Thallium

Metals -> Metals, Inorganic Compounds

Flammable agents - 3rd degree

-> NIOSH Emergency Response Categories

Trace element

11.8 g/cu cm

Relative density (water = 1): 11.9

1.10

11.8 @25 °C

Bluish-white, very soft, inelastic, easily fusible, heavy metal

Soft, blue-white metal

Somewhat softer than lead; when freshly melted resembles tin in whiteness; oxidizes rapidly, turning gray, then brownish black form an oxide coating

For more Solubility (Complete) data for THALLIUM, ELEMENTAL (20 total), please visit the HSDB record page.

Insoluble in water; reacts with acid

Dissolves in warm dilute mineral acids, forming thallous (+1) salts and liberating hydrogen gas

Solubility in water: none

1473 °C

1457 °C

1473 °C @760 [mm Hg]

577 °F

304 °C

304 °C

302 °F

304 °C

Vapor pressure: 1.59X10-5 Pa at 400 K; 0.0931 at 800 K; 16.9 Pa at 1000 K /Calculated/

1 Pa at 609 °C; 10 Pa at 704 °C; 100 Pa at 824 °C; 1 kPa at 979 °C; 10 kPa at 1188 °C; 100 kPa at 1485 °C

depends upon the specific compound

Thallium appears as bluish-white soft malleable metal or gray granules. Density 11.85 g / cm3. Emits toxic fumes when heated. May be packaged under water.

Appearance and odor vary depending upon the specific soluble thallium compound. [NIOSH]

BLUISH-WHITE VERY SOFT METAL. TURNS GREY ON EXPOSURE TO AIR.

Light-gray to tan powder with a slightly aromatic odor.

Bluish-white metal that turns gray on exposure to air.

Danger

H300: Fatal if swallowed [Danger Acute toxicity, oral]

P260, P264, P270, P271, P273, P284, P301+P316, P304+P340, P316, P319, P320, P321, P330, P403+P233, P405, and P501 (click each P-code to see the statement)

Danger

H300 (100%): Fatal if swallowed [Danger Acute toxicity, oral]

P260, P264, P270, P271, P273, P284, P301+P316, P304+P340, P316, P319, P320, P321, P330, P403+P233, P405, and P501 (click each P-code to see the statement)

Chemical: Thallium

Hazard Traits - Dermatotoxicity; Developmental Toxicity; Hepatotoxicity and Digestive System Toxicity; Neurotoxicity; Other Toxicological Hazard Traits; Reproductive Toxicity

Thallium: Does not have an individual approval but may be used under an appropriate group standard

The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)

Excerpt from ERG Guide 151 [Substances - Toxic (Non-Combustible)]:

Not combustible. Gives off irritating or toxic fumes (or gases) in a fire. Finely dispersed particles form explosive mixtures in air.

Pure thallium is a bluish-white metal that is found in trace amounts in the earth's crust. In the past, thallium was obtained as a by-product from smelting other metals; however, it has not been produced in the United States since 1984. Currently, all the thallium is obtained from imports and from thallium reserves.. In its pure form, thallium is odorless and tasteless. It can also be found combined with other substances such as bromine, chlorine, fluorine, and iodine. When it's combined, it appears colorless-to-white or yellow.. Thallium is used mostly in manufacturing electronic devices, switches, and closures, primarily for the semiconductor industry. It also has limited use in the manufacture of special glass and for certain medical procedures.

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 after 2-4 weeks 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. 433-4] After thallium poisoning by ingestion, patients may develop acute renal failure. [Rosenstock, p. 575] The toxicological significance of thallium is mainly restricted to some inorganic and organic salts of Tl+ such as TlCl, Tl2SO4 (used as a rodenticide), and thallium acetate. Intoxications by elemental thallium are comparatively rare. [Ullmann] Cases of occupational poisoning from skin contact in workers manufacturing rodenticides were described in the 1950s. Symptoms included vague ill health, paresthesias, and some hair loss. [Nordberg, p. 1236]

Pursuant to section 8(d) of TSCA, EPA promulgated a model Health and Safety Data Reporting Rule. The section 8(d) model rule requires manufacturers, importers, and processors of listed chemical substances and mixtures to submit to EPA copies and lists of unpublished health and safety studies. Thallium is included on this list with an effective date of June 1, 1987 and a sunset date of June 1, 1997.

Excerpt from ERG Guide 151 [Substances - Toxic (Non-Combustible)]:

In case of fire in the surroundings, use appropriate extinguishing media.

- Thallium is non-combustible.

Rinse and then wash skin with water and soap.

Rinse with plenty of water (remove contact lenses if easily possible).

Refer immediately for medical attention.

TIH (Toxic Inhalation Hazard) - Term used to describe gases and volatile liquids that are toxic when inhaled. Some are TIH materials themselves, e.g., chlorine, and some release TIH gases when spilled in water, e.g., chlorosilanes. [ERG 2016].

