General Description
Odorless white solid. Sinks in water.
Reactivity Profile
MERCUROUS CHLORIDE is incompatible with acetylene, ammonia, chlorine dioxide, azides, calcium (amalgam formation), sodium carbide, lithium, rubidium, copper .
Hazard
Toxic dose is uncertain.
Health Hazard
Acute poisoning can result from inhaling dust concentrations of 1.2-8.5 mg/m 3 in air; symptoms include pain and tightness in chest, coughing, and difficulty in breathing. Compound is an irritant, cathartic, or purgat ive; rarely, ``calomel sickness,'' a benign reaction with fever and rash, appears after about 1 week; seldom causes systemic poisoning but may be fatal if retained to 30-40 mg/kg. Contact with eyes causes mild irritation.
Description
Mercury(I) chloride, a colorless solid also known as the mineral calomel, is the compound with the formula Hg2Cl2, with
the connectivity Cl-Hg-Hg-Cl. It reacts with chlorine to form mercuric chloride, which resists further oxidation. Hg2Cl2 is
a linear molecule. Mercurous chloride forms through the reaction of elemental mercury and mercuric chloride.
Hg + HgCl2→Hg2Cl2
Definition
ChEBI: Dimercury dichloride is a mercury coordination entity.
Production Methods
Mercurous chloride
is produced by exposing mercury metal to limited
amounts of chlorine gas, insufficient to form mercuric chloride
as the major product; it can also be prepared by precipitation
from mercurous nitrate solution.
Carcinogenicity
An acute oral
dose in humans of 1 g HgCl2 may cause corrosive damage
to the GI tract; there is, however, little quantitative information
on dose–effect relationships during low-level
exposure to inorganic mercury. A dose of 2 g may be
expected to increase mortality greatly among victims of
the poison. Death from acute oral exposure is usually
caused by cardiovascular collapse and renal failure.
Ingestion of inorganic compounds may cause gastrointestinal
corrosion and irritation, such as vomiting, bloody diarrhea,
and stomach pains.
Environmental Fate
Calomel can generate reactive oxygen species and deplete
glutathione levels. Both genotoxic and nongenotoxic mechanisms
may contribute to renal carcinogenic effect of mercury.
Toxicity evaluation
Calomel decomposes gradually in the presence of sunlight.
It slowly decomposes to mercury and mercuric chloride under
aqueous conditions.
