Sodium Selenate

Signs and Symptoms of Sodium Selenate Exposure: Signs and symptoms of acute sodium selenate exposure include the following: garlic odor on breath, drooling, nasal irritation and burning sensation in nostrils, nausea, abdominal pain, vomiting, dizziness, and poor reflexes. Dypsnea (shortness of breath), pulmonary edema, hypotension, cardiopulmonary arrest, and coma may occur. Skin contact with sodium selenate often results in irritation and burns.

If material on fire or involved in fire: Extinguish fire using agent suitable for type of surrounding fire. Material itself does not burn or burns with difficulty. Use water in flooding quantities as fog. Use foam, dry chemical or carbon dioxide.

Personnel protection: Wear appropriate chemical protective gloves, boots and goggles. Wear positive pressure self-contained breathing apparatus when fighting fires involving this material.

SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.

Environmental considerations: Land spill: Dig a pit, pond, lagoon, or holding area to contain liquid or solid material. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be contained with a flexible impermeable membrane liner./ Cover solids with a plastic sheet to prevent dissolving in rain or fire fighting water.

Environmental considerations: Water spill: Adjust pH to neutral (pH 7). If dissolved, apply sodium sulfide (Na2S) solution to precipitate heavy metals. Allow to aerate. Use mechanical dredges or lifts to remove immobilized masses of pollutants and precipitates.

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number D010, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

Recycling: As the price of selenium is very high, recovery of it by processing selenium-containing waste is economical. For example, selenium refineries are equipped with wet scrubbers that employ an approx 50% soln of hydrobromic acid containing free bromine. The acid fumes are adsorbed in a lime and soda bed, and the selenium separated from the hydrobromic acid soln by distillation is recycled. Otherwise, solid or sludgy selenium-containing wastes from the manufacture or repair of xerox drums or from paint production are disposed of in special dumps. Recommendable methods: Chemical reduction, solidification & landfill. Not recommendable methods: Thermal destruction & discharge to sewer. Peer review: Reduction with SO2 /sulfur dioxide/ to SE /selenium/ metal. Do not use metal and acids to reduce disodium selenate as this will produce toxic gaseous hydrogen selenide. (Peer-review conclusions of an IRPTC expert consultation (May 1985))

Personnel protection: Avoid breathing dusts and fumes from burning material. Keep upwind.

Where there is any possibility of exposure of an employee's body to selenium, selenium oxychloride, sodium selenite, sodium selenate, selenium dioxide, or liquids containing these compounds, facilities for quick drenching of the body should be provided within the immediate work area for emergency use. /Selenium and its inorganic salts/

Non-impervious clothing which becomes contaminated with selenium, sodium selenite, sodium selenate, selenium dioxide or liquids containing these compounds should be removed promptly and not reworn until the contaminant is removed from the clothing. /Selenium and its inorganic salts/

Eye Exposure: If selenium or its inorganic compounds get into the eyes, wash eyes immediately with large amounts of water, lifting the lower and upper lids occasionally. Get medical attention immediately. /Selenium and its inorganic salts/

For more Preventive Measures (Complete) data for SODIUM SELENATE (8 total), please visit the HSDB record page.

0.2 [mg/m3], as Se

8 hr Time Weighted Avg (TWA): 0.2 mg/cu m. /Selenium and compounds, as Se/

Excursion Limit Recommendation: Excursions in worker exposure levels may exceed 3 times the TLV-TWA for no more than a total of 30 minutes during a work day, and under no circumstances should they exceed 5 times the TLV-TWA, provided that the TLV-TWA is not exceeded. /Selenium and compounds, as Se/

EYES: irrigate opened eyes for several minutes under running water. INGESTION: do not induce vomiting. Rinse mouth with water (never give anything by mouth to an unconscious person). Seek immediate medical advice. SKIN: should be treated immediately by rinsing the affected parts in cold running water for at least 15 minutes, followed by thorough washing with soap and water. If necessary, the person should shower and change contaminated clothing and shoes, and then must seek medical attention. INHALATION: supply fresh air. If required provide artificial respiration.

