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The National Pollutant Inventory (NPI) provides information on the types and amounts of pollutants being emitted in the Australian community.
This page provides facts about cyanide (inorganic) compounds. It describes how you might be exposed to this substance, how exposure might effect you and the environment, common uses, comparative data about cyanide (inorganic) compounds and its 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 cyanide (inorganic) compounds emissions in Australia.
Very small amounts of cyanide in the form of vitamin B-12 (cyanocobalamin) are needed as part of a healthy diet. Cyanide is very toxic to humans and inhalation exposure can be rapidly fatal. Brief exposures to lower levels may result in shortness of breath, convulsions, and loss of consciousness. Exposure to high levels for short periods may result in irritation of the eyes, nose and throat, headache, pounding of the heart, shortness of breath, harm to the central nervous system, the respiratory system, and the cardiovascular system, and quickly lead to death. Long term exposure to low levels of cyanide may cause deafness, vision problems, and loss of muscle coordination. It may also effect the thyroid gland, which may cause cretinism (retarded physical and mental growth in children), or enlargement and over activity of the gland. These long-term effects are seen in people who eat large amounts of cassava, a cyanide containing vegetable.
Cyanide can enter the body when a person breathes air containing hydrogen cyanide or dust from cyanide compounds. This is most common for people who smoke or work in areas of higher exposure or near to facilities where cyanide compounds are used or produced. Cyanide may also enter the body when a person eats food or drinks water containing it. Cyanide released to the soil may pass into underground water systems. Cyanide is able to pass through the skin.
Workers in the industries that use or produce cyanide compounds are at risk of exposure. Consumers can be exposed to cyanide by exposure to air from production and processing facilities such silver and gold mining operations, chemical processing facilities, steel and iron industries, metallurgical industries, metal plating and finishing facilities and petroleum. Consumers may also be exposed to cyanide when using consumer products containing cyanide, such as pesticides. People who live in areas of high motor vehicle traffic, smoke, or breath smoke from burning trash are also at higher risk of exposure to cyanide.
See
Sources
for more information.
Worksafe Australia:
For Hydrogen cyanide, eight hour time weighted average (TWA) exposure limit: 11 mg/m?.
For other cyanide compounds, the TWA exposure limit is 5 mg/m? . Worksafe Australia reports hydrogen cyanide, potassium cyanide, and sodium cyanide are all very toxic by inhalation.
Australian Drinking Water Guidelines (NHMRC and ARMCANZ, 1996):
Maximum of 0.08 mg/L (i.e. 0.00008 g/L)
The Australian NOHSC National Exposure Standards Database link is probably the most useful source of information.
Cyanides have high acute (short-term) toxicity to aquatic life, birds, and animals. Insufficient data are available to evaluate the acute toxicity of cyanides on plants on land. Cyanides have high chronic (long-term) toxicity to aquatic life. Insufficient data are available to evaluate the chronic toxicity to plants, birds, or land animals. Cyanides are not expected to bioaccumulate.
Cyanide compounds will be in the atmosphere as gases or small particles. They will then settle into the soil or water depending upon where the air currents carry them. Most cyanide compounds are water-soluble. These can contaminate ground water. They will evaporate out of the water. In the water cyanides are not persistent, they breakdown in a matter of days.
Cyanide enters the environment from both natural and human processes. In air it is found mainly as the gas hydrogen cyanide, a small amount is present as fine dust particles. Most cyanide in surface water will form hydrogen cyanide and evaporate. It takes years for cyanide to breakdown from the air.
Australian Water Quality Guidelines for Fresh and Marine Waters: (ANZECC, 1992):
Maximum of 0.005 mg/L (i.e. 0.00000 g/L)
Note that the emissions data in the
NPI
database is not directly comparable with these guidelines.
Cyanide salts are mainly used in electroplating, metallurgy, the production of orgainc chemicals (acrylonitrile, methyl methacrylate, adiponitrile), photographic development, the extraction of gold and silver from ores, tanning leather and in the making of plastics and fibres. They are also used to manufacture fumigation chemicals, insecticides and rodenticides.
Silver and gold mining operations (water or soil release), chemical processing facilities (water or air release), steel and iron industries (water or air release), metallurgical industries (water release), metal plating and finishing facilities (water release) and petroleum refineries are the largest point sources of cyanide(water or air release).
Use of pesticides (air, water, soil release) Burning of waste, tobacco products, certain plastics, wool, silk, and paper release cyanide to the air. Metal cleaning facilities tanneries, and photographic facilities may release cyanide to the air or water.
Some plants manufacture certain chemicals which when they decompose release cyanide. One of these chemicals (amygdalin) is found in the pits of apricots, peaches, cherries, apples, pears, and similar fruits and in sweet almonds. Enzymes in the human intestine are capable of releasing cyanide from this chemical, resulting in poisoning. Certain blue-green algae can produce cyanide as they metabolise nitrates.
Perhaps the largest source of mobile emissions of cyanide to the air is motor vehicle exhaust.
Consumer products containing cyanide products are pesticides, rodenticides, and other animal poisons, silver and metal polishes and photographic solutions.
Approximately 400 substances were considered for inclusion on the
NPI
reporting list. A ranking and total hazard score was given based on health and environmental hazards and human and environmental exposure to the substance.
Cyanide (inorganic) compounds was ranked as 27 out of 400. The total hazard score taking into account both human health and environmental criteria is 4.0.
On a health hazard rating of 0 - 3 cyanide (inorganic) compounds registers 1.8. A score of 3 represents a very high hazard to health, 2 represents a medium hazard and 1 is harmful to health.
