Hydrogen selenide

Toxic Gases & Vapors -> Hydrides

Flammable agents - 4th degree

2.12 at -42 °C/4 °C (liquid); 3.614 g/L (gas)

Relative density (water = 1): 2.1 (liquid)

2.80(relative gas density)

0.9 % at 73 °F (NIOSH, 2024)

377 mL in 100 mL water at 4 °C; 270 mL in 100 mL water at 22.5 °C

0.70 g/100 mL

Soluble in carbonyl chloride and carbon disulfide

Soluble in alkaline water

Solubility in water, ml/100ml at 22.5 °C: 270

Flammable gas

NA (Gas)

-42.3 °F at 760 mmHg (EPA, 1998)

-41.3 °C

-41 °C

-42 °F

-41.4 °C @760 [mm Hg]

-42 °F

-86.31 °F (EPA, 1998)

-65.73 °C

-66 °C

-87 °F

-64 °C

-87 °F

2.12 at -43.6 °F (EPA, 1998) - Heavier than air; will sink (Relative to Air)

2.00 (Air = 1)

Relative vapor density (air = 1): 2.8

2.12 at -43.6 °F

Odor Threshold Low: 0.3 [ppm]

Odor low: 0.0016 mg/cu m; Odor high: 12 mg/cu m; Description of odor: decayed horse radish.

... Concentrations of 0.3 ppm are readily detected by odor. ...

Irritating concn: 6 mg/cu m

Danger

H220 (100%): Extremely flammable gas [Danger Flammable gases]

P203, P210, P222, P260, P271, P273, P280, P284, P304+P340, P316, P320, P377, P381, P391, P403, P403+P233, P405, P410+P403, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 83 reports by companies from 4 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Danger

H220: Extremely flammable gas [Danger Flammable gases]

Hazard Traits - Ocular Toxicity; Respiratory Toxicity

The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)

It is extremely flammable; may be ignited by heat, sparks, or flames. Vapors may travel to a source of ignition and flash back. Container may explode in heat of fire. It is dangerous and forms explosive mixtures with air. It can decompose into toxic fumes. Incompatible with acid, water, halogenated hydrocarbons, oxidizers, hydrogen peroxide, and nitric acid. It should be stored out of the direct rays of the sun. Keep away from heat and flames. (EPA, 1998)

· These materials are extremely flammable.

Extremely flammable. Gas/air mixtures are explosive.

...highly flammable...

Dangerous fire hazard when exposed to heat or flame

It is a hazardous compound which can cause damage to the lungs and liver. Those experiencing dermatitis, chronic bronchitis, or any form of skin allergy or respiratory tract infection are at a greater risk. (EPA, 1998)

· TOXIC; Extremely Hazardous.

Experimental animals show signs of respiratory irritation and die after 8 hour exposures of 1 mg/m3 (0.3 ppm). Pathological examination shows evidence of liver damage. Inhalation of hydrogen selenide by workers has caused eye, nose, and respiratory irritation. Pulmonary edema is a potential toxic effect. [ACGIH] Hydrogen selenide is probably the only selenium compound that might pose a health concern in the workplace. [ATSDR ToxFAQs] Possible frostbite from contact with liquid; [NIOSH] A skin, eye, and respiratory tract irritant; May cause liver injury; May cause pulmonary edema; [ICSC] See Selenium.

2202 117

2202 117(anhydrous)

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]

Isolate for 1/2 mile in all directions if tank car or truck is involved in fire. Stay upwind; keep out of low areas. Withdraw immediately in case of rising sound from venting safety device or any discoloration of tank due to fire. Wear self-contained breathing apparatus and full protective clothing. Cool containers that are exposed to flames with water until well after the fire is out.

Shut off supply; if not possible and no risk to surroundings, let the fire burn itself out. In other cases extinguish with powder, carbon dioxide. In case of fire: keep cylinder cool by spraying with water. Combat fire from a sheltered position.

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.

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.

Signs and Symptoms of Hydrogen Selenide Exposure: Acute exposure to hydrogen selenide may include garlic odor of the breath, metallic taste, dizziness, weakness, fatigue, nausea, and vomiting. Bluing of skin, irritation of the eyes, nasal secretion, pain in the chest, difficulty in breathing, coughing, irritation of the respiratory tract resulting in bronchitis and pulmonary edema may also occur. In addition, CNS depression, hypotension (low blood pressure), cardiopulmonary arrest, and coma may also be observed.

General First Aid:

(General first aid procedures)

· Wear positive pressure self-contained breathing apparatus (SCBA).

TIH (Toxic Inhalation Hazard) - Term used to describe gases and volatile liquids that are toxic when inhaled. Some are TIH materials themselves, e.g., chlorine, and some release TIH gases when spilled in water, e.g., chlorosilanes. [ERG 2016].

