The inorganic compound with the formula HgI2. It is a reddish-orange powder that is readily soluble in hot alcohol and acetone. It is less soluble in ether, chloroform and ethyl acetate. It is very toxic by ingestion, inhalation and skin absorption. It also irritates eyes, and can cause dermatitis. It is a strong base and reacts violently with aluminium, copper, lead, zinc and silver. It is used for preparation of Nessler’s reagent, and to detect the presence of ammonia. It is also a semiconductor material, used in some x-ray and gamma ray detection and imaging devices operating at room temperature. In veterinary medicine it is used in blister ointments for exostoses and bursal enlargement. It is an ingredient in many popular skin-lightening creams and medicated soaps.
It is also used as an antithyroid agent, and as a sludge in sewage treatment plants. It is a known carcinogen and may cause birth defects in humans. It can also irritate the kidneys and lungs. Some products containing mercury are banned in Canada, but are still available over the counter or on the Internet. Call 311 to report stores that sell these products.
mercury iodide is a reducing agent that reacts with sodium azide to form mercury(II) azide, which is shock and heat sensitive. It is recommended to wear an NISOH certified respirator and protective gloves when handling this substance. It should be stored in a well-ventilated area away from incompatible substances such as bromides, chlorides, alkalis, ammonia, cyanides copper and lead salts, iodoform and hydrogen peroxide.