Osmium Tetroxide

Acrid, chlorine-like odor

Unpleasant odor.

5.1 (NIOSH, 2024) - Denser than water; will sink

5.10 (Calculated)

Relative density (water = 1): 4.9

5.1

5.1 @25 °C

5.10

Pale yellow solid; monoclinic crystals

Dimorphic compd with both crystalline and amorphous forms

Colorless, crystalline solid, or pale-yellow mass [Note: A liquid above 105 degrees F].

6 % at 77 °F (NIOSH, 2024)

Sol in benzene, alcohol, ether, ammonium hydroxide, and phosphorus oxychloride; solubility in carbon tetrachloride @ 25 deg: 375 g/100 g

Solubility (g/100 cc solvent): 5.70 g in water @ 10 °C; 6.23 g in water @ 25 °C; 250 +/- 10 g in carbon tetrachloride @ 20 °C

In water, 7.24 (g/100 g) at 25 °C

Solubility in water, g/100ml at 25 °C: 6

(77 °F): 6%

266 °F at 760 mmHg (NIOSH, 2024)

130.0 °C at 760 mm Hg; begins to sublime and distill well below bp

130 °C

266 °F

131.2 °C @760 [mm Hg]

266 °F

105 °F (NIOSH, 2024)

40.6 °C

42 °C

105 °F

40.6 °C

105 °F

Odor Threshold Low: 0.0019 [mg/m3]

Air odor threshhold: 0.0019 ppm v/v. Water odor threshhold: 0.012 ppm w/v (amount in water that generates the air odor threshhold in a closed system).

7 mmHg (NIOSH, 2024)

7.0 [mmHg]

11 mm Hg at 27 °C

Vapor pressure, kPa at 27 °C: 1.5

7 mmHg

11 [mm Hg] @27 °C

12.60 eV

12.60 eV

Danger

H300: Fatal if swallowed [Danger Acute toxicity, oral]

P260, P262, P264, P270, P271, P280, P284, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P320, P321, P330, P361+P364, P363, P403+P233, P405, and P501 (click each P-code to see the statement)

Danger

H300 (100%): Fatal if swallowed [Danger Acute toxicity, oral]

P233, P260, P262, P264, P270, P271, P280, P284, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P320, P321, P330, P342+P316, P361+P364, P363, P403, P403+P233, P405, and P501 (click each P-code to see the statement)

Chemical: Osmium oxide (OsO4), (T-4)-

Osmium (VIII) oxide: HSNO Approval: HSR002793 Approved with controls

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.)

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

· Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.

Not combustible but enhances combustion of other substances. Risk of fire and explosion on contact with combustible substances.

Not combustible.

Not combustible but enhances combustion of other substances.

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

· TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury or death.

A skin and respiratory irritant, OsO4 can cause pulmonary edema in animals exposed to high concentrations. [ACGIH] A lachrymator; [ChemFinder] Tear drawing and corrosive to the skin, eyes, and respiratory tract; May cause kidney injury after prolonged or repeated exposure; [ICSC] Osmium tetroxide can cause chronic bronchitis. [LaDou, p. 382] May cause severe burns; [CAMEO] Based on animal studies, osmium tetroxide bioaccumulates after chronic exposure and may cause kidney and liver damage. [HSDB] See Osmium.

2471 154

2471 154

P087; As stipulated in 40 CFR 261.33, when osmium tetroxide, 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 container or inner liner used to hold this waste or 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(e)).

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

In case of fire in the surroundings, use appropriate extinguishing media.

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

First rinse with plenty of water for at least 15 minutes, then remove contaminated clothes and rinse again. Refer for medical attention .

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

Rinse mouth. Give nothing to drink. Rest. 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.

Excerpt from NIOSH Pocket Guide for Osmium tetroxide:

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].

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. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Solid streams of water may spread the fire.

In case of fire in the surroundings: all extinguishing agents allowed.

Separated from combustible and reducing substances, food and feedstuffs. Ventilation along the floor.

Because of its high acute toxicity, osmium tetroxide should be handled in the laboratory using the "basic prudent practices" of Chapter 5.C, supplemented by the additional precautions for work with compounds of high toxicity (Chapter 5.D). In particular, all work with osmium tetroxide should be conducted in a fume hood to prevent exposure by inhalation, and splash goggles and impermeable gloves should be worn at all times to prevent eye and skin contact. Osmium tetroxide as solid or solutions should be stored in tightly sealed containers, and these should be placed in secondary containers.

