Information about EN ISO 4589-2 Oxygen Index

EN 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 EN 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.

The method is refered to in the standard for fire behavour of materials and components in railway applications EN 45545-2.

Example of products that can be tested according to this method

Plastic material, cable insulation, duct insulation, laminate, printed circuit board.

Material needed when testing 

Complete test series

At least 20 samples with the dimensions 80 – 150 mm x 10 mm, thickness 4 or 10 mm.

Reduced test series, one specified oxygen concentration 

8 samples with the dimensions 80 – 150 mm x 10 mm, thickness 4 or 10 mm.

The sample dimensions depend on the type of material. The above dimensions are for moulded or cellular materials. Verify dimensions with test lab.

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.


Related Information


Fire tests at RISE

Contact Persons

Anna Bergstrand

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RISE Research Institutes of Sweden, Phone 010-516 50 00, E-mail

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