Health Guide: Safe Use of Nickel in the Workplace
A Guide for Health Maintenance of Workers Exposed to Nickel, its Compounds and Alloys (May
1997)
This page is a brief introduction to "Health Guide: Safe Use of Nickel in the Workplace." The Guide addresses
the health and safety of those who are exposed to various types and forms of nickel-containing materials in
the workplace.
It is not intended to be relied upon as a definitive or exhaustive statement with respect to all aspects
of the safe use of nickel in the workplace.
The full-length (103-page) version of "Health Guide: Safe Use of Nickel in the Workplace" is available here
as a PDF download (450 kB).
You can also read it online (in HTML format) by clicking
here.
A brief summary of "Health Guide: Safe Use of Nickel in the Workplace" is also available here.
Other sources of information include the scientific literature and the advice of health and safety
professionals.
"Health Guide: Safe Use of Nickel in the Workplace" may already be available in your organization. If not,
your employer can obtain print copies from us.
Introduction
Why We Talk About The Safe Use Of Nickel
What We Mean When We Use The Word Nickel
Nickel Use
Toxicity and Avoidance
Skin Allergy
Lung Or Nasal Cancer
Swallowing Soluble Nickel
Responsibility and Common Sense
Why We Talk About The Safe Use Of Nickel
We address this issue because some nickel-bearing materials have been associated with adverse health effects under certain conditions of exposure. It is therefore important to ensure that measures are taken to minimize potential workplace risks.
What We Mean When We Use The Word Nickel
When the word "nickel" is used by itself, generically, we do not necessarily mean specifically nickel metal. It is a general reference to the element nickel, in any of the many forms it assumes in alloys, compounds and other nickel-containing materials. To avoid confusion we use the generic word sparingly and instead refer as much as possible to nickel metal or to specific nickel alloys, compounds or other nickel-containing materials, especially in reference to health effects. Each nickel-containing substance has its own unique physical, chemical and toxicological properties and thus can be expected to have its own unique effects on the human body. Each exposure situation must be assessed according to its own specific circumstances.
Only about 10% of all the primary nickel produced is used in pure metallic form, mainly for electoplating. Most nickel, at least 80%, is contained in thousands of different alloys including stainless steels, alloy steels and high nickel alloys. Each alloy has properties that are different from the others and from nickel metal. About 5% of primary nickel is consumed in various foundry applications and the remaining 5% in other relatively small uses including chemicals, catalysts, batteries, welding rods, coins, pigments, electronic components and printing inks. All of these nickel-containing materials are different in some respects and may behave differently when they come into contact with or enter the body.
There is a certain perception that materials which are regarded as toxic should necessarily be avoided. Just because something may be toxic, however, does not mean it should be or needs to be avoided. Gasoline is toxic but we use it every day. Chlorine and fluorine are toxic but drinking water is purposely chlorinated and fluorinated to purify and decrease tooth decay. Ammonia is toxic but is a principal component of fertilizer production. The list goes on.
The point is that a substance can be toxic but safe to use, as long as the substance is handled in the right way and exposures are kept to acceptable levels. Gasoline is kept in sealed tanks. Chlorine and fluorine are added to water in low concentrations. Ammonia is combined with other elements to produce compounds that have completely different chemical and physical properties than ammonia.
And so it is with nickel. Certain nickel-containing substances may be toxic under certain conditions but fortunately, such conditions can generally be avoided in the workplace and in the community at large. Two principal adverse health effects have been associated with nickel under certain circumstances -- one is skin allergy and the other is lung or nasal cancer.
It is estimated that as many as 10-20% of women and 1-2% of men have been sensitized to nickel. This tends to occur when there has been both DIRECT and PROLONGED skin contact with nickel metal that can dissolve in sweat and penetrate the skin. By contrast, many nickel alloys, including stainless steels, do not react with sweat and therefore do not cause nickel allergy.