Ventilate area of spill or leak. Collect material liquid containing osmium tetroxide should be absorbed in vermiculite, dry sand, earth, or a similar material.

Sweep spilled substance into containers; if appropriate, moisten first to prevent dusting then remove to safe place. Do NOT absorb in saw-dust or other combustible absorbents.

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

Environmental considerations: Water spill: Use natural barriers or oil spill control booms to limit spill travel. Remove trapped material with suction hoses.

For more Cleanup Methods (Complete) data for OSMIUM TETROXIDE (6 total), please visit the HSDB record page.

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number P087, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.[

Cautiously make a 5% solution of the material in water or dilute acid. There may be a vigorous, exothermic reaction and fumes may be generated due to hydrolysis of the material. Control any reaction by cooling and by the rate of addition. Gradually add dilute ammonium hydroxide to pH 10. Filter off any precipitate for disposal in a chemical landfill. If no precipitation occurs, gradually adjust the pH from 10 to 6, stopping when precipitation occurs.

Excess osmium tetroxide solutions can be rendered safer by reaction with sodium sulfite to produce insoluble osmium dioxide. Ethanol will also react to produce the dioxide. Corn oil or sodium sulfide may also be used to deactivate osmium tetroxide. Osmium-containing waste should be placed in a tightly sealed, labeled container and handled according to your institution's waste disposal guidelines. For more information on disposal procedures, see Chapter 7 of this volume.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

Evacuate danger area! Consult an expert! Personal protection: complete protective clothing including self-contained breathing apparatus. Ventilation. Do NOT let this chemical enter the environment. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Then store and dispose of according to local regulations. Do NOT absorb in saw-dust or other combustible absorbents.

LC50 Nitocra spinipes ((Harpacticoidea Crustacea) 10-50 ug/L/96 hr; static

EC50 Tubifex tubifex (Tubificid worm; intoxication, immobilization) 14 ug/L/24 hr (95% confidence interval: 9-21 ug/L); static /Technical product/

EC50 Tubifex tubifex (Tubificid worm; intoxication, immobilization) 9 ug/L/48 hr (95% confidence interval: 7-12.1 ug/L); renewal /Technical product/

EC50 Tubifex tubifex (Tubificid worm; intoxication, immobilization) 6.7 ug/L/96 hr (95% confidence interval: 5.1-7.2 ug/L); renewal /Technical product/

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

inhalation, ingestion, skin and/or eye contact

The acute toxicity of osmium tetroxide is high, and it is a severe irritant of the eyes and respiratory tract. Exposure to osmium tetroxide vapor can damage the cornea of the eye. Irritation is generally the initial symptom of exposure to low concentrations of osmium tetroxide vapor, and lacrimation, a gritty feeling in the eyes, and the appearance of rings around lights may also be noted. In most cases, recovery occurs in a few days. Concentrations of vapor that do not cause immediate irritation can have an insidious cumulative effect; symptoms may not be noted until several hours after exposure. Contact of the eyes with concentrated solutions of this substance can cause severe damage and possible blindness. Inhalation can cause headache, coughing, dizziness, lung damage, and difficult breathing and may be fatal. Contact of the vapor with skin can cause dermatitis, and direct contact with the solid can lead to severe irritation and burns. Exposure to osmium tetroxide via inhalation, skin contact, or ingestion can lead to systemic toxic effects involving liver and kidney damage. Osmium tetroxide is regarded as a substance with poor warning properties. Chronic exposure to osmium tetroxide can result in an accumulation of osmium compounds in the liver and kidney and damage to these organs. Osmium tetroxide has been reported to cause reproductive toxicity in animals; this substance has not been shown to be carcinogenic or to show reproductive or developmental toxicity in humans.

Burning sensation. Cough. Headache. Wheezing. Shortness of breath. Visual disturbances. Symptoms may be delayed.

Redness. Skin burns. Pain. Skin discoloration. Blisters.

Redness. Pain. Blurred vision. Loss of vision. Severe deep burns.

