ASTM D2863 Oxygen Index

Scope:

ASTM D2863 is a test method for calculating minimal oxygen concentrations in an oxygen/nitrogen mixture in a plastic sample to sustain a flaming burn. There is no correlation to real end-use conditions. The result of this test is expressed as percent volume of oxygen supporting flaming combustion in a flowing mixture of oxygen and nitrogen.

Test Procedure:

For ASTM D2863 test, the sample is placed vertically inside a glass chimney. The flow of oxygen-nitrogen environment is maintained from the bottom of the chimney. Then, the top edge of the chimney is ignited. The flow of oxygen concentration is reduced until the flame does not support it.

Specimen size:

There are six criteria for the test sample depending upon the category of the sample examined. The suggested scale is 80 to 150 mm long by 10 mm wide by 4 mm thick for the injected moulded samples. The results are recorded for different materials. Comparison of materials is done only in the case of samples of matching size.

Data:

The oxygen index is expressed as a percentage of maximum levels of oxygen tested. The findings of the test only apply to the behaviour of specimens under test procedure, and findings must not be applied to conclude fire hazards of the material or under other fire conditions.

Conclusion:

ASTM D2863 is a standard method which determines the minimum concentration of oxygen in an oxygen/nitrogen mixture that will support a flaming burn in a plastic sample.