Chromium (VI) 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 information on the = types and=20 amounts of pollutants being emitted in the Australian community.

This page provides facts about chromium (VI) 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 (VI) compounds = and its=20 physical and chemical properties.

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

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

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

Health effects

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

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

Speciation
Compounds of two species of chromium = are on=20 the NPI reporting list, chromium (VI) and chromium = (III).=20 The health effects of chromium (VI) compounds will be quite different = from that=20 of chromium (III) compounds.

Very small quantities of chromium (III) compounds are essential for = your=20 health and well-being. Chromium VI compounds are usually highly toxic. = Breathing=20 in chromium (VI) compounds can damage and irritate your nose, throat, = lungs,=20 stomach and intestines. It may lead to asthma and other allergic = reactions.=20 Exposure to chromium (VI) can cause stomach upsets, ulcers, convulsions, = kidney=20 and liver damage. Long-term exposure to airborne chromium (VI) can have = adverse=20 effects on the respiratory and the immune systems and can cause cancer. = Skin=20 contact with liquids and solids may lead to skin ulcers, redness and = swelling. A=20 US expert panel investigated chromium-contaminated soils in a = residential area=20 and concluded that soil concentrations of 2,800mg/kg (i.e. 2.8 g/kg) = chromium=20 (III) and 180 mg/kg (i.e. 0.18 g/kg) chromium (VI) do not pose a health = hazard=20 following acute or chronic exposure for residents living on or near the=20 contaminated sites. These findings and recent reports of Health-Based = Soil=20 Action Levels and case studies involving human exposure to chromium (VI) = in soil=20 and ground water put the relative toxicity of chromium (III) and = chromium (VI)=20 into perspective. Chromium (VI) is more toxic than chromium (III) but = low levels=20 can be tolerated. The human studies showed that the gastrointestinal = tract can=20 reduce ingested chromium (VI) to chromium (III) at concentrations up to = 10 mg=20 chromium (VI)/L and soil concentrations of 1240 ppm chromium (VI) do not = result=20 in allergic contact dermatitis in 99.9% of the general population.

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

Air-borne particles can be breathed in. Skin exposure to chromium = (VI) will=20 be especially noticed by those individuals with skin allergies.

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

Dangerous exposure to chromium (VI) happens mostly from breathing = workplace=20 air, from welding, chrome plating and handling some chromate = chemicals.

See Sources=20 for more information.

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

Australian Drinking Water Quality Guidelines (NHMRC and ARMCANZ,=20 1996):
0.05 mg/L (i.e. 0.00005 g/L).

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

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

Speciation
Compounds of two species of chromium = are on=20 the NPI reporting list, chromium (VI) and chromium = (III).=20 The environmental effects of chromium (VI) compounds will be quite = different=20 from that of chromium (III) compounds. Chromium (VI) can have a high to=20 moderate, acute toxic effect on plants, birds or land animals. This can = mean=20 death of animals, birds or fish and death or low growth rate in plants. = Chromium=20 (VI) does not breakdown or degrade easily and there is a high potential = for=20 accumulation of chromium (VI) in fish life.

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

Chromium (VI) released into the atmosphere is carried in the air as = particles=20 or dust for a period of time. As it settles it will contaminate soil and = water=20 with only small amounts dissolving. Rain will remove chromium (VI) = particles=20 from the atmosphere, depositing them in the ground, or they may be = transported=20 over long distances by wind.

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

Chromium (VI) is released into the air, soil and water during the = manufacture=20 and disposal of products and chemicals containing chromium (VI) or the = burning=20 of fossil fuels (coal, oil or gas). Airborne chromium (VI) particles = will settle=20 in less than 10 days, depending on particle size, and will stick = strongly to=20 soil particles. Small amounts may travel from the soil to groundwater. = Chromium=20 (VI) in water will stick to dirt particles that fall to the bottom with = only a=20 small amount dissolving.

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

Australian Water Quality Guidelines for Fresh and Marine Waters = (ANZECC,=20 1992): Maximum concentration in fresh water: 0.01 mg/L (i.e. 0.00001 = g/L);=20 maximum concentration in marine water: 0.05 mg/L (i.e. 0.00005 g/L).

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

Common uses

Is used to make bricks and linings for furnaces. Compounds are used = for=20 chrome plating (chromic acid), manufacture of dyes (soluble chromates), = wood=20 treatment and water treatment.

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 (VI) compounds

Industry = sources

Emissions to air and water from:
Chemical manufacturing industry = e.g. dyes=20 for paints, rubber and plastic products.
Metal finishing industry = e.g. chrome=20 plating.
Manufacturers of pharmaceuticals, wood, stone, clay and = glass=20 products.
Electrical and aircraft manufacturers, steam and air = conditioning=20 supply services.
Cement producing plants as cement contains=20 chromium.
Incineration of council refuse and sewage = sludge
Combustion of=20 oil and coal.

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

Facilities below the reporting threshold

Natural = sources

Chromium (VI) compounds are not found in nature. Chromium is usually = found as=20 the Cr(III) form, as the mineral Chromite and in many soils.

Transport = sources

Emission to air from the wearing down of brake linings containing=20 chromium.
Motor vehicle exhaust (crude oil contains traces of = chromium (III)=20 compounds, these may oxidise to the chromium (VI) state during fuel = combustion=20 in vehicle engines).

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

Some inks, paints and paper.
Some rubber and composite floor=20 coverings.
Some treated (preserved) timber products.
Some toner = powders=20 used in copying machines.

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 (VI) compounds was ranked as 2 out of 400. The total hazard = score=20 taking into account both human health and environmental criteria is = 5.5.

