ISO 4589-2 Oxygen Index

ISO 4589-2, Determination of burning behaviour by oxygen index.

Areas of use
All types of plastics that are self-supporting and in the form of vertical bars or sheet up to 10.5 mm thick. The materials can be solids, laminates or cellular.

When testing according to ISO 4589-2, the test results will show which oxygen concentration is needed for a specific material to burn continuously. Oxygen index means, the minimum concentration of oxygen, by volume percentage in a mixture of oxygen and nitrogen introduced at 23 ± 2 °C that will just support combustion of a material under specified test conditions.

Example of products that can be tested according to this method
Plastic materials, cable insulation, duct insulation, laminates.

Material needed when testing

Complete test series  At least 20 specimens the dimensions 80 - 150 mm x 10 mm, thickness 4 - 10.5 mm.
Reduced test series, one
specified oxygen concentration
8 specimens with dimensions 80 - 150 mm x 10 mm, thickness 4 - 10.5 mm.

Depending on the type of material the thickness is different. Verify with the test lab which thickness applies.

Test procedure
A small test specimen is supported vertically in a mixture of oxygen and nitrogen flowing upwards through a transparent chimney. The upper end of the specimen is ignited and the subsequent burning behaviour of the specimen is observed to compare the period for which burning continues, or the length of the specimen burnt, with specified limits for such burning. By testing a series of specimens in different oxygen concentrations, the minimum oxygen concentration is estimated.


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