Agent Name


Alternative Name

Mercury, elemental

CAS Number




Major Category



Quicksilver; [NIOSH] Mercury, elemental


Elements, Metallic


Metal: Silver-white, heavy, odorless liquid. [NIOSH]


MINING, SMELTING, OR METALLURGY: Cinnabar ore mining and crushing operations; gold extraction (cyanide leaching or amalgamation processes); MANUFACTURING: Thermometers, manometers & barometers; dental amalgam; polyurethane catalyst; switches & rectifiers; dry cell batteries; paints; USING OR DISPOSING: Open mercury cells in chloralkali plant for maintenance; use mercury amalgams in dental office; In gold extraction, mercury exposure occurs during the amalgamation stage and especially during the release of gold by heating. [Nordberg, 834]


Elemental liquid mercury is poorly absorbed from the GI tract, and it is considered nontoxic by ingestion in patients with normal GI anatomy and motility. Elemental mercury vapor is toxic predominantly to the lung and central nervous system. Pneumonitis can result from exposure to high concentrations of heated mercury vapor in a confined space. Otherwise, inhalation of mercury vapor is toxic over a period of months or years when air levels exceed 0.05-0.2 mg/m3. The main adverse effects after chronic exposure to mercury vapor are neuropsychiatric and include tremor, memory loss, insomnia, anorexia, irritability, and other mood changes. Kidney disease and peripheral neuropathy have been rarely reported after chronic exposure to mercury vapor. Acrodynia is a rare idiosyncratic disorder reported in children after mercury vapor exposure. [Olson, p. 305-7] Data is limited on the fetal effects of mercury in forms other than methyl mercury. Experimental animals exposed to high doses of mercury vapor and salts have increased developmental abnormalities. [ATSDR Case Studies #29] Mercury may produce slight hepatic injury in experimental animals. [Zimmerman, p. 419] Background levels of mercury are generally <10 ug/L for whole blood and <20 ug/L for urine. Regarding dental amalgams as a source of mercury vapor, occupational exposures can be controlled and personal exposures from fillings are insignificant. [Goldfrank, p. 1302, 1304] "Exposure to metallic mercury, for example from amalgam teeth fillings and other dental exposure, may give rise to sensitization." [Nordberg, p. 1041] See "Mercury, inorganic compounds."

Reference Link

ATSDR - ToxFAQs - Mercury

Exposure Assessment

Mercury in urine = 20 ug/g creatinine; sample prior to shift; Indicate average exposure during the past month; BEI for blood mercury withdrawn: may reflect recent exposure, but also affected by dietary exposure to methyl mercury in fish; [TLVs and BEIs]

Skin Designation (ACGIH)





0.02 mg/m3, as Hg


0.1 mg/m3, as Hg


0.02 mg/m3, as Hg, inhalable fraction


10 mg/m3, as Hg

Excerpts from Documentation for IDLHs

A single 4 hr. dose of 28.8 mg/m3 of mercury vapor caused severe damage to the kidneys, lungs and colon of rabbits, while a one hr. exposure caused mild injury.

Vapor Pressure

0.0012 mm Hg

Lethal Concentration

LCLo (rabbits) = 29 mg/m3/30 hr

Explanatory Notes

"Animal studies indicate that elemental mercury as a liquid or vapor can be absorbed percutaneously." Organic mercury is readily absorbed through skin. [ATSDR Case Studies] Boiling point = 674 degrees F. [NIOSH]

Half Life

Metallic and inorganic in whole body: 1-2 months; blood: 2 days to 1 month; methylmercury in blood: 1 month; methylmercury in whole body: 44-79 days; [TDR, p. 813]

Reference Link

ATSDR Medical Management - Mercury

Adverse Effects
Skin Sensitizer


Toxic Pneumonitis



Sensorimotor Neuropathy



Reproductive Toxin


IARC Carcinogen

Not Classifiable

ACGIH Carcinogen

Not Classifiable

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information


Chemical Information

Search ChemIDplus

Biomedical References

Search PubMed

Related Information in HazMap

Occupational diseases associated with exposure to this agent:


Industrial Processes with risk of exposure:


Activities with risk of exposure: