Germanium

Agent Name
Germanium
CAS Number
7440-56-4
Formula
Ge
Major Category
Metals
Synonyms
Germanium element; Germanium, metal powder; [ChemIDplus] Germanium pieces; [MSDSonline]
Category
Metalloid Compounds (Germanium)
Description
Lustrous greyish-white brittle metalloid; [Merck Index] Silver-colored odorless pieces; [MSDSonline]
Sources/Uses
Used to make rectifying devices (germanium diodes), transistors, and red-fluorescing phosphors; Also used in dental alloys, catalysts, electroplating, infrared optics, gamma-ray spectroscopy, fiber optics, and veterinary medications; [HSDB] Used in brazing alloys, gold alloys, and beryllium alloys; [Hawley] Mainly used to make infrared sensing systems; Use in semiconductors is declining; Worldwide uses are: fiber optic systems (30%), polymerization catalysts (25%), electronic/solar applications (15%), and other (phosphors, metallurgy, and chemotherapy); [Nordberg, p. 802]
Comments
A metalloid in group IVa of the periodic table along with carbon, silicon, tin, and lead; Comparatively low systemic toxicity: injures the kidneys, liver, and nerves; Topical application of Ge dioxide caused no irritation, but Ge tetrachloride, which hydrolyzes releasing HCL, caused ulcerations after 2 hours; Oral LD50 (rat) = 3700 mg/kg; Toxic signs after lethal doses included hypothermia, listlessness, tremor, convulsions, and respiratory paralysis; Liver injury is observed in high-dose acute, subacute, and chronic studies; Occupationally exposed workers had increased urinary albumin and transferrin; Patients taking high-dose germanium supplements have developed neuropathy; [Nordberg, p. 799-812] From 1982-1991, 18 cases of acute renal failure and 2 deaths were reported in patients taking 16 to 328 grams of germanium over a period of 4-36 months. This dose is 100 to 2000 times the average dietary intake (1.5 mg/day); [HSDB]
Biomedical References

Exposure Assessment

Lethal Concentration
LCLo (rat) = 3860 mg/m3/4h
Half Life
Inadequate data, but estimated at 1.5 days whole-body retention time in rats; [Nordberg, p. 557]

Adverse Effects

Neurotoxin
Sensorimotor
Hepatotoxin
Hepatoxic (a) from occupational exposure (secondary effect) or (b) in animal studies or in humans after ingestion
Nephrotoxin
Yes

Diseases, Processes, and Activities Linked to This Agent

Processes