The Bench · N° 37

Nickel in watches: what the release limit measures

Skin-contact rules focus on how much nickel a product releases over time, not simply whether an alloy contains nickel. Coatings must also remain effective through simulated wear.

Hen & Mills Editorial · 4 min read · 13 September 2026

A stainless-steel watch can contain nickel and still comply with rules intended to reduce nickel allergy. The key measurement is release, not total content.

For items intended to remain in direct and prolonged contact with skin, European rules limit the amount of nickel that may migrate from the surface. A separate, higher limit applies to posts inserted into pierced body parts.

The familiar figure for ordinary prolonged skin contact is 0.5 micrograms per square centimetre per week under the specified test framework.

Why nickel is used

Nickel contributes to the structure and corrosion behaviour of many stainless steels. Austenitic grades commonly used in watch cases and bracelets can contain a meaningful proportion.

The atoms are part of the alloy rather than a loose surface dust.

For most wearers, that composition causes no problem. People sensitised to nickel can react when sufficient nickel ions reach the skin.

Content and release are different

An alloy can contain nickel while releasing only a small amount under test conditions. Conversely, a thin surface treatment over a nickel-rich base may become a concern if it wears through.

This is why a compositional percentage alone does not determine compliance for prolonged skin contact.

The surface condition, corrosion resistance and exposure environment control how readily nickel migrates.

What the weekly unit means

The limit is expressed as mass released from a defined surface area over a defined time. It is not the amount of nickel allowed inside the whole case.

A laboratory method exposes the sample to an artificial sweat solution and measures the nickel released.

Results are interpreted with the method's uncertainty and regulatory provisions. A home spot test is not equivalent to that quantitative assessment.

Coated components

A coating can reduce contact between skin and a nickel-releasing base. Regulations require coated items to remain below the relevant release limit after a wear and corrosion simulation for the specified period.

The principle is important: a compliant new surface should not become non-compliant after trivial use.

Actual coating life still depends on thickness, adhesion, contact points and the wear the watch receives.

Where contact occurs

The caseback, bracelet, clasp and crown can touch skin. Sweat may also move dissolved material from one area to another.

The case middle may contact the wrist less often but can touch during movement. A leather or fabric strap changes contact patterns without isolating every metal component.

A product assessment considers the parts intended for direct and prolonged contact.

Stainless-steel grades

316L is widely used in watchmaking and contains nickel. Some brands use 904L-family steel, which also contains nickel and is selected for its own corrosion and finishing properties.

Neither name means nickel free. Good corrosion resistance can help limit release, but the finished component and test decide the relevant result.

Titanium and some other materials may be alternatives for sensitive wearers, though complete watch construction still needs checking.

Allergy and irritation

Nickel allergic contact dermatitis can cause itching, redness, dryness or blistering where exposure occurs. Sweat and friction can worsen irritation.

Similar symptoms can come from soap residue, strap materials, trapped moisture or other allergens. Appearance alone does not identify the cause.

A persistent or severe reaction deserves advice from a qualified health professional rather than repeated self-testing with the same watch.

What a dimethylglyoxime test can show

Consumer nickel spot tests commonly use dimethylglyoxime, which can produce a colour response when accessible nickel is present.

They can be useful screening tools, but technique, surface condition and detection limits affect the result. A negative spot test does not reproduce the official release test.

Do not apply an unapproved chemical to a valuable watch without understanding whether it can stain or damage the finish.

Sweat and corrosion

Chlorides, moisture and skin chemistry affect metal surfaces. Areas beneath a tight bracelet can remain warm and damp, increasing exposure.

Regular gentle cleaning and complete drying can reduce residues. The watch's water resistance and the manufacturer's care guidance determine whether rinsing is appropriate.

Cleaning cannot change an incompatible material into a suitable one for a sensitised wearer.

Scratches and wear

A solid stainless-steel component does not contain a nickel-free outer layer unless it has been specially coated or treated. A scratch may expose fresh alloy but does not necessarily produce an immediate regulatory failure.

On a coated component, a deep scratch can expose the substrate and change release behaviour locally.

Repeated abrasion at clasp edges and bracelet links deserves attention if a coating is part of the protective claim.

What to ask a manufacturer

Ask whether the complete watch has been assessed for nickel release under the relevant market rules, not merely whether the steel is surgical or high grade.

If the product is coated, ask what durability testing supports the skin-contact claim. If you have a known allergy, request the materials of the caseback, crown, clasp and bracelet separately.

Clear test information is more useful than a broad hypoallergenic label.

Choosing for sensitive skin

Uncoated titanium can be a practical option for many people, as can suitable ceramic with carefully selected metal hardware. Some nickel-free stainless alloys also exist.

A non-metal strap does not solve exposure if the caseback and buckle remain problematic.

Individual medical history matters, so a material tolerated by one wearer is not a guarantee for another.

The rule in plain language

The half-microgram figure is a migration limit for a square centimetre of skin-contact surface over a week. It is not a cap on the nickel mixed into a watch case.

That distinction explains why nickel-bearing stainless steel remains common in compliant products.

For an owner, the useful evidence is the tested release from the finished surface and how that surface holds up with wear.