Selenium dioxide

110.96

110.96

231-957-4

9N3UK29E57

0946

56753

3283|2811

DTXSID4021264

Lustrous tetragonal needles; yellowish green vapor|White or yellowish-white to slightly reddish, lustrous, crystalline powder or needles.

2811290090

34.1

-0.61840

white powder

3.954 g/cm³ @ Temp: 15 °C

340 °C

684.9 °C(lit.)

315°C

Index of refraction: less than 1.76 at 20 °C/D

H2O: 38.4 g/100 mL (14 ºC)

Store below +30°C.

1 mm Hg ( 157 °C)

Oral-rat LD50: 68.1 mg/kg; Oral-Mouse LC50: 23.3 mg/kg

Non-combustible; produces toxic selenide fumes in the fire

Vapor has a pungent sour smell

Acidic taste; leaves a burning sensation.

Dipole moment: 2.62 debye|Dissolves in water to form selenious acid|Electron affinity: 1.823 eV|Heat of formation: at 25 °C -238.5 kJ/mol|For more Other Experimental Properties (Complete) data for SELENIUM DIOXIDE (13 total), please visit the HSDB record page.

In presence of water will corrode most metals (USCG, 1999). Readily soluble in water forming selenious (selenous) acid.

Oxidizing Agents, Strong

Strong Oxidizing Agent

Inorganic oxidizing agents, such as SELENIUM DIOXIDE, react with reducing agents to generate heat and products that may be flammable, combustible, or otherwise reactive. SELENIUM DIOXIDE reacts with water, particularly hot water, to give selenious (selenous) acid, a weak acid that is corrosive. Stable to light and heat. Rapidly absorbs dry hydrogen fluoride, hydrogen chloride, hydrogen bromide to form the corresponding selenium oxohalide. A good oxidizing agent. Reacts oxidatively with ammonia to form dinitrogen gas and selenium [Merck]. Oxidizes many organic substances.

In presence of water will corrode most metals|... Soluble in water forming selenic acid, a corrosive material. ...

II

6.1

UN 3440 6.1/PG 3

2

36/38-50/53-33-23/25-51/53-20/22

26-61-60-45-28A-20/21-28

VS8575000

T,N,Xn

Treasury is low temperature, ventilated, dry; stored separately from oxidants, strong acids, food materials

Stable. Incompatible with organic materials, strong acids, ammonia, nitric acid, halogen acids. Protect from moisture.

P261-P273-P301 + P310-P311-P501

H301 + H331-H373-H410

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number D010; U204, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

Do not use metal and acid to reduce selenium compounds. This will produce toxic gaseous hydrogen selenide. /Selenium compounds/|Acids, strong oxidizers, chromium trioxide, potassium bromate. /Selenium/

WHO; Environ Health Criteria: Selenium 58: 1-306 (1987). EHC are designed for scientists and administrators responsible for the establishment of safety standards and regulations and provide basic scientific risk evaluations of a wide range of chemicals and groups of chemicals.[Available from, as of April 1, 2011: http://www.inchem.org/documents/ehc/ehc/ehc58.htm#SectionNumber:7.1]|US Dept of Interior/Fish & Wildlife Service Contaminant Reviews; Selenium Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review Biol Rept No (85)1.5 (1985)

Special Hazards of Combustion Products: Sublimes and forms toxic vapors when heated in fire. (USCG, 1999)|Not combustible. Gives off irritating or toxic fumes (or gases) in a fire.

|Danger|H301 (100%): Toxic if swallowed [Danger Acute toxicity, oral]|P260, P261, P264, P270, P271, P273, P301+P310, P304+P340, P311, P314, P321, P330, P391, P403+P233, P405, and P501|Aggregated GHS information provided by 241 companies from 18 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H301: Toxic if swallowed [Danger Acute toxicity, oral]|P260, P264, P270, P280, P301+P310, P305+P351+P338, P307+P311, P314, P321, P330, P337+P313, P405, and P501|H300: Fatal if swallowed [Danger Acute toxicity, oral]|P260, P264, P270, P280, P301+P310, P305+P351+P338, P307+P311, P309+P311, P314, P321, P330, P337+P313, P405, and P501

Excerpt from ERG Guide 151 [Substances - Toxic (Non-combustible)]: As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: Increase, in the downwind direction, as necessary, the isolation distance shown above. FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2016)

Excerpt from ERG Guide 151 [Substances - Toxic (Non-combustible)]: Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Cover with plastic sheet to prevent spreading. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. (ERG, 2016)

