Uranium Trioxide SDS


Name: Uranium trioxide (UO3), 100%

Synonyms: Uranium(VI) oxide, Uranus oxide

Formula: UO3


IBI Labs

3495 N. Dixie Hwy. Unit # 8

Boca Raton, FL 33431

Tel: 561-826-0061 Fax: 561-892-8450

Emergency Telephone Numbers


USA & Canada contact number: 1-800-535-5053

International contact number: 1-352-323-3500


OSHA Hazards

Toxic by inhalation, toxic by ingestion.

Target Organs: Kidney, liver, lungs, brain.

GHS Label Elements


Signal words: Danger

Hazard Statements

Toxic by inhalation and ingestion.

Danger of cumulative effects.

May damage kidneys.

Precautionary Statements:

Avoid Breathing Dust.

Avoid contact with skin, eyes, and clothing.

When using do not eat, drink, or smoke.

In case of accident or if you feel unwell seek medical advice immediately.

Use only with adequate ventilation.

GHS Classification

Skin Irritation (Category 2).

Eye Irritation (Category 2).

Specific target organ toxicity – repeated exposure (Category 2).

Specific target organ toxicity – acute exposure (Category 2).

GHS Hazard Ratings

R23/25: Toxic by inhalation and ingestion.

R33: Danger of cumulative effects.

S20/21: When using do not eat, drink, or smoke.

S45: In case of accident or if you feel unwell seek medical advice immediately.

S61: Avoid release to the environment.




  • Molecular Formula: O3U
  • CAS Number: [1344-58-7]
  • Appearance: Yellow-orange, dense, radioactive powder, or crystals
  • Melting point:  Decomposes
  • Boiling point: Decomposes
  • Flashpoint: Non-flammable solid
  • Water solubility: Insoluble
  • Solvent solubility: Nitric acid
  • Molecular weight: 286.027
  • Specific Gravity: 7.29
  • Density, g/cm3: 7,29 g/cm3
  • Chemical Family: metal oxide, radioactive

The half-lives of the various uranium isotopes are as follows:

233U = 1.59 X 105 y, 234U = 2.47 X 105 y; 235U = 7.04 X 108 y; 236U = 2.39 X 107 y; 238U = 4.51 X 109 y.

The specific activities of the various uranium isotopes are as follows:

  • 233U = 3.6 x 102 MBq/g (9.7 X 10-3 Ci/g)
  • 234U = 2.3 X 102 MBq/g (6.2 X 10-3 Ci/g)
  • 235U = 7.8 X 10-2 MBq/g (2.1 X 10-6 Ci/g)
  • 236U = 2.3 MBq/g (6.3 X 10-5 Ci/g)
  • 238U = 1.2 X 10-2 MBq/g (3.3 X 10-7 Ci/g)


In all routes of exposure, seek medical treatment immediately.


  • Remove from the exposure area to a restricted area with fresh air as quickly as possible.
  • If breathing has stopped, perform artificial respiration by administering oxygen; mouth-to-mouth resuscitation should be avoided to prevent exposure to the person rendering first aid.
  • Any evidence of serious contamination indicates that treatment must be instituted. (Inhalation of radioactive particles may indicate that other parts of the body were also contaminated, such as the digestive tract, skin, and eyes.)
  • If time permits, wipe the face with wet filter paper, force coughing, and blow off the nose.
  • Get medical attention immediately.
  • The patient may be contaminated with radioactive particles. Decontaminate any radiological contamination after an individual is stabilized from initial medical treatment.
  • Any personnel rendering first aid must be monitored for radioactivity and thoroughly decontaminated if necessary (IAEA #3, Pg. 65).

