Oxygen Index ASTM D2863

Measuring the Minimum Oxygen Concentration to Support Candle-Like Combustion of Plastics (Oxygen Index) ASTM D2863

ASTM D2863 is a standard method used to evaluate the minimum oxygen concentration required to maintain a flame on a plastic sample. The results of this test are not representative of real-life fire conditions, but can still provide valuable information about the behavior of plastic materials.

To conduct the test, a plastic sample is positioned vertically in a glass chimney. An oxygen/nitrogen mixture is established at the bottom of the chimney, and the top edge of the sample is then ignited. The oxygen concentration is gradually decreased until the flame is no longer sustained.

There are six different specifications for the size of the test sample, depending on the type of material being tested. For injection molded samples, a size of 80 to 150 mm in length, 10 mm in width, and 4 mm in thickness is recommended. It is important to note that results from different materials should only be compared if they were tested on similar-sized samples.

The oxygen index, expressed as a percentage, is calculated from the final oxygen concentration. The results of this test method pertain only to the behavior of the plastic sample under these specific conditions and should not be used to predict the fire hazard of the material in other forms or conditions.

ASTM D2863 provides a standardized method for determining the minimum oxygen concentration required to sustain a flame on a plastic sample. While the results may not be applicable to real-life conditions, they still offer valuable information about the behavior of plastic materials. It is important to follow the recommended sample size specifications and to be aware of the limitations of the test results when evaluating the fire performance of plastic materials.