What does hypoallergenic mean?
The term hypoallergenic simply means less likely to cause reaction. There is no formal testing or medical definition. Instead when talking about jewellery, hypoallergenic jewellery is made from materials less likely to cause a reaction.
If you have an allergy to some jewellery most of the time its either Nickel and Copper. So avoid jewellery that contains these, which is easier said than done! For example, surgical stainless Steel contains 12% Nickel, Sterling Silver contains 7.5% Copper and 18k Gold can contain 25% of anything! Any metal mixed with others is called an alloy.
So what metals are hypoallergenic? And are any better than others?
Unalloyed inert bio-compatible metals, such as Tantalum, Titanium or Niobium are the least likely to cause a reaction and are used in medical implants for this reason. Other materials called "hypoallergenic" may be in a grey area such as stainless steel. Below is a quick overview
The best hypoallergenic metals for jewellery:
Titanium is a natural element and extremely hard, 3x the strength of steel but 40% less weight.
Titanium grade 1-4 are pure grades. Grade 1 being the softest and most malleable. These grades are extremely good for things like earring findings, and wire work due to easily being formed.
Titanium grades 5 and 23 (Ti-6Al-4V) are most common for body jewellery, piercings, belly bars etc. Grade 5 is the most widely used grade of titanium around the world. Both grades 5 and 23 are titanium alloys, adding typically 6% aluminium and 4% vanadium, to create a grade significantly stronger than pure titanium. Titanium alloys are considered biocompatible, and these are used for implants. Titanium is long lasting, corrosion resistant and non toxic.
Niobium is another inert metal and is softer than titanium. It's added to other metals to give strength however for jewellery its mainly found in its pure form.
Niobium has a smoother surface finish than titanium on the microscopic level, for things like earring posts, this can help avoid irritation when passing through ears. Its less common to find than titanium and so often a higher cost. Like titanium it can be anodised a vast choice of colours. Niobium grades 1-2 are pure grades. Grade 4 is an alloy with 1% zirconium.
Tantalum is an element with exceptionally good corrosion resistance, even better than titanium. Its growing in popularity in medical applications because the properties of Tantalum closely match that of human bone allowing the bone to grow into implants better than titanium.
One down side is that its roughly 4x the density of Titanium, making it unsuitable for large pieces.
For Jewellery its still uncommon, even through its highly malleable, a great advantage. Not only is it a rarer element, its highly costly to produce but like Titanium and Niobium its great for anyone wanting something hypoallergenic.
We can only say 24k Gold is hypoallergenic as anything else is an alloy. Read below for lower karat Gold.
Rhodium is one of the rarest and thus most precious metals. Its used to plate white gold, giving it a whiter colour and used to alloy with platinum and palladium increasing their hardness. Rhodium is pretty much only used as a plating. Its also non-reactive so the plating forms a barrier between nickel alloyed white gold and the skin. Over time this wears off and exposes the skin to the alloy and possibly the nickel. If this happens to your white gold, you will see a change in colour to a more yellow tinge. To fix it you can go to a jeweller and get a new layer of rhodium plating added.
Platinum in jewellery is usually found as an alloy at normally 90-95% pure. So only a 5-10%mix. Its one of the precious metals and with 24k Gold one of the most expensive hypoallergenic metals. Its rarer than Gold and denser so you get less Platinum for your money.
Its very inert so has great corrosion resistance which means it doesn't tarnish or need a plating. In the medical industry its used for finer parts in implants, such as within pacemakers.
For jewellery pure platinum is too soft so alloying it is necessary. Several metals could be used such as Ruthenium, Iridium, Palladium or Cobalt depending on the manufacturing process and each type will differ in hardness. Platinum is often called hypoallergenic even as an alloy, although cobalt alloys in jewellery can cause a Nickel like reaction. Its very rare but some people have had a reaction to Platinum. One study (Dermatitis. 2008 May-Jun;19(3):146-7. )patch tested 446 people, 2 had a reaction.
Palladium is quite a new precious metal, best know for looking very much like platinum but being much more affordable. Its in the same group of metals as platinum so shares much the same properties. It doesn't tarnish, and is used in jewellery alloyed with ruthenium or iridium with the same amount of purity around 95%.
The main difference is that palladium is slightly lighter then platinum and slightly harder.
Palladium is quite inert and although reaction to it is rare, there still have been some cases where people have had reactions. A 10 year retrospective study on Palladium showed it was more common for an allergic reaction to occur from oral dental implants, than from skin contact. It concluded that in jewellery it was extremely rare.
