Many objects brought into a museum contain insects, bacteria and fungal spores. Common practice is to fumigate all such objects. The British Museum uses ethylene oxide as a fumigant. Literature suggests that residues, some toxic, may be formed in the objects by fumigation with ethylene oxide. This paper investigates possible residues in an attempt to isolate and detect them in a variety of materials. The effect of ethylene oxide on the mechanical properties of silk, cotton, wool and paper is also assessed.