EN 17084: Toxicity potential of combustion products

Toxicity testing according to NF X 70-100-1 and -2 standards is performed to determine the Conventional Index of Toxicity for non-listed products (CITNLP) used on trains. Testing is needed to meet requirements R22 and R23, as specified in standard EN 45545-2 on the fire behavior of materials used in railway vehicles. The method described in NF X 70-100-2 corresponds to Method 2 under the EN 17084 standard. During the analysis, the sample is burned in a tube furnace at 600 °C, and toxic smoke emissions evolving from the sample are collected and analyzed. The concentrations of the following eight gases are measured and used to calculate the CITNLP parameter: Carbon dioxide (CO2), Carbon monoxide (CO), Hydrogen fluoride (HF), Hydrogen chloride (HCl), Hydrogen bromide (HBr), Hydrogen cyanide (HCN), Sulfur dioxide (SO2), Nitrous oxide (NOx), including both NO2 and NO, expressed as NO2.

ISO 5659-2 outlines the procedure for measuring the optical density of smoke produced by a material placed in a closed test cabinet and exposed to thermal radiation. The standard was originally developed for plastics, but it can be applied to a range of other products and materials. In the test, representative specimens of the material are mounted horizontally in a test chamber, and their upper surface is exposed to a specified level of thermal irradiance (usually 25 kW/m2 or 50 kW/m2), with or without a pilot flame. The resulting smoke is collected, and its optical density is measured using a photometric method. Some of the key parameters measured include the maximum specific optical density (Ds,max), the specific optical densities at specified times (Ds(1,5), Ds(4), Ds(10)), and the cumulative specific optical densities during the first 4 minutes of the test (VOF4). A toxicity measurement can also be included to measure toxic gas emissions. Its results are reported as the conventional index of toxicity (CITG). The ISO 5659-2 smoke production test is often required as part of the EN 45545-2 fire safety evaluation of railway materials.

Fire testing according to EN ISO 9239-1 is used to evaluate the ability of flooring to withstand flames and radiant heat. Flame spread, smoke generation, and the lowest radiant heat to sustain burning are measured. The method is primarily used to classify floor coverings according to the European EN 13501-1 fire classification system. Depending on the results, floorings can be categorized as A2fl, Bfl, Cfl, or Dfl. A smoke production classification of s1 or s2 is also provided. Another use case is assessing the burning behavior of floor composites and interior horizontal surfaces used in rail vehicles according to the EN 45545-2 standard. The testing procedure is the following: 1) The test specimen is placed in a horizontal position below a gas-fired radiant panel inclined at 30°, where it is exposed to a defined heat flux. 2) A pilot flame is applied to the hotter end of the specimen. 3) Following ignition, any flame front that develops is noted, and a record is made of the progression of the flame front horizontally along the length of the specimen, measuring the time it takes for the fire to spread to defined distances. 4) Smoke production is recorded as light transmission in the exhaust stack. One specimen is tested in one direction (e.g. production direction) and another in the direction perpendicular to the first specimen. The test that yields the worst results is repeated twice in that direction.

The EN 16989 standard describes a testing procedure to evaluate the burning behavior of complete passenger seats intended for use on trains, trams, and other rail vehicles. It replaces ISO/TR 9705, which was previously used for this purpose. Passing tests conducted according to EN 16989 shows that the material complies with requirement R18 specified in the EN 45545-2 standard. Evaluated parameters include: Maximum average rate of heat emissions (MARHE), measured in kW, Total smoke production over 600 seconds (TSP600), measured in m2. A maximum threshold only applies to hazard level HL3, but the parameter should be determined for HL2 products as well, as a limit may be introduced in the future., Flame height above seat base, measured in mm. Seats are usually tested in both intact and vandalized forms to assess how exposing the interior of upholstered sections affects burning behavior.

ISO 5660-1 outlines a procedure for using a cone calorimeter to measure the heat release and smoke production rates of materials upon exposure to a predetermined heat flux. Before testing, representative specimens are conditioned at 23±2 ℃ and 50±5% RH until reaching constant mass. They are then wrapped in foil, placed in a sample holder within a retainer frame, and exposed to an irradiance of 50±1 kW/m2 (unless specified otherwise). The results will include the maximum average rate of heat emission (MARHE), which is required information for multiple material types when evaluating their fire safety in railway applications according to EN 45545-2. Other measured parameters include the following: Mass at the start and end of the experiment, Mass loss percentage, Average mass loss rate, Ignition and extinction times, Maximum rate of heat release (RHR), RHR at 180 and 300 seconds after starting the test, Total heat release (THR), Total smoke production per unit area (overall + before and after ignition). We can also offer other reaction-to-fire tests to meet EN 45545-2 requirements, including ISO 5658-2 and ISO 5659-2. Do not hesitate to contact our experts if you need a quote for the full set of tests.

ISO 5658-2 outlines a method for measuring the lateral flame spread along building and transport products placed in a vertical position. In the test, several representative sample specimens are exposed to a radiant heat flux, and the reaction to this is observed. Measured parameters include the time of ignition, the time of extinction, and the time it takes for the flame front to travel specified distances along the specimen. The results will also include the critical flux at extinguishment (CFE), measured in kW/m2. The CFE is required information when evaluating the reaction-to-fire characteristics of certain components used on trains according to EN 45545-2.

The burning rate of horizontally mounted materials designed to be used in vehicles and buses must be tested with the UN/ECE R118 annex 6 test before they can be approved for use. Measurlabs offers this and the other R118 tests with accreditation. In the test method, the exposed side of the test specimen is burned from underneath and the burning rate is measured and expressed in mm/min.

The melting behavior of fusible materials used in certain motor vehicles must be determined according to Annex 7 of UN/ECE Regulation 118. In the test, it is monitored whether the specimen ignites, creates flaming droplets, and if these droplets ignite cotton wool placed under the specimen. For the material to pass the test, there must be no formation of flaming drops that ignite the cotton wool. Measurlabs can offer accredited test reports for the UN/ECE R118 Annex 7 test, as well as the Annex 6 and Annex 8 tests. Non-isotropic materials must be tested from both sides, which means that double the number of samples is required.

This method is used to determine the gross heat of combustion of solid building products at constant volume in a bomb calorimeter. Results are reported in J/kg. If the product is non-homogeneous, meaning that it consists of multiple materials, each material must be tested separately. The result can be used to classify construction products into classes A1, A1fl, A1L, A2, A2fl, and A2L according to the fire classification standard EN 13501-1.

The ISO 4589-2 oxygen index test is used to evaluate the fire behavior of certain railway materials according to the EN 45545-2 standard. It is required to meet requirements R22, R23, and R24, which apply to products such as insulators, seals, pipes, and hoses. The oxygen index (OI) is the minimum volume-based percentage of oxygen in an oxygen-nitrogen mixture required to support the combustion of the sample under specified conditions. For a material to meet EN 45545-2 requirements, the OI must be at least 28% (hazard classes HL1 and HL2) or at least 32% (HL3). Testing is performed on 20 replicate samples, with the required specimen size depending on the material: 80−150 mm x 10 mm x 4 mm for mould-made materials, such as plastics, 80−150 mm x 10 mm x 10 mm for porous materials, such as foams, 140 mm x 52 mm x d, where d < 10.5 mm, for flexible films, sheets, and fabrics.