material is not sufficient; the system must be tested as a whole.
- The fire class of a product does not show the fire resistance of an assembly made from it.
Which decisions these results support
- The fire class in the declaration of performance for construction products
- Regulatory compliance in the selection of cables, flooring and interior linings
- Approval of interior materials for rail vehicles, ships and aircraft
- Approval of the facade system design
- Meeting insurance and project specification requirements
Related Tests
Frequently Asked Questions About Horizontal Flame
According to which standard is Horizontal Flame made?
Horizontal Flame is executed in scope ISO 3795, FMVSS 302, UL 94 HB, IEC 60695-11-10 Method A and GB 8410. The limit values and acceptance criteria to be applied are defined in the product standard; The version valid for your product is confirmed in writing at the offer stage.
Which products does Horizontal Flame apply to?
Mainly applied to Automotive interior trim and trim materials, Electrical product plastic parts, Insulation and filling materials and Ceiling and seat coverings. Whether your product is included in the scope is determined by examining its technical specifications and intended use.
Under what conditions is Horizontal Flame done?
The determining parameters are: Flame application — Standard defined burner and 15 seconds application (ISO 3795), Measurement — Burning speed is calculated from the progress time between the marking lines and Border — Maximum burning rate defined in ISO 3795 / FMVSS 302. The full terms are in the "Test Conditions" section on the page and vary depending on the product standard.
What kind of sample is needed for Horizontal Flame?
Sample size and thickness must comply with the standard, Layered materials should be tested with their actual structure and Conditioning must be completed. The number of samples is determined according to the product standard and the scope to be reported.
How long does Horizontal Flame take?
Typically 1–2 weeks. This duration belongs to the experiment itself; sample preparation, queuing and reporting are also evaluated. A realistic schedule for your product is given in the offer.
What is the Horizontal Flame result called "appropriate"?
The acceptance criterion is the maximum burning rate given in ISO 3795 / FMVSS 302; In some samples, the flame not reaching the first marking line is also a passing criterion.