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Chromium(III) oxide

PubChem CID
517277
Structure
Chromium(III) oxide_small.png
Molecular Formula
Synonyms
  • Chromium(III) oxide
  • 1308-38-9
  • Chromia
  • Dichromium trioxide
  • Chromium sesquioxide
Molecular Weight
151.990 g/mol
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Dates
  • Create:
    2005-03-27
  • Modify:
    2025-01-11
Description
Dichromium trioxide is a chromium oxide.
Chromium(III) oxide is an oxide of chromium that occurs in nature as the rare mineral eskolaite. It is commonly used as pigment, under the name viridian, in paints, inks, and glasses. Chromium is a chemical element which has the symbol Cr and atomic number 24. It is found naturally occuring in rocks, animals, plants, and soil, and is usually mined as chromite ore. Chromium is most toxic in its +6 oxidation state (chromium(VI)) due to its greater ability to enter cells and higher redox potential. Trivalent chromium (chromium(III)) however, is biologically necessary for sugar and lipid metabolism in humans. (L17, L523)
L17: Wikipedia. Chromium. Last Updated 5 March 2009. http://en.wikipedia.org/wiki/Chromium
L523: Wikipedia. Chromium(III) oxide. Last Updated 1 June 2009. http://en.wikipedia.org/wiki/Chromium(III)_oxide
See also: Chromic oxide (annotation moved to).

1 Structures

1.1 2D Structure

Chemical Structure Depiction
Chromium(III) oxide.png

1.2 3D Status

Conformer generation is disallowed since MMFF94s unsupported element

2 Names and Identifiers

2.1 Computed Descriptors

2.1.1 IUPAC Name

oxo(oxochromiooxy)chromium
Computed by Lexichem TK 2.7.0 (PubChem release 2021.10.14)

2.1.2 InChI

InChI=1S/2Cr.3O
Computed by InChI 1.0.6 (PubChem release 2021.10.14)

2.1.3 InChIKey

QDOXWKRWXJOMAK-UHFFFAOYSA-N
Computed by InChI 1.0.6 (PubChem release 2021.10.14)

2.1.4 SMILES

O=[Cr]O[Cr]=O
Computed by OEChem 2.3.0 (PubChem release 2024.12.12)

2.2 Molecular Formula

Cr2O3
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Cr2O3

2.3 Other Identifiers

2.3.1 CAS

1308-38-9
196696-68-1

2.3.2 Deprecated CAS

1093852-36-8, 1229022-62-1, 12689-83-7, 144855-63-0, 1610419-57-2, 164057-73-2, 165589-75-3, 185464-26-0, 196696-68-1, 294202-64-5, 499126-69-1, 960246-23-5
1229022-62-1, 12689-83-7, 144855-63-0, 1610419-57-2, 164057-73-2, 165589-75-3, 185464-26-0, 196696-68-1, 294202-64-5, 499126-69-1, 960246-23-5

2.3.3 European Community (EC) Number

2.3.4 ChEBI ID

2.3.5 DSSTox Substance ID

2.3.6 ICSC Number

2.3.7 Wikidata

2.3.8 Wikipedia

2.4 Synonyms

2.4.1 MeSH Entry Terms

  • chromic oxide
  • chromium (3+) oxide
  • chromium (III) oxide
  • chromium oxide hydrate
  • chromium oxide tetrahydrate
  • chromium oxide, 51Cr-labeled
  • chromium sesquioxide
  • chromium(III) oxide
  • dichromium trioxide

2.4.2 Depositor-Supplied Synonyms

3 Chemical and Physical Properties

3.1 Computed Properties

Property Name
Molecular Weight
Property Value
151.990 g/mol
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Hydrogen Bond Donor Count
Property Value
0
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Hydrogen Bond Acceptor Count
Property Value
3
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Rotatable Bond Count
Property Value
0
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Exact Mass
Property Value
151.865753 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Monoisotopic Mass
Property Value
151.865753 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Topological Polar Surface Area
Property Value
43.4 Ų
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Heavy Atom Count
Property Value
5
Reference
Computed by PubChem
Property Name
Formal Charge
Property Value
0
Reference
Computed by PubChem
Property Name
Complexity
Property Value
34.2
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Isotope Atom Count
Property Value
0
Reference
Computed by PubChem
Property Name
Defined Atom Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Undefined Atom Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Defined Bond Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Undefined Bond Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Covalently-Bonded Unit Count
Property Value
1
Reference
Computed by PubChem
Property Name
Compound Is Canonicalized
Property Value
Yes
Reference
Computed by PubChem (release 2021.10.14)

3.2 Experimental Properties

3.2.1 Physical Description

Pellets or Large Crystals, Other Solid; Pellets or Large Crystals; Dry Powder, Pellets or Large Crystals; Dry Powder; Other Solid; Dry Powder, Other Solid
Green, hygroscopic solid; [CHEMINFO] Insoluble in water; [ACGIH]
LIGHT-TO-DARK-GREEN POWDER.

3.2.2 Color / Form

Light to dark green, fine, hexagonal crystals
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013., p. 398
Green powder
International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983., p. 469
Bright-green, extremely hard crystals
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 298

3.2.3 Boiling Point

4000 °C
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 298

3.2.4 Melting Point

2435 °C
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013., p. 398

3.2.5 Solubility

In water, 3.13 ug/L at 20 °C, pH 6; 2.96 ug/L at 20 °C, pH 8
ECHA; Search for Chemicals. Chromium (III) Oxide (CAS 1308-38-9) Registered Substances Dossier. European Chemical Agency. Available from, as of Oct 22, 2015: https://echa.europa.eu/
Practically insoluble in water
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013., p. 398
Practically insoluble in alcohol, acetone; slightly soluble in acids, alkalies
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013., p. 398
Insoluble in acids, and alkalies
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 298
Solubility in water: none

3.2.6 Density

5.22 at 25 °C
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013., p. 398
5.22 g/cm³

3.2.7 Stability / Shelf Life

Stable under recommended storage conditions.
Sigma-Aldrich; Safety Data Sheet for Chromium(III) oxide. Product Number: 203068, Version 4.6 (Revision Date 09/16/2015). Available from, as of October 19, 2015: https://www.sigmaaldrich.com/safety-center.html

3.2.8 pH

Trivalent chromium compounds are amphoteric
Langard S, Lison D; Chromium, Molybdenum and Tungsten. Patty's Toxicology. 6th ed. (1999-2015). New York, NY: John Wiley & Sons, Inc. On-line Posting Date: 27 Jan 2012

3.2.9 Refractive Index

Index of refraction: 2.551
Weast, R.C. (ed.) Handbook of Chemistry and Physics, 68th ed. Boca Raton, Florida: CRC Press Inc., 1987-1988., p. B-85

3.2.10 Other Experimental Properties

Turns brown on heating, but reverts to green color on cooling. Crystalline chromic oxide is extremely hard; will scratch quartz, topaz, zircon.
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013., p. 398
In water, 10.3 ug/L at 20 °C /Chromium oxide hydrate/
ECHA; Search for Chemicals. Chromium (III) Oxide (CAS 1308-38-8-30-4) Registered Substances Dossier. European Chemical Agency. Available from, as of Oct 22, 2015: https://echa.europa.eu/
Electrical resistivity: 1.3x10+9, 2.3x10+7, 6.8x10+3, and 4.5x10+3 microohm-cm at 350, 1200, 600, and 1100 °C, respectively.
Weast, R.C. (ed.) Handbook of Chemistry and Physics, 68th ed. Boca Raton, Florida: CRC Press Inc., 1987-1988., p. D-40
Calculated lattice energy: 15,276 kJ/mol; thermochemical cycle lattice energy: 114,957 kJ/mol
Weast, R.C. (ed.) Handbook of Chemistry and Physics, 68th ed. Boca Raton, Florida: CRC Press Inc., 1987-1988., p. D-109
For more Other Experimental Properties (Complete) data for Chromium (III) oxide (8 total), please visit the HSDB record page.

3.3 SpringerMaterials Properties

3.4 Chemical Classes

Metals -> Chromium Compounds, Inorganic

3.4.1 Cosmetics

Hair dyeing; Cosmetic colorant
S13 | EUCOSMETICS | Combined Inventory of Ingredients Employed in Cosmetic Products (2000) and Revised Inventory (2006) | DOI:10.5281/zenodo.2624118

3.4.2 Food Additives

Drugs, Cosmetics, Devices -> FDA Regulatory Status of Color Additives

3.4.3 Polymers

Plastics -> Polyolefin-I; PUR; Polyolefin-II; PVC (soft); ABS; PVC (rigid); PET; PMMA; PA; PC; (E)PS
S47 | ECHAPLASTICS | A list from the Plastic Additives Initiative Mapping Exercise by ECHA | DOI:10.5281/zenodo.2658139
Plastics -> Pigments agents
S47 | ECHAPLASTICS | A list from the Plastic Additives Initiative Mapping Exercise by ECHA | DOI:10.5281/zenodo.2658139

4 Spectral Information

4.1 IR Spectra

4.1.1 FTIR Spectra

1 of 2
Technique
KBr WAFER
Source of Spectrum
SRL
Source of Sample
G. Siegle & Company, GmbH, Stuttgart-Feuerbach, Germany
Copyright
Copyright © 1980, 1981-2024 John Wiley & Sons, Inc. All Rights Reserved.
Thumbnail
Thumbnail
2 of 2
Technique
KBr pellet
Source of Sample
Bayer, Hoechst-Siegle
Copyright
Copyright © 1989, 1990-2024 Wiley-VCH Verlag GmbH & Co. KGaA. All Rights Reserved.
Thumbnail
Thumbnail

