Chromium 3+

Source of the photo: 
http://www.chemspider.com/Chemical-Structure.25743.html
Author of the description: 
Vaszita Emese

CHEMICAL SUBSTANCE DATASHEET

 

CHEMICAL SUBSTANCE IDENTIFICATION

Chemical name                 

 Chromium (3+)

Synonyms                           

 Chromium (III) ion, chromium(3+), Chromium(III) cation

 [1,2]

IUPAC name

 Chromium III [2]

CAS No

 16065-83-1 [1, 2]

REACH registration number

 

EC No

 605-220-6 [1, 2]

Molecular formula              

 Cr3 +

Substance group/chemical family

 

Appearance

Physical state

Odour

Form

    Colour

 

 

 

 

 Silvery, rather brittle metal. Similar to aluminum, but exhibits several oxidation states [8]

USES AND HANDLING ISSUES

Relevant identified uses

 The metal chromium is used mainly for making steel and other alloys. Chromium compounds, in either the chromium (III) or chromium (VI) forms, are used for chrome plating, the manufacture of dyes and pigments, leather and wood preservation, and treatment of cooling tower water. Smaller amounts are used in drilling mud, textiles, and toner for copying machines. [3]

Handling considerations

 

PHYSICO-CHEMICAL PROPERTIES

Molecular weight                                  

  51.996 g/mol [1]

Bulk density/Specific gravity

 8.94 g/cm3 [8]

pH

 

Particle size

  

EC

 

Melting point

  1900°C [1]

Boiling point

  2672°C  [8]

Flash point

 

Flammability

 

Vapour density

 

Vapour pressure

 

Solubility in water

The chromium (III) compounds are sparingly soluble in water and may be found in water bodies as soluble chromium (III) complexes. [3]

Solubility in organic solvents

 

Solubility in inorganic solvents

 

Hydrolysis

 

Ionicity in water

 

Surface tension

 

Dispersion properties

 

Specific surface

 

Stability and reactivity

Chemical stability

Chromium compounds are most stable in the trivalent state under environmental conditions and occur in nature in ores, such as ferro-chromite (FeCr2O4). [3]

Reactivity hazards

 

Corrosivity

 

Polimerization

 

Incompatibility with various substances

 

Special remarks on reactivity

 Ammonia reacts with chromium(III) ion to precipitate gray-green chromium(III) hydroxide. [8]

Strong bases such as NaOH also precipitate Cr(OH)3, but the precipitate dissolves in excess hydroxide. [8]

In basic solution, hydrogen peroxide oxidizes Cr(III) to Cr(VI). [8]

Physical, chemical and biological coefficient

Koc

 

Kow

 

pKa

 

log Kp

  

Henry-constant

 

ENVIRONMENTAL FATE AND BEHAVIOUR

Artificial pollution sources

 

General terrestrial fate

 Cr3+ enters early-forming phases in igneous rocks.

Cr3+ is commonly concentrated in residual soils and sediments.

Cr3+ is essential to nutrition of at least some vertebrates  [5]

General aquatic fate

 

General atmospheric fate

 

General persistence and degradability

 

Abiotic degradation and metabolites

 

Biodegradation and metabolites

 

Bioconcentration

 

Volatilization

 

Photolysis

 

Hydrolysis

 

Soil adsorption and mobility

 Cr(III) is the primary form of Cr that is retained by sorption. The kinetics of Cr(III) sorption is rapid in clays, sands, and soil containing Fe and manganese oxides. [3]

ENVIRONMENTAL CONCENTRATIONS

Measured data

 Chromium compounds are stable in the trivalent (III) state and occur in nature in this state in ores, such as ferro-chromite. [3]

ECOTOXICOLOGICAL INFORMATION

General adverse effects on ecosystem

Acute toxicity (LC50, EC50)

Aquatic systems

 48-h CE50: 3.24 mg/l (Daphnia similis) [4]

 Chromium (III) oxide is not sufficiently soluble in environmental media to cause acute toxicity to aquatic invertebrates at the level of the lowest acute effect concentration (expressed as the EC50). [7]

Terrestrial systems

   Based on the lack of a potential for toxicity to aquatic organisms and/or bioaccumulation and its behaviour (poor solubility) in soils, chromium (III) oxide is expected to have a low potential for toxicity in soils. [7]

Chronic toxicity (NOEC, LOEC)

Aquatic systems

 Based on the poor solubility of chromium (III) oxide in environmental media, inhibition of activated sludge respiration or toxicity to microorganisms is not expected. [7]