Selenium compounds have ... been tested for their ability to counteract testicular damage caused by cadmium. Selenide, selenite, selenate, and selenocysteine were most efficient, whereas selenomethionine was much less active. The former compounds both increased the testicular uptake and caused a redistribution of cadmium to high-molecular weight proteins. /Selenate/

The chemopreventive efficacies of selenate, selenite, selenium dioxide, selenomethionine and selenocystine were examined during the promotion phase of carcinogenesis in the 7,12-dimethylbenz(a)anthracene-induced mammary tumor model in rats. Each agent was added to the diet of a final concentration of 3 ppm selenium. In general, there was no significant difference in the potency of these five selenium compounds in inhibiting the development of mammary tumors. The interaction of vitamin E (500 ppm) with either selenite or selenomethionine was further characterized in a second carcinogenesis study. Results of this experiment suggested that vitamin E enhanced the protective effect of selenite but not that of selenomethionine. In an attempt to explore the synergistic mechanism of selenium and vitamin E, the effects of these two agents on mitogen induced blastogenesis and natural killer cytotoxic activity were also investigated. No consistent changes in these in vitro immune functions were detected resulting from supranutritional feeding of either selenite or vitamin E or both. ... /Selenate/

2-month-old male rats kept on a standard laboratory diet containing 0.06 ug Se/g dry weight were found to be more sensitive to the toxic action of selenite than female rats of corresponding age. This sex-dependent difference was not found in 20-day-old animals. Previous sc administration of 1 umol of selenium in the form of sodium selenite lowered the sensitivity of male rats to the toxic effects of selenite. The protective effect of this dose persisted for 18 days. A similar protective action against the lethal effects of selenite in adult male rats was exhibited by sodium selenate, selenomethionine, and dimethylselenide, all in an amount equal to 1 umol of selenium; pretreatment with trimethylselenonium iodide showed only an insignificant mortality decrease. Three days intake of deionized water with an addition of 0.1 or 1.0 ug selenium/mL also protected male rats against lethal doses of selenite. Peroral pretreatment of adult females did not decrease their sensitivity to the lethal effects of selenite.

The study was conducted to determine the effect of four forms of selenium on inhibition of DMBA-induced mammary tumors. BALB/c virgin female mice were fed the AIN-76 diet containing 0.2 or 2.0 ppm Se as selenite, selenate, selenomethionine, or selenocystine prior to and for 6 months post DMBA-treatment. At necropsy, mammary glands were histologically treated for confirmation of adenocarcinomas and the livers were removed for analysis of glutathione-peroxidase (GSHPx) activity and selenium concentrations. Dietary levels or forms of selenium had no effect on body weights. Inorganic selenium fed at 2.0 ppm Se (selenite and selenate) decreased mammary tumor incidence, but organic selenium (selenomethionine and selenocystine) had no effect on mammary tumor incidence. Hepatic GSHPx activity was highest with the 2.0 ppm selenium as selenocystine diet, but hepatic selenium levels were highest with the 2.0 ppm selenium as selenite. This study showed that the dietary form of selenium affects inhibition of mammary tumorigenesis. Furthermore, the study suggested that the pathways for selenium incorporation into GSHPx and for tumor inhibition are different. /Selenite, selenate, selenomethionine, selenocystine/

Chronic oral exposure to high concentrations of selenium compounds can produce a disease called selenosis. The major signs of selenosis are hair loss, nail brittleness, and neurological abnormalities (such as numbness and other odd sensations in the extremities). Animal studies have shown that selenium may also affect sperm production and the female reproductive cycle. (L619)

EC50; Species: Ankistrodesmus falcatus (Green Algae); Conditions: freshwater, static, 24 °C, pH 7.0, hardness 16-17 mg/L CaCO3, alkalinity 11-11.5 mg/L CaCO3; Concentration: 33 ug/L for 14 days; Effect: growth, general

EC50; Species: Microcoleus vaginatus (Blue-Green Algae); Conditions: freshwater, static, 24 °C, pH 7.0; Concentration: 8511 ug/L for 14 days; Effect: growth, general

EC50; Species: Pseudokirchneriella subcapitata (Green Algae); Conditions: freshwater, static, 24 °C, pH 7.0, hardness 16-17 mg/L CaCO3, alkalinity 11-11.5 mg/L CaCO3; Concentration: 277 ug/L for 14 days; Effect: growth, general

EC50; Species: Pseudokirchneriella subcapitata (Green Algae,~10000 cells/mL); Conditions: freshwater, static; Concentration: 199 ug/L for 96 hr; Effect: decreased population growth rate

For more Ecotoxicity Values (Complete) data for SODIUM SELENATE (85 total), please visit the HSDB record page.