4.2 Raman Spectra

1 of 2
Instrument Name
Bio-Rad FTS 175C with Raman accessory
Technique
FT-Raman
Source of Sample
Fluka Chemie AG, Buchs, Switzerland
Catalog Number
27085
Copyright
Copyright © 1980, 1981-2024 John Wiley & Sons, Inc. All Rights Reserved.
Thumbnail
Thumbnail
2 of 2
Instrument Name
Bio-Rad FTS 175C with Raman accessory
Technique
FT-Raman
Source of Sample
Fluka Chemie AG, Buchs, Switzerland
Catalog Number
27085
Copyright
Copyright © 1980, 1981-2024 John Wiley & Sons, Inc. All Rights Reserved.
Thumbnail
Thumbnail

6 Chemical Vendors

7 Food Additives and Ingredients

7.1 Color Additive Status

Color Additive
Use
Drugs, Cosmetics, Devices
Restrictions
Externally applied drugs and cosmetics, including eye area use. Contact lenses.
End Note
1 - The color additives Antarctic krill meal, Astaxanthin, Astaxanthin dimethyldisuccinate, Ultramarine blue, Canthaxanthin, Haematococcus algae meal, Synthetic iron oxide, Dried algae meal, Tagetes (Aztec marigold) meal and extract, Corn endosperm oil, Paracoccus pigment, and Phaffia yeast are approved for specific uses in animal food (see 21 CFR 73.32. 73.35, 73.37, 73.50, 73.75, 73.185, 73.200, 73.275, 73.295, 73.315, 73.352, and 73.355, respectively).
Color additive regulations in 21 eCFR
Other regulations in 21 eCFR

8 Pharmacology and Biochemistry

8.1 Absorption, Distribution and Excretion

The intestinal absorption of trivalent and hexavalent chromium (Cr) given orally (experiment I) or infused in the intestine (experiment II) was investigated in rats. The nonabsorbable form of chromium ((51)Cr2O3) and water-soluble and more absorbable Na2(51)CrO4 (the hexavalent form of Cr) were compared. Total retention of chromium given orally ranged around 15 percent of the dose, regardless of the chromium compounds applied. The absorption rate of chromic oxide, which is considered a nonabsorbable compound, was 14.4 as a percentage of chromium intake. This result indicates that some loss of chromium has to be taken into account in metabolic trials made by the indicator method. In isolated rat intestine, from the injected Cr 2.5% of chromic oxide and 43.2% of sodium chromate were absorbed during an hour (experiment II). The absorbed chromium was transferred to the liver where the liver tissue retained 10.9% of chromic oxide and 51.1% of sodium chromate. Radioactivity of v. cava caudalis following intestinal injection of Na2CrO4 was thirtyfold greater than after Cr2O3 dosing. This phenomenon can be explained by the lower blood clearance of chromate. Different absorption rate of chromate depending on the route of administration could be due to the fact that the hexavalent form given orally was reduced to Cr3+ in the acidic environment of the stomach. When Na2CrO4 was infused directly in the intestine of rats, such reduction could not occur. This means that the acidic gastric juice might play a role in inhibiting the intestinal absorption of Na2CrO4 when this compound is given orally.
Febel H et al; Acta Vet Hung. 49 (2): 203-9 (2001)
In this study, Escherichia coli DH5alpha (ATCC 35218) were exposed to 0-100 ug/mL chromium oxide nanoparticles (Cr2O3, Nps) for 15-120 min to study the internalization of Nps by flowcytometry. A concentration-duration dependent increased side scatter (SSC) confirmed the internalization of Cr2O3 NPs by the E. coli. This study suggests that the uptake of Nps by bacterial cells can be rapidly monitored with flow cytometry for toxicity and risk assessment.
Khatoon I; J Biomed Nanotechnol. 7 (1): 168-9 (2011)
The aim of this study was to find out how marker characteristics could affect digestive transit time in Gallus gallus. One soluble marker, Cr-EDTA, and two insoluble markers, Cr2O3 and chromium-mordanted plant cells of two sizes, were used. Three- to six-week-old chickens were killed in series after the oral administration of the markers at intervals of 0, 0.5, 1, 2, 3, 5, 7, and 9 hr. The amount of chromium in each digestive segment was determined by atomic absorption. There were some differences in the initial distribution of markers; whereas almost the total amount of the chromium-mordanted rice husk of the largest size was found in the crop at time 0, less than half of the Cr-EDTA was found. Marker emptying out of the crop was fast and not related to either the type or size. In contrast, the emptying rate of the gizzard depended on marker particle size. As far as the ceca were concerned, the ileocecal junction allowed the passage of soluble Cr-EDTA whereas solid markers were impeded (Cr2O3) or not allowed to pass through at all (vegetable fiber of any size). It can be concluded that marker selection is of major importance to transit time studies in chickens, since its characteristics can determine transit time in an absolute way.
Vergara P et al; Q J Exp Physiol. 74 (6): 867-74 (1989)
Small intestinal digestibility can be measured by comparing feed with effluent collected from an ileal T-cannula. Nevertheless, a nondigestible, nonabsorbable marker, such as chromic oxide (Cr2O3), must be included in the diet because simple T-cannula do not divert chyme completely. This study was conducted to evaluate the excretion pattern of Cr2O3 in cannulated dogs because the kinetics of Cr2O3 has not been previously investigated in this nonruminant species. Chromic oxide was added to four diets fed to eight cannulated mixed-breed dogs in a Latin-square design. The four diets contained reciprocal proportions of protein from texturized vegetable protein (0% to 57%) and from beef (100% to 43%), so protein and carbohydrate digestibility varied among diets. All feces were collected during wk 2 and all ileal effluent during wk 3 of each diet period. Ileal recovery of Cr2O3 was almost complete (94%) and was greater than fecal recovery (87%) (P < or =0.03). Recovery was not different among diet groups. Ileal DM digestibility was approximately 2 percentage units lower on d 1 (P < or = 0.007) than on d 2 to 4. Nevertheless, ileal DM digestibility varied little on these subsequent days so single-day collections should be accurate. Chromic oxide concentration in chyme varied widely during each collection but increased at the start and declined towards the end of each collection. Spot sampling may therefore result in inaccurate estimates of nutrient digestibility.
Hill RC et al; J Anim Sci. 74 (7): 1629-34 (1996)

8.2 Metabolism / Metabolites

Chromium is absorbed from oral, inhalation, or dermal exposure and distributes to nearly all tissues, with the highest concentrations found in kidney and liver. Bone is also a major storage site and may contribute to long-term retention. Hexavalent chromium's similarity to sulfate and chromate allow it to be transported into cells via sulfate transport mechanisms. Inside the cell, hexavalent chromium is reduced first to pentavalent chromium, then to trivalent chromium by many substances including ascorbate, glutathione, and nicotinamide adenine dinucleotide. Chromium is almost entirely excreted with the urine. (A12, L16)
A12: Salnikow K, Zhitkovich A: Genetic and epigenetic mechanisms in metal carcinogenesis and cocarcinogenesis: nickel, arsenic, and chromium. Chem Res Toxicol. 2008 Jan;21(1):28-44. Epub 2007 Oct 30. PMID:17970581
L16: ATSDR - Agency for Toxic Substances and Disease Registry (2008). Toxicological profile for chromium. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). http://www.atsdr.cdc.gov/toxprofiles/tp7.html

9 Use and Manufacturing

9.1 Uses

EPA CPDat Chemical and Product Categories
The Chemical and Products Database, a resource for exposure-relevant data on chemicals in consumer products, Scientific Data, volume 5, Article number: 180125 (2018), DOI:10.1038/sdata.2018.125
Sources/Uses
Used in abrasives, refractory materials, semiconductors, pigments, alloys, textile printing inks, and catalysts; [Merck Index] Used as a pigment in polymers and latex paints; [HSDB]
Merck Index - O'Neil MJ, Heckelman PE, Dobbelaar PH, Roman KJ (eds). The Merck Index, An Encyclopedia of Chemicals, Drugs, and Biologicals, 15th Ed. Cambridge, UK: The Royal Society of Chemistry, 2013.
Industrial Processes with risk of exposure
For chromic oxide (USEPA/OPP Pesticide Code: 021103) there are 0 labels match. /SRP: Not registered for current use in the U.S., but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./
National Pesticide Information Retrieval System's Database on Chromic Oxide (1308-38-9). Available from, as of October 29, 2015: https://npirspublic.ceris.purdue.edu/ppis/
In abrasives, refractory materials, electric semiconductors; as pigment, particularly in coloring glass; in alloys; in printing fabrics and banknotes; catalyst for organic and inorganic reactions.
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013., p. 398
Used in dyeing polymers, ... colorant for latex paints.
IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V49 81 (1980)
In metallurgy in the manufacture of chromium metal and aluminum-chromium master alloys.
IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V49 81 (1990)
For more Uses (Complete) data for Chromium (III) oxide (11 total), please visit the HSDB record page.
Plastics -> Typical concentration range in plastic materials -> 1%
S47 | ECHAPLASTICS | A list from the Plastic Additives Initiative Mapping Exercise by ECHA | DOI:10.5281/zenodo.2658139
Chromium(III) oxide is commonly used as pigment, under the name viridian, in paints, inks, and glasses. (L523)
L523: Wikipedia. Chromium(III) oxide. Last Updated 1 June 2009. http://en.wikipedia.org/wiki/Chromium(III)_oxide