Skin contact:

  • Remove the patient to a suitable area for decontamination as quickly as possible.
  • Remove clothing and shoes immediately.
  • Thoroughly wash the patient with soap and water, paying particular attention to the head, fingernails, and palms of the hands.
  • Upon completion of washing, monitor the patient for radioactivity. The skin must be decontaminated as quickly as possible.
  • Minute skin injuries greatly increase the danger of isotope penetration into the patient; shaving should not be attempted.
  • If water and soap have been inadequate in removing the radioactive compound, decontaminating compounds consisting of surfactants and absorbent substances may be effective. Complex reagents may also be of use.
  • The use of organic solvents is to be avoided, as they may increase the solubility and absorption of the radioactive substance.
  • Skin contamination with radiation may be an indication that other parts of the body have been exposed.
  • Contaminated clothing must be stored in a metal container for later decontamination or disposal.
  • The water used to wash the patient must be stored in metal containers for later disposal.
  • Any personnel rendering first aid to the patient must be monitored for radioactivity and decontaminated if necessary (IAEA #47, Pg. 9; IAEA #3, Pg. 62).

Eye contact:

  • Remove the patient to a restricted area for decontamination and thoroughly wash the eyes with water, occasionally lifting the upper and lower lids (approximately 15 minutes).
  • Following the water treatment, provide an isotonic solution.
  • Do not use eye baths, rather provide a continuous and copious supply of fluid. Monitor the patient for radioactivity. If activity is present, rewash the eyes, and re-monitor until little or no radioactivity is present. Get medical attention immediately.
  • Any water used to wash the patient’s eyes must be stored in a metal container for later disposal.
  • Any other articles used to decontaminate the patient must also be stored in metal containers for later decontamination or disposal.
  • Any personnel rendering first aid to the patient must be monitored for radioactivity and decontaminated if necessary (IAEA #3, Pg. 65; IAEA #47, Pg. 35).


  • In the case of ingestion of radioactive substances, the mouth should be rinsed out immediately after the accident, and care should be taken not to ingest the water used for this purpose.
  • Vomiting should be induced either mechanically, or with syrup of ipecac.
  • Do not induce vomiting in an unconscious person. Lavage may be useful. Care should be taken to avoid aspiration.
  • The vomit and lavage fluids should be saved for examination and monitoring. Further action depends on the nature of the radioactive substance.
  • Get medical attention immediately.
  • The gastric fluids and fluids used for lavage must be stored in metal containers for later disposal.
  • The patient must be monitored for radioactivity and decontaminated, if necessary, before being transported to a medical facility.
  • Any personnel involved in rendering first aid to the patient must be monitored for radioactivity and decontaminated if necessary (IAEA #47, Pg. 9; IAEA #3, Pp. 59, 66)

Note to physician:

  • There is no antidote for radiation sickness.
  • Treatment should be symptomatic and supportive, regardless of the dose received.
  • In all cases, medical attention should be obtained immediately although chelating agents act on uranium, they should not be used because the increased migrant fraction leads through renal precipitation to a greater kidney burden than would be received if there were no treatment at all; there is thus the risk of serious toxic nephritis.
  • The basic treatment should be the administration of a bicarbonate solution given locally and in intravenous perfusion (one bottle of 250 mL at 1.4%). From IAEA safety series #47 – Manual on early medical treatment of possible radiation injury – 1978. Pg. 28.

Most Important Symptoms and Effects

  • Inhalation: May cause irritation and kidney damage, yellowing of the skin and eyes, lack of appetite, nausea, vomiting, diarrhea, dehydration, blood in the urine, weakness, drowsiness, coordination, twitching, sterility, blood disorders, convulsions, and shock.

In addition to effects from short-term exposure, anemia, cataracts, lung damage, liver damage, and bone effects may occur.

  • Ingestion: May cause kidney damage.
  • Skin contact: May irritate.
  • Eye contact: May cause irritation, redness, and swelling. Additional effects may include sores and eye damage. In addition to the effects of short-term exposure, cataracts may occur.


Suitable extinguishing media: Dry chemical, carbon dioxide, water spray or regular foam (2012 Emergency Response Guidebook, (ERG 2012), developed jointly by Transport Canada (TC), the U. S. Department of Transportation (DOT) and the Secretariat of Transportation and Communications of Mexico (SCT).) For Larger Fires, use water spray or fog (flooding amounts) (2012 Emergency Response Guidebook, ERG 2012.)

Fire and explosion hazard: Negligible when exposed to flame or heat.

Hazardous combustion products: Thermal decomposition may release toxic/hazardous gases.

