Hydrogen selenide

80.976

81.932175

231-978-9

0284

2202

DTXSID20872822

Colorless gas

0

-0.15580

GasVapor; Liquid

2.12 g/cm³ @ Temp: -42 °C

-65.73 °C

-41.3 °C

NA (Gas)

mL/100mL H2O: 377 (4°C), 270 (22.5°C) [MER06]; mL/l00g H2O at standard temp, pressure: 386 (0°C), 351 (10°C), 289 (20°C) [LAN05]

(70°F): 9.5 atm

2.12 at -43.6°F

Flammable Gas

Odor resembling decayed horseradish

Aqueous solution is weakly acidic, although it is stronger than aqueous acetic acid

pKa1 = 3.89; pKa2 = 11.0

2.79 times as heavy as air|Heat of formation: 85.7 kJ/mol at 25 °C; decomposed by moist air, liberating elemental selenium|Incompatible with strong oxidizers, water, halogenated hydrocarbons; conversion: 1 ppm = 3.31 mg/cu m|Ionization energy: 9.892 eV|For more Other Experimental Properties (Complete) data for HYDROGEN SELENIDE (7 total), please visit the HSDB record page.

9.88 eV

Flammable Gas

The gas is heavier than air and may travel along the ground; distant ignition possible.

Molar enthalpy of vaporization = 19.7 kJ/mol at -41.25 °C

Critical temp: 411 K; critical pressure: 8.92 MPa

2.3

UN 2202

23/25-33-50/53

(1/2)-20/21-28-45-60-61

MX1050000

T, N

Fireproof. Separated from strong oxidants. Keep in the dark. Cool.

Stable. Highly flammable. Readily forms explosive mixtures with air. Incompatible with oxidizing agents, acids, water, halogenated hydrocarbons.

P210, P260, P264, P270, P280, P305+P351+P338, P307+P311, P314, P321, P337+P313, P377, P381, P403, P405, P410+P403, P501

H220

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.|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.|Recommendable: Chemical reduction, solidification landfill. Not recommendable: Thermal destruction, discharge to sewer. 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. ... If possible, convert selenium compounds to an insoluble form with sulfur dioxide before landfill or solidification. Do not use metal and acid to reduce selenium compounds. This will produce toxic gaseous hydrogen selenide.

Dangerous fire and explosion risk, strong oxidizing agent. Concentrated solutions are highly toxic and strongly irritating.|Dangerous; will react vigorously with powerful oxidizing agents, such as hydrogen peroxide and nitric acid.|Dangerous; forms explosive mixtures with air.|Strong oxidizers, acids, water, halogenated hydrocarbons.|For more Hazardous Reactivities and Incompatibilities (Complete) data for HYDROGEN SELENIDE (8 total), please visit the HSDB record page.

U.S. Dept Health & Human Services/Agency for Toxic Substances & Disease Registry; Toxicological Profile for Selenium (September 2003). The ATSDR toxicological profile succinctly characterizes the toxicologic and adverse health effects information for a hazardous substance.[Available from, as of March 22, 2011: http://www.atsdr.cdc.gov/substances/indexAZ.asp#S]|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)|WHO; Environmental Health Criteria 58: Selenium (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]

Extremely flammable. Gas/air mixtures are explosive.|Flammable - 4th degree, Reactive - 3rd degree

|Danger|H220 (100%): Extremely flammable gas [Danger Flammable gases]|P210, P260, P271, P273, P284, P304+P340, P310, P320, P377, P381, P391, P403, P403+P233, P405, P410+P403, and P501|Aggregated GHS information provided by 83 companies from 4 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H220: Extremely flammable gas [Danger Flammable gases]|P210, P260, P264, P270, P280, P305+P351+P338, P307+P311, P314, P321, P337+P313, P377, P381, P403, P405, P410+P403, and P501

Compressed gases may create low temperatures when they expand rapidly. Leaks and uses that allow rapid expansion may cause a frostbite hazard. Wear appropriate personal protective clothing to prevent the skin from becoming frozen.|Wear appropriate eye protection to prevent eye contact with the liquid that could result in burns or tissue damage from frostbite.|Quick drench facilities and/or eyewash fountains should be provided within the immediate work area for emergency use where there is any possibility of exposure to liquids that are extremely cold or rapidly evaporating.|Respirator Recommendations: Up to 0.5 ppm: [Table#1620]|For more Personal Protective Equipment (PPE) (Complete) data for HYDROGEN SELENIDE (7 total), please visit the HSDB record page.|(See protection codes)

...highly flammable...|Dangerous fire hazard when exposed to heat or flame

During attempted conversion of recovered selenium metal to the dioxide by heating in oxygen, a vigorous explosion occurred. This was attributed to selenium catalysed oxidation of traces of organic impurities in the selenium.

