NICKEL

Nickel is a hard, silvery white metal. It is produced by mining and refining sulphide and oxide ores. Nickel is also recycled from scrap metal.

FORMS OF NICKEL

Metallic nickel exists either by itself or with other metals. Workers may be exposed to metallic nickel during production or use of stainless steel or other metals. Welding, cutting or "hard-facing" are other activities.

Insoluble nickel is combined with other substances, usually sulphur or oxygen. The combination will not dissolve in water. Insoluble nickel is found in mining, refining and welding.

Soluble nickel is the combination of nickel and other chemicals will dissolve in water. Electroplating and nickel refining are industries where soluble nickel is present.

Nickel Carbonyl this is a gas formed during refining of nickel.

MAJOR USES OF NICKEL

Common uses of nickel include production of stainless steel and other corrosion-resistant metals containing nickel. Other products which contain nickel include rechargeable (NiCad) batteries, coins, welding rods and wires, electronic or computer equipment, and pigments for paints or ceramics. Nickel is also used in electroplating, electroforming and sintered metal coatings.

EXPOSURE TO NICKEL

Workers may be exposed to nickel during:

• mining and refining of nickel ores
• manufacturing products containing nickel
• manufacturing products from stainless steel
• recycling, handling or using these products
• electroplating and electroforming
• welding

Nickel is naturally present in the environment. People may also be exposed to nickel in food and water. Some consumer products that may contain nickel include jewellery, kitchen tools and coins.

HEALTH EFFECTS FROM NICKEL

Exposure to nickel can cause several health effects. How nickel enters the body and its form will determine the effect on health.

Routes of Entry
The most hazardous route of exposure is by inhalation. If soluble nickel is inhaled, it dissolves and moves through the body going mostly to the kidneys and liver. Insoluble and metallic nickel remains in the lungs. Workers may also come into skin contact with nickel. Only a small portion of nickel which is ingested (eaten) is absorbed by the body.

Respiratory Effects
Inhalation of soluble nickel can cause irritation of the nose and sinuses and could also lead to loss of the sense of smell (anosmia) or perforation of the nasal septum (the wall between the nostrils). This mainly occurs in electroplating. Long-term exposure may lead to asthma, bronchitis or other respiratory diseases.

Skin Effects
Skin contact with metallic or soluble nickel compounds can produce allergic contact dermatitis or "nickel itch". This is the most common health problem caused by exposure to nickel. Since this is a skin allergy, it will affect people both at and away from work.

Cancer
Inhalation of nickel can cause cancer of the lungs, nose and sinuses. Cancers of the larynx (throat) and stomach have also been attributed to inhalation of nickel. Nickel carbonyl and insoluble nickel compounds are the forms of nickel responsible for cancer.

Most of the cancer studies have examined nickel mining and refining. There have been fewer studies of workers exposed to nickel in industries such as stainless steel production, nickel plating and welders working with stainless steel. These workers are also exposed to other substances, such as chromium, which may cause the same diseases (see OHCOW Information Bulletins - Hexavalent Chromium and Electroplating: A Focus on Chrome Plating).

Poisoning
Inhalation of nickel carbonyl can cause headaches, nausea, vomiting, chest pain and breathing problems. Symptoms may not start until 12 to 36 hours after exposure. High exposure can cause pneumonia and death.

Animal Tests
Animal tests have found that nickel can cause kidney cancer and cancer in other parts of the body. Tests performed on rats found that nickel could cause birth defects and stillbirths.

WORKER PROTECTION

How workers are protected from nickel depends on the process or work being performed.

Ventilation and other engineering controls are the best way to reduce worker exposure. In large processes, such as nickel refining or steel production, general ventilation moves air in and out of the building. The intent is to take nickel and other contaminants out of the work area. For smaller processes, such as welding or electroplating, local exhaust ventilation is preferred. This type of ventilation removes contaminants at the source. There are many ventilation designs intended for welding and electroplating shops (see OHCOW Information Bulletin - Electroplating: A Focus on Chrome Plating).

Other engineering controls include adding a layer of foam or other material to tanks holding electroplating or other nickel solutions. The layer of foam reduces the amount of mist released from the tank.

If engineering controls do not provide complete protection, personal protective equipment is required. Respirators may be required during welding or other processes. If a leak occurs during handling of nickel carbonyl, supplied-air respirators are needed. Gloves and other protective clothing should be worn when working with soluble nickel compounds or nickel solutions. There are guidebooks which help in choosing the right respirators, gloves and other protective clothing.

EVALUATION OF CONTROLS

The concentration of airborne nickel can be measured by air sampling. Because of the difference in potential health effects, the form of nickel (metallic, insoluble or soluble) has to be considered. If the form of nickel is not known, or the air sampling does not identify it, the sampling results should be interpreted as if the most hazardous were present.

Air sampling will not measure skin contact with nickel. Air sampling usually will not consider short, high exposures that might occur during metal plating or other work. If these might occur, air sampling should be done for just these periods instead of the entire work shift.

Medical examinations of the skin, lungs and nasal passages may detect early signs of toxic or allergic reactions to nickel. Early detection of any of these problems means that changes in the workplace are needed. Making these changes should allow workers to continue their work without harming their health.

If a worker believes that his/her health has been affected by nickel, he/she should see a doctor and inform the Joint Health and Safety Committee or the health & safety representative. The Occupational Health Clinics for Ontario Workers Inc. can assist in the medical and occupational hygiene evaluations for nickel exposure.

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Every effort has been made to ensure the accuracy of the information in this workbook. OHCOW assumes no responsibility for how this information is used.
Revised December 1998