Special protective equipment and precautions for firefighters: Move the container from the fire area if you can do it without risk. Apply cooling water to the sides of containers exposed to flames until well after the fire is out (2012 Emergency Response Guidebook, ERG 2012). Do not move damaged containers, move undamaged containers out of the fire zone. For massive fires in cargo areas, use unmanned hose holders or monitor nozzles (2012 Emergency Response Guidebook, ERG 2012). Contact the local, State, or Department of Energy radiological response team. Use suitable agents for surrounding fire. Cool containers with flooding amounts of water, apply from as far a distance as possible. Avoid breathing dust or vapor, keep upwind. Keep unnecessary people out of the area until declared safe by the radiological response team.


Personal precautions and protective equipment: Do not touch damaged containers or spilled material. Damage to the outer container may not affect the primary inner container. Emergency procedures and materials for containment and clean-up: For small liquid spills, pick up with sand, earth, or other absorbent material. For large spills, dike far ahead of the spill for later disposal. Keep unnecessary people at least 150 feet upwind; greater distances may be necessary if advised by a qualified radiation authority. Isolate the hazard area and deny entry. Enter the spill area only to save life, limit entry to the shortest possible time. Detain uninjured persons and equipment exposed to radioactive material until arrival or instruction of qualified radiation authority. Delay cleanup until arrival or instruction of qualified radiation authority.


Precautions for safe handling

  • Avoid contact with skin, eyes, and clothing.
  • When using do not eat, drink, or smoke.
  • Avoid Breathing Dust.
  • Wash thoroughly after handling.
  • Use only with adequate ventilation.

Conditions for safe storage

  • Store in the radioactive materials area.
  • Keep the storage container tightly closed.
  • Store separately from incompatible materials.
  • Observe all Federal, State, and local regulations regarding storage of this substance.


Exposure Limits

Uranium, insoluble compounds (As U):

  • 0.05 mg/m3 OSHA PEL-TWA
  • 0.2 mg/m3 ACGIH TWA; 0.6 mg/m3 ACGIH STEL 0.2 mg/m3 NIOSH Recommended TWA; 0.6 mg/m3 NIOSH Recommended STEL

Occupational exposure to radioactive substances must adhere to standards established by the Occupational Safety and Health Administration. 29 CFR 1910.96, and/or the Nuclear Regulatory Commission, 10 CFR Part 20. For DOE and its contractors 10 CFR 835, Occupational Radiation Protection must be followed.

Engineering Controls

Ventilation: At a minimum, provide local exhaust or process enclosure ventilation. Depending upon the specific workplace activity and the radioactivity of the isotope, a more stringent ventilation system may be necessary to comply with exposure limits set forth by law (10 CFR 20.103)

Radiation shielding: One method of controlling external radiation exposure is to provide adequate shielding. The absorbing material used, and the thickness required to attenuate the radiation to acceptable levels depends on the type of radiation, its energy, the flux, and the dimensions of the source.

Alpha particles: For the energy range of alpha particles usually encountered, a fraction of a millimeter of any ordinary material is sufficient for absorbance. Thin rubber, acrylic, stout paper, or cardboard will suffice.

Beta particles: Beta particles are more penetrating than alpha and require more shielding. Materials composed mostly of elements of low atomic number such as acrylic, aluminum, and thick rubber are most appropriate for the absorption of beta particles. For example, 1/4 inch of acrylic will absorb all beta particles up to 1 MeV. With high-energy beta radiation from large sources, Bremsstrahlung (X-ray production) contribution may become significant, and it may be necessary to provide additional shielding of high atomic weight material, such as lead, to attenuate the Bremsstrahlung radiation.

Gamma rays: The most suitable materials shielding gamma radiation are lead and iron. The thickness required would depend on whether the source is producing narrow or broad beam radiation. Primary and secondary protective barriers may be required to block all radiation.

Personal Protective Equipment

Clothing, gloves, and eye protection equipment will protect against alpha particles, and some protection against beta particles, depending on thickness, but will not shield gamma radiation.

Eye protection: Employees must wear appropriate eye protection that will not allow the introduction of particles into the eyes. Contact lenses should not be worn.