0.006 [ppm]

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.

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.

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.

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)

The substance can be absorbed into the body by inhalation.

inhalation, skin and/or eye contact

Oral (L619) ; inhalation (L619) ; dermal (L619)

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)

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

ON CONTACT WITH LIQUID: FROSTBITE.

Redness. Pain.

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

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)

/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.

/LABORATORY ANIMALS: Acute Exposure/ The acute toxic effects of hydrogen selenide were investigated in guinea-pigs exposed for 10, 30, or 60 min to concentrations ranging from 0.002 to 0.57 mg/L. All animals exposed to 0.02 mg/L, for 60 min, died within 25 days; 93% of those exposed to 0.043 mg/L, for 30 min, died within 30 days, and all exposed to 0.57 mg/L, for 10 min, died within 5 days. Decreasing the concentrations of hydrogen selenide, and increasing the time of exposure to 2, 4, or 8 hr produced death in 50% of the guinea-pigs, within 8 hr.

/LABORATORY ANIMALS: Acute Exposure/ Lymphoid hyperplasia was noted in the spleen of guinea pigs following a single 4-hour exposure at 8 mg selenium/cu m as hydrogen selenide.

/LABORATORY ANIMALS: Acute Exposure/ In guinea pigs exposed to hydrogen selenide for 2, 4, or 8 hours, 5/16 died within 10 days of exposure at 12 mg selenium/cu m, 3/16 died at 6 mg selenium/cu m, and 8/16 died at 6 mg selenium/cu m, respectively.

/LABORATORY ANIMALS: Acute Exposure/ ... Single, 8 hr exposures of guinea pigs at 1 mg/cu m (0.3 ppm) of hydrogen selenide resulted in the death of 50% of the animals. The animals exhibited symptoms of respiratory irritation and injury to the liver.

/LABORATORY ANIMALS: Acute Exposure/ At a concentration of 7.8 mg selenium/cu m, hydrogen selenide produced diffuse bronchopneumonia and pneumonitis in guinea pigs after a 4-hour exposure.

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/.

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.

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.

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.

(AZ) ARIZONA 10 ug/L /Selenium/

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

Hydrogen selenide

1

10000

0.07

15

Flammable chemical that can be released at a facility.

(AZ) ARIZONA 45 ug/L /Selenium/

(CT) CONNECTICUT 10 ug/L /Selenium/

(ME) MAINE 35 ug/L /Selenium/

(MN) MINNESOTA 30 ug/L /Selenium/

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).

Selenium may be absorbed through inhalation and ingestion, while some selenium compounds may also be absorbed dermally. Once in the body, selenium is distributed mainly to the liver and kidney. Selenium is an essential micronutrient and is a component of glutathione peroxidase, iodothyronine 5'-deiodinases, and thioredoxin reductase. Organic selenium is first metabolized into inorganic selenium. Inorganic selenium is reduced stepwise to the intermediate hydrogen selenide, which is either incorporated into selenoproteins after being transformed to selenophosphate and selenocysteinyl tRNA or excreted into the urine after being transformed into methylated metabolites of selenide. Elemental selenium is also methylated before excretion. Selenium is primarily eliminated in the urine and feces, but certain selenium compounds may also be exhaled. (L619)

Used in semiconductor preparation and in organic synthesis; a product of the reaction of acids and inorganic selenides; [ACGIH]

Semiconductor Manufacturing [Category: Industry]

Preparation of metallic selenides and organoselenium compounds; in doping as mix for preparation of semiconductor materials containing controlled amounts of significant impurities.

Hydrogen selenide is used in organic synthesis, as well as to dope semiconductors with selenium. (L733)

Hydrogen selenide may be prepared by the action of acids or water on some metal selenides, usually aluminum selenide or iron selenide, or by passing hydrogen and selenium vapor over pumice at 177 °C resulting in a ca 58% yield.

Prepared by heating selenium and hydrogen in a sealed tube at 440 °C; ... by passing a mixture of hydrogen and selenium vapor over pumice stone at 440 °C; ... by warming potassium or ferrous selenide with hydrochloric acid; ... by the action of water on aluminum selenide.

Most binary selenides are formed by heating selenium in the presence of the element, reduction of selenites or selenates with carbon or hydrogen, and double decomposition of heavy-metal salts in aqueous solution or suspension with a soluble selenide salt, eg, Na2Se or (NH4)2Se. /Binary selenides/

Hydrogen selenide can be obtained either directly from the elements at ca. 400 °C or by decomposition of the selenides of iron, magnesium, or aluminum with hydrochloric acid.