Sample

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10.5.2. Sampling
At least five samples shall be taken from the material under test. In materials having burning rates differing according to the direction of the material (this being established by preliminary tests) the five (or more) samples shall be taken and be placed in the test apparatus in such a way that the highest burning rate will be measured.
When the material is supplied in set widths, a length of at least 500 mm covering the entire width shall be cut. From the piece so cut, the samples shall be taken at not less than 100 mm from the edge of the material and at points equidistant from each other.
Samples shall be taken in the same way from finished products when the shape of the product so permits. If the thickness of the product is over 13 mm it shall be reduced to 13 mm by a mechanical process applied to the side which does not face the passenger compartment.
Composite materials (see paragraph 10.2.2.) shall be tested as if they were homogeneous.
In the case of materials comprising superimposed layers of different composition which are not composite materials, all the layers of material included within a depth of 13 mm from the surface facing towards the passenger compartment shall be tested individually.
10.5.3. Conditioning
The samples shall be conditioned for at least 24 hours, but not more than 7 days, at a temperature of 23 °C ± 2 °C and a relative humidity of 50 ± 5 per cent, and shall be maintained under these conditions until immediately prior to testing.
10.6. Procedure
10.6.1. Place samples with napped or tufted surfaces on a flat surface, and comb twice against the nap using the comb (paragraph 10.4.5.).
10.6.2. So place the sample in the sample holder (paragraph 10.4.2.) that the exposed side faces downwards, towards the flame.
10.6.3. Adjust the gas flame to a height of 38 mm using the mark in the chamber, the air intake of the burner being closed. The flame shall burn for at least one minute, for stabilization, before the first test is started.
10.6.4. Push the sample holder into the combustion chamber so that the end of the sample is exposed to the flame, and after 15 seconds cut off the gas flow.
10.6.5. Measurement of burning time starts at the moment when the foot of the flame passes the first measuring point. Observe the flame propagation on the side (upper or lower) which burns faster.
10.6.6. Measurement of burning time is completed when the flame has come to the last measuring point or when the flame is extinguished before reaching that point. If the flame does not reach the last measuring point, measure the burnt distance up to the point where the flame was extinguished. Burnt distance is the part of the sample destroyed, on the surface or inside, by burning.
10.6.7. If the sample does not ignite or does not continue burning after the burner has been extinguished, or the flame goes out before reaching the first measuring point, so that no burning time is measured, note in the test report that the burning rate is 0 mm/min.
10.6.8. When running a series of tests or performing repeat tests, make sure before starting a test that the temperature of the combustion chamber and sample holder does not exceed 30 °C.
10.7. Calculation
The burning rate B, in millimetres per minute, is given by the formula:
B = s/t x 60;
where:
s is the burnt distance, in millimetres,
t is the time, in seconds, taken to burn the distance s.
10.8. Indices of difficulty of the secondary characteristics
No secondary characteristics are involved.
10.9. Interpretation of results
10.9.1. Safety glazing faced with plastics material (paragraph 2.4. of this Regulation) and glass-plastics (paragraph 2.5. of this Regulation) shall be considered satisfactory from the point of view of the fire-resistance test if the burn rate does not exceed 90 mm/min.
10.9.2 Rigid plastic panes (paragraph 2.6.1. of this Regulation), flexible plastic panes (paragraph 2.6.2. of this Regulation) and rigid plastic double glazed units shall be considered satisfactory from the point of view of the fire resistance test if the burn rate does not exceed 110 mm/min.
11. Test of resistance to chemicals
11.1. Chemicals used for the test
11.1.1. Non-abrasive soap solution: 1 per cent by weight of potassium oleate in deionised water;
11.1.2. Window-cleaning-solution: an aqueous solution of isopropanol and dipropylene glycol monomethyl ether in concentration between 5 and 10 per cent by weight each and ammonium hydroxide in concentration between 1 and 5 per cent by weight;
11.1.3. Undiluted denatured alcohol: 1 part by volume methyl alcohol in 10 parts by volume ethyl alcohol;
11.1.4. Petrol or equivalent reference petrol: a mixture of 50 per cent by volume toluene, 30 per cent by volume 2,2,4\-trimethylpentane, 15 per cent by volume 2,4,4-trimethyl-1-pentene and 5 per cent by volume ethyl alcohol:
N.B. The composition of the petrol used shall be recorded in the test report;
11.1.5. Reference kerosene: a mixture of 50 per cent by volume n-octane and 50 per cent by volume n-decane.

11.2. Test method