Clothing: Disposable overgarments, including head coverings and foot coverings, should be worn by any employee handling any radioactive substance. These garments are also recommended even if the employee is working with a “glove box” containment system. Certain clothing fibers may be useful in dosimetry so clothing should be kept.

In the event of an accident, large-scale release or a large-scale clean-up of full protective clothing will be necessary.

Gloves: Employees must wear appropriate protective gloves to prevent contact with this substance. Used gloves may present a radiation hazard and should be disposed of as radioactive waste.

Respirator: The following respirators and maximum use concentrations are recommendations by the U.S. Department of Health and Human Services, NIOSH pocket guide to chemical hazards; NIOSH criteria documents or by the U.S. Department of Labor, 29 CFR 1910 Subpart Z.

The specific respirator selected must be based on contamination levels found in the workplace, must not exceed the working limits of the respirator, and be jointly approved by the National Institute for Occupational Safety and Health and the Mine Safety and Health Administration (NIOSH-MSHA).

At any detectable concentration: Any self-contained breathing apparatus with a full facepiece operated in a pressure-demand or other positive-pressure mode.

Any supplied-air respirator with a full facepiece operated in a pressure-demand or other positive-pressure mode or other positive-pressure modes with an auxiliary self-contained breathing apparatus operated in pressure-demand or other positive-pressure mode.

Escape – any air-purifying, full-facepiece respirator with a high-efficiency particulate filler.

Any appropriate escape-type, self-contained breathing apparatus.

For Firefighting and Other Immediately Dangerous to Life or Health Conditions

Use any self-contained breathing apparatus with a full facepiece respirator and a high-efficiency particulate filter.

Use any supplied air respirator with a full facepiece operated in a pressure-demand or other positive-pressure mode or other positive-pressure modes with an auxiliary self-contained breathing apparatus operated in pressure-demand or other positive-pressure modes.


Reactivity: See below.

Chemical stability: Stable under normal temperatures and pressures.

Possibility of hazardous reactions: No potentially hazardous conditions could be found in the literature, nor could any accidents be recalled in which uranium oxide reacted in a hazardous manner.

Conditions to avoid: Excessive heat.

Hazardous decomposition products: Thermal decomposition may release hazardous and toxic gases.

Incompatible Materials

Bromine Trifluoride: Reaction is rapid below the boiling point of the trifluoride.


Likely Routes of Exposure

  • Inhalation
  • Ingestion
  • Skin and eye contact.

Uranium oxide is a skin, eye, and mucous membrane irritant, as well as a nephrotoxin. Chronic inhalation may affect the lungs and lymph nodes. Pneumoconiosis may occur. If uranium is deposited in the bone, there is a potential for blood disorders such as anemia and leukopenia. In humans, cancer of the lung, lymphatic and hemopoietic systems, and osteosarcoma have been reported. Uranium compounds usually do not constitute an external radiation exposure hazard since uranium emits mainly alpha radiation at a low energy level. It may constitute an internal radiation hazard if it is absorbed into the body, thus delivering alpha emission onto tissues in which it is stored. Significant quantities of highly enriched material may also pose a gamma radiation hazard.

  • Inhalation

Radioactive/Nephrotoxin. 30 mg/m3 is immediately dangerous to life and health.

May irritate.

In animals, repeated inhalation of insoluble uranium compounds resulted in fibrotic changes indicative of radiation damage in the lungs and tracheobronchial lymph nodes. Pneumoconiosis may occur. If uranium is deposited in the bone, there is a potential for blood disorders such as anemia and leukopenia. In humans, cancer of the lung, lymphatic and hemopoietic systems, and osteosarcoma have been reported. Uranium is a nephrotoxin and exposure may lead to kidney failure. Kidney failure may result in liver damage. See the following section on the effects of alpha radiation and radiation sickness.

