Toxicity barium compounds

Barium metal and most barium compounds are highly poisonous. A notable exception is barium sulfate which is nontoxic because of its extreme iasolubihty ia water. Barium ion acts as a muscle stimulant and can cause death through ventricular fibrillation of the heart. Therefore, care must be taken to avoid contact with open areas of the skin. Workers must wear respirators (of type approved for toxic airborne particles), goggles, gloves, and protective clothing at all times. The toxic barium aluminate residue obtained from barium production is detoxified by reaction with a solution of ferrous sulfate and converted iato nontoxic barium sulfate. According to OSHA standards, the TWA value for Ba and Ba compounds ia air is 0.5 mg/m. ... 

Because of its extreme insolubiUty, barium sulfate is not toxic the usual antidote for poisonous barium compounds is to convert them to barium sulfate by administering sodium or magnesium sulfate. In medicine, barium sulfate is widely used as an x-ray contrast medium (see Imaging TECHNOLOGY X-RAY technology). It is also used in photographic papers, filler for plastics, and in concrete as a radiation shield. Commercially, barium sulfate is sold both as natural barite ore and as a precipitated product. Blanc fixe is also used in making white sidewall mbber tires or in other mbber appHcations. 

Toxicity. The toxicity of barium compounds depends on solubility (47—49). The free ion is readily absorbed from the lung and gastrointestinal tract. The mammalian intestinal mucosa is highly permeable to Ba " ions and is involved in the rapid flow of soluble barium salts into the blood. Barium is also deposited in the muscles where it remains for the first 30 h and then is slowly removed from the site (50). Very Httle is retained by the fiver, kidneys, or spleen and practically none by the brain, heart, and hair. 

Many of bariums compounds are toxic, especially barium chloride, which affects the functioning of the heart, causing ventricular fibrillation, an erratic heartbeat that can lead to death. 

Several of bariums compounds are explosive as well as toxic if ingested or inhaled. Care should be used when working with barium and other alkali metals in the laboratory or in industry. 

The toxicity of barium compounds depends on their solubility, with the more soluble forms being more toxic than the relatively insoluble forms, which are inefficient sources of Ba ions. ... 

All barium salts, especially the water and acid-soluble compounds, are highly toxic. Barium ion can cause death through ventricular fibrillation of the heart. It is a stimulant to the heart muscle. Intake of a few grams of barium salt can be lethal to humans. The insoluble salts such as barium sulfate, however, have little toxic action. 

Strontium, Barium Strontium was discovered near, and named after, the small town of Strontian, Scotland, in 1787. There are no commercial uses for the pure metal, but the carbonate salt, SrC03, is used in the manufacture of glass for color TV picture tubes. Barium is found principally in the minerals witherite (BaC03) and barite (BaSC ), after which it is named. Though water-soluble salts of barium are extremely toxic, barium sulfate is so insoluble that it is used in medicine as a contrast medium for stomach and intestinal X rays. Like strontium, barium metal has no commercial uses, but various compounds are used in glass manufacture and in drilling oil wells. 

When evaluating the health effects of barium compounds, it is important to keep in mind that different barium compounds have different solubilities in water and body fluids and therefore serve as variable sources of the Ba + ion. The Ba + ion and the soluble compounds of barium (notably chloride, nitrate, hydroxide) are generally highly toxic to humans and experimental animals. The insoluble barium compounds (notably sulfate and carbonate) are inefficient sources of the Ba + ion and therefore are generally nontoxic. Throughout the following section (2.2), the health effects by route of exposure of both soluble and insoluble barium compounds are discussed. 

According to the SARA Section 313 Toxics Release Inventory (TRI), an estimated total of 16.3 million pounds of barium and barium compounds were released to the environment from manufacturing and processing facilities in the United States in 1987 (TR11989) (see Table 5-1). Most of these barium releases were to land. The quality of the TRI data must be viewed with caution since the 1987 data represent first-time, incomplete reporting of estimated releases by these facilities. Only certain types of facilities were required to report. This is not an exhaustive list. 

Akinfieva TA, Gerasimova IL. 1984. [Comparative toxicity of some barium compounds.] Gig Tr Prof Zabol 6 45-46. (Russian)... 

SAFETY PROFILE Very toxic. Fire hazard by chemical reaction with easily oxidized materials. Explodes at 300°. Mixtures with sulfur are unstable storage hazards igniting immediately at 91 °C and after a 2-11 day delay period at room temperature. Incompatible with Al, As, C, Cu, metal sulfides, organic matter, P, and reducing materials. When heated to decomposition it emits toxic fumes of Br . See also BARIUM COMPOUNDS (soluble) and BROMINE. 

OSHA PEL TWA 0.5 mg(Ba)/m3 ACGIH TLV TWA 0.5 mg(Ba)/m3 Not Classifiable as a Human Carcinogen DFG MAK 0.5 mg(Ba)/m3 SAFETY PROFILE A poison by ingestion, subcutaneous, intravenous, and intraperitoneal routes. Inhalation absorption of barium chloride equals 60-80% oral absorption equals 10-30%. Experimental reproductive effects. Mutation data reported. See also BARIUM COMPOUNDS (soluble). When heated to decomposition it emits toxic fumes of Cl". 

DOT CLASSIFICATION 6.1 Label Poison SAFETY PROFILE A deadly poison. See also CYANIDE and BARIUM COMPOUNDS (soluble). When heated to decomposition it emits toxic fumes of CN". 

DFG MAK 1 mg(Zr)/m3 SAFETY PROFILE Moderately toxic by ingestion and intraperitoneal routes. Inhalation produces interstitial pneumonitis. See also ZIRCONIUM COMPOUNDS and BARIUM COMPOUNDS. 

The radioactive properties of radium are the greatest concern and overwhelm all else. All radioactive materials may cause harm when decay particles are released that disrupt many critical cell functions, including DNA replication. Radioactive materials may also produce toxicity not related to their radioactive behavior. Like barium compounds, radium... 

Barium sulfate is the insoluble substance taken orally before stomach X-rays are made because the barium atoms absorb X-rays well. Even though barium ions are quite toxic, barium sulfate can still be taken orally without danger. The compound is so insoluble that it passes through the digestive system essentially unchanged. 

Barium burns quickly in the air and reacts with water to produce hydrogen. Some barium compounds can be quite toxic. For instance, ingesting the soluble form of barium chloride can damage the heart, causing an erratic heartbeat—a condition known as ventricular fibrillation. However, if barium is in an insoluble form, it is not toxic, and in fact has some valuable applications. 

Caution Beryllium and soluble barium compounds are extremely toxic. 

The Canadian Council of Ministers of the Environment recommends an interim soil quality criterion of 750 mg kg for agricultural use (Anonymous 1999). The toxic action of barium compounds is determined by their solubility, and the only risk deriving from near-insoluble barium sulfate is that of soluble barium salts present as impurities. Hence, the concentration of acid-soluble substances in barium sulfate for pharma-... 

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