Metallic nickel is a silvery, hard metal or a gray powder not commonly found in nature. It typically exists as a trace constituent in many different minerals, particularly those containing magnesium and iron. In Canada, nickel is usually found in sulphide ores, especially pentlandite, together with copper, cobalt, gold and silver. Nickel’s properties of corrosion and heat resistance, hardness and strength make it an ideal component of alloys.
Most nickel compounds are green to black in colour, yellow when heated, and dissolve easily in water. There are numerous other synonyms and product names for nickel and its compounds; see HSDB for more information.
Nickel compounds were classified by IARC as Group 1, carcinogenic to humans, with a definite link to human lung, nasal, and paranasal cancer. This evaluation was primarily linked to the nickel compounds containing oxygen and sulphur that are commonly encountered in nickel refining work, but the weight of epidemiological evidence for the carcinogenicity of soluble nickel warranted classification of nickel compounds in general as carcinogenic to humans. In a recent IARC review of Group 1 agents, nickel compounds' Group 1 classification was reaffirmed.
Metallic nickel was classified as Group 2B, possibly carcinogenic to humans, due to insufficient epidemiological evidence in humans. Metallic nickel is a lung carcinogen in rats, however, and also caused local sarcomas after injection in rats and hamsters.
Working with nickel (e.g. in nickel refining or welding) can cause chronic bronchitis and decreased lung function, as well as immunological and renal outcomes. It is not clear if these effects are due entirely to nickel, since exposure to other substances (e.g. cobalt) also occurs in these settings. Nickel exposure is also a very common cause of allergic contact dermatitis. 10-20% of the population reports a reaction, usually from jewellery and other consumer products. Some people who are sensitized to nickel may have asthma that is related to their nickel exposure.
stel = short term exposure limit (15 min. maximum)
i = inhalable fraction
Canadian Environmental Guidelines
Nickel and its compounds were not included in the Canadian government environmental guidelines reviewed.[9-12]
DSL – eight nickel compounds are included (already risk managed)
Schedule 1, paragraph 'a'
Nickel and its compounds were not included in other Canadian government chemical listing reviewed.
Statistics from a large nickel producer, indicate that global nickel consumption in 2007 was distributed as follows: stainless steel production, 61%; nickel-based alloys, 12%; electroplating, 9%; casting and alloy steels, 9%; rechargeable batteries, 4%; coins, 2%; and other, 3%. Pure nickel is also used as a catalyst, in magnets, electrical contacts and electrodes, spark plugs, machinery parts, and surgical and dental prostheses.
Canadian Production and Trade
In 2007, Canada produced 15% of the world’s nickel, second only to Russia. There are 10 nickel producers at 6 different locations in Canada: central Ontario, northern Manitoba, northern Quebec, and Labrador. Further processing occurs in Sudbury, Ontario; Thompson, Manitoba; and Fort Saskatchewan, Alberta. Ontario mines produced 53% of all Canadian nickel in 2006.
Nickel is commonly recycled; in 2007, 47% of nickel used globally in the production of stainless steel was recycled.
Production and Trade
Export: Mainly to China
139 t of ‘nickel ores and concentrates’
Export: Mainly to US, China
88,304 t of ‘unwrought nickel’
Import: Mainly from Australia
20,281 t of 'nickel ores and concentrates'
Import: Mainly from Canada*, Norway
1,962 t of 'unwrought nickel'
Inhalation of particles and fumes and dermal contact are the main routes of occupational exposure.
The main occupations exposed include workers in nickel refineries or nickel processing plants, as well as occupations involving alloy nickel production, stainless steel production, welding, electroplating, grinding and cutting operations.
The primary source of exposure to nickel for most Canadians is food and water.
Nearly all water supplies and most foods in Canada contain small amounts of nickel. Chocolate, soybeans, nuts and oatmeal have naturally higher levels.
Environmental exposure to nickel also occurs from inhalation of dust and contact with nickel containing objects such as jewelry.
Nickel is found naturally in soil and in meteorites. It is also released and transported in the environment from windblown dust and volcanic eruptions.
Anthropogenic sources include nickel mining and industries producing alloys or nickel compounds. Oil and coal burning power plants and trash incinerators are additional sources. The type of nickel in the atmosphere depends on the source of emission.
Background concentrations of nickel vary across the country; levels in Ontario soils can be up to 43 parts per million.
Searches of environmental and consumer product databases yielded the following results on current potential for exposure to nickel in Canada:
NPRI and US Household Products Database
Search term: 'nickel and its compounds'
Released into Environment
Petroleum refineries, power generation, nickel refineries, mining and foundries (333 companies)
Sent to off-site recycling
US Household Products 2010
Electrical grease, batteries, and concrete colourant