Chromium (III) compounds fact sheet

Health=20 effects=20
Environmental=20 effects=20
Common=20 uses=20
Sources=20 of emissions=20
Comparison=20 to other substances=20
Physical=20 and chemical properties=20
Sources=20 of information used in preparing this fact sheet

The National Pollutant Inventory (NPI) = provides=20 information on the types and amounts of pollutants being emitted in the=20 Australian community.

This page provides facts about chromium (III) compounds. It describes = how you=20 might be exposed to this substance, how exposure might effect you and = the=20 environment, common uses, comparative data about chromium (III) = compounds and=20 its physical and chemical properties.

For more information about some of the terms used in this page, see = the NPI=20 glossary.

The National Pollutant Inventory (NPI) = holds data for=20 all sources of chromium (III) compounds emissions in Australia .

Australia's=20 chromium (III) compounds emission report

Health effects

What=20 effect might chromium (III) compounds have on my health?=20
How=20 might chromium (III) compounds enter my body?=20
How=20 might I be exposed to chromium (III) compounds?=20
What=20 are the chromium (III) compounds health guidelines?

What effect might = chromium=20 (III) compounds have on my health?

This depends on how much chromium a person has been exposed to, for = how long,=20 the nature of the chromium compound(s), and current state of health. = Trivalent=20 chromium compounds are considerably less toxic than the hexavalent = compounds and=20 are neither irritating nor corrosive under normal conditions. However, = all forms=20 of chromium can be toxic at high levels. People who are allergic to = chromium may=20 have asthma attacks after breathing high levels of chromium (III) in = air.=20 Repeated or prolonged skin contact may cause irritation. In severe = cases, skin=20 allergy can occur with itching, redness and/or an eczema-like rash.

How might chromium = (III)=20 compounds enter my body?

Chromium can be inhaled or ingested.

How might I be = exposed to=20 chromium (III) compounds?

Chromium(III) is an essential nutrient in the diet of humans and = animals in=20 very small amounts. Very small amounts of chromium (III) are in everyday = foods.=20 Other forms of chromium are not needed by living organisms. The general=20 population is exposed to chromium (III) in food, drinking water and in = air.=20 Atmospheric contamination is caused by the combustion of natural gas, = oil and=20 coal.

See Sources=20 for more information.

What are the chromium (III) = compounds=20 health guidelines?

Worksafe Australia :
The eight hour time weighted average (TWA) = exposure=20 for chromium (III) compounds (as Cr) is 0.5 mg/m3.

Addit= ional=20 information on current health and environmental guidelines =

The Australian NOHSC National Exposure Standards Database link is = probably=20 the most useful source of information.

Environmental=20 effects

What=20 effect might chromium (III) compounds have on the environment?=20
How=20 might chromium (III) compounds enter the environment?=20
Where=20 in the environment do chromium (III) compounds end up?=20
What=20 are the chromium (III) compounds environmental guidelines? =

What effect might = chromium (III)=20 compounds have on the environment?

Chromium (III) and chromium (VI) both have high chronic toxicity to = aquatic=20 life. No data are available on the long-term effects of chromium to = plants,=20 birds, or land animals. Chromium (III) has moderate acute toxicity to = aquatic=20 life. No data are available on the short-term effects of chromium to = plants,=20 birds, or land animals. Fish do not appear to take up or store chromium = in their=20 bodies.

How might chromium (III) = compounds=20 enter the environment?

Chromium can be transported as particles released into the atmosphere = or as=20 dissolved compounds in natural waters.

Where in the environment do = chromium=20 (III) compounds end up?

Chromium (III) can be found in nature and low background levels in = air, water=20 and food occur everywhere. Manufacturing, disposal of products or = chemicals=20 containing chromium, or burning of fossil fuels release chromium to the = air,=20 soil, and water. Chromium particles settle from air in less than 10 = days.=20 Chromium sticks strongly to soil particles. Most chromium in water = sticks to=20 dirt particles that fall to the bottom and only a small amount of = chromium=20 dissolves.

What are the chromium (III) = compounds=20 environmental guidelines?

Australian Water Quality Guidelines for Fresh and Marine Waters: = (ANZECC,=20 1992):
Maximum of 0.01 mg/L (i.e. 0.00001 g/L) in fresh waters and = 0.05 mg/L=20 (i.e. 0.00005 g/L) in marine waters respectively. Important: These are = total=20 chromium concentrations and are based on the assumption that all = chromium is in=20 the more toxic chromium (VI) form.