On an environmental rating of 0 - 3 cyanide (inorganic) compounds registers 2.2. A score of 3 represents a very high hazard to the environment and 0 a negligible hazard.
Factors taken into account to obtain this ranking and these scores include the extent of the material's toxic or poisonous nature and/or its lack of toxicity, and the measure of its ability to remain active in the environment and whether it accumulates in living organisms. It does not take into account exposure to the substance. Environmental exposure is reflected in the
NPI
rank for this substance (see comparative data below). A substance that scores highly as an environmental hazard is oxides of nitrogen at 3.0 and one of the lower scores is carbon monoxide at 0.8. A substance that scores highly as a health hazard is arsenic at 2.3 and one of the lowest scores is ammonia at 1.0.
| Substance name
|
Cyanide (inorganic) compounds
|
| CASR number
|
57-12-5
Molecular formula
Synonyms Cyanide is a substance that is found in combination with other chemicals in the environment. The more common ones are Hydrogen cyanide (CASR# 74-90-8); sodium cyanide (CASR# 143-33-9); potassium cyanide (CASR# 151-50-8) and calcium cyanide (CASR# 592-01-8). Synonyms for CN- are: Cyanides; Isocyanide; Cyanide ion; Cyanide anion; CYANIDE(
1-
) ION.
|
| Molecular formula
|
CN
-
|
| Synonyms
|
Cyanide is a substance that is found in combination with other chemicals in the environment. The more common ones are Hydrogen cyanide (CASR# 74-90-8); sodium cyanide (CASR# 143-33-9); potassium cyanide (CASR# 151-50-8) and calcium cyanide (CASR# 592-01-8). Synonyms for CN- are: Cyanides; Isocyanide; Cyanide ion; Cyanide anion; CYANIDE(
1-
) ION.
|
Physical properties:
Hydrogen cyanide exists as colourless or pale blue liquid or gas with a bitter almond odour detectable at 1 to 5 ppm.Calcium cyanide, potassium cyanide, and sodium cyanide are all examples of simple cyanide salts. They are all white solids, are soluble in water, and smell like bitter almond.
Melting Point (?C) Hydrogen cyanide: -13.4; Sodium cyanide: 563.7; Potassium cyanide: 634.5
Boiling Point (?C) Hydrogen cyanide: 25.6; Sodium cyanide: 1496; Potassium cyanide: 1625
Density (kg/m?): Hydrogen cyanide: 0.699 (liquid); Sodium cyanide: 1.6; Potassium cyanide: 1.52.
|
Chemical properties:
Cyanides are a group of compounds based on a structure formed when carbon and nitrogen are combined. When cyanide combines with chemicals from the metals groups it forms simple salts. Calcium cyanide, potassium cyanide, and sodium cyanide all will liberate hydrogen cyanide (which is also soluble in water and smells like bitter almonds) in acidic water.
|
- Agency for Toxic Substances and Disease Registry (1989), Public Health Statement Cyanide (accessed, May, 1999)
- Agency for Toxic Substances and Disease Registry (1997), ToxFAQS Cyanide (accessed, May, 1999)
- Australian and New Zealand Environment and Conservation Council (ANZECC) (1992), Australian Water Quality Guidelines for Fresh and Marine Waters.
- CalEPA Air Resources Board Toxic Air Contaminant Summary Cyanide Compounds (accessed, May, 1999)
- ChemFinder WebServer Project (1995), Calcium Cyanide (accessed, May, 1999)
- ChemFinder WebServer Project (1995), Cyanide (accessed, May, 1999)
- ChemFinder WebServer Project (1995), Sodium Cyanide (accessed, May, 1999)
- Environmental Defense Fund (1998), Calcium Cyanide: The Chemical Scorecard: (accessed, May, 1999)
- Environmental Defense Fund (1998), Potassium Cyanide: The Chemical Scorecard: (accessed, May, 1999)
- Environmental Health Center, a division of the National Safety Council, Environment Writer -- Chemical Backgrounders Cyanide Compounds (accessed, May, 1999)
- National Environment Protection Council (1998a), National Environment Protection Measure for the National Pollutant Inventory (accessed, May, 1999)
- National Health and Medical Research Council (NHMRC) and Agriculture and Resource Management Council of Australia and New Zealand (ARMCANZ) (1996), Australian Drinking Water Guidelines.
- New Jersey Department of Health, Right to Know Program (1986), TRIFacts, Sodium Cyanide (accessed, May, 1999)
- NTP Chemical Repository, Radian Corporation, Potassium Cyanide (AUGUST 29, 1991) (accessed, May, 1999)
- NTP Chemical Repository, Radian Corporation, Sodium Cyanide (AUGUST 29, 1991) (accessed, May, 1999)
- Technical Advisory Panel (1999), Final Report to the National Environment Protection Council.
- University of California, Davis; School of Veterinary Medicine, Vermont SIRI MSDS Archive Site: Sodium cyanide, technical (accessed, May, 1999)
- Worksafe Australia (1996), Exposure Standard Hydrogen cyanide (accessed, May, 1999)
- Worksafe Australia (1996), Hazardous Substance Hydrogen cyanide (salts) (accessed, May, 1999)
- Worksafe Australia (1996), Hazardous Substance Potassium cyanide (accessed, May, 1999)
- Worksafe Australia (1996), Hazardous Substance Sodium cyanide (accessed, May, 1999)
There is more information that may be useful in understanding some of the issues surrounding the
NPI
.