Nickel metal is commonly used as an undercoat in making jewelry. So long as the nickel is adequately covered with precious metals or other materials, sensitization does not occur. It is when the nickel is not covered, as in cheap, nickel-plated earrings or other jewelry, that direct and prolonged skin contact and resulting problems can occur.
Transient contact with nickel metal in massive form, such as coins, for example, is generally not a problem. Then nickel metal must be in contact with skin for long enough to react with sweat and dissolve some of the nickel. The dissolved nickel can penetrate the skin and cause an allergic reaction. Such prolonged contact with nickel metal does not generally happen in the workplace but if it does, as perhaps in a mint, it would be a sensible precaution to wear gloves.
Contact with certain nickel compounds also can be a problem, notably water-soluble nickel salts such as nickel sulfate, chloride and sulfamate. If you work in an electroplating shop or a plant making chemicals, catalysts, batteries, pigments or any other plant that produces or uses soluble nickel compounds or nickel metal in either powder form or aqueous solutions, it is probably advisable to wear gloves.
Nickel allergy is generally recognized by an irritating rash that is usually seen where nickel contacts the body but occasionally may appear elsewhere. The most common form of nickel allergy in the workplace is hand eczema. If you have any such symptoms, consult your physician.
In the past, personnel employed in certain dusty nickel refineries experienced excess rates of lung and nasal cancers. These cancers were predominantly associated with breathing high concentrations, typically 10 milligrams of nickel per cubic metre or higher, or airborne, insoluble oxides and sulfides of nickel, mainly in roasting and sintering operations. Breathing mists or soluble nickel sulfate, typically one milligram nickel per cubic metre or higher, in certain areas of the refineries appears to have aggravated the effects of insoluble particles, and may have had an independent effect in causing elevated levels of respiratory cancer. Most of the workers involved were also exposed to other metals, and many of them smoked.
A recent study has found some nasal cancers in workers who apparently were exposed to soluble nickel compounds at concentrations below one milligram nickel per cubic metre. These workers were also exposed to sulfuric acid-containing mist, which has been identified as a cause of respiratory cancers, including lung and nasal cancers.
The foregoing underscores the need to take adequate protective measures and to follow good housekeeping and personal hygiene practices to minimize the risk of inhaling excessive amounts of nickel-containing materials. In some situations, an employer may recommend or require that protective clothing or equipment, such as respiratory masks, be worn. If you must smoke, it is advisable to wash your hands before rolling cigarettes.
Nickel is a natural constituent of many foods and is also a trace element in drinking water. Thus we eat and drink some nickel every day in our normal diets along with many other minerals.
There is currently no study showing that ingested nickel is a cause of cancer in humans or that it makes people sensitive to nickel. Some research suggests that the condition of some individuals already sensitized to nickel might be aggravated by ingested nickel, but the amounts required to cause an allergic "flare" appear to be several times the normal daily intake of nickel.
If you accidentally swallow too much of a soluble nickel compound such as nickel sulfate or chloride, you could have a gastro- intestinal attack that might be accompanied by vomiting, diarrhea, giddiness or breathlessness. In the unlikely event this occurs, seek medical assistance.
Responsibility and Common Sense
In a growing number of countries, employers are legally required to protect the health and safety of their employees. Even where there is no such legal requirement, employers are recognizing the need to protect the health and safety of their workers.
Labels and material safety data sheets, MSDS, are now commonplace in many workplaces. They warn and inform about the hazards or risks of handling and using various materials, what precautions should be adopted, what remedial action should be taken in the event of accidents and so on.
In addition, employers are increasingly required to adopt both health and exposure surveillance programs and to implement various control measure, as necessary, to ensure safe workplaces and to protect worker health. Details of such health and safety measures are provided in the comprehensive "Health Guide".
Every employee must also share responsibility for health and safety. These should be a priority for everyone. Rules and regulations are fine as far as they go, but nothing can replace the exercise of individual responsibility and plain common sense. Personal hygiene is as important at work as at home, if not more so. Smoking in the workplace should be discouraged or perhaps better, eliminated. Employers and employees both have a role to play in helping to ensure that workplaces are and remain as safe as possible.