Addit= ional=20 information on current health and environmental guidelines =

Common uses

Chromium metal is used as an alloying element to harden steel and to=20 manufacture stainless steel. Chromium compounds are used for chrome = plating=20 (e.g. protective coatings for automotive and equipment accessories), as = dyes, as=20 inorganic paint pigments, for leather tanning, as fungicides and wood=20 preservatives, and as catalysts. More applications are in the = photographic=20 industry (sensitiser), in industrial water treatment (including = treatment of=20 cooling tower water), as medicinal astringents and antiseptics, and in = nuclear=20 and high temperature research. Chromium (III) compounds are employed as = pigment,=20 as catalyst, as tanning agent in the tanning industry, in the production = of pure=20 chromium metal and chromium (VI) compounds, and in the production of = refractory=20 bricks. More specifically, chromium (III) oxide is used as a paint = pigment, a=20 fixative for certain textile dyes and as a catalyst. Chromium (III) = acetate is=20 used to fix certain textile dyes, to harden photographic emulsions and = as a=20 catalyst. Chromium (III) nitrate is used in the preparation of chrome = catalysts,=20 in textile printing operations, and as a corrosion inhibitor. Chromic = sulfate is=20 used in tanning, green paints, inks and text dyes and in ceramics.

Sources of emissions

Industry=20 sources=20
Diffuse=20 sources, and industry sources included in diffuse emissions data=20
Natural=20 sources=20
Transport=20 sources=20
Consumer=20 products that may contain chromium (III) compounds

Industry = sources

Emissions to air and water may result from leather tanning = industries,=20 chemical manufacturing industries (e.g. dyes for paints, rubber and = plastic=20 products), metal finishing industries (e.g. chrome plating), = manufacturers of=20 pharmaceuticals, wood, stone, clay and glass products, electrical and = aircraft=20 manufacturers, steam and air conditioning supply services, cement = producing=20 plants (cement contains chromium), incineration of council refuse and = sewage=20 sludge, and combustion of oil and coal.

Diffuse sources, and = industry=20 sources included in diffuse emissions data

Chromium may be oxidised and leached from stainless steel into a=20 water-soluble form.

Natural = sources

Chromium is a relatively common element, naturally occurring in = rocks, soil,=20 plants, animals, and in volcanic dust and gases. Oil and coal contain = traces of=20 chromium (III). Chromium is chiefly found as the chromium (III) form in = nature,=20 and rarely as chromium (VI) compounds.

Transport = sources

Motor vehicle exhaust may contain chromium.

Consumer products that may contain = chromium=20 (III) compounds

Some textile and some leather products.

Comparison to other = substances

NPI=20 rank

NPI = rank

Approximately 400 substances were considered for inclusion on the = NPI=20 reporting list. A ranking and total hazard score was given based on = health and=20 environmental hazards and human and environmental exposure to the = substance.

Chromium (III) compounds was ranked as 60 out of 400. The total = hazard score=20 taking into account both human health and environmental criteria is = 3.2.

On a health hazard rating of 0 - 3 chromium (III) compounds registers = 1.2. A=20 score of 3 represents a very high hazard to health, 2 represents a = medium hazard=20 and 1 is harmful to health.

On an environmental rating of 0 - 3 chromium (III) compounds = registers 2.0. A=20 score of 3 represents a very high hazard to the environment and 0 a = negligible=20 hazard.

Factors taken into account to obtain this ranking and these scores = include=20 the extent of the material's toxic or poisonous nature and/or its lack = of=20 toxicity, and the measure of its ability to remain active in the = environment and=20 whether it accumulates in living organisms. It does not take into = account=20 exposure to the substance. Environmental exposure is reflected in the = NPI rank=20 for this substance (see comparative data below). A substance that scores = highly=20 as an environmental hazard is oxides of nitrogen at 3.0 and one of the = lower=20 scores is carbon monoxide at 0.8. A substance that scores highly as a = health=20 hazard is arsenic at 2.3 and one of the lowest scores is ammonia at = 1.0.

