Determination of burning behavior of plastics by oxygen index
The Oxygen Index is a method to measure the minimum oxygen concentration to support candle-like combustion of plastics. It is determined by measuring the minimum volumetric concentration of oxygen that will just support combustion in a flowing mixture of oxygen and nitrogen.
Summary of Test Method
A test specimen is placed vertically in a mixture of oxygen and nitrogen flowing upwards through a transparent chimney. The upper end of the specimen is ignited by a flame, which is withdrawn immediately after ignition. The subsequent burning behavior of the specimen is observed. In several tests with different oxygen concentration the minimal concentration which just supports the burning of the sample after ignition is determined.
