The NASA Johnson Space Center White Sands Test Facility (WSTF) evaluated the ignition hazards of a section of Buna N rubber suspected to be lodged in a gaseous oxygen system. A configuration simulation tester was used to test for the minimum mass of Buna N required to cause an ignition hazard, which meant ignition of the Inconel 718 metal structures of the oxygen system. High-density polyethylene (HOPE), a comparison material with a higher heat of combustion than Buna N, was also tested. Analytical techniques were performed on the Buna N rubber and the HOPE to investigate the polymer-to-metal ignition process. The minimum weight required to cause ignition in the Inconel 718 was 1.5 mg, which was more than the 0.1–0.2 mg of contaminant found in the oxygen system. HOPE had a lower propensity to ignite the Inconel 718 even though it has a much higher heat of combustion than Buna N; this result was explained in terms of the different structures of the two polymers. Additional testing was conducted to examine the differences of two different batches of Buna N at 10 ± 0.5-mg samples. Buna N was found to be batch sensitive in its ignition performance; batch differences were more easily discernible by analytical techniques.