9.1.1 Use Classification

Plastics -> Polymer Type -> Polyolefin-I; PUR; Polyolefin-II; PVC (soft); ABS; PVC (rigid); PET; PMMA; PA; PC; (E)PS
S47 | ECHAPLASTICS | A list from the Plastic Additives Initiative Mapping Exercise by ECHA | DOI:10.5281/zenodo.2658139
Cosmetics -> Hair dyeing; Cosmetic colorant
S13 | EUCOSMETICS | Combined Inventory of Ingredients Employed in Cosmetic Products (2000) and Revised Inventory (2006) | DOI:10.5281/zenodo.2624118
Plastics -> Pigments agents
S47 | ECHAPLASTICS | A list from the Plastic Additives Initiative Mapping Exercise by ECHA | DOI:10.5281/zenodo.2658139

9.1.2 Industry Uses

  • Catalyst
  • Paint additives and coating additives not described by other categories
  • Other
  • Pigments
  • Corrosion inhibitor
  • Fixing agent (mordant)
  • Intermediate
  • Not Known or Reasonably Ascertainable
  • Pigment
  • Other (specify)

9.1.3 Consumer Uses

  • Pigments
  • Other
  • Corrosion inhibitor
  • Processing aids not otherwise specified
  • Paint additives and coating additives not described by other categories
  • Pigment
  • Other (specify)
  • Fixing agent (mordant)
  • Not Known or Reasonably Ascertainable

9.1.4 Household Products

Household & Commercial/Institutional Products

Information on 71 consumer products that contain Dichromium trioxide in the following categories is provided:

• Home Maintenance

• Personal Care

9.2 Methods of Manufacturing

The industrial production of chromium(III) oxide involves the reduction of solid sodium dichromate, generally with sulfur. The finely divided components are thoroughly mixed, fed into a brick-lined furnace, and brought to dark-red heat. The reaction proceeds exothermically. After the reaction mass has cooled, it is broken up and the sodium sulfate produced is leached out with water. The remaining solid is separated, rinsed, dried, and ground.
Anger G et al; Chromium Compounds. Ullmann's Encyclopedia of Industrial Chemistry 7th ed. (1999-2015). NY, NY: John Wiley & Sons. Online Posting Date: June 15, 2000
Prepared by reaction of sodium dichromate or chromate with sulfur.
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013., p. 398
Anhydrous chromic oxide is produced commercially by heating chromic hydroxide, by heating dry ammonium dichromate, or by heating sodium dichromate with sulfur and washing out the sodium sulfate. The hydrated material is made commercially by calcining sodium dichromate with boric acid and hydrolyzing chromic borate.
IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V49 71 (1990)
(1) By heating chromium hydroxide, (2) by heating dry ammonium dichromate, (3) by heating sodium dichromate with sulfur and washing out the sodium sulfate.
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 298
Sodium dichromate + ammonium chloride/ammonium sulfate (reduction); sodium dichromate + sulfur + metallurigal coke/hardwood/molasses
Ashford, R.D. Ashford's Dictionary of Industrial Chemicals. London, England: Wavelength Publications Ltd., 1994., p. 219

9.3 Formulations / Preparations

Chromic oxide is available in several grades depending on its use in metallurgical and refractory industries. A typical analysis of a metallurgical grade is 99.4% chromium (as chromic oxide) and less than 0.1% moisture. A typical analysis of a refractory grade is 98.5-99.4% chromium (as chromic oxide), 0.1% alkali metals (as sodium oxide), 0.1% other metal oxides (mainly aluminium, iron and magnesium), and average particle size, 0.5-3.5 um. ... Chromic oxide pigment (dark chromium oxide) typically contains >99.0% chromium as chromic oxide.
IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V49 64 (1990)
Six grades from 3-6 mm to -325 mesh, 99 to 99.999% purity /available from Cerac, Inc/
Kuney, J.H. and J.N. Nullican (eds.) Chemcyclopedia. Washington, DC: American Chemical Society, 1988., p. 180
Metallurgical grade; powder grade
Kuney, J.H. and J.N. Nullican (eds.) Chemcyclopedia. Washington, DC: American Chemical Society, 1988., p. 180
Chromite ore
IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V49 121 (1990)
Chromium oxide nanoparticles
Singh G et al; J Biomed Nanotechnol. 7 (1): 166-7 (2011)

9.4 U.S. Production

Aggregated Product Volume

2019: 10,000,000 - <50,000,000 lb

2018: 10,000,000 - <50,000,000 lb

2017: 10,000,000 - <50,000,000 lb

2016: 10,000,000 - <50,000,000 lb

(1972) 5.58X10+9 GRAMS
SRI
(1975) 5.09X10+9 GRAMS (CHROME OXIDE GREEN)
SRI
(1984) 7.47X10+9 G /CHROME OXIDE GREEN/
BUREAU OF THE CENSUS. CURRENT INDUSTRIAL REPORTS: INORGANIC CHEMICALS 1984 p.18
Non-confidential 2012 Chemical Data Reporting (CDR) information on the production and use of chemicals manufactured or imported into the United States. Chemical: Chromium oxide. National Production Volume: 27,072,114 lb/yr.
USEPA/Pollution Prevention and Toxics; 2012 Chemical Data Reporting Database. Chromium oxide (1308-38-9). Available from, as of October 26, 2015: https://java.epa.gov/oppt_chemical_search/

9.5 U.S. Imports

(1975) 3.45X10+8 G (ANHYD CHROME OXIDE GREEN)
SRI
(1984) 1.83X10+9 G /HYDRATED & CHROMIUM OXIDE GREEN/
BUREAU OF THE CENSUS. U.S. IMPORTS FOR CONSUMPTION AND GENERAL IMPORTS 1984 p.1-381

9.6 U.S. Exports

(1975) 1.63X10+8 G-INCL ANHYDRIDES, HYDROXIDES
SRI

9.7 General Manufacturing Information

Industry Processing Sectors
  • Construction
  • Custom Compounding of Purchased Resins
  • All Other Chemical Product and Preparation Manufacturing
  • Not Known or Reasonably Ascertainable
  • Plastics Material and Resin Manufacturing
  • Petrochemical Manufacturing
  • Non-metallic Mineral Product Manufacturing (includes clay, glass, cement, concrete, lime, gypsum, and other non-metallic mineral product manufacturing)
  • Printing Ink Manufacturing
  • Synthetic Dye and Pigment Manufacturing
  • Pesticide, Fertilizer, and Other Agricultural Chemical Manufacturing
  • All Other Basic Inorganic Chemical Manufacturing
  • All Other Basic Organic Chemical Manufacturing
  • Paint and Coating Manufacturing
  • Petroleum Refineries
  • Asphalt Paving, Roofing, and Coating Materials Manufacturing
  • Industrial Gas Manufacturing
  • Wholesale and Retail Trade
  • Miscellaneous Manufacturing
EPA TSCA Commercial Activity Status
Chromium oxide (Cr2O3): ACTIVE
Stabilization of collagen for various applications employs chemicals such as aldehydes, metal ions, polyphenols, etc. Stability against enzymatic, thermal and mechanical degradation is required for a range of biomedical applications. The premise of this research is to explore the use of nanoparticles with suitable functionalization/encapsulation to crosslink with collagen, such that the three dimensional architecture had the desired stability. Collagen solution prepared as per standard protocols is treated with chromium(III) oxide nanoparticules encapsulated within a polymeric matrix (polystyrene-block-polyacrylic acid /PAA/ copolymer). Selectivity towards encapsulation was ensured by the reaction in dimethyl sulfoxide, where the PS groups popped out and encapsulated the Cr(2)O(3). Subsequently when immersed in aqueous solution, PAA units popped up to react with functional groups of collagen. The interaction with collagen was monitored through techniques such as CD, FTIR, viscosity measurements, stress analysis. CD studies and FTIR showed no degradation of collagen. Thermal stability was enhanced upon interaction of nanostructures with collagen. Self-assembly of collagen was delayed but not inhibited, indicating a complete binding of the metal oxide encapsulated polymer to collagen. Metal oxide nanoparticles encapsulated within a polymeric matrix could provide thermal and mechanical stability to collagen. The formed fibrils of collagen could serve as ideal material for various smart applications such as slow/sustained drug release. The study is also relevant to the leather industry in that the nanostructures can diffuse through the highly networked collagen fibre bundles in skin matrix easily, thus overcoming the rate limiting step of diffusion.
Sangeetha S et al; Colloids Surf B Biointerfaces. 100: 36-41(2012)

10 Safety and Hazards

10.1 Hazards Identification

10.1.1 GHS Classification

1 of 3
View All
Note
This chemical does not meet GHS hazard criteria for 57.4% (1093 of 1904) of all reports. Pictograms displayed are for 42.6% (811 of 1904) of reports that indicate hazard statements.
Pictogram(s)
Irritant
Health Hazard
Signal
Danger
GHS Hazard Statements

H302 (24.2%): Harmful if swallowed [Warning Acute toxicity, oral]

H317 (25.9%): May cause an allergic skin reaction [Warning Sensitization, Skin]

H319 (24.5%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]

H360 (14.8%): May damage fertility or the unborn child [Danger Reproductive toxicity]

Precautionary Statement Codes

P203, P261, P264, P264+P265, P270, P272, P280, P301+P317, P302+P352, P305+P351+P338, P318, P321, P330, P333+P317, P337+P317, P362+P364, P405, and P501

(The corresponding statement to each P-code can be found at the GHS Classification page.)

