The stability of ethylene oxide under adverse pressurization conditions has been demonstrated by a series of tests in which the compound was pressurized at rates as great as 200,000 psi/sec and was ejected through small, sharpedge orifices at high pressure drops. No detonations occurred in these tests, or even when the material was suddenly pressurized with oxygen and ejected against a stainless steel block maintained at 1000 F.