Thorium Metal SDS

Revision Date: 01/30/2023


Chemical Name: Thorium (Metal) 



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

Highly toxic by inhalation.

Highly toxic by ingestion.


TARGET ORGANS: Kidney, liver, lungs, brain.

GHS Classification

Acute toxicity, Oral (Category 2).

Acute toxicity, Inhalation (Category 2).

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

Acute aquatic toxicity (Category 2).

Chronic aquatic toxicity (Category 2).

GHS Label elements, including precautionary statements:


Signal word: Danger.

Hazard Statements

H300 + H330 Fatal if swallowed or inhaled.

H373 May cause damage to organs through prolonged, or repeated exposure.

H411 Toxic to aquatic life with long lasting effects.

H250 Catches fire spontaneously if exposed to air.

Precautionary statement(s):

P220 Keep/store away from clothing/combustible materials.

P260 Do not breath dust/fume/gas/mist/vapors/spray.

P264 Wash hands thoroughly after handling.

P273 Avoid release to environment.

P284 Wear respiratory protection.

P310 Immediately call Poison Center or doctor/physician.

Other hazards:


NFPA Rating

Health hazard: 3

Fire 0

Reactivity 3

CERCLA Ratings (SCALE 0-3)

Health U

Fire 0

Reactivity 3

Persistence 3


  • CAS RN: [7440-29-1]
  • Molecular Formula: Th
  • Chemical Family: Metal
  • Molecular Weight: 232.04
  • Solubility: Insoluble in water, slightly soluble in acid
  • Appearance: Grayish white, dense, silvery, radioactive solid that is strongly electropositive
  • Melting Point, °C: 1755°C
  • Boiling Point, °C: 4787°C
  • Specific Gravity: 11.71
  • Reactions: On vigorous shaking the metallic particles exhibit luminescence. It is ductile and malleable, and ignites spontaneously in air.


  • In all routes of exposure, seek medical treatment immediately.
  • Medical problems take priority over radiologic concerns (See treatment/first-aid measures below).

First Aid Measures


  • Remove to fresh air.
  • If breathing becomes difficult, call a physician.


  • If swallowed, wash out mouth with water provided person is conscious.
  • Call a physician.

Skin contact: In case of contact, immediately wash skin with soap and copious amounts of water.

Eye contact:

  • In case of contact with eyes, flush with copious amounts of water for at least 20 minutes.
  • Assure adequate flushing by separating the eyelids with fingers.
  • Call a physician.

Most Important Symptoms and Effects, Acute and Delayed

  • Uranium is a nephrotoxin, damaging the kidneys.
  • Uranium is a skin, eye, and mucous membrane irritant.


Fire and Explosion Hazard:

  • Dangerous fire hazard when exposed to heat or flame.
  • Dangerous explosion hazard when exposed to heat or flame.
  • Pyrophoric.

Suitable extinguishing media: Dry chemical, carbon dioxide, water spray or regular foam.

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

Special Protective Equipment and Precautions for Firefighters

  • Move container from fire area if you can do it without risk.
  • Wear self-contained breathing apparatus if necessary.
  • Apply cooling water to sides of containers exposed to flames until well after fire is out.
  • Do not move damaged containers; move undamaged containers out of fire zone.
  • For massive fire in cargo area, use unmanned hose holder or monitor nozzles.
  • Contact the local, State, or Department of Energy radiological response team.
  • Use suitable agent for surrounding fire.
  • Cool containers with flooding amounts of water, apply from as far a distance as possible. Avoid breathing dusts or vapors, keep upwind.
  • Keep unnecessary people out of area until declared safe by radiological response team.


Personal Precautions and Protective Equipment

  • Avoid contact with eyes, skin, and clothing. Avoid breathing dust.
  • Wear respiratory protection, gloves, over garment and goggles.
  • Evacuate personnel to safe areas.

Emergency Procedures and Methods and Materials for Containment and Clean-up

  • Do not touch damaged containers or spilled material.
  • Damage to outer container may not affect primary inner container.
  • For small liquid spills, take up with sand, earth, or other absorbent material. F
  • For large spills, dike far ahead of spill for later disposal.
  • Keep unnecessary people at least 150 feet upwind; greater distances may be necessary if advised by qualified radiation authority.
  • Isolate hazard area and deny entry.
  • Enter spill area only to save life, and limit entry to 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.  
  • Contact the local, State, or Department of Energy radiological response team.
  • Use suitable agent for surrounding fire.
  • Cool containers with flooding amounts of water, apply from as far a distance as possible.
  • Avoid breathing dusts or vapors, keep upwind.
  • Keep unnecessary people out of area until declared safe by radiological response team.