Store separated from strong acids, fluorine, other halogens food and feedstuffs

In the presence of water, a hydroxide is formed. Thallium is therefore stored under petroleum spirit, glycerine, or deaerated water. On prolonged storage under water with free access of air, metallic thallium becomes covered with large crystals of thallium(I) carbonate, and the water becomes saturated with this salt. To protect against oxidation, rods of thallium are coated with paraffin.

1. Ventilate area of spill. ... 2. For small quantities, sweep onto paper or other suitable material, place in sealed container for disposal. Large quantities may be reclaimed; However, if this is not practical, collect spilled material in the most convenient & safe manner & deposit in sealed containers for disposal. 3. Liquids containing sol thallium compounds may be absorbed in vermiculite, dry sand, earth, or a similar material & deposited in sealed containers for disposal. /Thallium and thallium cmpd/

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

Sweep spilled substance into sealable containers. Carefully collect remainder, then remove to safe place. Do NOT let this chemical enter the environment. (Extra personal protection: P3 filter respirator for toxic particles.)

Reuse: Return to the suppliers. Recommendable methods: Solidification, & landfill. Not recommendable method: Thermal destruction. Peer review: Convert sol cmpd to insol form, solidify and landfill. (Peer-review conclusions of an IRPTC expert consultation (May 1985))

Do not eat, drink, or smoke during work. Wash hands before eating.

Remove contaminated clothes. Rinse and then wash skin with water and soap. Refer for medical attention.

Where thallium compounds must be used, strict safety precautions should be observed to prevent ingestion, inhalation or skin contact. Food, drink and cigarettes ... prohibited at the work site. /Thallium and thallium compounds/

One of the main methods of removing thallium (both radioactive and normal) from humans is to use Prussian blue, which is a material which absorbs thallium. Up to 20 g per day of Prussian blue is fed by mouth to the person, and it passes through their digestive system and comes out in the stool. Hemodialysis and hemoperfusion are also used to remove thallium from the blood serum. At later stage of the treatment additional potassium is used to mobilize thallium from the tissue.

Among the distinctive effects of thallium poisoning are loss of hair (which led to its initial use as a depilatory before its toxicity was properly appreciated) and damage to peripheral nerves (victims may experience a sensation of walking on hot coals), although the loss of hair only generally occurs in low doses; in high doses the thallium kills before this can take effect. (Wikipedia) Thallium toxicity is complex and severe. It affects several systems in human body, including liver, gastrointestinal, cardiovascular, reproductive, renal, and nervous systems. Among them, liver is an important organ which possibly assists metabolic reduction of metals; hence, it could be a noticeable organ for thallium toxicity. This is confirmed by the other study on thallium-induced toxicity in experimental animals which reported highest accumulation in liver, kidney, and ileum. (A15464)

The substance can be absorbed into the body by ingestion.

Thallium can be absorbed into the body by inhalation, ingestion, and skin contact. Ingestion is an important route of exposure.

Dermal; inhalation; ingestion

Thallium(I) compounds have a high aqueous solubility and are readily absorbed through the skin. Part of the reason for thallium's high toxicity is that, when present in aqueous solution as the univalent thallium(I) ion (Tl+), it exhibits some similarities with essential alkali metal cations, particularly potassium (due to similar atomic radii). It can thus enter the body via potassium uptake pathways. Other aspects of thallium's chemistry differ strongly from that of the alkali metals, such its high affinity for sulfur ligands. Thus this substitution disrupts many cellular processes (for instance, thallium may attack sulfur-containing proteins such as cysteine residues and ferredoxins). (Wikipedia) A 2013 study found evidence that the thallium(I)-induced liver toxicity is a result of the disruptive effect of this metal on the mitochondrial respiratory complexes (I, II, and IV), which are the obvious causes of metal-induced reactive oxygen species formation and ATP depletion. The latter two events, in turn, trigger cell death signaling via opening of mitochondrial permeability transition pore and cytochrome c expulsion. (A15464)

No acute symptoms expected.

Abdominal pain. Nausea. Vomiting. Headache. Weakness. Muscle pain. Blurred vision. Restlessness. Convulsions. Increased heart rate. Symptoms may be delayed.

- Acute eye exposure is unlikely to result in any local or systemic effects other than mild local irritation.

- Adverse effects due to thallium poisoning are usually delayed by 12 to 24 hours in acute poisoning and reach their maximum by the second or third week after exposure.

- See Ingestion Exposure.

- See Ingestion Exposure.