This compound is highly toxic if inhaled or ingested. Dust mask; rubber gloves; protective clothing (USCG, 1999)|SRP: Local exhaust ventilation should be applied wherever there is an incidence of point source emissions or dispersion of regulated contaminants in the work area. Ventilation control of the contaminant as close to its point of generation is both the most economical and safest method to minimize personnel exposure to airborne contaminants. Ensure that the local ventilation moves the contaminant away from the worker.|All sources of selenium oxide or fumes should be fitted with exhaust ventilation systems with an air speed of at lease 30 m/min. /Selenium compounds/|... Dispensing & weighing /selenium dioxide/ powder can be carried out in efficient fume cupboards wearing gloves, whereas cleaning ... electrostatic precipitators & ducting containing red fume mixt of selenium & selenium dioxide can only be done /with/ ... completely impervious suits supplied by air lines.|Wear appropriate personal protective clothing to prevent skin contact. /Selenium/|For more Personal Protective Equipment (PPE) (Complete) data for SELENIUM DIOXIDE (8 total), please visit the HSDB record page.

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. Keep run-off water out of sewers and water sources. /Selenium compound, solid, nos/|Personnel protection: Wear appropriate chemical protective clothing. Wear positive pressure self-contained breathing apparatus when fighting fires involving this material. /Selenium compound, solid, nos/

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.

All sources of selenium oxide or fumes should be fitted with exhaust ventilation systems with an air speed of at least 30 m/min. ... smoking, eating and drinking at the workplace should be prohibited, and messrooms and sanitary facilities including showers and locker rooms should be provided ... wherever possible, operations should be mechanized, automated or provided with remote control.|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.|Skin Exposure: If selenium or its inorganic compounds get on the skin, immediately wash the contaminated skin. If selenium, sodium selenite, sodium selenate, or selenium dioxide soak through the clothing, remove the clothing immediately and wash the skin. If irritation persists after washing, get medical attention.|Smoking, eating, & drinking at the workplace should be prohibited, & messrooms & sanitary facilities incl showers & locker rooms should be provided at a point distant from exposure areas. Wherever possible, operations should be mechanized, automated, or provided with remote control. /selenium oxide/|For more Preventive Measures (Complete) data for SELENIUM DIOXIDE (13 total), please visit the HSDB record page.

/GUIDE 154: SUBSTANCES - TOXIC AND/OR CORROSIVE (NON-COMBUSTIBLE)/ Health: TOXIC; inhalation, ingestion, or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.|/GUIDE 154: SUBSTANCES - TOXIC AND/OR CORROSIVE (NON-COMBUSTIBLE)/ Fire or Explosion: Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated.|/GUIDE 154: SUBSTANCES - TOXIC AND/OR CORROSIVE (NON-COMBUSTIBLE)/ Public Safety: CALL Emergency Response Telephone Number ... As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. Ventilate enclosed areas.|/GUIDE 154: SUBSTANCES - TOXIC AND/OR CORROSIVE (NON-COMBUSTIBLE)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible.|For more DOT Emergency Guidelines (Complete) data for SELENIUM DIOXIDE (8 total), please visit the HSDB record page.

The dioxide itself forms selenious acid with water or sweat, and the acid is an irritant.|Causes intense local irritation of skin, eyes ... .

Permissible Exposure Limit: 8 Hr Time Weighted Avg: 0.2 mg/cu m. /Selenium compounds (as Se)/

Recommended Exposure Limit: 10 Hr Time-Weighted Avg: 0.2 mg/cu m. /Selenium; The REL also apply to other selenium compounds (as Se) except selenium hexafluoride./

Evacuate danger area! Consult an expert! Sweep spilled substance into covered containers. Carefully collect remainder. Then store and dispose of according to local regulations. Personal protection: complete protective clothing including self-contained breathing apparatus. Do NOT let this chemical enter the environment.

Separated from food and feedstuffs. Dry.

Evaporation at 20 °C is negligible; a harmful concentration of airborne particles can, however, be reached quickly when dispersed.

The substance is corrosive to the eyes, skin and respiratory tract. Inhalation may cause lung oedema. The substance may cause effects on the eyes. This may result in allergic-type reaction of the eyelids (rose eye). Medical observation is indicated.

Repeated or prolonged contact may cause skin sensitization. The substance may have effects on the respiratory tract, gastrointestinal tract, central nervous system and liver. This may result in nasal irritation, persistent garlic odour, stomach pain, nervousness and liver impairment.

PREVENT DISPERSION OF DUST! STRICT HYGIENE!

Use local exhaust or breathing protection.

Protective gloves. Protective clothing.

Wear face shield or eye protection in combination with breathing protection.

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 dioxide is included on this list.

D010; A waste containing selenium (such as selenium dioxide) may or may not be characterized a hazardous waste following testing by the Toxicity Characteristic Leaching Procedure as prescribed by the Resource Conservation and Recovery Act (RCRA) regulations.[40 CFR 261.24 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of March 8, 2011: http://www.ecfr.gov]|U204; A toxic waste when a discarded commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or manufacturing chemical intermediate.[40 CFR 261.33 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of March 8, 2011: http://www.ecfr.gov]

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 10 lb or 4.54 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).

