Agent Name |
Thallium and soluble compounds |
CAS Number |
7440-28-0; varies |
Formula |
Tl, varies |
Major Category |
Metals |
Synonyms |
Thallium, elemental; Thallium metal; Thallium compouinds; Thallous oxide; Thallium nitrate; Thallium acetate; Thallium sulfate; Thallium carbonate; [ACGIH] |
Category |
Metals, Inorganic Compounds |
Description |
Appearance and odor vary depending upon the specific soluble thallium compound. [NIOSH] |
Sources/Uses |
Coal-burning and smelting emissions are the major sources of release of thallium into the environment. [ATSDR ToxProfiles] METALLURGY: Alloy production; MANUFACTURING: Rodenticides, Electronic components, Optical lenses, Costume jewelry; USING OR DISPOSING: Grind or machine thallium-containing alloys; Clean fossil fuel furnaces or flues; |
Comments |
Chronic poisoning can cause peripheral neuropathy, liver injury, and hair loss (alopecia). Occupational exposure may occur through alloy production, machining thallium-containing alloys, or manufacturing of rodenticides, electronic components, optical lenses, or costume jewelry. It is used as an alloy with mercury to make switches in the semiconductor industry. "A urine thallium concentration of 100 ug/L corresponds to a 40-hour/week exposure to 0.1 mg/m3." Most reported cases of thallium poisoning follow ingestion. Occupational cases have been reported after skin absorption. [ACGIH] Thallous acetate and thallic chloride are slightly more toxic than the less soluble thallic oxide and thallous iodide. Symptoms are usually delayed for 12-14 hours after ingestion and include gastroenteritis (sometimes hemorrhagic) and shock. Chronic symptoms appear 2-4 weeks later in patients who survive: painful paresthesias and later hair loss. Urinary thallium levels of >20 mcg/L suggests excessive exposure. Thallium is radiopaque and may be detected in plain x-rays. [Olson, p. 354] After thallium poisoning by ingestion, patients may develop acute renal failure. [Rosenstock, p. 575] |
Restricted |
Thallium rodenticides were banned in the U.S. in 1972. |
Exposure Assessment |
Skin Designation (ACGIH) |
Yes |
Bioaccumulates |
Yes |
TLV (ACGIH) |
0.1 mg/m3, as Tl |
PEL (OSHA) |
0.1 mg/m3, as Tl |
IDLH (NIOSH) |
15 mg/m3, as Tl (soluble compounds) |
Excerpts from Documentation for IDLHs |
Human data : Lethal oral doses ranging from 0.9 to 9.4 mg/kg have been reported [Gekkan Yakuji 1980; Tanaka et al. 1978; Venugopal and Luckey 1978; Yakkyoku 1977]. [Note: an oral dose ranging from 0.9 to 9.4 mg/kg is equivalent to a 70-kg worker being exposed to concentrations ranging from about 40 to 450 mg/m3 for 30 minutes, assuming a breathing rate of 50 liters per minute and 100% absorption.] |
Explanatory Notes |
Melting Point = 577 degrees F; |
Half Life |
Whole body: 22 days; [TDR, p. 1129] |
Reference Link |
ATSDR - ToxFAQs - Thallium |
Adverse Effects |
Neurotoxin |
Sensorimotor Neuropathy |
Hepatotoxin |
Hepatotoxin, Secondary |
Nephrotoxin |
Yes |
Links to Other NLM Databases |
Health Studies |
Human Health Effects from Hazardous Substances Data Bank: THALLIUM COMPOUNDS THALLIUM, ELEMENTAL
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