Alpha radiation: Alpha radiation is densely ionizing with very high energy and will kill cells immediately adjacent to the source of contact. Damaged cells may not recover or be repaired. Alpha emitters may or may not be absorbed, depending on the solubility and particle size. Insoluble compounds may remain at or near the site of deposition, and soluble compounds may rapidly enter the bloodstream. Heavier particles will be brought up to the throat by ciliary action and may then be ingested. The lighter particles may be lodged deep in the alveolar air sacs and remain. The damage depends on how quickly they are eliminated, and the susceptibility of the tissue in which they are stored. A single large dose of radiation may lead to radiation sickness.

The effects of chronic exposure to internally deposited alpha radiation are dependent upon the dose and target organ(s). If the total dose is sufficient, radiation sickness may occur. Possible disorders include lung cancer, sterility, anemia, leukemia, or bone cancer.

Radiation sickness: Whole body doses of 200-1000 Rads may cause anorexia, apathy, nausea, and vomiting and may become maximal within 6-12 hours. An asymptomatic period of 24-36 hours may be followed by lymphopenia and slowly developing neutropenia. Thrombocytopenia may become prominent within 3-4 weeks. The lymph nodes, spleen, and bone marrow may begin to atrophy. If bone marrow depression reaches a critical level, death may occur from overwhelming infection. Whole-body doses of 400 or more Rads may cause intractable nausea, vomiting, and diarrhea that may lead to severe dehydration, vascular collapse, and death. Regeneration of the intestinal epithelium may occur but may be followed by hematopoietic failure within 2-3 weeks. Whole body doses of 600 or more Rads may be fatal due to gastrointestinal or hematopoietic malfunction, with doses fatal 3000 Rads generally causing nausea, vomiting, listlessness, and drowsiness ranging from apathy to prostration, tremors, convulsions, ataxia, and death within a few hours. The gonads are also particularly radio-sensitive among men. In women, loss of fertility may be indicated by loss of menstruation.

The delayed effects of radiation may be due either to a single large overexposure or continuing low-level overexposure and may include cancer, genetic effects, shortening of life span, and cataracts. Cancer is observed most frequently in the hematopoietic system, thyroid, bone, and skin. Leukemia is among the most likely forms of malignancy. Lung cancer may also occur due to radioactive materials residing in the lungs. Genetic effects may range from point mutations to severe chromosome damage such as strand breakage, translocation, and deletions. If the germ cells have been affected, the effects of the mutation may not become apparent until the next generation, or even later.

  • Skin contact

There is no evidence that insoluble uranium compounds can be absorbed through the skin; insoluble salts produced no signs of poisoning after skin contact. Animal tests on a variety of uranium compounds caused varying degrees of eye damage, with the oxides causing the mildest. Uranium oxide may irritate the skin.

Prolonged skin contact with insoluble uranium compounds should be avoided because of potential radiation damage to basal cells. Dermatitis has occurred because of handling some insoluble uranium compounds. Repeated or prolonged contact may cause conjunctivitis. Cataract formation as in acute exposure may occur with significant exposure. See the following sections regarding alpha radiation and radiation sickness.

Alpha radiation: Alpha radiation is not usually an external hazard. However, local damage may occur at the site of the wound. Absorption or penetration through damaged skin may result in radiation sickness. Prolonged or repeated contact may result in radiation sickness.

Radiation sickness: The clinical course of radiation sickness depends upon the dose, dose rate, area of the body affected, and time after exposure. External and internal radioactivity of any type may cause radiation sickness.

Radiation sickness has three (3) clearly defined syndromes, described in detail in the inhalation section.

  • Eye contact

Dust may be irritating to the eyes. A variety of soluble and insoluble compounds or uranium were tested on the eyes of rabbits. The insoluble compounds caused the mildest degree of injury. The effects of eye contact with any uranium compound tend to be necrosis of the conjunctivae and eyelids and ulceration of the cornea.

Prolonged exposure to uranium may produce conjunctivitis, or the symptoms of radiation injury, such as cataracts. See the following sections regarding the effects of alpha radiation on the eyes, and radiation sickness.

Alpha radiation: Radiation affects the eye by inducing acute inflammation of the conjunctiva and the cornea. The most sensitive part of the eye is the crystalline lens. A late effect of eye irradiation is cataract formation. It may begin anywhere from 6 months to several years after a single exposure. Cataract formation begins at the posterior pole of the lens and continues until the entire lens has been affected. Growth of the opacity may stop at any point. The rate of growth and the degree of opacity are dependent upon the dose of radiation.