D010; A solid waste containing selenium (such as selenium dioxide) 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.|U204; As stipulated in 40 CFR 261.33, when selenium dioxide, as a commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate, becomes a waste, it must be managed according to Federal and/or State hazardous waste regulations. Also defined as a hazardous waste is any residue, contaminated soil, water, or other debris resulting from the cleanup of a spill, into water or on dry land, of this waste. Generators of small quantities of this waste may qualify for partial exclusion from hazardous waste regulations (40 CFR 261.5).

The atmospheric level of selenium in most urban regions ranges from 0.1 to 10 ng/cu m. A greater part of the atmospheric selenium is bound to fly ash and to suspended particles that contain from 1.4 to 11 ug/g and from 1 to 110 ug/g, respectively.

most toxic

Acute toxicity tests showed that selenium dioxide (SeO2) was a strong antagonist against mercuric chloride toxicity in goldfish (Carassius auratus). Paradoxically, whole body accumulations of total mercury (Hg) were significantly increased with the admin of selenium (Se).|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. ...|Studies of lipid peroxidation induced by nickel in experimental animals are reviewed. Male Sprague-Dawley rats injected subcutaneously with nickel chloride show significantly increased lipoperoxidation (as indicated by the presence of thiobarbituric-acid (TAB) chromogens) in the liver, kidney, and lung and dose related increases in hepatotoxicity (as measured by serum aspartate-aminotransferase). ... When pretreated with ... selenium dioxide ..., followed by 500 ug/kg nickel-chloride, the increase of TBA chromogens in rat kidney homogenates is partially suppressed by selenium dioxide. ...|The effects of selenium on cadmium toxicokinetics and on the ability of cadmium to induce metallothionein, a metal-binding protein that is thought to confer tolerance to cadmium toxicity /is determined/. To assess the acute protective effects of selenium, male Wistar (WFr) rats were given selenium (as SeO2; 10 umol/kg, sc) at -24, and +24 hr relative to cadmium (as CdCl2; 45 umol/kg, sc). Over a 14-day period this dose of cadmium killed 6 out of 10 rats, while 100% of the cadmium-treated rats given concurrent selenium treatments survived. The acute increases in testicular weight that were seen with cadmium, indicative of edematous damage, were also prevented by concurrent selenium treatments.

LD50 Mouse (male) oral 16 mg/kg/day|LD50 Rat oral 48 mg/kg/day|LD50 Rabbit subcutaneous 4 mg/kg

/PLANTS/ The feasibility of using selenite ion (selenium dioxide (SeO2) or sodium selenite (Na2SeO3)) as a systemic deer repellent for the protection of Douglas fir seedlings is evaluated. When applied to the soil, the selenium (Se) is absorbed by the seedling roots, transported to the foliage, and thereafter volatilized. Acute phytotoxicity is observed only when Se foliar concn exceed 100 ppm, while animal repellency is demonstrated at concn as low as 1-2 ppm. ...

Selenium dioxide is formed by combustion of elemental selenium present in fossil fuels or rubbish.|Up to 90% of the selenium content in ambient air is emitted during the burning of fossil fuels. Selenium dioxide is formed during combustion of elemental selenium present in fossil fuels.

ATMOSPHERIC FATE: Volatile selenium dioxide is expected to exist in the gaseous state in the atmosphere(1,2). Selenium dioxide released to the air from the combustion of fossil fuels is expected to be reduced to elemental selenium by sulfur dioxide formed during the combustion(2). Selenium dioxide reacting with atmospheric moisture generates selenious acid aerosols(2).

... by ingestion and inhalation (dust).|Selenium dioxide can affect the body if it is inhaled, if it comes in contact with the eyes or skin, or if it is swallowed. Selenium dioxide may enter the body through the skin.|ACUTE POISONING THROUGH INHALATION MAY OCCUR IN INDUSTRY (SELENIUM DUST & FUMES, SELENIUM DIOXIDE & HYDROGEN SELENIDE). ...|Selenium fumes may contain selenium dioxide in concentrations as high as 50% and are often described as the main selenium problem in the work environment.|For more Probable Routes of Human Exposure (Complete) data for SELENIUM DIOXIDE (9 total), please visit the HSDB record page.

... In vitro experiments suggested that trace amounts of hydrogen selenide, which is an intermediate of selenite metabolism, probably induced hemolysis. For evaluation of the therapeutic value of hemoperfusion in selenium poisoning, in vitro hemoperfusion experiments were performed, which revealed only a moderate effect on selenium blood levels.