On a health hazard rating of 0 - 3 chromium (VI) compounds registers = 2.5. 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 (VI) compounds registers = 3.0. 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 (VI) compounds
CASR number	7440-47-3 (Cr metal), 18540-29-9 (Cr (VI))
Molecular formula	Cr⁶⁺
Synonyms	Chromium (VI) is an oxidation state of the element chromium. = Other=20 common oxidation states of chromium include 0 (the metallic = element=20 chromium), and III (the state in which chromium is found in = nature.=20 Chromium (III) compounds are dealt with elsewhere in the NPI). = Hexavalent=20 chromium compounds (VI) include ammonium dichromate, barium = chromate,=20 calcium chromate, chromium trioxide, lead chromate, sodium = dichromate,=20 strontium chromate, potassium chromate, potassium dichromate, = sodium=20 chromate, and zinc chromate.
*Physical = properties:* Vary=20 widely depending on the particular compound, for example: Most = Cr(VI)=20 compounds are soluble in water, however, barium chromate (a yellow = powder=20 with specific gravity =3D 4.49) and lead chromate (an = orange-yellow powder=20 with specific gravity =3D 6.3) are insoluble in water, and calcium = chromate=20 (a yellow powder) is slightly soluble in water. Sodium dichromate = is in=20 the form of red to orange crystals, with specific gravity =3D = 2.35, and is=20 soluble in water. Chromic acid (H2CrO4) exists only as salts (e.g. = lead=20 chromate, barium chromate) or in solution.
*Chemical = properties:* Chromic=20 acid is very reactive. Most Cr(VI) solutions are powerful = oxidising agents=20 in acidic conditions, but much less oxidising under alkaline = conditions.=20 Chromium trioxides are soluble in alcohol, ethanol, sulfuric acid, = and=20 nitric acid; when heated to decomposition chromium trioxides emit = smoke=20 and irritating fumes. Lead chromate is insoluble in water, acetic = acid,=20 and ammonia, but is soluble in acid and alkalies; when heated to=20 decomposition emits toxic fumes of lead. Potassium chromate and = potassium=20 dichromate are soluble in cold and hot water and insoluble in = alcohol.=20 Sodium dichromate is soluble in cold and hot water and insoluble = in=20 alcohol; toxic fumes of sodium monoxide are emitted when this = compound is=20 heated to decomposition. Strontium chromate is soluble in cold and = hot=20 water, hydrochloric acid, nitric acid, acetic acid, and ammonium = salts.=20 Zinc chromate is insoluble in cold water and acetone, dissolves in = hot=20 water, and is soluble in acid and liquid = ammonia.

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

Agency for Toxic Substances and Disease Registry (1989), Public = Health=20 Statement (accessed, December, 1998)=20
Agency for Toxic Substances and Disease Registry (1997), ToxFAQS=20 (accessed, December, 1998)=20
Australian and New Zealand Environment and Conservation Council = (ANZECC)=20 (1992), Australian Water Quality Guidelines for Fresh and Marine = Waters.=20
Environmental Defense Fund (1998), Chromium and Compounds, = Hexavalent=20 Chromium (accessed, December, 1998)=20
Environmental Defense Fund (1998), Chromium The Chemical Scorecard = (accessed, December, 1998)=20
Finley, B.L. and Paustenback, D.J., J. Soil Contamination, 6(6), = 649,=20 1997.=20
Meagher, D (1991), The Macmillan Dictionary of The Australian = Environment,=20 Macmillan Education Australia Pty Ltd.=20
National Environment Protection Council (1998), National = Environment=20 Protection Measure for the National Pollutant Inventory. (accessed, = December=20 1998)=20
National Library of Medicine (1998), Fact Sheet: Toxic Chemical = Release=20 Inventory Facts (accessed, December, 1998)=20
National Health and Medical Research Council (NHMRC) and = Agriculture and=20 Resource Management Council of Australia and New Zealand (ARMCANZ) = (1996),=20 Australian Drinking Water Guidelines.=20
New Jersey Department of Health, Right to Know Program (1988), = TRIFacts=20 (accessed, December, 1998)=20
Proctor, D.M., Shay, E.C. and Scott, P.K., J. Soil Contamination,=20 6(6),595, 1997.=20
Richardson, M (1992), Dictionary of Substances and their Effects, = Royal=20 Society of Chemistry, Clays Ltd, England.=20
Sheehan, P.J., Meyer, D.M., Sauer, M.M. and Paustenback, D.J., J,=20 Toxicology and Environmental Health, 32, 161-201, 1991.=20
Sittig, M (1991), Handbook of Toxic and Hazardous Chemicals and=20 Carcinogens, 3rd edition, Noyes Publications, USA.=20
Technical Advisory Panel (1999), Final Report to the National = Environment=20 Protection Council.=20
US Department of Health and Human Services (1990), NIOSH Pocket = Guide to=20 Chemical Hazards, Publication No. 90-117.=20
US Environmental Protection Agency and the Office of Air Quality = Planning=20 & Standards (1998), Chromium and Compounds (accessed, December, = 1998)=20
US Environmental Protection Agency and the Office of Ground Water = and=20 Drinking Water (1995), Drinking Water and Health, Consumer Factsheet=20 (accessed, December, 1998)=20
Worksafe Australia (1995), Chromium toxicity in the respiratory = system,=20 author A Bonin (accessed, December, 1998)=20
Worksafe Australia (1996), Hazardous Substance Chromium (accessed, = December, 1998

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

Ba= ckground=20 information