EN ISO 9239-1 "Determination of the burning behaviour of flooring products using a radiant heat source" is the test method of the Euroclass system for flooring products as defined in the Construction Products Regulation.
The radiant panel test for flooring evaluates the propensity of a floor system to spread fire when exposed to intense radiant heat from a radiant panel combined with a flaming ignition source. The radiant panel simulates the impact of thermal radiation levels on the floor of a corridor whose surface is heated by flames, hot gases or both, during the early stages of fire development in an adjacent room or compartment. The method determines the minimum level of heat energy required to sustain combustion of a material.
This property, called critical heat flux (CHF), is an essential part of a fire risk assessment and provides a convenient way to rank products with respect to fire behaviour.
The test method can be applied to all types of floor coverings, such as textile, cork, wood, rubber and plastic carpets, as well as coatings. The test results reflect the performance of the floor covering, including each substrate if applicable. Changes to the backing, binding, underlay or other changes to the floor covering may affect the results.
The test samples should be representative of the final application of the floor covering. Including a chosen substrate (e.g. Euroclass A1 or A2 or a wood-based support class Dfl), the combined floor covering shall not exceed 40 mm in thickness.
The horizontally oriented specimen is exposed to the radiant heat of a radiant panel placed at an angle of 30°. The radiant panel generates a heat flux ranging from 10.9 kW/m² to 1.1 kW/m². A line burner is located at the end with the high heat flux. During the test, the flame spread is recorded as a function of the time required to spread over certain distances. Also, the smoke spread during the test is recorded by measuring the light transmission in the discharge pipe.
The distance of flame spread at extinction or after 30 minutes is related to the CHF, the critical heat flux when extinguishing. This CHF is defined as the incident heat flux (kW/m²) at the surface of a specimen at the point where the flame does not continue and can subsequently extinguish.