Mercuric cyanide is an odorless, white crystalline solid; turns gray to dark brown when exposed to light. Molecular weight= 252.63; Decomposes at 319℃. Hazard Identification (based on NFPA-704 M Rating System): Health 3, Flammability 0, Reactivity 0. Soluble in water.
WHITE FINE CRYSTALLINE POWDER
Mercuric cyanide is an odorless, white crystalline solid; turns gray to dark brown when exposed to light
Mercuric cyanide finds veterinary application as a topical antiseptic for cats and other animals.
Medicine (antiseptic), germicidal soaps, manufacturing cyanogen gas, photography.
ChEBI: Mercury dicyanide is a mercury coordination entity.
One part of HgO is digested for a few hours on a water bath
with one part of Prussian blue and 10 parts of H2O. The mercuric cyanide crystals
separate on evaporation of the solution.
Odorless tetragonal crystals or white powder. Toxic by inhalation (dust, and the hydrogen cyanide from decomposition) and by ingestion. Toxic oxides of nitrogen are produced in fires. It is used in medicine, germicidal soaps, photography, and in making cyanogen gas.
Soluble in water. Gradually decomposed by water to give off hydrogen cyanide, a flammable poison gas.
MERCURIC CYANIDE is rapidly decomposed by acids to give off hydrogen cyanide, a flammable poison gas. Decomposed in the light. May tend to explosive instability. Capable of violent reaction with oxidizing agents. Fusion with metal chlorates, perchlorates, nitrates or nitrites can cause a violent explosion [Bretherick 1979. p. 101].
Toxic by ingestion, inhalation, and skin
absorption.
Symptoms of both cyanide and mercury intoxication can occur. Acute poisoning has resulted from inhaling dust concentrations of 1.2-8.5 mg/m 3 of air; symptoms include tightness and pain in chest, coughing, and difficul ty in breathing; cyanide poisoning can cause anxiety, confusion, dizziness, and shortness of breath, with possible unconsciousness, convulsions, and paralysis; breath may smell like bitter almonds. Ingestion causes necrosis, pain, vomiting, an d severe purging, plus the above symptoms. Contact with eyes causes ulceration of conjunctiva and cornea. Contact with skin causes irritation and possible dermatitis; systemic poisoning can occur by absorption through skin.
Mercuric cyanide is a highly poisonous compound. Its components, mercury(II) and the cyanide ions, are both highly toxic. Its toxicity, however, is lower than that of sodium and potassium cyanides.
Acute toxic symptoms from oral intake of this compound in humans are hypermotility, diarrhea, nausea or vomiting, and injury to kidney and bladder. Toxic symptoms may be manifested in humans from consuming 15–20 g of this compound. Lower doses may produce somnolence. An intraperitoneal dosage of 7.5 mg/kg was fatal to rats.
LD50 value, oral (mice): 7.5 mg/kg.
Special Hazards of Combustion Products: Fumes from fire may contain toxic mercury and hydrogen cyanide.
Poison by ingestion,
subcutaneous, intravenous, and
intraperitoneal routes. Human systemic
effects by ingestion: nausea or vomiting,
hypermotility, dlarrhea, kidney changes,
somnolence. Hydrolyzes to toxic fumes. A
frictionand impact-sensitive explosive. It
may initiate detonation of liquid hydrogen
cyanide. Incompatible with fluorine,
magnesium, sodium nitrite. When heated to
decomposition it emits very toxic fumes of
Hg, NOx, and CN-. See also CYANIDE
and MERCURY COMPOUNDS.
Mercuric cyanide is used in medicine,
germicidal soaps, photography and in making cyanogen
gas
If this chemical gets into the eyes, remove any contact lenses at once and irrigate immediately for at least 15 min, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts the skin, remove contaminated clothing and wash immediately with soap and water. Seek medical attention immediately. If this chemical has been inhaled, remove from exposure, begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR if heart action has stopped. Transfer promptly to a medical facility. When this chemical has been swallowed, get medical attention. Give large quantities of water and induce vomiting. Do not make an unconscious person vomit. Antidotes and special procedures for medical personnel: The drug NAP (n-acetyl penicillamine) has been used to treat mercury poisoning, with mixed success. Note to physician: For severe poisoning BAL [British AntiLewisite, dimercaprol, dithiopropanol (C3H8OS2)] has been used to treat toxic symptoms of certain heavy metals poisoning including mercury. Although BAL is reported to have a large margin of safety, caution must be exercised, because toxic effects may be caused by excessive dosage. Most can be prevented by premedication with 1-ephedrine sulfate (CAS: 134-72-5).
Color Code—Blue: Health Hazard/Poison: Store in a secure poison location. Prior to working with this chemical you should be trained on its proper handling and storage. Mercuric cyanide must be stored to avoid contact with fluorine, magnesium, and sodium nitrite, since violent reactions occur. Mercuric cyanide should not contact acid or heat because it will release flammable hydrogen cyanide gas. Store in tightly closed containers in a cool, well-ventilated area away from light. Protect containers from physical damage.
UN1636 Mercuric cyanide, Hazard Class: 6.1;
Labels: 6.1-Poisonous materials
Crystallise it from water. The solubility in H2O is 8% at ~20o and 33% at ~100o; in EtOH it is 8% at ~20o and in MeOH it is 25% at ~20o. [Blitz Z Anorg Allgem Chem 170 161 1928.] POISONOUS.
Violent reaction with fluorine, magnesium, sodium nitrite, acids. Heating or contact with acid
releases toxic mercury and flammable hydrogen cyanide
gas. Incompatible with oxidizers (chlorates, nitrates,
peroxides, permanganates, perchlorates, chlorine, bromine,
fluorine, etc.); contact may cause fires or explosions. Keep
away from alkaline materials, strong bases, strong acids,
oxoacids, epoxides
Return to supplier for mercury recovery and deactivation.
