Nickel
Ni·Affects skin,, lungs
A common industrial metal used in stainless steel, plating, and batteries. Triggers contact dermatitis in sensitized people and irritates airways through inhaled shower vapor.
Ni
EPA limit
No federal MCL (EPA standard was remanded in 1995; some states set their own limits)
Most at risk
Nickel-sensitized individuals, residents near plating or battery manufacturing sites, well users in stainless steel manufacturing corridors
Found in
City water · Well water · Industrial areas
AquaOx filters
YesKDF-55 + activated carbon
What it does to you
Health effects
Skin sensitization is the most common nickel-related health effect. An estimated 10 to 20 percent of the general population is nickel-allergic, and contact with nickel in shower water or through dishes can trigger eczema, dermatitis, and rashes in sensitized people.
Inhaled nickel (most relevant to shower vapor and to occupational dust exposure) is classified by IARC as carcinogenic to humans, primarily for lung and nasal cancers in industrial settings. Drinking water exposure is far less concerning than inhalation, but chronic high doses can stress the kidneys and the gastrointestinal tract.
Nickel is also a trace nutrient at very low levels. The toxicity concern is about exceeding background, not about any presence at all. The original federal MCL of 0.1 mg/L was remanded in 1995 on procedural grounds, and the EPA has not reissued one; several states (including Minnesota and California) maintain their own guidance levels.
Where it comes from
How it gets into your water
Nickel reaches drinking water primarily through industrial discharge: metal plating and finishing, stainless steel manufacturing, battery production (especially nickel-cadmium and nickel-metal-hydride), and the corrosion of nickel-bearing alloys in plumbing and fixtures. Improperly disposed nickel waste accounts for a large share of contamination at EPA Superfund sites.
Natural sources contribute a small baseline from the weathering of nickel-bearing rock. Coal combustion and the incineration of nickel-containing products (catalysts, batteries) add atmospheric deposition that eventually reaches surface water.
Faucets and fittings that contain nickel can also leach trace amounts directly at the tap, especially when water sits in the line overnight.
Metal plating and stainless steel manufacturing
Major industrial discharge source
Battery production and recycling
Nickel-cadmium and nickel-metal-hydride cells
Nickel-plated fittings
Leaching from faucets and valves
Natural geology
Weathering of nickel-bearing minerals
Find out for yourself
Is it in your water?
Because there is no federal MCL, utilities aren't required to report nickel in the Consumer Confidence Report (though some do under unregulated contaminant monitoring rules). Detectable nickel is common at low levels in both city water and well water.
Private well users near plating operations, stainless steel manufacturing, or battery facilities should test specifically for nickel. Anyone with confirmed nickel contact allergy who sees skin reactions worsening with shower exposure has a behavioral reason to test as well, even at concentrations below the historic 100 ppb screening level.
The fix
How AquaOx filters it
AquaOx's KDF-55 copper-zinc media reduces nickel through redox chemistry, converting soluble nickel ions into insoluble forms that get trapped in the filter bed. The activated carbon stage provides additional adsorption capacity.
Because AquaOx is whole-house, it also filters nickel from your shower and bath water, which matters specifically for the nickel-allergic. If you've ever noticed a worsening rash after showering in a new home or new municipality, water-borne nickel is one of the suspects worth eliminating.