Cyanide is contained in silver polish, insecticides, rodenticides, and some plants. Inhalation of hydrogen cyanide may cause death within a minute; oral doses act more slowly, requiring several minutes to hours. Cyanide combines with cytochromes and catalase to produce tissue asphyxia. The treatment for cyanide poisoning includes the administration of IV sodium thiosulfate, which hastens the transformation of the cyanide to thiocyanate, which is excreted in the urine.