Valuable art objects made of wood and other organic materials are often attacked by insect pests. Numerous chemical agents are available to prevent destruction of these objects by insects. Gaslike fumigants such as hydrogen cyanide (ZYKLON), methyl bromide (HALTOX) and ethylene oxide (ETOX, ETOXIAT) have the advantage in contrast to contact-type insecticides that they destroy not only those pests located on the surface but also those which have penetrated to the inside of objects. Furthermore, not only the mature insect is reached but the insect at all stages of its development as well.