TERRESTRIAL FATE: In alkaline, well-oxidized soil environments, selenates, Se(VI) predominate; selenates are very mobile because of their high water solubility and low tendency to adsorb onto soil particles(1). No sorption of sodium selenate was observed in 10 of 11 soils; a log Kd value of 0.958 was determined in Kula soil (pH 5.9, 6.62% TOC, 73.7% sand, 25.4% silt, 0.9% clay)(2). In soils, inorganic selenium compounds can be methylated by microorganisms and subsequently volatilize to the atmosphere(1,3); dimethylselenide and dimethyl diselenide are the principal products(3).

AQUATIC FATE: In aqueous solution, selenates are stable under alkaline oxidizing conditions(1).

Selenium readily substitutes for sulfur in biomolecules and in many biochemical reactions, especially when the concentration of selenium is high and the concentration of sulfur is low. Inactivation of the sulfhydryl enzymes necessary for oxidative reactions in cellular respiration, through effects on mitochondrial and microsomal electron transport, might contribute to acute selenium toxicity. Selenomethionine (a common organic selenium compound) also appears to randomly substitute for methionine in protein synthesis. This substitution may affect the structure and functionability of the protein, for example, by altering disulfide bridges. Inorganic forms of selenium appear to react with tissue thiols by redox catalysis, resulting in formation of reactive oxygen species and causing damage by oxidative stress. (L619)

/AQUATIC SPECIES/ An aquatic insect, the southern house mosquito (Culex quinquefasciatus: Diptera), was used to test the individual and joint effects of dissolved sodium selenate (Se) and methyl mercury chloride (MeHg). ... Ovipositional preference tests and 14-day chronic toxicity studies /were conducted/ to determine lethal and sublethal responses of C. quinquefasciatus to a range of Se and MeHg concentrations and mixtures. No evidence was found for female ovipositional preference in field trials using artificial ponds. Larvae were more sensitive to MeHg than Se, with LC(50) values of 30 ug/L (CI = 28-31 ug/L) and 11 mg/L (CI = 10-12 mg/L) respectively. In addition, larval survival was significantly reduced at concentrations as low as 25 ug/L of MeHg and 8 mg/L of Se. A synergistic interaction was observed in the toxicity of the Se-MeHg mixtures to C. quinquefasciatus larvae. Larval mosquito survival was significantly reduced at 7.5 ug/L MeHg + 2.75 mg/L Se and an LC(50) value of 9 ug/L MeHg + 3.4 mg/L Se was determined for a fixed ratio mixture. The rate of growth of the larvae was analyzed using a Growth Index that provided a sensitive measure of the developmental effects of toxicant exposure. Sodium selenate at concentrations as low as 2 mg/L caused a significant decrease in growth between larvae in treatment versus control solutions after only 4 days. Similarly, MeHg at concentrations as low as 25 ug/L and a Se-MeHg mixture of 3 ug/L MeHg plus 1.1 mg/L Se caused significant growth reductions after only 2 and 3 days, respectively...

/AQUATIC SPECIES/ ... Selenate toxicity was determined in standardized test waters with varying sulfate concentrations using Ceriodaphnia dubia, Gammarus pseudolimnaeus, Hyalella azteca, and Pimephales promelas as the test organisms. Analysis of test results indicated that a significant relationship does exist between acute selenate toxicity and ambient sulfate concentrations... /Selenate/

