Selenium safety

Selenium is a vital microelement for people. It has dual properties. Selenium is an essential nutrient at low concentration levels and it becomes toxic at higher concentration levels. Deficiency of selenium results in weakness and hard diseases. Selenium is a building material of many hormones and ferments it neutralizes free radicals, radioactive radicals in organism. The range of selenium safety concentration in food and water is very narrow. The daily normal amount of human consumption of selenium is 10-20 p.g, maximum safe concentration of selenium in water is 5-10 p.g/1. It becomes toxic at 20-30 p.g and bigger content in different objects. 

Caution Selenium compounds are exceedingly toxic (Note 1). Hydrogen peroxide attacks the skin and may decompose violently (Note 2). The reaction should be carried out behind a safety screen and in an efficient fume hood, and the operator should wear safety glasses and rubber gloves. 

Fine powdered cadmium reacts violently with selenium when it is heated. Nevertheless, the reaction is less violent than that of zinc with selenium. Therefore, one has to be careful when preparing cadmium selenide. The particle size of both reagents is a crucial safety factor regarding this reaction. 

Lemly, A.D. 1993a. Teratogenic effects of selenium in natural populations of freshwater fish. Ecotoxicol. Environ. Safety 26 181-204. 

Lee T, Tera F (1986) The meteoritic chromium isotopic composition and limits for radioactive Mn in the early solar system. Geochim Cosmochim Acta 50(2) 199-206 Lemly AD (1985) Toxicology of selenium in a freshwater reservoir Implications for environmental hazard evaluation and safety. Ecotoxicol Environ Saf 10 314-338 Lemly AD (1998) Pathology of Selenium Poisoning in Fish. In Environmental Chemistry of Selenium. 

Sulphuric acid-selenium reagent, approx 98% m/m H SO - Safety note wear PPE because this is highly corrosive. Add 4 g selenium powder to 400 ml sulphuric acid (approx. 98% m/m H SO ), and heat until just fuming. Stir occasionally with a glass rod until all the selenium has dissolved to give a dark green solution. Carefully remove from the hotplate and allow to cool. Make up to approximately 1 I with sulphuric acid. 

Acid-digest solution, 0.4% selenium in sulphuric acid (approximately 98% m/m H2SO4) - wear PPE. See Chapter 4 for full details of making this highly corrosive solution, and note the safety precautions. 

Lemly, A.D. 2004. Aquatic selenium pollution is a global environmental safety issue. Ecotoxicol. Environ. Saf. 59 44-56. 

Schrauzer, G.N. 2001. Nutritional selenium supplements product types, quality, and safety. J. Am. Coll. Nutr. 20, 1-4. 

Maximum limits for inorganic trace impurities (e.g., arsenic, cadmium, fluoride, lead, mercury, selenium) will be included in any monographs for which consumer safety or manufacturing experience indicates their desirability. No limits for... 

U.S. Department of Labor, Occupational Safety and Health Administration (OSHA). 2004. Chemical sampling information Selenium compounds (as Se). Washington, D.C. OSHA. 

International Program on Chemical Safety and the Commission of the European Communities (IPCS CEC). 1999. Selenium. Card No. 0072. Geneva, Switzerland World Health Organization. 

OSHA PEL TWA 0.01 mg(As)/m3 Cancer Hazard TWA 0.2 mg(Se)/m3 ACGIH TLV TWA 0.01 mg/m Confirmed Human Carcinogen BEL 35 n (As)/L inorganic arsenic and methylated metabolites in urine TWA 0.2 mg(Se)/m3 DFG MAK DFG TRK 0.2 mg/m calculated as arsenic in that portion of dust that can possibly be inhaled 0.1 mg(Se)/m3 NIOSH REL CL 2 ng(As)/m3 SAFETY PROFILE Confirmed human carcinogen. When heated to decomposition it emits fumes of As and Se. Incompatible with oxidizing materials. When heated to decomposition it emits highly toxic fumes of Se and arsenic. See ARSENIC COMPOUNDS and SELENIUM COMPOUNDS. 

SAFETY PROFILE Confirmed human carcinogen with experimental tumorigenic data. See also ARSENIC COMPOUNDS and SELENIUM COMPOUNDS. When heated to decomposition it emits very toxic fumes of As and Se. 

SAFETY PROFILE Confirmed human carcinogen. Selenium compounds are considered to be poisons. When heated to decomposidon it emits toxic fumes of Cd and Se. See also CADMIUM COMPOUNDS and SELENIUM COMPOUNDS. 

NIOSH REL (Chromium(VI)) TWA 0.025 mg(Cr(VI))/mh CL 0.05/15M SAFETY PROFILE Confirmed human carcinogen. Poison by subcutaneous route. Mutation data reported. A powerful oxidizer. A powerful irritant of skin, eyes, and mucous membranes. Can cause a dermatitis, bronchoasthma, chrome holes, damage to the eyes. Dangerously reactive. Incompatible with acetic acid, acetic anhydride, tetrahydronaphthalene, acetone, alcohols, alkali metals, ammonia, arsenic, bromine penta fluoride, butyric acid, n,n-dimethylformamide, hydrogen sulfide, peroxyformic acid, phosphorus, potassium hexacyanoferrate, pyridine, selenium. 

SAFETY PROFILE Poison by ingestion and inhalation. A corrosive irritant to skin, eyes (at 2 ppm), and mucous membranes. Potentially explosive reaction with chlorobenzene + sodium, dimethyl sulfoxide, molten sodium, chromyl chloride, nitric acid, sodium peroxide, oxygen (above 100°C), tetravinyl lead. Reacts with carboxylic acids (e.g., acetic acid) to form violently unstable products. Violent reaction or ignition with Al, chromium pentafluoride, diallyl phosphite + allyl alcohol, F2, hexafluoroisopropylideneaminolithium, hydroxylamine, iodine chloride, PbOa, HNO2, organic matter, potassium, selenium dioxide, sulfur acids (e.g., sulfuric acid. 

SAFETY PROFILE Poison by intravenous route. Moderately toxic by ingestion. Experimental reproductive effects. When heated to decomposition it emits toxic fumes of Se and K2O. See also SELENIUM COMPOUNDS. 

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