Disposal Considerations

Waste Disposal Methods: DISPOSE OF IAW LOCAL, STATE & FEDERAL ENVIRONMENTAL REGULATIONS (TITLE 10 CFR). Disclaimer (provided with this information by the compiling agencies): This information is formulated for use by elements of the Department of Defense. The United States of America in no manner whatsoever, expressly, or implied, warrants this information to be accurate and disclaims all liability for its use. Any person utilizing this document should seek competent professional advice to verify and assume responsibility for the suitability of this information to their situation.


Precautions for safe handling:

  • Avoid contact with skin and eyes.
  • Wash hands thoroughly after handling.

Conditions for safe storage:

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


Exposure Limits:


0.2 mg/m3 OSHA TWA; 0.6 mg/m3 OSHA STEL

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


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. IF purchased by DOE or DOE governed facilities subject to 10 CFR 835. Subject to foreign entity radiation protection regulations.


At a minimum, provide local exhaust or process enclosure ventilation.

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, or a few inches of air is sufficient for absorbency. Rubber, cardboard, or any such material 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. 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. In the quantities shipped, Certified Reference Materials will not emit significant amounts of beta particles.

Gamma rays: The most suitable materials shielding gamma radiation are lead and iron. Normal and depleted uranium are not normally considered gamma emitters. In the quantity shipped, enriched Certified Reference Materials will pose only a negligible gamma hazard.

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

Clothing: Disposable over-garments, including head coverings and foot covering, should be worn by any employee engaged in handling any radioactive substance. These garments are also recommended even if the employee is working with a “glovebox” containment system.

In the event of an accident, full protective clothing will be necessary.

Gloves: Employee must wear appropriate protective gloves to prevent contact with this substance. Used gloves may be contaminated and should be disposed of as radioactive waste.

**Clothing, glove, and eye protection equipment will provide protection against alpha particles.

Respirators: 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).

Thorium, Insoluble compounds (As U)

At Any Detectable Concentration:

  • Any self-contained breathing apparatus that has a full facepiece, and is operated in a pressure-demand, or other positive-pressure mode.
  • Any supplied air respirator that has a full facepiece, and is operated in a pressure-demand, or other positive-pressure mode in combination 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 filer.
  • Any appropriate escape-type, self-contained breathing apparatus.

For Firefighting and Other Immediately Dangerous to Life or Health Conditions:

  • Any self-contained breathing apparatus that has a full facepiece respirator with a high-efficiency particulate filter.
  • Any supplied-air respirator that has a full facepiece, and is operated in a pressure-demand, or other positive-pressure mode in combination with an auxiliary self-contained breathing apparatus operated in pressure-demand, or other positive-pressure mode.

Potential Health Effects


  • Short term exposure: may cause lack of appetite, nausea, vomiting, diarrhea, dehydration, kidney damage, blood in the urine, jaundice, weakness, drowsiness, incoordination, twitching, sterility, blood disorders, convulsions, and shock. Exposure to radioactive substances increases one’s risk of developing cancer.
  • Long term effects: In addition to effects from short-term exposure, anemia, cataracts, and lung damage may occur.


  • Short term exposure: No information available on significant adverse effects.
  • Long term effects: May cause skin irritation.


  • Short term exposure: May cause irritation. Additionally, eye damage, including ulcerations, may occur.
  • Long term effects: It is unlikely that long term eye contact would occur as the effects of

Note: Short term exposure, over a period, would result in serious eye damage. However, if long term exposure did occur, cataracts may also occur.


  • Short term exposure: May cause kidney damage and increased cancer risk.
  • Long term effects: Same effects as short-term exposure.

Carcinogen Status





Chemical stability:

  • Clean Uranium turnings or chips oxidize readily in air.
  • If confined in a container without air movement, they can ignite spontaneously.  Moisture increases this reactivity.
  • Uranium turnings stored in water will form a hydride and ignite during warm weather.

Possibility of Hazardous Reactions (Polymerization): No data available.

Conditions to Avoid:

  • May ignite itself if exposed to air.
  • May burn rapidly with flare-burning effect and re-ignite after fire is extinguished.

Incompatible Materials

CHLORINE: Violent Reaction.

AIR: Violent Reaction.

FLUORINE: Violent Reaction.

NITRIC ACID: Reacts explosively, or with the formation of an explosive surface coating or residue.


DINITROGEN TETROXIDE: Explodes or forms an explosive surface coating or residue.

SELENIUM: Reacts violently or incandesces.

SULFUR: Reacts violently or incandesces.

WATER: Violent Reaction Hazard.

AMMONIA: Reacts violently or incandesces at dull red heat.



NITRYL FLUORIDE: Violent Reaction, or glowing or white incandescence.

CARBON DIOXIDE: At 750°C Interaction is so rapid that ignition will occur with the finely divided metal, and at 800°C the massive metal will ignite.

CARBON TETRACHLORIDE: Use of a carbon tetrachloride fire extinguisher on a small uranium fire led to an explosion.