ECHA C&L Notifications Summary

Aggregated GHS information provided per 1904 reports by companies from 26 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Reported as not meeting GHS hazard criteria per 1093 of 1904 reports by companies. For more detailed information, please visit ECHA C&L website.

There are 22 notifications provided by 811 of 1904 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.

10.1.2 Hazard Classes and Categories

Acute Tox. 4 (24.2%)

Skin Sens. 1 (25.9%)

Eye Irrit. 2 (24.5%)

Repr. 1B (14.8%)

Respiratory sensitization - Category 1

Skin sensitization - Category 1

Hazardous to the aquatic environment (Acute) - Category 1

Hazardous to the aquatic environment (Long-term) - Category 1

10.1.3 Fire Hazards

Not combustible.

10.1.4 Hazards Summary

CrIII compounds do not cause chrome ulcerations but may cause allergic dermatitis in workers with prior sensitization to CrVI compounds. [ILO Encyclo] CrIII is an essential trace mineral in the human diet. [ATSDR Case Studies] An eye and respiratory tract irritant; [ICSC] May cause GI irritation if ingested; [MSDSonline] See Chromium.

10.1.5 Skin, Eye, and Respiratory Irritations

Probably a severe eye, skin, & mucous membrane irritant.
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 921
Eczematous dermatitis due to trivalent chromium compounds has been reported. /Trivalent chromium compounds/
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 919

10.1.6 EPA Hazardous Waste Number

D007; A waste containing chromium may or may not be characterized as a hazardous waste following testing by the Toxicity Characteristic Leaching Procedure as prescribed by the Resource Conservation and Recovery Act (RCRA) regulations. /Chromium/

10.2 Safety and Hazard Properties

10.2.1 OSHA Standards

Permissible Exposure Limit: Table Z-1 8-hr Time Weighted Avg: 0.5 mg/cu m. /Chromium(III) compounds, as Cr/
29 CFR 1910.1000 (USDOL); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of November 3, 2015: https://www.ecfr.gov

10.2.2 NIOSH Recommendations

Recommended Exposure Limit: 10-hour Time-Weighted Average: 0.5 mg/cu m. /Chromium(III) compounds (as Cr)/
NIOSH. NIOSH Pocket Guide to Chemical Hazards. Department of Health & Human Services, Centers for Disease Control & Prevention. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2010-168 (2010). Available from: https://www.cdc.gov/niosh/npg

10.3 First Aid Measures

Inhalation First Aid
Fresh air, rest.
Skin First Aid
Rinse skin with plenty of water or shower.
Eye First Aid
First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.
Ingestion First Aid
Rinse mouth.

10.4 Fire Fighting

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

10.4.1 Fire Fighting Procedures

Wear self-contained breathing apparatus for firefighting if necessary
Sigma-Aldrich; Safety Data Sheet for Chromium(III) oxide. Product Number: 203068, Version 4.6 (Revision Date 09/16/2015). Available from, as of October 19, 2015: https://www.sigmaaldrich.com/safety-center.html
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide
Sigma-Aldrich; Safety Data Sheet for Chromium(III) oxide. Product Number: 203068, Version 4.6 (Revision Date 09/16/2015). Available from, as of October 19, 2015: https://www.sigmaaldrich.com/safety-center.html
Respiratory protection from chromium metal and insoluble chromium salts while fighting fires: self-contained breathing apparatus with a full facepiece operated in pressure-demand or other positive pressure mode. /Chromium metal and insoluble chromium salts/
Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) Publication No. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981., p. 6

10.4.2 Firefighting Hazards

Chromium oxides
Sigma-Aldrich; Safety Data Sheet for Chromium(III) oxide. Product Number: 203068, Version 4.6 (Revision Date 09/16/2015). Available from, as of October 19, 2015: https://www.sigmaaldrich.com/safety-center.html

10.5 Accidental Release Measures

10.5.1 Spillage Disposal

Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting.

10.5.2 Cleanup Methods

ACCIDENTAL RELEASE MEASURES; Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid dust formation. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Avoid breathing dust. Environmental precautions: Do not let product enter drains. Methods and materials for containment and cleaning up: Pick up and arrange disposal without creating dust. Sweep up and shovel. Keep in suitable, closed containers for disposal.
Sigma-Aldrich; Safety Data Sheet for Chromium(III) oxide. Product Number: 203068, Version 4.6 (Revision Date 09/16/2015). Available from, as of October 19, 2015: https://www.sigmaaldrich.com/safety-center.html
If chromium metal or insoluble chromium salts are spilled, the following steps should be taken: 1. Remove all ignition sources where metallic chromium has been spilled. 2. Ventilate area of spill. 3) Collect spilled material in the most convenient and safe manner and deposit in sealed containers for reclamation or for disposal in a secured sanitary landfill. Liquid containing chromium metal or insoluble chromium salts should be absorbed in vermiculite, dry sand, earth, or a similar material. /Chromium metal and insoluble chromium salts/
Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) Publication No. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981., p. 4

10.5.3 Disposal Methods

Wastewater treatment sludge from the production of chrome green pigments is a poor candidate for incineration. /Chrome green pigments/
USEPA; Engineering Handbook for Hazardous Waste Incineration p.3-5 (1981) EPA 68-03-3025
Product: Offer surplus and non-recyclable solutions to a licensed disposal company. Contaminated packaging: Dispose of as unused product.
Sigma-Aldrich; Safety Data Sheet for Chromium(III) oxide. Product Number: 203068, Version 4.6 (Revision Date 09/16/2015). Available from, as of October 19, 2015: https://www.sigmaaldrich.com/safety-center.html
Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number D007, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste. /Chromium/
40 CFR 240-280, 300-306, 702-799 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of November 24, 2015: https://www.ecfr.gov
SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.
For more Disposal Methods (Complete) data for Chromium (III) oxide (9 total), please visit the HSDB record page.

10.5.4 Preventive Measures

SRP: The scientific literature for the use of contact lenses by industrial workers is inconsistent. The benefits or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.
Further processing of solid materials may result in the formation of combustible dusts. The potential for combustible dust formation should be taken into consideration before additional processing occurs. Provide appropriate exhaust ventilation at places where dust is formed.
Sigma-Aldrich; Safety Data Sheet for Chromium(III) oxide. Product Number: 203068, Version 4.6 (Revision Date 09/16/2015). Available from, as of October 19, 2015: https://www.sigmaaldrich.com/safety-center.html
Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands.
Sigma-Aldrich; Safety Data Sheet for Chromium(III) oxide. Product Number: 203068, Version 4.6 (Revision Date 09/16/2015). Available from, as of October 19, 2015: https://www.sigmaaldrich.com/safety-center.html
Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday.
Sigma-Aldrich; Safety Data Sheet for Chromium(III) oxide. Product Number: 203068, Version 4.6 (Revision Date 09/16/2015). Available from, as of October 19, 2015: https://www.sigmaaldrich.com/safety-center.html
For more Preventive Measures (Complete) data for Chromium (III) oxide (12 total), please visit the HSDB record page.

10.6 Handling and Storage

10.6.1 Storage Conditions

Keep container tightly closed in a dry and well-ventilated place. Hygroscopic Handle and store under inert gas. Keep in a dry place. Storage class (TRGS 510): Non Combustible Solids
Sigma-Aldrich; Safety Data Sheet for Chromium(III) oxide. Product Number: 203068, Version 4.6 (Revision Date 09/16/2015). Available from, as of October 19, 2015: https://www.sigmaaldrich.com/safety-center.html

10.7 Exposure Control and Personal Protection

10.7.1 Permissible Exposure Limit (PEL)

0.5 [mg/m3]

10.7.2 Immediately Dangerous to Life or Health (IDLH)

25 mg/cu m (as Cr(III)). /Chromium(III) compounds (as Cr)/
NIOSH. NIOSH Pocket Guide to Chemical Hazards. Department of Health & Human Services, Centers for Disease Control & Prevention. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2010-168 (2010). Available from: https://www.cdc.gov/niosh/npg

10.7.3 Threshold Limit Values (TLV)

0.003 [mg/m3], as Cr(III), inhalable particulate matter
8 hr Time Weighted Avg (TWA): 0.5 mg/cu m. /Chromium and Cr(III) inorganic compounds, as Cr/
American Conference of Governmental Industrial Hygienists TLVs and BEIs. Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati, OH 2015, p. 21
A4; Not classifiable as a human carcinogen. /Chromium and Cr(III) inorganic compounds, as Cr/
American Conference of Governmental Industrial Hygienists TLVs and BEIs. Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati, OH 2015, p. 21
Excursion Limit Recommendation: Excursions in worker exposure levels may exceed 3 times the TLV-TWA for no more than a total of 30 minutes during a work day, and under no circumstances should they exceed 5 times the TLV-TWA, provided that the TLV-TWA is not exceeded. /Chromium and Cr(III) inorganic compounds, as Cr/
American Conference of Governmental Industrial Hygienists TLVs and BEIs. Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati, OH 2015, p. 5
(as Cr(III), inhalable fraction): 0.003 mg/m

10.7.4 Occupational Exposure Limits (OEL)

EU-OEL
(as Cr(III)): 2 mg/m

10.7.5 Other Standards Regulations and Guidelines

Max allowable concn (USSR) 0.01 mg/cu m
International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983., p. 469

10.7.6 Inhalation Risk

A harmful concentration of airborne particles can be reached quickly when dispersed.