/AQUATIC SPECIES/ The acute and chronic toxicity to Daphnia magna Straus of selenium introduced as sodium selenate was examined, as was the acute toxicity of selenium introduced as sodium selenite. Acute toxicity was determined by standard, static 48-hr tests. Chronic toxicity was determined by a 32-day static renewal test. Nominal, initially measured and finally measured total and dissolved selenium concentrations were determined during the chronic test. Analysis of the chronic toxicity data was based on days to first brood, number of young per brood and total number of young produced per adult. These analyses indicate that with one exception, no statistically significant effects (p = 0.05) were observed at < 2.0 mg/L Se, giving rise to a maximum acceptable toxicant concentration (MATC) of 1.73 mg/L Se. Dry-weight analyses of adults at the termination of the chronic test and for fifth-brood young indicate an MATC of 1.2 mg/L Se. The 48-hr EC50 for selenate was 5.3 + or - 0.6 mg/L Se. The 48-hr EC50 for selenite was 1.1 + or - 0.2 mg/L Se. However, a 7-day EC50 determined during chronic selenate exposure was 1.9 (1.78-2.01) mg/L Se. This lethal threshold concentration is not significantly different from the chronic MATC.

Short-term oral exposure to high concentrations of selenium may cause nausea, vomiting, and diarrhea. Brief exposures to high levels of elemental selenium or selenium dioxide in air can result in respiratory tract irritation, bronchitis, difficulty breathing, and stomach pains. Longer-term exposure to either of these air-borne forms can cause respiratory irritation, bronchial spasms, and coughing. (L619)

The following link will take the user to the National Toxicology Program (NTP) Test Agent Search Results page, which tabulates all of the "Standard Toxicology & Carcinogenesis Studies", "Developmental Studies", and "Genetic Toxicity Studies" performed with this chemical. Clicking on the "Testing Status" link will take the user to the status (i.e., in review, in progress, in preparation, on test, completed, etc.) and results of all the studies that the NTP has done on this chemical.[Available from: http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=ntpsearch.searchresults&searchterm=13410-01-0]

D010; A solid waste containing selenium (such as sodium selenate) may or may not become characterized as a hazardous waste when subjected to the Toxicity Characteristic Leaching Procedure listed in 40 CFR 261.24, and if so characterized, must be managed as a hazardous waste.

Listed as a hazardous air pollutant (HAP) generally known or suspected to cause serious health problems. The Clean Air Act, as amended in 1990, directs EPA to set standards requiring major sources to sharply reduce routine emissions of toxic pollutants. EPA is required to establish and phase in specific performance based standards for all air emission sources that emit one or more of the listed pollutants. Selenium cmpds are included on this list. /Selenium cmpds/

Releases of CERCLA hazardous substances are subject to the release reporting requirement of CERCLA section 103, codified at 40 CFR part 302, in addition to the requirements of 40 CFR part 355. Sodium selenate is an extremely hazardous substance (EHS) subject to reporting requirements when stored in amounts in excess of its threshold planning quantity (TPQ) of 100/10,000 lbs. Extremely hazardous substances that are solids are subject to either of two threshold planning quantities ... The lower quantity applies only if the solid exists in powdered form and has a particle size less than 100 microns; or is handled in solution or in molten form; or meets the criteria for a National Fire Protection Association (NFPA) rating of 2, 3 or 4 for reactivity. If the solid does not meet any of these criteria, it is subject to the upper ... threshold planning quantity ... .

(AZ) ARIZONA 10 ug/L /Selenium/

(NY) NEW YORK 10 ug/L /Selenium/

(AZ) ARIZONA 45 ug/L /Selenium/

(CT) CONNECTICUT 10 ug/L /Selenium/

(ME) MAINE 35 ug/L /Selenium/

(MN) MINNESOTA 30 ug/L /Selenium/

Used as insecticide for plant protection and for various veterinary applications; [HSDB] Used as a reagent and insecticide for non-edible plants; [Hawley] An important additive to fertilizers; [Ullmann]

Farming (Pesticides) [Category: Industry]

Insecticide in some horticultural applications

Reagent, insecticide for nonedible plants

Added to chromium-plating baths to improve corrosion protection from pitting, blistering, and rusting, especially of plated automobile articles exposed to salt ... used in commercial greenhouses, primarily for growing carnations and chrysanthemums.

In glass manufacture; in medicinals to control animal diseases.