Abdominal cramps. Burning sensation. Shock or collapse. See Inhalation.

irritation eyes, respiratory system; lacrimation (discharge of tears), visual disturbance; conjunctivitis; headache; cough, dyspnea (breathing difficulty); dermatitis

Initial medical screening: Employees should be screened for history of certain medical conditions which might place employee at increased risk from osmium tetroxide exposure: Eye disease: osmium tetroxide is an eye irritant and in workers has caused symptoms and signs of keratitis epithelia with corneal edema. Persons with pre-existing eye disorders may be more susceptible to the effects of disease; Pulmonary disease: In persons with impaired pulmonary function, especially those with obstructive airway diseases, the breathing /of osmium tetroxide may result in/ exacerbation of symptoms due to its irritant properties Kidney disease: osmium tetroxide causes mild kidney damage in animals. Persons with pre-existing kidney disease may be more susceptible to the effects of this agent; Skin disease: osmium tetroxide is a primary skin irritant. Persons with pre-existing skin disorders may be more susceptible to the effects of this agent.

/HUMAN EXPOSURE STUDIES/ /A 1946 report described/ concentrations of osmium tetroxide ranging from 0.1 to 0.6 mg/cu m /were found/ in the air of a precious metal refining plant. The workers suffered from lacrimation and vison disturbances such as gritty feeling in the eyes and the appearance of rings around lights. Some employees complained of headache, conjunctivitis and cough.

/SIGNS AND SYMPTOMS/ Osmium tetroxide vapors ... /in low concentration caused/ bronchitis, bronchial spasms and difficulty in breathing ... Longer exposure can result in damage to cornea, blindness... inflammatory disorders of lungs and kidneys. Upon contact it discolors the skin green or black and causes dermatitis and ulceration.

/SIGNS AND SYMPTOMS/ With sufficient concentration.../eye/ irritation with lacrimation and sensation of foreign body is induced... This may be accompanied by irritation of nose and throat. Respiratory irritation...and with repeated exposure asthma may develop.

/SIGNS AND SYMPTOMS/ Concentrations of vapor which do not cause immediate sensation of irritation have insidious cumulative action with latent period... Symptoms and signs are... keratitis epithelialis with corneal epithelial edema. Victim sees halos or colored rings around lights, suffers blurring of vision and painful scratchy sensation in eyes.

For more Human Toxicity Excerpts (Complete) data for OSMIUM TETROXIDE (11 total), please visit the HSDB record page.

UNCLAIMED OSMIUM TETROXIDE FROM COPPER SMELTERS ... REACHES WASTEWATER STREAMS

Osmium tetroxide is the most industrially important osmium compound(1); its use as an oxidation catalyst(1) may result in the release of osmium compounds through various waste streams(SRC).

P087; As stipulated in 40 CFR 261.33, when osmium tetroxide, 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 container or inner liner used to hold this waste or 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(e)).

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 1000 lb or 454 kg. The toll free number of the NRC is (800) 424-8802; In the Washington D.C. metropolitan area (202) 426-2675. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b).

The lungs and respiratory tract retain most of the inhaled /osmium tetroxide/ vapors.

No information is available that would suggest osmium accumulation in animal tissues or its dermal absorption.

Used primarily for staining of biological and pathological tissues for microscopic study; [ACGIH]

Chief /laboratory/ use of osmium tetroxide is as a biological stain for adipose tissues in histopathological laboratories

Osmium tetroxide is a highly oxidizing, corrosive compound commonly found in electron microscopy laboratories

General purpose reagent. Medical Specialty Pathology. Product Code KEE

Catalyzes chlorate, peroxide, periodate and other oxidations

For more Uses (Complete) data for OSMIUM TETROXIDE (12 total), please visit the HSDB record page.

(1978) No Data

(1983) No Data

(1987) No Data

(1977) No Data

(1982) No Data

(1987) No Data

(1977) PROBABLY GREATER THAN 1.82X10+6 G

(1982) PROBABLY GREATER THAN 9.08X10+6 G

(1987) No Data

Oxidation of osmium-containing solutions eg, sodium osmate or osmium metal with nitric acid; oxidation of osmium metal in air.

By heating powdered osmium in air, or by treating it with nitric acid, aqua regia or chlorine.

... Prepared by strongly heating osmium in a stream of oxygen at 500-800 °C.

Osmium oxide (OsO4), (T-4)-: ACTIVE

Osmium tetroxide /is/ wrongly termed osmic acid ...

The most important starting material for synthesis of osmium complexes is OsO4.

Osmium is ...most important industrially as osmium tetroxide.