. "Appendix 3 Barium and Barium Salts." Spacecraft Water Exposure Guidelines for Selected Contaminants: Volume 2. Washington, DC: The National Academies Press, 2007.
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Spacecraft Water Exposure Guidelines: For Selected Contaminants, Volume 2
TABLE 3-1 Physical and Chemical Properties of Ba and Ba Compounds
Compound
Form
Molecular Weight
Solubility
Comment
Ba
Ba
137.3
Insoluble in water; soluble in alcohol
Ba chloride
BaCl2
208.2
375 g/L at 26°C
65.95% Ba
Ba chloride dehydrate
BaCl2·2H2O
244.3
375 g/L at 26°C
56.2% Ba
Ba acetate
Ba(CH3COO)2
255.5
1 g/1.5 mL
53.77% Ba
Ba sulfate
BaSO4
233.4
1.6 mg/L at 20°C
Also known as “barite”; 58.84% Ba
Ba carbonate
BaCO3
197.37
20 mg/L at 20°C
69.58% Ba
Ba sulfide
BaS
169.42
1.1 mg/L
81.08% Ba
Ba nitrate
Ba(NO3)2
261.38
Freely soluble
52.55% Ba
Source: Data from Merck 1989.
McCabe et al. (1970) and Calabrese (1977) reported that Ba was present in about 2,600 analyzed drinking water samples. It was found at about 1.5 milligrams (mg) per L in samples from areas of northern Illinois and northern Iowa. Because the solubility of Ba depends on the concentrations of total sulfate in the medium and because sufficient concentrations of sulfates are in the natural waters, it is difficult to maintain more than 1.5 mg/L in water (EPA 1985). The World Health Organization (WHO) has reported that the range of daily dietary intake of Ba is 300-1,770 g per day (4-25 µg per kilogram body weight per day). WHO (1990) also reported that the concentrations of Ba measured in U.S. drinking waters are 1-20 g/L. Several other reports indicated that the concentrations are much higher (Kopp 1969; Calabrese 1977).
Ba compounds are used to make not only drilling lubricants but also paints and pigments, textile dyes, greases, bricks, tile, glass, and rubber. Ba nitrate (Ba(NO3)2) is used in pyrotechnics. Because of its high radiopacity, BaSO4 has been used by doctors for taking x-rays of the stomach, intestines, and respiratory and urinary tract systems and in bronchography. A high-density suspension of Ba sulfate—usually 340 g suspended in 150 mL of water—is administered orally for radiologic evaluation of the small bowel. This represents a dose of 4.89 g per kilogram (kg).
