The disclosure relates to a fumigant/sterilant comprising an effective amount of cyanogen mixed with a predetermined quantity of carbon dioxide such that in use, the fumigant/sterilant remains below its flammability limit, wherein the amount of cyanogen present is 1 to 26 wt% and the amount of carbon dioxide present is 99 to 72 wt %, and wherein said cyanogen is in the form of a liquefied gas and said carbon dioxide is liquid carbon dioxide. Said fumigant/sterilant is suitable for fumigating and/or sterilising soil or commodities such as timber in enclosed spaces with reduced health and safety risk.
