CAS 1309-37-1PubChem CID 518696
Iron oxide (Fe2O3)
- IUPAC name
- oxo(oxoferriooxy)iron
- Molecular formula
- Fe2O3
- Molecular weight
- 159.69 g/mol
- Exact mass
- 159.854615 Da
- Topological polar surface area
- 43.4 Ų
- Hydrogen-bond donors
- 0
- Hydrogen-bond acceptors
- 3
- Covalent units
- 1
- Defined stereocentres
- 0
Also known as
Iron trioxideIron oxide, rediron(3+) oxideiron (III) oxideAnhydrous Ferric OxideAnhydrous Iron (III) OxideCHEBI:50819Ferrum Oxydatum
16 more reported names
Iron oxide,Hematite 8124Anhydrous Iron (III)RefChem:55186Ferric oxide (anhydrous)616-935-811554 Red1K09F3G675215-168-2Anchred standardAnhydrous iron oxideAnhydrous oxide of ironArmenian boleBayer S 11Bayferrox 105MBlack oxide of iron
External database identifiers
- ChEBI:CHEBI:50819
Evidence from additional scientific databases
NIH PubChem PUG-View
Exact identifier match518696
Attributed physical-property, hazard, environmental and use annotations.
- Color/Form: Reddish-brown hexagonal crystals Source: Hazardous Substances Data Bank (HSDB)
- Color/Form: Reddish or blueish-black powder Source: Hazardous Substances Data Bank (HSDB)
- Color/Form: Steel gray to red hexagonal Source: Hazardous Substances Data Bank (HSDB)
- Color/Form: Red-brown solid. /Iron oxide dust and fume, as Fe/ Source: Hazardous Substances Data Bank (HSDB)
- Color/Form: A fine, red powder of ferric oxide. /Rouge/ Source: Hazardous Substances Data Bank (HSDB)
- Density: 5.25 g/cu cm Source: Hazardous Substances Data Bank (HSDB)
- Density: 5.24 g/cm³ Source: ILO-WHO International Chemical Safety Cards (ICSCs)
- Density: 5.24 Source: Occupational Safety and Health Administration (OSHA)
- Density: 5.24 Source: The National Institute for Occupational Safety and Health (NIOSH)
- Melting Point: Iron 2664 °F Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
- Melting Point: 1539 °C Source: Hazardous Substances Data Bank (HSDB)
- Melting Point: 1565 °C Source: ILO-WHO International Chemical Safety Cards (ICSCs)
- Melting Point: 2664 °F Source: Occupational Safety and Health Administration (OSHA)
- Melting Point: 2664 °F Source: The National Institute for Occupational Safety and Health (NIOSH)
- Melting Point: 2849 °F Source: The National Institute for Occupational Safety and Health (NIOSH)
- Physical Description: Dry Powder; Other Solid; Dry Powder; Large Crystals; Liquid; Liquid; Dry Powder; Large Crystals; Liquid; Wet Solid; Other Solid; CBI; Large Crystals; Wet Solid; Other Solid; Dry Powder Source: EPA Chemical Data Reporting (CDR)
- Physical Description: Reddish-brown solid; Note: Exposure to fume may occur during the arc-welding of iron; [NIOSH] Insoluble in water; [CHEMINFO] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
- Physical Description: REDDISH BROWN-TO-BLACK CRYSTALS OR POWDER. Source: ILO-WHO International Chemical Safety Cards (ICSCs)
- Physical Description: Reddish-brown solid. Source: Occupational Safety and Health Administration (OSHA)
- Physical Description: Reddish-brown solid. [Note: Exposure to fume may occur during the arc-welding of iron.] Source: The National Institute for Occupational Safety and Health (NIOSH)
- Physical Description: A fine, red powder of ferric oxide. [Note: Usually used in cake form or impregnated in paper or cloth.] Source: The National Institute for Occupational Safety and Health (NIOSH)
- Refractive Index: Index of refraction: 3.01, 2.94 (LI) Source: Hazardous Substances Data Bank (HSDB)
- Solubility: Soluble in acids; insoluble in water, alcohol, ether Source: Hazardous Substances Data Bank (HSDB)
- Solubility: Solubility in water: none Source: ILO-WHO International Chemical Safety Cards (ICSCs)
- Solubility: Insoluble Source: The National Institute for Occupational Safety and Health (NIOSH)
- Vapor Pressure: 0 mm Hg (approximate) Source: Hazardous Substances Data Bank (HSDB)
- Vapor Pressure: 0 mmHg (approx) Source: Occupational Safety and Health Administration (OSHA)
- Vapor Pressure: 0 mmHg (approx) Source: The National Institute for Occupational Safety and Health (NIOSH)
- IARC Carcinogenic Agent: Ferric oxide Source: International Agency for Research on Cancer (IARC)
- IARC Carcinogenic Classes: Group 3: Not classifiable as to its carcinogenicity to humans Source: International Agency for Research on Cancer (IARC)
- IARC Monographs: Volume 1: (1972) Some Inorganic Substances, Chlorinated Hydrocarbons, Aromatic Amines, N-Nitroso Compounds, and Natural Products; Volume Sup 7: Overall Evaluations of Carcinogenicity: An Updating of IARC Monographs Volumes 1 to 42, 1987; 440 pages; ISBN 92-832-1411-0 (out of print) Source: International Agency for Research on Cancer (IARC)
- Publication Year: 1987 Source: International Agency for Research on Cancer (IARC)
- Evaluation Year: 1987 Source: International Agency for Research on Cancer (IARC)
- Exposure Routes: inhalation Source: The National Institute for Occupational Safety and Health (NIOSH)
- Exposure Routes: inhalation, skin and/or eye contact Source: The National Institute for Occupational Safety and Health (NIOSH)
- First Aid: (General first aid procedures); Breathing: Respiratory support Source: The National Institute for Occupational Safety and Health (NIOSH)
