Nickel in water: origin, allergies, risks, and filtration
Nickel is a metal naturally present in the Earth's crust. In drinking water, it can come from certain geological formations, industrial activities, as well as water contact with faucets, fittings, metal coatings, or alloys containing nickel. Its concentration can increase when water remains in contact with these materials for long periods. Excessive exposure is notably capable of causing or worsening reactions in certain individuals already sensitized to nickel.
- Chemical symbol
- Ni
- Atomic number
- 28
- Family
- Transition metal
- EU value
- 20 µg/L
What is nickel?
Nickel is a chemical element with the symbol Ni and atomic number 28. It belongs to the transition metal family. In its pure state, it appears as a hard, silvery-white metal that is resistant to corrosion.
In the environment, nickel is generally associated with other elements in ores, rocks, and soils. In water, it can be present in a dissolved state, associated with particles, or bound to organic matter.
The chemical form of nickel influences its mobility, bioavailability, and the necessary treatment method. Soluble nickel compounds can be transported in water more easily than nickel fixed to particles.
Keep in mind: the presence of nickel at the tap does not necessarily mean the water source is contaminated. Some nickel may be released locally by materials inside the building.
What is nickel used for?
Nickel's resistance to corrosion and high temperatures explains its use in many industrial sectors.
- manufacture of stainless steels;
- production of heat- and corrosion-resistant alloys;
- metal coatings and surface nickel plating;
- manufacture of rechargeable batteries;
- production of automotive and aeronautical parts;
- manufacture of coins;
- electrical and electronic equipment;
- catalysts used in certain chemical processes;
- faucets, valves, fittings, and industrial equipment;
- manufacture of certain jewelry and metal objects.
Discharges linked to mining, metallurgy, surface treatment, the combustion of certain fuels, and industrial waste can contribute to its presence in the environment.
How does nickel get into water?
Geological origin
Nickel is naturally present in certain rocks and soils. Their weathering can release small amounts of nickel into groundwater, rivers, and reservoirs.
Mining and industrial activities
The extraction and processing of ores, metallurgy, alloy manufacturing, surface treatment, and certain chemical activities can locally contaminate soils and water.
Urban waste and debris
Wastewater, sludge, electronic waste, batteries, and industrial residues can also contribute to the dispersal of nickel in the environment.
Materials in contact with water
In buildings, nickel can be released by faucets, fittings, nickel-plated coatings, certain alloys, or metal equipment. This leaching depends on the material's composition and the water chemistry.
Why can faucets release nickel?
Sanitary equipment can contain nickel in its alloy or coating. When water sits for several hours without flowing, the contact time with metal surfaces increases. The concentration measured at the first draw in the morning can then be higher than that of the supply water.
Leaching can be notably influenced by:
- water stagnation duration;
- age and quality of the faucet or fitting;
- condition of the metal coating;
- water pH;
- temperature;
- chloride concentration;
- water hardness and alkalinity;
- presence of other metals in the installation.
After a long period of stagnation, letting the water run until it becomes noticeably cooler can reduce exposure to locally released metals. The water flushed out this way can be collected for cleaning or watering plants.
A high concentration found only in the first draw, but low after flushing, generally points to a source within the faucets or internal plumbing.
Does stainless steel release nickel into water?
Many stainless steels contain nickel, notably associated with iron and chromium. This composition improves their corrosion resistance and stability.
High-quality stainless steel, suitable for contact with water and used under normal conditions, possesses a protective passive layer that strongly limits metal leaching. The presence of nickel in the alloy therefore does not mean that it will be released in significant quantities.
However, leaching can be promoted by unsuitable material, a damaged surface, high acidity, a high chloride concentration, the use of corrosive products, or abnormal conditions of use.
Do not confuse the presence of nickel in the composition of stainless steel with automatic water contamination. Only a water analysis can determine the amount actually released.
What are the health risks of nickel?
The effects of nickel depend on its chemical form, the dose absorbed, the duration of exposure, and individual sensitivity.
For ingestion exposure, the critical effects studied include skin reactions in previously sensitized individuals and, at higher doses, various general effects observed in toxicological studies.
One-time exposure to a very high amount of soluble nickel salts can cause digestive disturbances, such as nausea, abdominal pain, vomiting, or diarrhea.