10.7.7 Effects of Short Term Exposure

May cause mechanical irritation to the eyes and respiratory tract.

10.7.8 Personal Protective Equipment (PPE)

Respiratory protection: Respiratory protection is not required. Where protection from nuisance levels of dusts are desired, use type N95 (US) or type P1 (EN 143) dust masks. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).
Sigma-Aldrich; Safety Data Sheet for Chromium(III) oxide. Product Number: 203068, Version 4.6 (Revision Date 09/16/2015). Available from, as of October 19, 2015: https://www.sigmaaldrich.com/safety-center.html
Body Protection: Choose body protection in relation to its type, to the concentration and amount of dangerous substances, and to the specific work-place.The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.
Sigma-Aldrich; Safety Data Sheet for Chromium(III) oxide. Product Number: 203068, Version 4.6 (Revision Date 09/16/2015). Available from, as of October 19, 2015: https://www.sigmaaldrich.com/safety-center.html
Skin protection: Handle with gloves.
Sigma-Aldrich; Safety Data Sheet for Chromium(III) oxide. Product Number: 203068, Version 4.6 (Revision Date 09/16/2015). Available from, as of October 19, 2015: https://www.sigmaaldrich.com/safety-center.html
Eye/face protection: Safety glasses with side-shields conforming to EN 166 Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).
Sigma-Aldrich; Safety Data Sheet for Chromium(III) oxide. Product Number: 203068, Version 4.6 (Revision Date 09/16/2015). Available from, as of October 19, 2015: https://www.sigmaaldrich.com/safety-center.html
For more Personal Protective Equipment (PPE) (Complete) data for Chromium (III) oxide (10 total), please visit the HSDB record page.

10.7.9 Preventions

Exposure Prevention
PREVENT DISPERSION OF DUST!
Inhalation Prevention
Use local exhaust or breathing protection.
Skin Prevention
Protective gloves.
Eye Prevention
Wear safety goggles.
Ingestion Prevention
Do not eat, drink, or smoke during work.

10.8 Stability and Reactivity

10.8.1 Reactivity Alerts

10.8.1.1 CSL Reaction Information
CSL No
Reactants/Reagents
N,N-DIMETHYLFORMAMIDE + CHROMIUM(III) OXIDE
Warning Message
explosive
GHS Category
Explosive
Reference Source
User-Reported
Modified Date
7/8/18
Create Date
6/27/17

10.8.2 Hazardous Reactivities and Incompatibilities

The reaction of lithium and chromic oxide occurs around 180 °C with consequent temperature rise to 965 °C.
National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 491-108
A vigorous reaction occurs between oxygen difluoride and ... chromic oxide. ...
National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 491-138
Contact between /glycerol & chromic oxide/ may produce an explosion.
National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 491-63
Chlorine trifluoride reacts violently, producing flame, with ... chromium oxide.
National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 491-55
For more Hazardous Reactivities and Incompatibilities (Complete) data for Chromium (III) oxide (7 total), please visit the HSDB record page.

10.9 Regulatory Information

The Australian Inventory of Industrial Chemicals
Chemical: Chromium(III) oxide (Cr2O3)
REACH Registered Substance
New Zealand EPA Inventory of Chemical Status
Chromium oxide (Cr2O3): Does not have an individual approval but may be used under an appropriate group standard

10.9.1 Federal Drinking Water Standards

Maximum contaminant level for inorganic contaminants: Contaminant: Chromium; MCL 0.1 mg/L. /Chromium/
40 CFR 141.62; U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of November 4, 2015: https://www.ecfr.gov

10.9.2 Federal Drinking Water Guidelines

Maximum contaminant level goal for inorganic contaminants: Contaminant: Chromium; MCLG 0.1 mg/L. /Chromium/
40 CFR 141.51 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of November 3, 2015: https://www.ecfr.gov

10.9.3 State Drinking Water Guidelines

(MN) MINNESOTA 20000 ug/L /Chromium III ion/
USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93) To Present

10.9.4 Clean Water Act Requirements

Toxic pollutant designated pursuant to section 307(a)(1) of the Federal Water Pollution Control Act and is subject to effluent limitations. /Chromium and compounds/
40 CFR 401.15 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of November 3, 2015: https://www.ecfr.gov

10.9.5 RCRA Requirements

D007; A solid waste containing chromium may or may not become characterized as a hazardous waste when subjected to the Toxicity Characteristic Leaching Procedure listed in 40 CFR 261.24, and if so characterized, must be managed as a hazardous waste. /Chromium/
40 CFR 261.24 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of November 3, 2015: https://www.ecfr.gov

10.9.6 FDA Requirements

Certification of this color additive when used in coloring externally applied drugs, including those intended for use in the area of the eye, in amounts consistent with good manufacturing practice, is not necessary for the protection of the public health, and therefore batches thereof are exempt from the certification pursuant to section 721(c) of the act.
21 CFR 73.1327 (USFDA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of November 4, 2015: https://www.ecfr.gov
Certification of this color additive when used in coloring externally applied cosmetics, including cosmetics intended for use in the area of the eye, in amounts consistent with good manufacturing practice, is not necessary for the protection of the public health, and therefore batches thereof are exempt from the certification pursuant to section 721(c) of the act.
21 CFR 73.2327 (USFDA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of November 4, 2015: https://www.ecfr.gov
Certification of this color additive, when used as a color additive in contact lenses in amounts not to exceed the minimum reasonably required to accomplish the intended coloring effect, is not necessary for the protection of the public health, and therefore batches thereof are exempt from the certification pursuant to section 721(c) of the act.
21 CFR 73.3111 (USFDA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of November, 2015: https://www.ecfr.gov

10.10 Other Safety Information

Chemical Assessment
IMAP assessments - Chromium(III) oxide (Cr2O3): Human health tier I assessment

11 Toxicity

11.1 Toxicological Information

11.1.1 Toxicity Summary

IDENTIFICATION AND USE: Chromic oxide (Cr(2)O(3)) is a green powder. It is not registered for current use in the U.S., but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses. It is used in abrasives and electric semiconductors; in alloys; in printing fabrics and banknotes. It is also used in dyeing polymers; colorant for latex paints, in manufacturing of chromium metal and aluminum-chromium master alloys. It's other uses include catalyst in organic synthesis, green granules in asphalt roofing, component of refractory brick. Chromic oxide is a color additive in drug use. HUMAN EXPOSURE AND TOXICITY: Fine chromic oxide particles were insoluble in the culture medium; on the contrary, Cr(2)O(3) nanoparticles released soluble hexavalent chromium into the culture medium. Human lung carcinoma A549 cells and human keratinocyte HaCaT cells showed an increase in intracellular reactive oxygen species (ROS) level and activation of antioxidant defense systems on exposure to Cr(2)O(3) nanoparticles. The cellular influences of Cr(2)O(3) nanoparticles matched those of hexavalent chromium. Human lung epithelial cells exposure to chromic oxide nanoparticles led to DNA damage, which was detected by comet assay and cytokinesis block micronucleus assay. The cell exposure lead to mitochondria-mediated apoptosis. ANIMAL STUDIES: In rats in a 13-week nose-only inhalation study that included a 13-week recovery period, chromic oxide caused pathological changes in the bronchial and mediastinal lymphatic tissue and lungs, consisting of the presence of pigment-laden macrophages, lymphoid and septal hyperplasia, and interstitial inflammation similar to that observed with other inert dusts. In experiments with rats 4/20 animals developed lung sarcomas 16-19 months after a single intraperitoneal injection of 20 mg chromic oxide. No effects on reproduction were reported in nine pairs of rats fed up to 5% chromium(III) oxide in a supplemented bread, 5 days/week for 60 days before grossly observable malformations or adverse effects occurred in the pups. Exposure to chromic oxide increased sister chromatid exchanges in Chinese hamster V79 cells. Exposure for 18 hr to Cr(2)O(3) induced in Chinese hamster cells a statistically significant increase in the mutation frequency of up to 10-fold over the control. ECOTOXICITY STUDIES: In seeds of Triticum aestivum exposure to 25-100 ug/mL Cr(2)O(3) nanoparticles inhibited the seed germination and seedling growth in concentration dependent manner.
Trivalent chromium may also form complexes with peptides, proteins, and DNA, resulting in DNA-protein crosslinks, DNA strand breaks, DNA-DNA interstrand crosslinks, chromium-DNA adducts, chromosomal aberrations and alterations in cellular signaling pathways. It has been shown to induce carcinogenesis by overstimulating cellular regulatory pathways and increasing peroxide levels by activating certain mitogen-activated protein kinases. It can also cause transcriptional repression by cross-linking histone deacetylase 1-DNA methyltransferase 1 complexes to CYP1A1 promoter chromatin, inhibiting histone modification. Chromium may increase its own toxicity by modifying metal regulatory transcription factor 1, causing the inhibition of zinc-induced metallothionein transcription. (A12, L16, A34, A35, A36)
A12: Salnikow K, Zhitkovich A: Genetic and epigenetic mechanisms in metal carcinogenesis and cocarcinogenesis: nickel, arsenic, and chromium. Chem Res Toxicol. 2008 Jan;21(1):28-44. Epub 2007 Oct 30. PMID:17970581
A34: Kim G, Yurkow EJ: Chromium induces a persistent activation of mitogen-activated protein kinases by a redox-sensitive mechanism in H4 rat hepatoma cells. Cancer Res. 1996 May 1;56(9):2045-51. PMID:8616849
A35: Schnekenburger M, Talaska G, Puga A: Chromium cross-links histone deacetylase 1-DNA methyltransferase 1 complexes to chromatin, inhibiting histone-remodeling marks critical for transcriptional activation. Mol Cell Biol. 2007 Oct;27(20):7089-101. Epub 2007 Aug 6. PMID:17682057
A36: Kimura T: [Molecular mechanism involved in chromium(VI) toxicity]. Yakugaku Zasshi. 2007 Dec;127(12):1957-65. PMID:18057785
L16: ATSDR - Agency for Toxic Substances and Disease Registry (2008). Toxicological profile for chromium. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). http://www.atsdr.cdc.gov/toxprofiles/tp7.html