If material on fire or involved in fire: Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Use water spray to knock-down vapors. Approach fire with caution. If fire is prolonged and material is confined in the container, consider evacuation of one (1) mile radius. If fire becomes uncontrollable or container is exposed to direct flame, consider evacuation of one (1) mile radius.|Personnel protection: Wear positive pressure self-contained breathing apparatus. Wear appropriate chemical protective clothing.

If exposed to prolonged fire or intense heat the containers may violently rupture or rocket.

Personnel protection: Avoid breathing vapors. Keep upwind. Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water. Approach fire with caution.|If material not on fire and not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors.|Work clothing that becomes wet should be immediately removed due to its flammability hazard (i.e., for liquids with a flash point <100 °F).|SRP: Contaminated protective clothing should be segregated in such a manner so that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. The completeness of the cleaning procedures should be considered before the decontaminated protective clothing is returned for reuse by the workers. Contaminated clothing should not be taken home at the end of shift, but should remain at employee's place of work for cleaning.|For more Preventive Measures (Complete) data for HYDROGEN SELENIDE (9 total), please visit the HSDB record page.

If ... THERE IS NO FIRE, go directly to the Table of Initial Isolation and Protective Action Distances /(see table below)/ ... to obtain initial isolation and protective action distances. IF THERE IS A FIRE, or IF A FIRE IS INVOLVED, go directly to the appropriate guide /(see guide(s) below)/ and use the evacuation information shown under PUBLIC SAFETY. /Hydrogen selenide, anhydrous/|/GUIDE 117: GASES - TOXIC - FLAMMABLE (EXTREME HAZARD)/ Health: TOXIC; Extremely Hazardous. May be fatal if inhaled or absorbed through skin. Initial odor may be irritating or foul and may deaden your sense of smell. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control may cause pollution. /Hydrogen selenide, anhydrous/|/GUIDE 117: GASES - TOXIC - FLAMMABLE (EXTREME HAZARD)/ Fire or Explosion: These materials are extremely flammable. May form explosive mixtures with air. May be ignited by heat, sparks or flames. Vapors from liquefied gas are initially heavier than air and spread along ground. Vapors may travel to source of ignition and flash back. Runoff may create fire or explosion hazard. Cylinders exposed to fire may vent and release toxic and flammable gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket. /Hydrogen selenide, anhydrous/|/GUIDE 117: GASES - TOXIC - FLAMMABLE (EXTREME HAZARD)/ Public Safety: CALL Emergency Response Telephone Number ... As an immediate precautionary measure, isolate spill or leak area for at least 100 meters (330 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Many gases are heavier than air and will spread along ground and collect in low or confined areas (sewers, basements, tanks). Keep out of low areas. Ventilate closed spaces before entering. /Hydrogen selenide, anhydrous/|For more DOT Emergency Guidelines (Complete) data for HYDROGEN SELENIDE (9 total), please visit the HSDB record page.

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./|The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.|The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.

Concentrations of 1.5 ppm or higher are strongly irritating to the eyes and nasal passages.

Permissible Exposure Limit: 8 hr Time Weighted Avg: 0.05 ppm (0.2 mg/cu m), as Se.

Recommended Exposure Limit: 10 Hour Time-Weighted Average: 0.05 ppm (0.2 mg/cu m).

Evacuate danger area! Consult an expert! Personal protection: complete protective clothing including self-contained breathing apparatus. Ventilation. NEVER direct water jet on liquid.

Fireproof. Separated from strong oxidants. Keep in the dark. Cool.

A harmful contamination of the air can be reached very quickly on evaporation of this substance at 20 °C.

The substance is irritating to the eyes and respiratory tract. Inhalation of this gas may cause pneumonitis. Exposure at high levels could cause death.

NO open flames, NO sparks and NO smoking. Closed system, ventilation, explosion-proof electrical equipment and lighting.

STRICT HYGIENE!

Use closed system or ventilation.

Cold-insulating gloves.

Wear safety goggles or face shield.

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. Hydrogen selenide is included on this list.