The concentrations usually observed in drinking water are much lower than the doses associated with acute intoxication. Risk management primarily concerns repeated exposure, a confirmed exceedance, or a particularly sensitive individual.
What is the link between nickel and allergies?
Nickel is one of the most frequent causes of contact allergy. Sensitization generally occurs after repeated skin contact with objects containing or releasing nickel, such as certain jewelry, buttons, watches, or metal accessories.
In a sensitized person, the ingestion of a sufficient amount of nickel can sometimes trigger or worsen skin manifestations. This reaction is sometimes referred to as systemic nickel contact dermatitis.
Possible manifestations include:
- eczema or worsening of existing eczema;
- redness;
- itching;
- skin lesions on the hands or other parts of the body;
- reactivation of previously affected areas.
A skin allergy to nickel does not automatically mean that drinking water will provoke a reaction. The response depends on the amount ingested and each person's own sensitivity. A diagnosis and a potential low-nickel diet must be managed by a healthcare professional.
Is nickel in water carcinogenic?
Certain nickel compounds are recognized as carcinogenic in the context of occupational exposure, mainly through the inhalation of dust, fumes, or aerosols containing nickel.
These data should not be directly applied to the ingestion of low concentrations in drinking water. The route of exposure, chemical form, dose, and exposed organs are different.
The World Health Organization's guideline value for drinking water is based on effects related to oral exposure, not on occupational risks associated with inhalation.
Important distinction: saying that certain nickel compounds can be carcinogenic via occupational inhalation does not mean that water containing a low trace of nickel automatically presents the same risk.
What are the environmental risks of nickel?
Nickel is naturally present in soils and sediments. However, an excessive concentration can become toxic to certain aquatic organisms, plants, and microorganisms.
Its mobility depends notably on pH, mineral composition, organic matter, and oxidation-reduction conditions. In more acidic waters, nickel can become more soluble and bioavailable.
It can accumulate in sediments or be absorbed by certain organisms. Ecotoxicological effects vary according to the species and water hardness.
What is the limit value for nickel in drinking water?
| Organization or regulation | Value | Interpretation |
|---|---|---|
| European Union | 20 µg/L | Mandatory parametric value provided by the European Drinking Water Directive. |
| World Health Organization | 70 µg/L | Health guideline value for nickel in drinking water. |
| United States – EPA | No mandatory federal limit in effect | The former 0.1 mg/L limit was vacated by a court decision in 1995. Some historical EPA documents still mention it but specify that it is no longer applicable. |
20 µg/L corresponds to 0.020 mg/L and 70 µg/L to 0.070 mg/L.
The European value is more restrictive than the WHO guideline value. A concentration between 20 and 70 µg/L may therefore exceed the European regulatory value, even if it remains below the WHO guideline.
How to analyze nickel in water?
Nickel cannot be reliably identified by the color, taste, or odor of the water. An analysis by a competent laboratory is required.
Techniques such as inductively coupled plasma mass spectrometry or atomic absorption spectrometry make it possible to measure very low concentrations.
When a source linked to faucets is suspected, several types of sampling can be useful:
- a first-draw sample after several hours of stagnation;
- a sample after flushing the water;
- a sample taken directly from the water supplied upstream of the building;
- a comparison between several faucets;
- a measurement before and after the filtration device.
Comparing the results allows you to determine whether the nickel comes primarily from the resource, the public water system, the interior plumbing, or a specific piece of equipment.
Which technologies can reduce nickel in water?
Treatment depends on the concentration, the chemical form of the nickel, the pH, the water hardness, and the presence of other contaminants.
Technologies that may be used include:
- adsorption onto suitable media;
- ion exchange;
- reverse osmosis;
- nanofiltration;
- chemical precipitation for collective installations;
- coagulation followed by filtration;
- certain media combining activated carbon, minerals, and ion exchange;
- replacing plumbing fixtures when they are the source.
Standard activated carbon is primarily used for organic compounds, chlorine, and taste and odor issues. Its effectiveness against dissolved nickel depends heavily on its formulation and the supplementary media present in the cartridge.
A cartridge should only be considered effective against nickel if this performance is supported by a clearly identifiable test report. The general claim "reduces heavy metals" is not sufficient on its own to determine performance regarding nickel.
After installing a treatment system, a comparative analysis before and after filtration is the best way to verify its effectiveness under real-world conditions of use.
