British Standard 3N 100:1985 specifies the general design requirements for aircraft oxygen systems and specifies three tests of material compatibility in the presence of oxygen. The “bomb” test measures the spontaneous ignition temperature (SIT), which is used as a parameter in categorizing materials for use with gaseous oxygen. The British Standard recognizes that the results of SIT in the “bomb” test may vary with experimental parameters, such as oxygen pressure, sample heating rate, and sample mass and condition (for example, the size of the test specimens). The effects of varying the experimental parameters used in the Standard “bomb” test have been studied using three commonly used materials: Fluorel®, Vespel® SP-21 and Nylon 6/6. The oxygen pressure, heating rate, and condition of samples have a pronounced effect on SIT. The SIT increased with the heating rate, but decreased with increasing pressure and exposed surface area. The results from the “bomb” test must be subjected to statistical analysis because of a wide range of measurements for nominally identical samples in the computer-controlled bomb.