11.1.2 Evidence for Carcinogenicity

WEIGHT OF EVIDENCE CHARACTERIZATION: Applying the criteria for evaluating the overall weight of evidence for carcinogenicity to humans outlined in EPA's guidelines for risk assessment (1986), trivalent chromium is most appropriately designated a Group D -- Not classified as to its human carcinogenicity. Using the Proposed Guidelines for Carcinogen Risk Assessment (1996), there are inadequate data to determine the potential carcinogenicity of trivalent chromium ... However, the classification of hexavalent chromium as a known human carcinogen raises a concern for the carcinogenic potential of trivalent chromium. HUMAN CARCINOGENICITY DATA: Occupational exposure to trivalent chromium and other chromium compounds by inhalation has been studied in the chromate manufacturing and ferrochromium industries; however, exposures all include mixed exposures to both Cr(III) and Cr(VI). Cr(VI) species is the likely etiological agent in reports of excess cancer risk in chromium workers. Data addressing exposures to Cr(III) alone are not available and data are inadequate for an evaluation of human carcinogenic potential. ... ANIMAL CARCINOGENICITY DATA: The data from oral and inhalation exposures of animals to trivalent chromium do not support documentation of the carcinogenicity of trivalent chromium. IARC concluded that animal data are inadequate for the evaluation of the carcinogenicity of Cr(III) compounds. Furthermore, although there is sufficient evidence of respiratory carcinogenicity associated with exposure to chromium, the relative contribution of Cr(III), Cr(VI), metallic chromium, or soluble versus insoluble chromium to carcinogenicity cannot be elucidated... /Chromium (III), insoluble salts/
U.S. Environmental Protection Agency's Integrated Risk Information System (IRIS). Summary on Chromium (III), insoluble salts (16065-83-1). Available from, as of October 29, 2015: https://www.epa.gov/iris/
A4; Not classifiable as a human carcinogen. /Chromium and Cr(III) inorganic compounds/
American Conference of Governmental Industrial Hygienists TLVs and BEIs. Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati, OH 2016, p. 21
Evaluation: There is inadequate evidence in humans for the carcinogenicity of metallic chromium and of chromium(III) compounds. There is inadequate evidence in experimental animals for the carcinogenicity of metallic chromium, barium chromate and chromium(III) compounds. Overall evaluation: Metallic chromium and chromium(III) compounds are not classifiable as to their carcinogenicity to humans (Group 3). /Metallic chromium and chromium(III) compounds/
IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V49 213 (1990)

11.1.3 Carcinogen Classification

Carcinogen Classification
3, not classifiable as to its carcinogenicity to humans. (L135)

11.1.4 Health Effects

Chromium in its trivalent state is not very toxic. It may be oxidized to hexavalent chromium, a known carcinogen. Hexavalent chromium has also been shown to affect reproduction and development. (A12)
A12: Salnikow K, Zhitkovich A: Genetic and epigenetic mechanisms in metal carcinogenesis and cocarcinogenesis: nickel, arsenic, and chromium. Chem Res Toxicol. 2008 Jan;21(1):28-44. Epub 2007 Oct 30. PMID:17970581

11.1.5 Exposure Routes

Oral (L16) ; inhalation (L16) ; dermal (L16)
L16: ATSDR - Agency for Toxic Substances and Disease Registry (2008). Toxicological profile for chromium. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). http://www.atsdr.cdc.gov/toxprofiles/tp7.html

11.1.6 Symptoms

Inhalation Exposure
Cough.
Eye Exposure
Redness.
Chromium in its trivalent state is not very toxic, but it may be oxidized to hexavalent chromium. Breathing hexavalent chromium can cause irritation to the lining of the nose, nose ulcers, runny nose, and breathing problems, such as asthma, cough, shortness of breath, or wheezing. Ingestion of hexavalent chromium causes irritation and ulcers in the stomach and small intestine, as well as anemia. Skin contact can cause skin ulcers. (L16)
L16: ATSDR - Agency for Toxic Substances and Disease Registry (2008). Toxicological profile for chromium. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). http://www.atsdr.cdc.gov/toxprofiles/tp7.html

11.1.7 Adverse Effects

ACGIH Carcinogen - Not Classifiable.

11.1.8 Treatment

There is no know antidote for chromium poisoning. Exposure is usually handled with symptomatic treatment. (L16)
L16: ATSDR - Agency for Toxic Substances and Disease Registry (2008). Toxicological profile for chromium. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). http://www.atsdr.cdc.gov/toxprofiles/tp7.html

11.1.9 Interactions

In inhalation chambers, male Wistar rats of the strain TNO-W74 were continuously exposed to submicron aerosols of sodium dichromate and to a pyrolyzed Cr(VI)/Cr(III) (3:2) oxide mixture. The sodium dichromate (Na2Cr2O7) aerosol had the chromium concentrations of 25, 50 and 100 micrograms/cu m, the chromium oxide mixture (Cr5O12) had the chromium concentration of 100 micrograms/cu m. After 18 months of inhalation the rats were held under conventional conditions for a further year. The experimental groups consisted of 20 rats and the control group of 40 rats. More than 90% of the rats in each group reached 2 years. At the end of the study the mortality rates amounted to 35%, 45% and 25% in the 3 sodium dichromate aerosol groups, respectively, and 50% in the chromium oxide mixture aerosol group, which was not significantly different from that of the controls (42.5%), living under the same conditions in filtered fresh air. In all sodium dichromate exposed groups significant effects were neither found clinically nor from hematology and clinical chemistry compared to the controls. In the chromium oxide mixture group, however, there was a number of significant findings. Elevated white and red blood cell counts and serum cholesterol as well as decreased serum total immunoglobulin levels at different stages of the study were observed together with few local lung effects determined histopathologically in this group. We assume that these effects are mainly due to the increased chromium lung burden of the rats. At the end of the study the lung chromium retention was about 10 times higher for the rats exposed to chromium oxide versus sodium dichromate at an aerosol Cr-concentration of 100 micrograms/cu m, while the kidney chromium retention was measured to be nearly equal in both groups. Three primary lung tumors (2 adenomas and 1 adenocarcinoma) and 1 malign tumor of the pharynx were found at the highest Cr-concentration (100 micrograms/cu m) of the sodium dichromate aerosol, 1 primary adenoma of the lung was in the chromium oxide mixture group exposed also to a Cr-concentration of 100 micrograms/cu m. No primary lung tumors were observed in the other experimental and control groups. These results indicate a weak carcinogenicity at 100 micrograms/cu m for the rats continuously exposed to submicron Na2Cr2O7 and Cr5O12 aerosols. Thus, there may be a small carcinogenic risk from occupational relevant chromium air levels. /Pyrolzed Cr(VI)/Cr(III) oxide mixture/
Glaser U et al; Toxicology. 42 (2-3): 219-32 (1986)

11.1.10 Antidote and Emergency Treatment

/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Inorganic acids and related compounds/
Currance, P.L. Clements, B., Bronstein, A.C. (Eds).; Emergency Care For Hazardous Materials Exposure. 3rd revised edition, Elsevier Mosby, St. Louis, MO 2007, p. 172-3
/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist respirations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. Activated charcoal is not effective. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Do not attempt to neutralize because of exothermic reaction. Cover skin burns with dry, sterile dressings after decontamination ... . /Inorganic acids and related compounds/
Currance, P.L. Clements, B., Bronstein, A.C. (Eds).; Emergency Care For Hazardous Materials Exposure. 3rd revised edition, Elsevier Mosby, St. Louis, MO 2007, p. 173
/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Early intubation, at the first sign of upper airway obstruction, may be necessary. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's(LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Consider vasopressors if patient is hypotensive with a normal fluid volume. Watch for signs of fluid overload ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Inorganic acids and related compounds/
Currance, P.L. Clements, B., Bronstein, A.C. (Eds).; Emergency Care For Hazardous Materials Exposure. 3rd revised edition, Elsevier Mosby, St. Louis, MO 2007, p. 173
Emergency and supportive measures. 1. Inhalation. Give supplemental oxygen. Treat wheezing and monitor the victim closely for delayed-onset noncardiogenic pulmonary edema. Delays in the onset of pulmonary edema of up to 72 hours have been reported after inhalation of concentrated solutions of chromic acid. 2. Ingestion. a. Diluted immediately with water. treat hemorrhagic gastroenteritis with aggressive fluid and blood replacement. Consider early endoscopy to assess the extent of esophageal or gastric injury. b. Treat hemoglobinuria resulting from hemolysis with alkaline diuresis as far rhabdomyolysis. Treat methemoglobinemia if it occurs. /Chromium/
OLSON, K.R. (Ed). Poisoning and Drug Overdose, Sixth Edition. McGraw-Hill, New York, NY 2012, p. 178
For more Antidote and Emergency Treatment (Complete) data for Chromium (III) oxide (7 total), please visit the HSDB record page.

