chemistry

Nickel Directive

Nickel Directive is a chemistry topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Nickel Directive rather than just read about it. In short: The Nickel Directive was a European Union directive regulating the use of nickel in jewellery and other products that come into contact with the skin. Since 1 June 2009, it has been subsumed into the REACH Regulation, specifically item 27 of Annex XVII to that regulation.

Key takeaways

Nickel Directive belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Nickel Directive to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Nickel Directive from memory before moving on to harder problems.

Reference excerpt

The Nickel Directive was a European Union directive regulating the use of nickel in jewellery and other products that come into contact with the skin. Since 1 June 2009, it has been subsumed into the REACH Regulation, specifically item 27 of Annex XVII to that regulation. Nevertheless, the term Nickel Directive is still used to refer to the restrictions on nickel usage and the prescribed test method for quantifying nickel release from products EN 1811. Allergy to nickel is a common cause of contact dermatitis, with roughly 10% of the population in Western Europe and North America being sensitive to nickel. Initial sensitisation frequently occurs from jewellery such as ear studs and other body piercings, and nickel allergy is more prevalent among women than men. Once sensitised, an individual can develop contact dermatitis from shorter term contact with nickel-containing products: this is a particular problem given the use of nickel in coinage, such as the European one- and two-euro coins and the Canadian five-cent piece. This led to moves by two European countries to prevent the initial sensitisation of jewellery wearers by limiting the use of nickel in piercing studs and other products which are in prolonged contact with the skin, and then to the European Union Nickel Directive in 1994. The Nickel Directive imposes limits on the amount of nickel that may be released from jewellery and other products intended to come into direct and prolonged contact with the skin. These limits, known as migration limits, are:

0.2 μg/cm2/week for post assemblies which are inserted into pierced ears and other pierced parts of the human body; 0.5 μg/cm2/week for other products intended to come into direct and prolonged contact with the skin. Nickel release is measured by a test method known as EN 1811, which involves placing the object in an artificial sweat solution for one week, then measuring nickel by atomic absorption spectroscopy or any other appropriate technique (e.g. ICP-MS). Other, equivalent test methods may also be accepted. Wear and corrosion can be simulated by a method known as EN 12472.

Research A study published in the March 2004 issue of the British Journal of Dermatology, which examined the effects of nickel exposure from coins, cited the directive as an important policy, and recommended Nordic gold as a better material for minting coins.

Notes and references

Notes

References

Illustrations

Worked examples

Example 1 — a first encounter with Nickel Directive

Start with the simplest possible case. Write down what Nickel Directive claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Nickel Directive before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Nickel Directive ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Nickel Directive

In research: Nickel Directive appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Nickel Directive in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Nickel Directive is common in secondary-school and first-year university syllabi. It links to neighbouring topics European Union directives, Nickel, Regulation of chemicals in the European Union, so understanding it makes those chapters shorter.
In everyday life: Look for Nickel Directive outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Nickel Directive in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Nickel Directive means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Nickel Directive out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Nickel Directive in simple terms?

Why does Nickel Directive matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Nickel Directive?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Nickel Directive.