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Chemical Datasheet


7 - Radioactive
Chemical Identifiers | Hazards | Response Recommendations | Physical Properties | Regulatory Information | Alternate Chemical Names

Chemical Identifiers

The Chemical Identifier fields include common identification numbers, the NFPA diamond U.S. Department of Transportation hazard labels, and a general description of the chemical. The information in CAMEO Chemicals comes from a variety of data sources.
CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 1314-20-1
  • Radioactive
NIOSH Pocket Guide International Chem Safety Card
none none
NFPA 704
data unavailable
General Description
White powder. Density 9.7 g / cm3. Not soluble in water. Used in high-temperature ceramics, gas mantles, nuclear fuel, flame spraying, crucibles, non-silicia optical glass, catalysis, filaments in incandescent lamps, cathodes in electron tubes and arc-melting electrodes.


The Hazard fields include special hazard alerts air and water reactions, fire hazards, health hazards, a reactivity profile, and details about reactive groups assignments and potentially incompatible absorbents. The information in CAMEO Chemicals comes from a variety of data sources.
Reactivity Alerts
Air & Water Reactions
Insoluble in water.
Fire Hazard
Excerpt from ERG Guide 161 [Radioactive Materials (Low Level Radiation)]:

Some of these materials may burn, but most do not ignite readily. Many have cardboard outer packaging; content (physically large or small) can be of many different physical forms. Radioactivity does not change flammability or other properties of materials. (ERG, 2024)
Health Hazard
Excerpt from ERG Guide 161 [Radioactive Materials (Low Level Radiation)]:

Radiation presents minimal risk to transport workers, emergency response personnel and the public during transportation accidents. Packaging durability increases as potential hazard of radioactive content increases. Very low levels of contained radioactive materials and low radiation levels outside packages result in low risks to people. Damaged packages may release measurable amounts of radioactive material, but the resulting risks are expected to be low. Some radioactive materials cannot be detected by commonly available instruments. Packages do not have RADIOACTIVE I, II, or III labels. Some may have EMPTY labels or may have the word "Radioactive" in the package marking. (ERG, 2024)
Reactivity Profile
Has only weak oxidizing powers. Redox reactions can however still occur. Not water-reactive. Soluble in sulfuric acid.
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents

No information available.

Response Recommendations

The Response Recommendation fields include isolation and evacuation distances, as well as recommendations for firefighting, non-fire response, protective clothing, and first aid. The information in CAMEO Chemicals comes from a variety of data sources.
Isolation and Evacuation
Excerpt from ERG Guide 161 [Radioactive Materials (Low Level Radiation)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 25 meters (75 feet) in all directions.

LARGE SPILL: Consider initial downwind evacuation for at least 100 meters (330 feet).

FIRE: When a large quantity of this material is involved in a major fire, consider an initial evacuation distance of 300 meters (1000 feet) in all directions. (ERG, 2024)
Excerpt from ERG Guide 161 [Radioactive Materials (Low Level Radiation)]:

Presence of radioactive material will not influence the fire control processes and should not influence selection of techniques. If it can be done safely, move undamaged containers away from the area around the fire. Do not move damaged packages; move undamaged packages out of fire zone.

SMALL FIRE: Dry chemical, CO2, water spray or regular foam.

LARGE FIRE: Water spray, fog (flooding amounts). (ERG, 2024)
Non-Fire Response
Excerpt from ERG Guide 161 [Radioactive Materials (Low Level Radiation)]:

Do not touch damaged packages or spilled material. Cover liquid spill with sand, earth or other non-combustible absorbent material. Cover powder spill with plastic sheet or tarp to minimize spreading. (ERG, 2024)
Protective Clothing
Excerpt from ERG Guide 161 [Radioactive Materials (Low Level Radiation)]:

Positive pressure self-contained breathing apparatus (SCBA) and structural firefighters' protective clothing will provide adequate protection. (ERG, 2024)
DuPont Tychem® Suit Fabrics
No information available.
First Aid
Excerpt from ERG Guide 161 [Radioactive Materials (Low Level Radiation)]:

Refer to the "General First Aid" section. Specific First Aid: Medical problems take priority over radiological concerns. Use first aid treatment according to the nature of the injury. Do not delay care and transport of a seriously injured person. Injured persons contaminated by contact with released material are not a serious hazard to health care personnel, equipment or facilities. (ERG, 2024)

Physical Properties

The Physical Property fields include properties such as vapor pressure and boiling point, as well as explosive limits and toxic exposure thresholds The information in CAMEO Chemicals comes from a variety of data sources.

Note: For Vapor Density and Specific Gravity, comparing the value to 1.0 can tell you if the chemical will likely sink/rise in air or sink/float in fresh water (respectively). Short phrases have been added to those values below as an aid. However, make sure to also consider the circumstances of a release. The Vapor Density comparisons are only valid when the gas escaping is at the same temperature as the surrounding air itself. If the chemical is escaping from a container where it was pressurized or refrigerated, it may first escape and behave as a heavy gas and sink in the air (even if it has a Vapor Density value less than 1). Also, the Specific Gravity comparisons are for fresh water (density 1.0 g/mL). If your spill is in salt water (density about 1.027 g/mL), you need to adjust the point of comparison. There are some chemicals that will sink in fresh water and float in salt water.
Chemical Formula:
  • O2Th
Flash Point: data unavailable
Lower Explosive Limit (LEL): data unavailable
Upper Explosive Limit (UEL): data unavailable
Autoignition Temperature: data unavailable
Melting Point: data unavailable
Vapor Pressure: data unavailable
Vapor Density (Relative to Air): data unavailable
Specific Gravity: data unavailable
Boiling Point: data unavailable
Molecular Weight: data unavailable
Water Solubility: data unavailable
Ionization Energy/Potential: data unavailable
IDLH: data unavailable

AEGLs (Acute Exposure Guideline Levels)

No AEGL information available.

ERPGs (Emergency Response Planning Guidelines)

No ERPG information available.

PACs (Protective Action Criteria)

Chemical PAC-1 PAC-2 PAC-3
Thorium oxide; (Thorium dioxide) (1314-20-1) 30 mg/m3 330 mg/m3 2000 mg/m3
(DOE, 2024)

Regulatory Information

The Regulatory Information fields include information from the U.S. Environmental Protection Agency's Title III Consolidated List of Lists, the U.S. Cybersecurity and Infrastructure Security Agency's Chemical Facility Anti-Terrorism Standards, and the U.S. Occupational Safety and Health Administration's Process Safety Management of Highly Hazardous Chemicals Standard List (see more about these data sources).

EPA Consolidated List of Lists

Regulatory Name CAS Number/
313 Category Code
CAA 112(r)
Thorium dioxide 1314-20-1 313

(EPA List of Lists, 2024)

CISA Chemical Facility Anti-Terrorism Standards (CFATS)

No regulatory information available.

OSHA Process Safety Management (PSM) Standard List

No regulatory information available.

Alternate Chemical Names

This section provides a listing of alternate names for this chemical, including trade names and synonyms.