11.1.11 Human Toxicity Excerpts

/HUMAN EXPOSURE STUDIES/ The International Agency for Research on Cancer considers the carcinogenicity of welding fume of priority for re-evaluation. Genotoxic effects in experimental animals are still inconclusive. Here, we investigated the association of personal exposure to metals in respirable welding fumes during a working shift with oxidatively damaged guanosine in DNA of white blood cells (WBC) and in postshift urine samples from 238 welders. Medians of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) were 2.35/10(6) dGuo in DNA of WBC and 4.33 ug/g creatinine in urine. The median of 8-oxo-7,8-dihydroguanosine (8-oxoGuo) was 7.03 ug/g creatinine in urine. The extent of both urinary parameters was higher in welders applying techniques with high particle emission rates to stainless steel than in tungsten inert gas welders (8-oxodGuo: 9.96 vs. 4.49 ug/L, 8-oxoGuo: 15.7 vs. 7.7 ug/L), but this apparent difference diminished after creatinine adjustment. We applied random intercept models to estimate the influence of airborne and systemic exposure to metals on oxidatively damaged guanosine in WBC and urine together with covariates. We observed a highly significant nonlinear association of urinary 8-oxoGuo with serum ferritin (P < 0.0001) and higher 8-oxoGuo concentrations for respirable iron >1,000 ug/cu m compared to < or = 57 ug/cu m. Similar effects were found for manganese. Airborne chromium but not nickel was associated with all oxidatively modified guanosine measures, whereas urinary chromium as well as nickel showed associations with urinary modified guanosines. In summary, oxidatively damaged urinary guanosine was associated with airborne and systemic exposure to metals in welders and showed a strong relation to body iron stores. /Chromium oxide/
Pesch B et al; Arch Toxicol. 89 (8): 1257-69 (2015)
/ALTERNATIVE and IN VITRO TESTS/ Chromium oxide (Cr2O3 ) nanoparticles (NPs) are being increasingly used as a catalyst for aromatic compound manufacture, abrading agents and as pigments (e.g.,Viridian). Owing to increased applications, it is important to study the biological effects of Cr2O3 NPs on human health. The lung is one of the main exposure routes to nanomaterials; therefore, the present study was designed to determine the genotoxic and apoptotic effect of Cr2O3 NPs in human lung epithelial cells (A549). The study also elucidated the molecular mechanism of its toxicity. Cr2O3 NPs led to DNA damage, which was deduced by comet assay and cytokinesis block micronucleus assay. The damage could be mediated by the increased levels of reactive oxygen species. Further, the oxygen species led to a decrease in mitochondrial membrane potential and an increase in the ratio of BAX/Bcl-2 leading to mitochondria-mediated apoptosis induced by Cr2O3 NPs, which ultimately leads to cell death. Hence, there is a need of regulations to be imposed in NP usage. The study provided insight into the caspase-dependent mechanistic pathway of apoptosis.
Senapati VA et al; J Appl Toxicol. 35 (10): 1179-88 (2015)
/ALTERNATIVE and IN VITRO TESTS/ Chromium(III) oxide (Cr(2)O(3)) is used for industrial applications such as catalysts and pigments. In the classical form, namely the fine particle, Cr(2)O(3) is insoluble and chemically stable. It is classified as a low-toxicity chromium compound. Recently, industrial application of nanoparticles (a new form composed of small particles with a diameter of < or =100 nm, in at least one dimension) has been increasing. Cellular effects induced by Cr(2)O(3) nanoparticles are not known. To shed light upon this, the release of soluble chromium from Cr(2)O(3) nano- and fine-particles in culture medium was compared. Fine Cr(2)O(3) particles were insoluble in the culture medium; on the contrary, Cr(2)O(3) nanoparticles released soluble hexavalent chromium into the culture medium. Cr(2)O(3) nanoparticles showed severe cytotoxicity. The effect of Cr(2)O(3) nanoparticles on cell viability was higher than that of fine particles. Cr(2)O(3) nanoparticles showed cytotoxicity equal to that of hexavalent chromium (K(2)Cr(2)O(7)). Human lung carcinoma A549 cells and human keratinocyte HaCaT cells showed an increase in intracellular reactive oxygen species (ROS) level and activation of antioxidant defense systems on exposure to Cr(2)O(3) nanoparticles. Exposure of Cr(2)O(3) nanoparticles led to caspase-3 activation, showing that the decrease in cell viability by exposure to Cr(2)O(3) nanoparticles was caused by apoptosis. Cellular responses were stronger in the Cr(2)O(3) nanoparticles-exposed cells than in fine Cr(2)O(3) - and CrCl(3) -exposed cells. Cellular uptake of Cr(2)O(3) particles were observed in nano- and fine-particles. The cellular influence of the extracellular soluble trivalent chromium was lower than that of Cr(2)O(3) nanoparticles. Cr(2)O(3) nanoparticles showed cytotoxicity by hexavalent chromium released at outside and inside of cells. The cellular influences of Cr(2)O(3) nanoparticles matched those of hexavalent chromium. In conclusion, Cr(2)O(3) nanoparticles have a high cytotoxic potential.
Horie M et al; Environ Toxicol. 28 (2): 61-75 (2013)

11.1.12 Non-Human Toxicity Excerpts

/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ The toxicity of trivalent chromium compounds; chromic oxide and basic chromium sulfate, was investigated in rats in a 13-week nose-only inhalation study that included a 13-week recovery period. Nose-only exposures to insoluble chromic oxide dust at 4.4, 15, or 44 mg/cu m or soluble basic chromium sulfate dust at 17, 54, or 168 mg/cu m (trivalent chromium equivalent concentrations of 3, 10, and 30 mg/cu m) were carried out for 6 hr/day, 5 days/week. No compound-related mortality occurred. General toxic effects, only observed with high-exposure levels of basic chromium sulfate, included sporadic signs of labored breathing and depressed body weights. No apparent compound-related effects were noted for sperm motility or morphology, for any concentration of either test material. Bronchoalveolar lavage fluid evaluations showed test material in mononuclear cells with chromic oxide and increased neutrophils, protein, lactic dehydrogenase and cellular debris with basic chromium sulfate. The principle effects for both materials were primarily to the respiratory tract. Chromic oxide caused pathological changes in the bronchial and mediastinal lymphatic tissue and lungs, consisting of the presence of pigment-laden macrophages, lymphoid and septal hyperplasia, and interstitial inflammation similar to that observed with other inert dusts. Basic chromium sulfate produced more severe and widespread effects in the nasal cavity, larynx, lungs, and mediastinal lymph node. Effects were characterized by accumulation of foreign material, infiltration of alveolar macrophages, septal cell hyperplasia, and granulomatous and chronic inflammation. Pigment was still present in chromic oxide and, to a lesser extent, in basic chromium sulfate-treated animals after the 13-week recovery period, with partial recovery of the pathological lesions. A NOAEL was not established for either test material, but 4.4 mg/cu m was thought to be near the NOAEL level for subchronic exposure to chromic oxide. The results of this study indicate significant differences in toxicity to the respiratory tract between trivalent chromium compounds chromic oxide and basic chromium sulfate. These are likely related to differences in acidity and water solubility, rather than chromium concentration per se. This conclusion is substantiated by the lack of effect on other internal organs.
Derelanko MJ et al; Toxicol Sci. 52 (2): 278-88 (1999)
/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ This study was conducted to determine if the level of dietary chromic oxide will affect glucose utilization and tissue chromium retention by channel catfish. Purified diets containing graded levels of supplemental chromic oxide (0, 50, 100, 200, 400, 1000, 5000 and 10,000 mg/kg diet) and glucose as the carbohydrate source were fed to channel catfish fingerlings for 10 wk. Another diet containing dextrin as the carbohydrate source and without chromic oxide supplementation was also fed and served as the control diet. Fish fed the dextrin diet had significantly (P < 0.05) greater weight gain, feed efficiency ratio and protein efficiency ratio but lower plasma glucose concentrations than fish fed the glucose diets irrespective of the level of chromic oxide supplementation. The growth performance and postprandial plasma glucose concentrations of channel catfish fed glucose diets supplemented with various chromic oxide levels were not significantly different. No obvious trends were observed in the whole-body composition of fish fed glucose diets containing various chromic oxide levels. Carbohydrate source or the level of dietary chromic oxide did not significantly affect chromium concentrations in the whole-fish carcass. These results suggest that the level of dietary chromic oxide had no significant effect on glucose utilization or chromium retention by channel catfish. It is suggested that chromic oxide is sufficiently inert to be used as an external marker in digestibility studies in channel catfish.
Ng WK, Wilson RP; J Nutr. 127 (12): 2357-62 (1997)
/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ In experiments with Wistar and random-bred rats (sex, age and distribution unspecified), 4/20 animals developed lung sarcomas 16-19 months after a single intraperitoneal injection of 20 mg chromic oxide.
IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V49 120 (1990)
/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ Strain A mice in a group of 25 males and 25 females (age unspecified) were each given an intravenous injection into the tail vein of 5 mg chromite ore (39-60% chromic oxide; particle size, 1.6 um) suspended in saline. The animals were killed at 3, 4.5 and 6 months. There was no difference in the incidence of pulmonary adenomas between treated mice and 75 untreated controls.
IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V49 120 (1990)
For more Non-Human Toxicity Excerpts (Complete) data for Chromium (III) oxide (12 total), please visit the HSDB record page.