- First Aid: (General first aid procedures); Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.; Breathing: Fresh air Source: The National Institute for Occupational Safety and Health (NIOSH)
- Note: This chemical does not meet GHS hazard criteria for 66.9% (2296 of 3433) of all reports. Source: European Chemicals Agency (ECHA)
- Signal: Warning Source: European Chemicals Agency (ECHA)
- GHS Hazard Statements: H319 (18.5%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H411 (12%): Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard] Source: European Chemicals Agency (ECHA)
- Precautionary Statement Codes: P264+P265, P273, P280, P305+P351+P338, P337+P317, P391, and P501 (click each P-code to see the statement) Source: European Chemicals Agency (ECHA)
- ECHA C&L Notifications Summary: Aggregated GHS information provided per 3433 reports by companies from 44 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.; Reported as not meeting GHS hazard criteria per 2296 of 3433 reports by companies.; There are 40 notifications provided by 1137 of 3433 reports by companies with hazard statement code(s).; Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website. Source: European Chemicals Agency (ECHA)
- Signal: Danger Source: NITE-CMC
- GHS Hazard Statements: H370: Causes damage to organs [Danger Specific target organ toxicity, single exposure]; H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure] Source: NITE-CMC
- Precautionary Statement Codes: P260, P264, P270, P308+P316, P319, P321, P405, and P501 (click each P-code to see the statement) Source: NITE-CMC
- GHS Hazard Statements: H315: Causes skin irritation [Warning Skin corrosion/irritation]; H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]; H335: May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]; H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure] Source: NITE-CMC
- Precautionary Statement Codes: P260, P261, P264, P264+P265, P270, P271, P280, P302+P352, P304+P340, P305+P354+P338, P317, P319, P321, P332+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement) Source: NITE-CMC
- Target Organs: respiratory system Source: The National Institute for Occupational Safety and Health (NIOSH)
- Target Organs: Eyes, skin, respiratory system Source: The National Institute for Occupational Safety and Health (NIOSH)
- Consumer Uses: Other; Soil amendments (fertilizers); Catalyst; Filler; Not Known or Reasonably Ascertainable; Pigment; Intermediate; Dye Source: EPA Chemical Data Reporting (CDR)
- Industry Uses: Reducing agent; Soil amendments (fertilizers); Catalyst; Not Known or Reasonably Ascertainable; Filler; Oxidizing agent; Adsorbent; Laboratory chemicals; Dye; Pigment; Solids separation (precipitating) agent, not otherwise specified; Intermediate; Heat stabilizer; Processing aids, specific to petroleum production; Other; Alloys; Abrasives Source: EPA Chemical Data Reporting (CDR)
- Sources/Uses: Iron oxide is used in pigments, abrasives (jeweler's rouge), and magnetic tapes. Exposure can occur in mining, smelting, grinding steel, polishing, and welding; [ACGIH] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
- Industrial Processes with risk of exposure: Steel Producing [Category: Industry]; Abrasive Blasting [Category: Clean]; Metal Preparation and Pouring [Category: Foundry]; Welding [Category: Weld]; Painting (Pigments, Binders, and Biocides) [Category: Paint]; Mining [Category: Industry]; Cement Producing [Category: Industry]; Metal Extraction and Refining [Category: Industry] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
- Uses: Polishing agent for glass, precious metals, diamonds; in magnets, magnetic tapes; as catalyst; pigment for paper, linoleum, ceramics, glass; paint for ironwork, ship hulls; in electrical resistors and semiconductors; as colloidal solutions as stain for polysaccharides. Source: Hazardous Substances Data Bank (HSDB)
- Uses: As a pigment, mfr of ferrites for electronic uses. Source: Hazardous Substances Data Bank (HSDB)
- Uses: Metallurgy, gas purification, paint and rubber pigment, component of thermite, polishing compounds, mordant, lab reagent, catalyst (p-hydrogen), feed additive, electronic pigments for TV, permanent magnets, memory cores for computers, magnetic tapes. Source: Hazardous Substances Data Bank (HSDB)
- Uses: Used almost exclusively to color decorative concrete; in paints and coatings Source: Hazardous Substances Data Bank (HSDB)
- Uses: For more Uses (Complete) data for FERRIC OXIDE (8 total), please visit the HSDB record page. Source: Hazardous Substances Data Bank (HSDB)
Mapped by: Existing checksum-valid CAS to unique PubChem CID match. Retrieved: 2026-08-31. Open source record
Scientific classifications and hazard annotations provide context and do not replace the market-specific regulatory decision shown above.
Additional source coverage and match status
| Source | Result | Checked |
|---|---|---|
| NIH PubChem PUG-View | Exact match | 2026-08-31 |
A recorded no-match is useful evidence that the source was checked; it is not a claim that the substance does not exist elsewhere.
Retrieved from NIH PubChem on 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.