More = information about ranking NPI=20 substances

Physical and chemical = properties

Substance name	Chromium (III) compounds
CASR number	16065-83-1
Molecular formula	Cr³⁺
Synonyms	Chromic ion, Chromium ion, Trivalent chromium Trivalent = chromium=20 compounds include: chromic oxide (CASR# 1308-38-9), chromium = acetate=20 (CASR# 1066-30-4), chromium nitrate (CASR# = 13548-38-4), chromium=20 chloride (CASR# 10025-73-7), chromium phosphate (CASR# = 7789-04-0),=20 and chromium sulfate (CASR# 10101-53-8)
*Physical = properties:* Chromium=20 is a white, hard, lustrous and brittle metal that is extremely = resistant=20 to ordinary corrosive agents.=20 Atomic Number: 24 Atomic Mass: 52.0 Melting Point (=B0C): = about=20 1860 Boiling Point (=B0C): about 2670 Specific Gravity: = 7.2 Properties vary widely depending on the particular compound. = Chromic=20 oxide is a bright green hygroscopic powder with melting point of = 2435 =B0C,=20 boiling point of 4000 =B0C and specific gravity of 5.2. Chromium = acetate is=20 a grey-green to blue green pasty mass. Chromium nitrate is a pale = green=20 powder. Chromium chloride is a hygroscopic compound with melting = point of=20 1152 =B0C and specific gravity of 2.8. All chromium compounds have = no taste=20 or odour.
*Chemical = properties:* The most=20 stable oxidation state of the element chromium is chromium (III), = found in=20 chromite. Chromite is the most important chromium ore mined for = the=20 recovery of chromium. Another oxidation state of practical = importance is=20 chromium (VI) (CASR# 18540-29-9), but whilst there are some = natural=20 sources for chromium (VI), the majority originates from industrial = activities. Chromium is chiefly found in its trivalent form in = natural=20 environments, except in sea water where chromium in its hexavalent = state=20 is prevailing, but at extremely low concentrations. Compared to = chromium=20 (III), chromium (VI) is assumed to be about 100 to 1000 times more = toxic.=20 Although each form can be converted to the other form under = certain=20 conditions, chromium (III) is not oxidised to chromium (VI) in the = natural=20 soil environment. Water solubility of chromium and its salts = ranges from=20 low to high, e.g chromium (III) oxide is insoluble in water, and = chromic=20 (III) acetate, chromium (III) nitrate and chromium (III) sulfate = are=20 soluble in water. Pure chromium metal (oxidation state of 0) which = dissolves readily in non-oxidising mineral acids such as = hydrochloric and=20 sulfuric acids is not found in nature. Chromium (VI) compounds are = dealt=20 with elsewhere in the NPI.

Sources of information used in = preparing this=20 fact sheet

Agency for Toxic Substances and Disease Registry (ATSDR), ToxFAQs, = Chromium (accessed, May, 1999)=20
Australian and New Zealand Environment and Conservation Council = (ANZECC)=20 (1992), Australian Water Quality Guidelines for Fresh and Marine = Waters.=20
ChemFinder WebServer Project (1995), Chromium (accessed, May, = 1999)=20
ChemFinder WebServer Project (1995), Chromium (III) (accessed, = May, 1999)=20
Environmental Health Center (a division of the National Safety = Council)=20 Environment Writer - Chemical Backgrounders (July 1, 1997), Chromium = and=20 Chromium compounds (accessed, May, 1999)=20
Integrated Risk Information System (IRIS, September 3, 1998), = Chromium=20 (III), insoluble salts (accessed, May, 1999)=20
Kimbrough, D. E., Cohen, Y., Winer, A. M., Creelman, L., and = Mabuni, C., A=20 critical assessment of chromium in the environment, Critical Reviews = in=20 Environmental Science and Technology 29:1 (1999), 1-46.=20
Merian, E. (editor, 1991), Metals and Their Compounds in the = Environment =FB=20 Occurrence, Analysis, and Biological Relevance, VCH.=20
Technical Advisory Panel (1999), Final Report to the National = Environment=20 Protection Council.=20
US EPA TTNWeb and US OAQPS UATW, Health Effects Notebook for = Hazardous Air=20 Pollutants (December 1994), Chromium and Compounds (accessed, May, = 1999)=20
US EPA, Office of Water, National Primary Drinking Water = Regulations,=20 Consumer Version (January 23, 1998), Factsheet on Chromium (accessed, = May,=20 1999)=20
WebElements =FB The periodic table on the WWW (May 1999), Chromium = (accessed, May, 1999)=20
Worksafe Australia (1996), Exposure Standards Database, Chromium = (III)=20 compounds (as Cr) (accessed, May, 1999)=20
Worksafe Australia (1996), Hazardous Substances Database, Chromium = (accessed, May, 1999)

There is more information that may be useful in understanding some of = the=20 issues surrounding the NPI.

Ba= ckground=20 information