11.1.13 TSCA Test Submissions

Chromic Oxide (CAS #1308-38-9) was one of two materials evaluated for subchronic toxicity. The test material was administered via nose-only inhalation to Fischer 344 rats (15/sex/group) at exposure concentrations of 4.4, 15, and 44 mg/cu m, with one control group. Exposures were conducted for 6 hr/day, for 13 weeks, except weekends and holidays. After 13 weeks of exposure, 10 animals/sex/group were sacrificed and given a complete necropsy and histologic examination along with hematologic, serum biochemistry, urologic, ophthalmologic and sperm characterizations. The remaining animals underwent a 13-week post exposure recovery, followed by a complete necropsy and limited histologic examination. During weeks 7 and 8, additional Fischer rats (5/sex/group) were exposed for 5 consecutive days at each exposure level, then evaluated for bronchoalveolar fluid (BALF) parameters. There were no exposure-related effects in clinical signs, ophthalmologic, body weight-gain, or sperm characteristic evaluations. None of the hematologic, serum biochemical, or urinalysis parameters were significantly different from controls. The BALF parameters were not significantly different, however, yellow crystalline material was observed in the mononuclear cells of all treated groups. Gross examination at terminal sacrifice revealed treatment- and concentration-related green discoloration in the lungs and mediastinal lymph nodes which, in the recovery group, occurred with slightly decreased incidence and severity. The mean, absolute and relative lung weights of male rats in the highest exposure group were significantly different from controls (p
Industrial Health Foundation Inc; Thirteen Week Subchronic Inhalation Toxicity (with Recovery) Study on Chromic Oxide and Basic Chrome Sulfate in Rats; (1996); EPA Doc No. 8EHQ-0996-13745; Fiche No. OTS0558617

11.2 Ecological Information

11.2.1 Ecotoxicity Excerpts

/PLANTS/ In this study, seeds of Triticum aestivum L. (Poaceae) were exposed to 0-100 ug/mL chromium oxide nanoparticles (Cr2O3, Nps) to study the phytotoxic effects on seed germination and seedling growth. It has been observed that 25-100 ug/mL Cr2O3, Nps inhibited the seed germination and seedling growth in concentration dependent manner. The present study suggests that release of Cr2O3, Nps in environment may adversely affect the wheat production.
Vajpayee P et al; J Biomed Nanotechnol. 7(1): 205-6 (2011)

11.2.2 Natural Pollution Sources

Chromium (III) oxide occurs in chromium-rich tremolite skarns, metaquartzites, and chlorite veins (Outokumpu, Finland); on greywacke pebbles in a glacial boulder clay deposit (Callowhill Upper, Ireland); as pebbles in streams (Merume River, Guyana); a very rare component in chondrite meteorites(1).
(1) RRuff Project; Eskolaite. Department of Geosciences, University of Arizona, Tucson, AZ. Available from, as of Oct 23, 2015: https://rruff.info/doclib/hom/eskolaite.pdf

11.2.3 Artificial Pollution Sources

Large amounts of slag, containing 2-6% chromium (III) oxide, byproducts of ferrochrome and chromium steel production, are present in a "sintered form" and are unavailable for incorporation into plants or microorganisms(1). Chromiium (III) oxide pigments are reported to pose a major problem in removal from wastewaters(2).
(1) Nat'l Research Council Canada; Effects of Chromium in the Canadian Environment p.53 (1976) NRCC No 15017
(2) Wisniewska M, Szewczuk-Karpisz K; Environ Sci Pollut Res Int 20(6): 3657-69 (2013)

11.2.4 Environmental Abiotic Degradation

The results of laboratory studies suggest that active photo- and thermal- chemistry will occur when boundary layer materials containing chromium(III) or chromium oxide such as stainless steel, roofs, automobile bumpers etc. are exposed to NO2 under tropospheric conditions(1).
(1) Nishino N, Finlayson-Pitts BJ; Phys Chem Chem Phys 14(45): 15840-8 (2012)

11.2.5 Sediment / Soil Concentrations

High chromium content has been associated with infertility of some soils. For example, the soil in a small area near Rockville, MD that supported minimal vegetation contained 1,000-3,900 ppm chromium as chromium (III) oxide. /Total chromium/
NAS; Medical and Biological Effects of Environmental Pollutants: Chromium p.9 (1974)

11.2.6 Average Daily Intake

According to the 2012 TSCA Inventory Update Reporting data, 17 reporting facilities estimate the number of persons reasonably likely to be exposed during the manufacturing, processing, or use of chromium (III) oxide may be as low as <10 workers up to the range of 100-499 workers per plant; the data may be greatly underestimated due to confidential business information (CBI) or unknown values(1).
(1) US EPA; Chemical Data Reporting (CDR). Non-confidential 2012 Chemical Data Reporting information on chemical production and use in the United States. Available from, as of Oct 22, 2015: https://java.epa.gov/oppt_chemical_search/
NIOSH (NOES Survey 1981-1983) has statistically estimated that 88,897 workers (11,984 of these are female) were potentially exposed to chromium (III) oxide in the US(1). Occupational exposure to chromium (III) oxide may occur through inhalation and dermal contact with this compound at workplaces where chromium (III) oxide is produced or used(SRC).
(1) NIOSH; NOES. National Occupational Exposure Survey conducted from 1981-1983. Estimated numbers of employees potentially exposed to specific agents by 2-digit standard industrial classification (SIC). Available from, as of Oct 22, 2015: https://www.cdc.gov/noes/
Dental technicians working in areas of cast prothetics containing chromium and no effective ventilation were exposed to chromium (III) oxide levels 0.15-9.6 mg/cu m(1).
(1) Vollmer D et al; Zeitschrift fur die Gesamte Hygiene und ihre Grenzgebiete. 34: 317-9 (1988)

12 Literature

12.1 Consolidated References

12.2 NLM Curated PubMed Citations

12.3 Springer Nature References

12.4 Thieme References

12.5 Wiley References

12.6 Chemical Co-Occurrences in Literature

12.7 Chemical-Gene Co-Occurrences in Literature

12.8 Chemical-Disease Co-Occurrences in Literature

13 Patents

13.1 Depositor-Supplied Patent Identifiers

13.2 WIPO PATENTSCOPE

13.3 Chemical Co-Occurrences in Patents

13.4 Chemical-Disease Co-Occurrences in Patents

13.5 Chemical-Gene Co-Occurrences in Patents

14 Interactions and Pathways

14.1 Chemical-Target Interactions

15 Biological Test Results

15.1 BioAssay Results

16 Classification

16.1 MeSH Tree

16.2 ChEBI Ontology

16.3 ChemIDplus

16.4 UN GHS Classification

16.5 EPA CPDat Classification

16.6 NORMAN Suspect List Exchange Classification

16.7 EPA DSSTox Classification

16.8 Consumer Product Information Database Classification

16.9 EPA TSCA and CDR Classification

16.10 EPA Substance Registry Services Tree

16.11 MolGenie Organic Chemistry Ontology

17 Information Sources

  1. Australian Industrial Chemicals Introduction Scheme (AICIS)
  2. CAS Common Chemistry
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  5. EPA Chemicals under the TSCA
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    https://www.epa.gov/tsca-inventory
  6. EPA DSSTox
    CompTox Chemicals Dashboard Chemical Lists
    https://comptox.epa.gov/dashboard/chemical-lists/
  7. European Chemicals Agency (ECHA)
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    https://echa.europa.eu/web/guest/legal-notice
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  9. ILO-WHO International Chemical Safety Cards (ICSCs)
  10. New Zealand Environmental Protection Authority (EPA)
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    https://www.epa.govt.nz/about-this-site/general-copyright-statement/
  11. ChEBI
  12. Toxin and Toxin Target Database (T3DB)
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    http://www.t3db.ca/downloads
  13. Comparative Toxicogenomics Database (CTD)
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    https://www.whatsinproducts.com/contents/view/1/6
    Consumer Products Category Classification
    https://www.whatsinproducts.com/
  15. EPA Chemical and Products Database (CPDat)
  16. Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
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    https://creativecommons.org/licenses/by/4.0/
    NORMAN Suspect List Exchange Classification
    https://www.norman-network.com/nds/SLE/
  18. NITE-CMC
    Chromium (III) oxide - FY2006 (New/original classication)
    https://www.chem-info.nite.go.jp/chem/english/ghs/06-imcg-0364e.html
    Chromium (III) oxide - FY2014 (Revised classification)
    https://www.chem-info.nite.go.jp/chem/english/ghs/14-mhlw-2036e.html
  19. FDA Regulatory Status of Color Additives
  20. Pistoia Alliance Chemical Safety Library
    N,N-DIMETHYLFORMAMIDE + CHROMIUM(III) OXIDE
    https://safescience.cas.org/
  21. SpectraBase
  22. Springer Nature
  23. SpringerMaterials
  24. Thieme Chemistry
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    https://creativecommons.org/licenses/by-nc-nd/4.0/
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  27. Wiley
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  29. Medical Subject Headings (MeSH)
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  30. GHS Classification (UNECE)
  31. EPA Substance Registry Services
  32. MolGenie
    MolGenie Organic Chemistry Ontology
    https://github.com/MolGenie/ontology/
  33. PATENTSCOPE (WIPO)
CONTENTS