The following medical procedures should be made available to each employee who is exposed to ... thallium /and thallium/ compounds at potentially hazardous levels: Initial Medical Examination: A complete history and physical examination: The purpose is to detect existing conditions that might place the exposed employee at increased risk, and to establish a baseline for future health monitoring. Examination of the eyes, nervous system, lung, liver, kidneys, gastrointestinal tract, and body hair should be stressed. Urinalysis: Since kidney damage has been observed in humans exposed to thallium, a urinalysis should be obtained to include at a minimum specific gravity, albumin, glucose, and a microscopic /examination/ on centrifuged sediment. Periodic Medical Examination: These medical examinations should be repeated on an annual basis. /Thallium and thallium compounds/

Respiratory Symptom Questionnaires: Questionnaires have been published by the American Thoracic Society and the British Medical Research Council. These questionnaires have been found to be useful in identification of people with chronic bronchitis, however certain pulmonary function tests such as FEV 1 ... have been found to be better predictors of chronic airflow obstruction. /Thallium/

/EPIDEMIOLOGY STUDIES/ ... Data /were presented/ on the health of workers employed in a magnesium sea water battery plant; exposure to thallium was in the form of fume from alloying in the furnaces, skin contact in the strip-rolling of the thallium-magnesium alloy, and as a dust generated in the scrap-brushing of the alloy. Some workers had exposures above 0.1 mg/cu m as indicated by urinary thallium concentrations of up to 236 ug/L. A urine thallium concentration of 100 ug/L corresponds to a 40-hour/week exposure to 0.1 mg/cu m. There were no statistically significant differences in cardiovascular or gastrointestinal effects in the cohort of 86 exposed workers compared with 79 unexposed controls in the same factory. /Thallium alloy dusts/

Pursuant to section 8(d) of TSCA, EPA promulgated a model Health and Safety Data Reporting Rule. The section 8(d) model rule requires manufacturers, importers, and processors of listed chemical substances and mixtures to submit to EPA copies and lists of unpublished health and safety studies. Thallium is included on this list with an effective date of June 1, 1987 and a sunset date of June 1, 1997.

Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 1000 lb or 454 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b). No reporting of releases of this hazardous substance is required if the diameter of the pieces of the solid metal released is larger than 100 micrometers (0.004 inches).

(AZ) ARIZONA 13 ug/L

(MN) MINNESOTA 0.6 ug/L

Thallium inhibits enzymes, but nothing is really known of a biochemical lesion. In fatal cases, there usually is extensive peripheral paralysis and cardiovascular involvement. The immediate cause of death may be peripheral respiratory failure of cardiac arrest. /Thallium/

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;

Thallium rodenticides were banned in the U.S. in 1972.

Metal Machining [Category: Heat or Machine]

Thallium-203 is a target for accelerator production of thalium-201, which is used in cardiac imaging.

The unalloyed metal is unsuitable for direct use, owing to its unfavorable mechanical properties and marked tendency to oxidize.

In semi-conductor industry; alloyed with mercury for switches and closures which operate at subzero temperatures.

(1984) NO PRODUCTION IN 1984 /100% IMPORTED/

(1990) NO PRODUCTION IN 1990 /100% IMPORTED/

(2002, 2003, 2004, 2005, 2006) No reported mine production; flue dust and residues from base-metal smelters, from which thallium metal and compounds may be recovered, are being exported to Canada, France, The united Kingdom, and other countries.

Flue dusts from lead and zinc smelting. The thallium compounds recovered are treated to obtain the metal by electrolysis, precipitation, or reduction.

The simplest process is leaching with water without pretreatment. With airborne dusts from lead or zinc smelting works, or cementation slimes, a yield of 85-90% of the thallium can be obtained. The thallium-containing liquor, which usually also contains cadmium and zinc, is filtered, precipitated with zinc amalgam, and the relatively pure metal is obtained by an electrolytic process.

... Methods ... /for/ pretreating the starting material before leaching ... include: oxidative roasting at 500 °C, sulfatization at 175-250 °C, and alkaline pretreatment. Leaching of the raw material after pretreatment can extract 50-60% of the thallium. Flue dusts that contain bismuth, copper, zinc, iron, arsenic, cadmium, thallium, selenium, etc., are given an alkaline pretreatment (fusion with caustic soda and lead sulfide). The alkaline slag so formed is granulated with hot water. On cooling, sodium and thallium arsenates are precipitated, and processed to obtain the thallium.

The thallium is usually precipitated and recovered as a sparingly soluble salt (cementation thallium and thallium amalgam) from liquors produced in a variety of concentration methods, with and without pretreatment, and also from liquors that are themselves the raw materials.

For more Methods of Manufacturing (Complete) data for THALLIUM, ELEMENTAL (6 total), please visit the HSDB record page.

Grade: Technical, high-purity

Rods, 3/8" diameter X 1" long, 99.995% purity grade; 25- 100- & 500-G lots (metal); 99.9% & 99.99% pure rods and chunks (metal)

Thallium: ACTIVE

... In manufacture of highly refractive optical glass. Has been used in admixture with 97-98% of inert substances as poison for rats and other rodents.

IN 1984, CONSUMPTION DEMAND FOR THALLIUM WAS SUPPLIED 100% BY IMPORTS.