Mercury(I) chloride

  • Mercurous chloride
  • Calomel
  • Dimercury dichloride
Formula
Hg2Cl2
Structure
Description
Odorless white solid.
Uses
Dark green Bengal lights.

Registry Numbers and Inventories.
CAS
10112-91-1
EC (EINECS/ELINCS)
233-307-5
EC Index Number
080-003-00-1
EC Class
Harmful; Irritant; Dangerous for the Environment
RTECS
OV8740000
RTECS class
Agricultural Chemical and Pesticide
UN (DOT)
2025
Merck
12,5951
Beilstein/Gmelin
25976 (G)
EPA OPP
52201
Swiss Giftliste 1
G-1355
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
Cl2Hg2
Formula mass
472.08
Melting point, °C
383
Boiling point, °C
384
Vapor pressure, mmHg
0.0001 (80.6 C)
Density
7.1 g/cm3 (25 C)
Solubility in water
Insoluble
Thermal expansion
0.000103/K

Hazards and Protection.
Storage
Do not store in direct sunlight. Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances.
Handling
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Use with adequate ventilation. Minimize dust generation and accumulation. Avoid contact with eyes, skin, and clothing. Do not ingest or inhale. Use only in a chemical fume hood.
Protection
Eyes: Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHA's eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear appropriate protective gloves to prevent skin exposure. Clothing: Wear appropriate protective clothing to prevent skin exposure.
Respirators
Follow the OSHA respirator regulations found in 29CFR 1910.134 or European Standard EN 149. Always use a NIOSH or European Standard EN 149 approved respirator when necessary.
Small spills/leaks
Vacuum or sweep up material and place into a suitable disposal container. Wash area with soap and water. Clean up spills immediately, using the appropriate protective equipment. Avoid generating dusty conditions. Isolate area and deny entry. Provide ventilation.
Stability
Stable under normal temperatures and pressures. May decompose when exposed to light.
Incompatibilities
Substance may react with acacia, ammonia, alkali chlorides, bromides, carbonates, cocaine, copper salts, cyanides, hydroxides, iodine, iodoform, lead salts, silver salts, soap, sulfates, and sulfites.
Decomposition
Hydrogen chloride, mercury/mercury oxides.

Fire.
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. Use extinguishing media appropriate to the surrounding fire. Substance is noncombustible. Extinguishing media: Substance is noncombustible; use agent most appropriate to extinguish surrounding fire.
Fire potential
Non-Combustible
Combustion products
Fumes from fire may contain toxic vapors of substance.
Health
2
 
Flammability
0
 
 
Reactivity
0
 

Health.
Exposure limit(s)
TLV (as Hg): ppm; 0.1 mg/m3 (skin) (ACGIH 1991-1992).
Poison_Class
2
Exposure effects
May cause kidney injury. May cause reproductive and fetal effects. Chronic exposure to mercury may cause permanent central nervous system damage, fatigue, weight loss, tremors, personality changes. May cause tremors, irritability, loss of memory and intellect. May also cause Pink disease characterized by skin, cardiovascular, and neurobehavioral abnormalities. Chronic exposure to mercury vapors may produce weakness, fatigue, anorexia, loss of weight and gastrointestinal disturbances which is collectively referred to as asthenic-vegetative syndrome or micromercurialism. Chronic exposure to mercury compounds may produce immunologic glomerular disease.
   Ingestion
Harmful if swallowed. May cause kidney damage. May cause severe digestive tract irritation with abdominal pain, nausea, vomiting and diarrhea. May cause central nervous system depression. Inorganic mercury compounds may cause central and peripheral nervous system effects. May cause weakness, fatigue, vascular collapse, and esophagus
   Inhalation
May cause respiratory tract irritation. Irritation may lead to chemical pneumonitis and pulmonary edema. May cause gastrointestinal effects including gum and mouth inflammation, jaw necrosis, and loosening of the teeth. May cause kidney damage. Acute exposure to high concentrations of mercury vapors may cause severe respiratory tract irritation.
   Skin
May cause skin irritation. May be absorbed through the skin.
   Eyes
May cause eye irritation. Contact may cause ulceration of the conjunctiva and cornea.

First aid
 
   Ingestion
Do NOT induce vomiting. If victim is conscious and alert, give 2-4 cupfuls of milk or water. Get medical aid immediately.
   Inhalation
Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical aid.
   Skin
Get medical aid. Flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse.
   Eyes
Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately.

Transport.
UN number
2025
Response guide
Hazard class
6.1
Packing Group
I; II; III
 
USCG CHRIS Code
MRR