Terrestrial systems

 Based on the lack of a potential for toxicity to aquatic organisms and/or bioaccumulation and its behaviour (poor solubility) in soils, chromium (III) oxide is expected to have a low potential for toxicity in soils. [7]

HUMAN HEALTH EFFECTS and PROTECTION

Routes of human exposures

 The general population is exposed to chromium (generally chromium [III]) by eating food, drinking water, and inhaling air that contains Cr (III). Dermal exposure to chromium may occur during the use of consumer products that contain chromium, such as wood treated with copper dichromate or leather tanned with chromic sulfate.[3, 6]

General effects

 

Endocrine disruption

 

Mutagenicity

 

Carcinogenicity

 No data are available on the carcinogenic potential of chromium (III) compounds alone. [3, 6]

EPA has classified chromium (III) as a Group D, not classifiable as to carcinogenicity in humans. [3, 6]

EPA has stated that "the classification of chromium (VI) as a known human carcinogen raises a concern for the carcinogenic potential of chromium (III)". [3, 6]

Reprotoxicity

 No information is available on the reproductive or developmental effects of chromium (III) in humans. A study of mice fed high levels of chromium (III) in their drinking water has suggested a potential for reproductive effects, although various study characteristics preclude a definitive finding.  No developmental effects were reported in the offspring of rats fed chromium (III) during their developmental period. [3, 6]

Teratogenicity

 

Skin, eye and respiratory irritations

The respiratory tract is the major target organ for chromium (III) toxicity. [3, 6]

Metabolism:

absorption, distribution & excretion

 

Exposure limits

 The average daily intake from air, water, and food is estimated to be less than 0.2 to 0.4 micrograms (μg), 2.0 μg, and 60 μg, respectively. Occupational exposure to chromium occurs from chromate production, stainless-steel production, chrome plating, and working in tanning industries; occupational exposure can be two orders of magnitude higher than exposure to the general population. People who live in the vicinity of chromium waste disposal sites or chromium manufacturing and processing plants have a greater probability of elevated chromium exposure than the general population. [3, 6]

Drinking water MAC

 

Other information

Chromium (III) is an essential element in humans, with a daily intake of 50 to 200 μg/d recommended for adults. [3]

Animal toxicity data

Acute toxicity (LD50)

 Acute animal tests have shown chromium (III) to have moderate toxicity from oral exposure. [2]

Chronic toxicity (NOEL, LOEL)

 

ENVIRONMENTAL STANDARDS AND REGULATIONS

EINECS regulation

̵

OSHA regulations etc.

 

 

 

OTHER INFORMATION, SPECIAL REMARKS

Classification and proposed labelling with regard to toxicological data

Warning! According to the classification provided by companies to ECHA in CLP notifications this substance may cause an allergic skin reaction. [2]

 

 

CREATED, LAST UPDATE

Created

2019. 03. 29.

Last update

2019. 04. 01.

REFERENCES

 [1] PubChem:  https://pubchem.ncbi.nlm.nih.gov/compound/Chromium_III_#section=Top, Accessed: 2019.03.29

 [2] ECHA, European Chemical Agency, Chromium III, https://echa.europa.eu/hu/substance-information/-/substanceinfo/100.111.676, Accessed: 2019.03.29

 [3] Wilbur S, Abadin H, Fay M, et al . (2012) Toxicological Profile for Chromium. Agency for Toxic Substances and Disease Registry (US), Atlanta (GA) https://www.ncbi.nlm.nih.gov/books/NBK158851/, Accessed: 2019.03.29

 [4] Melnikov P, de Freitas T.C.M. (2011) Evaluation of Acute Chromium (III) Toxicity in Relation to Daphnia similis, Journal of Water Resource and Protection, 3, 127-130. doi:10.4236/jwarp.2011.32015, Accessed: 2019.03.29

  [5] Mindat.org, The Mineralogy of Chromium, https://www.mindat.org/element/Chromium, Accessed 2019.03.29

  [6]Chromium Compounds – EPA, https://www.epa.gov/sites/production/files/2016-09/documents/chromium-compounds.pdf  Accessed 2019.03.29

  [7] ECHA, European Chemical Agency. Chromium (III) oxide.  https://echa.europa.eu/hu/registration-dossier/-/registered-dossier/15477/6/2/4, Accessed: 2019.04.01.

  [8] Arizona State University. Properties of some metals, Chromium, Cr 3+ http://www.public.asu.edu/~jpbirk/qual/qualanal/chromium.html  Accessed: 2019.04.01.