Sulfuryl fluoride, which is useful as a fumigant, may be contaminated with sulfur dioxide and possibly other impurities such as sulfuryl chloride, depending on the way it is produced. According to the invention, sulfur dioxide and, if applicable, sulfuryl chloride fluoride are removed from a contaminated sulfuryl fluoride product by using aluminum oxide as an adsorbing agent. The method of the invention is highly advantageous because it eliminates the need to use activated carbon as an additional adsorbent.