From the ethylene oxide MSDS:
explosive limits: 3-100%, flash point <-18°C, boiling point 10.4°C
They use ethylene oxide as the fuel in these big fuel-air-bombs.
It's also said to be incompatible to temps above 52°C, oxidizers, ALKALIS, acids, alkohols, mercaptams, copper, SILVER, magnesium, mercury and their salts.