CHLORINE: Ignites at 150-180°C,

BROMINE VAPOR: Ignites at 210-240°C,

IODINE VAPOR: Ignites at 260°C,

ACIDS: Reacts with liberation of hydrogen, and formation of salts of tetravalent uranium.

Hazardous Decomposition Products:

Thermal decomposition may release toxic and/or hazardous gases.




Contains a radioactive isotope which may produce cancer and genetic mutation.

IARC: No chemical component of this product present at levels greater than or equal to 0.1% is identified as probable, possible, or confirmed human carcinogen by IARC.

NTP: No chemical component of this product present at levels greater than or equal to 0.1% is identified as a known, or anticipated carcinogen by NTP.

OSHA: No chemical component of this product present at levels greater than or equal to 0.1% is identified as a carcinogen or potential carcinogen by OSHA.

Carcinogen status: Not carcinogenic as a chemical. Ionizing radiation is carcinogenic.

The toxicity of thorium metal has not been quantified. Thorium may be a skin, eye, and mucous membrane irritant, as well as a nephrotoxin. Thorium metal usually does not constitute an external radiation exposure hazard since it 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.

Health Effects

  • Inhalation: 


RADIOACTIVE/NEPHROTOXIN. 30 mg/m3 immediately dangerous to life and health.

Acute exposure: Thorium may enter the body through inhalation of fine particles that are approximately 1 micron in diameter. Uranium poisoning is characterized by generalized health impairment. It may cause changes in the kidneys, liver, lungs, and cardiovascular, nervous, and hemopoietic systems, and disorders of protein and carbohydrate metabolism. Symptoms may include oliguria, hematuria, albuminuria, and jaundice.

Chronic exposure: Workers exposed to high average levels of thorium dust have not had increased mortality rates from lung cancer, leukemia, bone cancer, or diseases of the respiratory and genitourinary systems. Lung cancer in uranium miners is probably the result of inhalation of radon daughters found in these mines. Chronic poisoning gives chest findings of pneumoconiosis, pronounced blood changes, and generalized injury. Cancer or lymphatic and blood forming tissues may result. See the following sections regarding the effects of inhalation of an alpha emitter.

Alpha Radiation

Acute exposure: 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 swallowed. 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 increases cancer risk.

Chronic exposure: The effects of chronic exposure by internally deposited alpha radiation is dependent upon the dose and target organ(a). Possible disorders include lung cancer, sterility, anemia, leukemia, or bone cancer.

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, translocations, 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:



Acute exposure: There is no evidence that insoluble uranium compounds can be absorbed through the skin; insoluble salts produced no signs of poisoning after skin contact. Thorium may irritate the skin.

Chronic exposure: 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.

Alpha radiation

Acute exposure: Alpha radiation is not usually an external hazard. However, local damage may occur at the site of a wound. Absorption, or penetration through damaged skin may result in increased cancer risk.

Chronic exposure: Prolonged or repeated contact my result in increased cancer risk.

  • Eye contact:



Acute exposure: 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 thorium compound tend to be necrosis of the conjunctivae and eyelids, and ulceration of the cornea.

Chronic exposure: 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.

Alpha radiation

Acute exposure: 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.

Chronic exposure: 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.

  • Ingestion:



Acute exposure: Feeding studies on animals indicate that insoluble uranium is much less toxic than soluble uranium compounds. Thorium 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 thorium, after which time measurable uranium is present in the bone and kidney.

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

Alpha radiation

Acute exposure: The fate of ingested alpha emitters depends on their solubility and valence.

Chronic exposure: Repeated ingestion of alpha emitters may increase cancer risks.

First Aid for Thorium Compounds

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 administration of a bi-carbonated solution given locally, and in intravenous perfusion (one bottle of 250 ML at 1.4%).


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), International Civil Aviation Organization (ICAO), and 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:

Classification of substances with multiple hazards must be determined in accordance with the criteria presented in the regulations mentioned above. Due to the various quantities/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











This material is prepared for use as a standard or in interlaboratory comparison programs at analytical laboratories, which routinely handle Thorium. IBI Labs assumes that recipients of this material have developed internal safety procedures, which guard against accidental exposure to radioactive and toxic materials, contamination of the laboratory environment, or criticality. IBI Labs further expects that personnel who handle radioactive materials have been thoroughly trained in the safety procedures developed by and for their Laboratory.

The information and recommendations set forth herein are presented in good faith and believed to be correct as of the revision date. However, recipients of this material should use this information only as a supplement to other information gathered by them and should make independent judgement of the suitability and accuracy of this information. This statement is not intended to provide comprehensive instruction in developing an appropriate safety program and does not include all regulatory guidelines.

This information is furnished without warranty, and any use of the product not in conformance with this Safety Data Sheet, or in combination with any other product or process, is the responsibility of the user.


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