Nickel performance testing for Monderma Imperial filters
Nickel is among the heavy metals studied in the performance documents for Monderma Imperial GF and Imperial AMB filters, tested by Envirotek Laboratories in the United States according to performance protocols inspired by NSF/ANSI standards 42 and 53.
Nickel: contaminant included in performance tests
The available summary documents group nickel with lead, mercury, cadmium, arsenic, chromium, aluminum, copper, iron, zinc, and manganese.
The general range provided for the metals studied is between 95% and 99.9% reduction, depending on the contaminant and test conditions.
This collective range should not be presented as the exact individual rate for nickel until the detailed analytical line showing its initial and final concentration has been verified.
Cautious interpretation: nickel is indeed mentioned among the substances tested, but a performance range grouping several metals does not allow for the automatic attribution of the minimum, maximum, or average value to nickel.
Performance obtained in the laboratory may vary in real water based on initial concentration, pH, hardness, flow rate, contact time, competing contaminants, maintenance, and the state of wear of the cartridge.
Testing performed according to NSF/ANSI protocols does not necessarily mean the complete filter has official NSF certification for nickel reduction. Performance testing and certifications must be distinguished.
View Monderma certifications and analysesFrequently asked questions about nickel in water
What is the European limit for nickel in water?
The European directive sets a parametric value of 20 µg/L, or 0.020 mg/L.
What is the WHO guideline value?
The World Health Organization has set a guideline value of 70 µg/L, or 0.070 mg/L.
Does the EPA set a mandatory limit for nickel?
No. The former U.S. federal limit of 0.1 mg/L was repealed in 1995. Some older EPA documents still mention it but clarify that it is no longer legally applicable.
Can plumbing fixtures contaminate water with nickel?
Yes. Certain faucets, fittings, or metal coatings can release nickel, especially when water remains stagnant for long periods.
Should I let the water run in the morning?
After several hours of stagnation, letting the water run until it feels colder can reduce the amount of metals originating from interior plumbing. The flushed water can be collected for other uses.
Does stainless steel necessarily release nickel?
No. Quality stainless steel has a passive layer that strongly limits leaching. The amount released depends on the type of alloy, the state of the surface, and the water's composition.
Can nickel in water cause eczema?
In some individuals already sensitized to nickel, sufficient ingestion can sometimes trigger or aggravate skin manifestations. However, not all allergic people react to the low concentrations present in water.
Does boiling water remove nickel?
No. Boiling does not remove dissolved nickel. Evaporating part of the water can even slightly concentrate substances that do not evaporate.
Can you detect nickel by taste or color?
No. Clear water with no particular taste or odor can still contain nickel. A laboratory analysis is necessary.
Does an activated carbon filter remove nickel?
Not systematically. Effectiveness depends on the media formulation, the presence of supplementary resins or minerals, pH, and contact time. You must check the test results specific to the cartridge.
How can I tell if the nickel is coming from the faucet?
You can compare a sample taken from the first flow after stagnation with a sample taken after several minutes of flushing. A significant drop can indicate an origin located in the faucet or interior plumbing.
Associated contaminants
Nickel can be tested for alongside other metals originating from soils, industrial activities, pipes, or metal alloys.
Scientific and administrative sources
This factsheet is based on public bodies, international institutions, and governmental scientific databases. No commercial blogs, comparison sites, or affiliate sites are used as primary health sources.
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World Health Organization – Nickel
Official factsheet presenting the guideline value, sources of nickel in
water, health effects, and treatment processes.
Consult the official WHO factsheet -
WHO – Nickel in drinking water
Reference scientific document dedicated to the exposure, toxicology,
analysis, and treatment of nickel.
Consult the WHO scientific document -
European Union – Directive (EU) 2020/2184
Official text setting a parametric value of 20 µg/L for nickel in water
intended for human consumption.
Consult the directive on EUR-Lex -
Environmental Protection Agency – Nickel
Historical technical factsheet clarifying that the former U.S. federal
limit was repealed in 1995 and that no mandatory federal limit is
currently in effect.
Consult the EPA technical factsheet -
PubChem – National Institutes of Health
Official data on the symbol, atomic number, properties, and uses of
nickel.
Consult the PubChem factsheet -
Monderma – Certifications and laboratory analyses
Reports, performance documents, and information related to Monderma
Imperial filters.
Consult Monderma certifications and analyses