D010; A waste containing selenium (such as hydrogen selenide) 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]

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. Hydrogen selenide is an extremely hazardous substance (EHS) subject to reporting requirements when stored in amounts in excess of its threshold planning quantity (TPQ) of 10 lbs.

D010; A solid waste containing selenium (such as hydrogen selenide) 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.

LC50 Guinea pig inhalation 300 ppb/ 8 hr

Those ... who will be working with more reactive selenium cmpd such as ... hydrogen selenide ... should /be protected if they/ have a history of dermatitis, chronic bronchitis or any form of skin allergy or resp tract infection ... history of liver or kidney disease, jaundice or albuminuria ... Careful consideration must be given to /protecting workers during their reproductive years/.

ATMOSPHERIC FATE: Hydrogen selenide is volatile and is expected to exist in the gaseous state in the atmosphere(1,2). It is highly reactive in air and is rapidly oxidized to elemental selenium and water(2).

The solubility and mobility of selenium are dependent upon its valence and chemical state; under reducing conditions, selenium can form metal selenides, most of which have very low water solubilities, and volatile hydrogen selenide(1).

Methylated forms of selenium and hydrogen selenide are volatile and may escape to the atmosphere(2).

Inhalation|Acute poisoning through inhalation may occur in industry (selenium dust and fumes, selenium dioxide and hydrogen selenide).

After/ subacute hydrogen selenide poisoning ... urine excretion ... remain within normal limits, ie 0.01-0.1 mg selenium/L.

The incorporation of inorganic selenium into amino acids and selenoproteins has been characterized ... . Hydrogen selenide, which is the crucial intermediate, is bound to selenophosphate synthetase 2, a selenonoprotein, and selenophosphate is formed.|Inorganic selenium is reduced stepwise to the assumed key intermediate hydrogen selenide, and it (or a closely related species) is either incorporated into selenoproteins after being transformed to selenophosphate and selenocysteinyl tRNA according to the UGA codon encoding selenocysteinyl residue, or excreted into urine after being transformed into methylated metabolites of selenide. Consequently, selenium is mainly present in the mammalian body in forms of covalent carbon-selenium bonds, particularly selenoprotein P (the principal selenoprotein in plasma), selenoenzymes such as glutathione peroxidases (enzymes that catalyze the reduction of peroxidases and thereby protect cells from oxidative damage), type 1-iodothyronine deiodinase (which catalyzes the deiodination of thyroxine to triiodothyronine), and thioredoxin reductase (which may trigger cell signaling in response to oxidative stress).

(See procedures)

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

ON FROSTBITE: rinse with plenty of water, do NOT remove clothes.

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/ In humans, a concentration of 5 mg/cu m (1.5 ppm) hydrogen selenide was found to be intolerable due to eye and nasal irritation, while 1 mg/cu m (0.3 ppm) caused no irritation with exposure of a few minutes duration.|/SIGNS AND SYMPTOMS/ ... Five cases /were reported/ of industrial selenosis in laboratory workers caused by inhalation of less than 0.2 ppm of hydrogen selenide. Predominating symptoms were nausea, vomiting, metallic taste in the mouth, alliaceous /SRP: garlic like/ breath odor, and extreme lassitude and fatigue.|/SIGNS AND SYMPTOMS/ ... Running nose and eyes, coughing, sneezing, slight tightness of the chest, and ultimately, pulmonary edema ... /were/ symptoms of poisoning caused by inhalation of hydrogen selenide.|/SIGNS AND SYMPTOMS/ Hydrogen selenide inhalation may also cause acute intoxication at concn as low as 0.7 mg/cu m. Signs of toxicity include irritation of the respiratory tract, pulmonary edema, severe bronchitis and bronchial pneumonia.|For more Human Toxicity Excerpts (Complete) data for HYDROGEN SELENIDE (7 total), please visit the HSDB record page.

hydrogen selenide

The substance can be absorbed into the body by inhalation.|inhalation, skin and/or eye contact

irritation eyes, nose, throat; nausea, vomiting, diarrhea; metallic taste, garlic breath; dizziness, lassitude (weakness, exhaustion); liquid: frostbite; In Animals: pneumonitis; liver damage

Burning sensation. Cough. Sore throat. Metallic taste. Laboured breathing. Nausea. Weakness. Garlic odour.

ON CONTACT WITH LIQUID: FROSTBITE.

Redness. Pain.

Eyes, respiratory system, liver

Grade: 98% pure

Fire Hazards -> Flammable - 4th degree, Reactive - 3rd degree