Absorption of selenium may be demonstrated by presence of the element in the urine and by a garlic-like odor of the breath. Inhalation of dust can cause bronchial spasms, symptoms of asphyxiation, and pneumonitis. Acute symptoms of ingestion include sternal pain, cough, nausea, pallor, coated tongue, gastrointestinal disorders, nervousness, and conjunctivitis. Contact with eyes causes irritation. (USCG, 1999)

Consult physician after all exposures to this compound. INHALATION: remove victim to fresh air; give oxygen if needed. INGESTION: induce vomiting; follow with gastric lavage and saline cathartics. EYES: flush immediately and thoroughly with water. SKIN: flush with water. (USCG, 1999)

Fresh air, rest. Half-upright position. Artificial respiration may be needed. Refer for medical attention.

Remove contaminated clothes. Rinse skin with plenty of water or shower. Refer for medical attention .

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Selenium and Related Compounds/|Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for shock and treat if necessary ... . Monitor for pulmonary edema and treat if necessary ... . Treat seizures if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . /Selenium and Related Compounds/|Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... .Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Consider vasopressors if patient is hypotensive with a normal fluid volume. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Selenium and Related Compounds/|Emergency and supportive measures. Maintain an open airway and assist ventilation if necessary. Administer supplemental oxygen. Treat coma, convulsions, bronchospasm, hypotension, and pulmonary edema if they occur. Since hypotension is often multifactorial, evaluate and optimize volume status, peripheral vascular resistance, and myocardial contractility. Observe for at least 6 hours after exposure. ... /Selenium/|Decontamination: Inhalation. Immediately remove the victim from exposure and give supplemental oxygen if available. Skin and eyes. Remove contaminated clothing and wash exposed skin with soap and copious water. Irrigate exposed eyes with copious tepid water or saline. Ingestion. Ingestion of elemental selenium or selenium salts does not usually benefit from GI decontamination. In light of the risk of severe corrosive GI injury, gastric lavage plus activated charcoal may be of value for ingestion s of selenious acid seen within 1 hour. Invitro experiments indicate that vitamin C can reduce selenium salts to elemental selenium, which poorly absorbed. Its use has not been studied in vivo, but oral or nasogastric administration of several grams of ascorbic acid has been recommended. /Selenium/

/SIGNS AND SYMPTOMS/ Long-term Exposure: Prolonged exposure to selenium, sodium selenite, sodium selenate, or selenium dioxide may cause paleness, coated tongue, stomach disorders, nervousness, metallic taste and a garlic odor of the breath. ... Prolonged skin contact with selenium oxide or selenium oxychloride may cause skin sensitization.|/SIGNS AND SYMPTOMS/ Short-term Exposure: Inhalation of large quantities of selenium dioxide ... may cause severe breathing difficulties which may not appear for several hours after exposure. Skin contact with selenium dioxide ... may cause skin burns. Skin exposure to selenium dioxide dust may cause a skin rash. Splashes of selenium dioxide may cause eye irritation. Selenium dioxide dust may cause "rose eye" an allergy of the eyelids in which they may become puffy.|/SIGNS AND SYMPTOMS/ ... Selenium dioxide ... caused skin burns and dermatitis. The compound caused excruciating pain when it penetrated under the free edge of the fingernails. It also could cause conjunctivitis and, eventually, an allergic type reaction of the eyes in workers exposed to the dust.|/SIGNS AND SYMPTOMS/ Selenium dioxide is more than a primary irritant, it causes extremely painful burns on the skin which, however, always heal without a scar. Theoretically, the selenium dioxide powder itself does not burn the skin (and if dropped on to the skin should be immediately brushed off dry). However, in practice, in the industrial environment, there is sufficient moisture on the skin from sweating to be taken up by this white solid to form a sticky solution of selenious acid within seconds, or at the most, minutes, of coming into contact with the skin.|For more Human Toxicity Excerpts (Complete) data for SELENIUM DIOXIDE (17 total), please visit the HSDB record page.

Dioxide, Selenium

The substance can be absorbed into the body by inhalation of its aerosol and by ingestion.

Burning sensation. Cough. Laboured breathing. Sore throat. Shortness of breath. Symptoms may be delayed.

Redness. Pain. Skin burns. Blisters.

Redness. Pain. Severe deep burns.

It ... is the most widely used selenium compound in industry.

Grades or Purity: Commercial, 99.5+%|-20 mesh, 99.5 and 99.999% purity grades /available/

Selenium oxide: ACTIVE|Selenium oxide (SeO2): ACTIVE|Experimental use: The feasibility of using selenite ion as a systemic deer repellent for the protection of Douglas fir seedlings is evaluated. When applied to the soil, the Se is absorbed by the seedling roots, transported to the foliage, and thereafter volatilized. Animal repellency is demonstrated at concentration as low as 1-2 ppm.