Repeated or prolonged exposure to alpha radiation may result in cataract formation, as described above. Of the well-documented late effects of radiation on man, leukemia, and cataracts have been observed at doses lower than those producing skin scarring and cancer or bone tumors. The lens of the eye should be a critical organ.

Radiation sickness: The eyes are very radiosensitive; a single dose of 100 Rads may cause conjunctivitis and keratitis. It is unlikely that a dose sufficient to cause radiation sickness would occur if only the eyes were irradiated however, if eye damage by ionizing radiation occurs. It may be best to assume that other parts of the body have also been contaminated. Symptoms of radiation sickness are described in the inhalation section.

  • Ingestion

Feeding studies on animals indicate that insoluble uranium is much less toxic than soluble uranium compounds. Uranium entering the bloodstream will become stored in the bone marrow, but the majority will become lodged in the kidney, which is the major site of toxicity. More than a year and a half are required to rid the body of an accidental high dose of uranium, after which time measurable uranium is present in the bone and kidney.

The toxic action of uranium resides more in its chemical action on the renal tubules, rather than radiation effects. Rats injected with uranium metal in the femoral marrow developed sarcomas, whether this was due to metallo-carcinogenic or radio-carcinogenic ingestion of alpha emitters, and radiation sickness. Also, see the first aid section for uranium compounds.

Alpha radiation: The fate of ingested alpha emitters depends on their solubility and valence. High doses may lead to radiation sickness as described in inhalation exposure. Repeated ingestion of alpha emitters may lead to radiation sickness as described in inhalation exposure.

Radiation sickness: The symptoms of radiation sickness depend upon the dose received. It may result from acute or chronic exposure to any form of radiation. The symptoms are described in the inhalation section.

Carcinogenic Status

  • OSHA: N
  • NTP: N
  • IARC: N


Ecological Information

  • Environmental Impact Rating (0-4): No data available.
  • Acute Aquatic Toxicity: No data available.
  • Degradability: No data available.
  • Log Bioconcentration Factor (BCF): No data available.
  • Log Octanol/water partition coefficient: No data available.

Disposal Information

Observe all Federal, State, and local Regulations when disposing of this substance.


The U.S. Department of Transportation (D.O.T.) Code of Federal Regulations (49 CFR Parts 100- 185), the International Air Transportation Association (IATA), the International Civil Aviation Organization (ICAO), and the International Maritime Organization (IMDG) are all factored into the classification and transport of material.

Proper Shipping Name:

Hazard Class:

UN/ID Number:                              To be determined on a case-by-case basis.

Special Information:

Packing Group:

The classification of substances with multiple hazards must be determined following the criteria presented in the regulations mentioned above. Due to the various quantities and combinations of materials being shipped at one time, the information above must be determined based on the characteristics of the specific shipment.


  • CERCLA SECTION 103 (40 CFR 302.4): N
  • SARA SECTION 302 (40 CFR 355.30): N
  • SARA SECTION 304 (40 CFR 355.40): N
  • SARA SECTION 313 (40 CFR 372.65): N OSHA PROCESS SAFETY (29 CFR 1910.119): N


Copyright 2016 IBI Labs. License granted to make unlimited paper copies for internal use only.

IBI Labs requires that those who receive their materials comply with 29 CFR 1910.1200(h), which mandates that employers provide employees with effective information and training about hazardous chemicals in their workplace.

The contents of this document are believed to be accurate as of the date of revision and are provided in good faith. However, it is recommended that recipients use this information as supplementary and exercise caution and judgment regarding its accuracy and suitability. Please note that IBI Labs cannot accept responsibility for any indirect, incidental, or consequential damage resulting from the use of the information provided in this Safety Data Sheet.

IBI Labs makes no warranties, expressed or implied, including warranties of merchantability and fitness for a particular purpose. This information is provided without warranty, and any use of the product that does not conform to this Safety Data Sheet, or that is used in combination with any other product or process, is the responsibility of the user.

Revision Date: 04/24/2024


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