Its not a metal that is normally thought of for jewellery but as its light weight and easy to cast and work with, why not? Aluminium is the 3rd most abundant element on the planet, and its main advantage is its incredible lightness, lighter than titanium but just not as strong.
For jewellery it can be anodised a wide range of colours and polished to a give a great shine. The anodisation process occurs with dyes rather than changing the oxide layer (such as Titanium or Niobium). Given the light weight it can be used to create comfortable larger pieces, such as bangles/necklaces with many links.
Its advantage over Titanium, Niobium and Tantalum is that its fairly cheap tho as mentioned not as strong
The main metals in jewellery that cause a reaction
“Its turns your skin green!” followed by “Copper jewellery is good for you” are most shouted about with copper and with good cause. So why. Well Copper is a pure element and used because its a very soft metal, making it great for wire wrapping. When exposed to air Copper forms a patina and darkens. The green stains are from the oxidisation that happens when the copper reacts with sweat and other chemicals. The amount and how quickly skin turns green depends on your own body chemistry. Some people experience very little reaction.
If you really don't want copper to stain the skin you could coat it with a spray of clear UV stable lacquer, but we wouldn't call this hypoallergenic as all lacquers wear off especially in contact with the skin
Copper in any jewellery is likely to react with skin causing the unsightly green/black colouring this is more common with acidic skin.
Boooo… Nickel allergy is quite common. Its the material most people assume they are allergic to, and most often they are right! Although, you can also have a reaction to other metals. For many years Nickel was used as an alloy to harden most metals for jewellery making, especially Gold.
Common side effects are itching and redness, dry skin, blisters and worse. If this happens, no matter what jewellery you are wearing its best to remove the piece.
If you have developed a Nickel allergy, you can also have a reaction to other metals your body mistakes for nickel. This can happen when wearing things like Palladium with Cobalt in.
Metals that are more likely to cause a reaction to sensitive skin.
Gold is yes and no. I've often heard “I can only wear 18k Gold” and whilst the higher the karat more pure gold jewellery is, only 24k Gold can be said to be truly hypoallergenic as its not an alloy. However pure gold is hardly ever used for jewellery as its incredibly soft.
The purity of Gold is shown in the karat rating
20 karat = 83% Gold
18 karat = 75% Gold
14 karat = 58% Gold
12 karat = 50% Gold
9 karat = 37.5% Gold
The other metals Gold jewellery is alloyed with depends on the colour required and can vary for each piece, and there are no rules about which other are metals used.
Yellow gold is mostly alloyed with Copper and Silver, although Zinc and nickel can be used.
White gold is often alloyed with other white metals such as Nickel, Silver, Zinc. Palladium is often used in newer pieces as more people become aware of Nickel allergies. To improve the colour Rhodium plating is added and has the benefit of protecting the skin. See Rhodium above.
Rose gold is often Gold combined with Copper to give the distinctive reddish hue.
Most reactions to Gold jewellery occurs due to the Nickel added to make the piece harder. Always aim for a higher karat piece foe less reaction however. We could only say 24k Gold is hypoallergenic as everything else is a mix.
Silver is very soft metal and therefore mixed with other metals to help work the material and improve durability. Sterling silver is 92.5% silver, which the 925 mark means, mixed with other metals normally copper or zinc that some people can still have a reaction to.
Then the copper in the silver may react and create that weird green/black stain around the piercing. Severe reactions can be inflamed and dry skin, sometimes even breaking into blisters.Silver Jewellery also tarnishes due to the copper reacting to the air and skin. This tarnishing can then rub onto your skin causing black marks.
Keep silver jewellery clean and polished to limit the tarnishing, and the tarnishing shouldn't be an issue.
There are over 150 grades of stainless steel. Is strong, doesn't tarnish can be polished easily and is great value. Jewellery in stainless steel is commonly made from 316l or 316lvm and is often called medical grade stainless steel as it doesn't react to the skin….well, for most people.
316 does contain around 12% nickel but meets EU directives on nickel leaching, however it can still cause a reaction for some people with a sensitive nickel allergy.
For more information on stainless steel visit our “Is stainless steel hypoallergenic?” page
Its a mix of Copper and Tin, sometimes mixed with other metals in lesser amounts such as Aluminium, or even Nickel. If you are looking for a bronze bracelet then it is worth seeing if they mention the composition.
The main thing with Bronze is it reacts when in contact with the skin for a while. It's the Copper content that will cause a oxidation layer and turn areas of the skin green.
Tungsten is extremely hard, dense, and very tough, this density means Tungsten rings feel very heavy for the size. Straight Tungsten rings are more likely to include the element Cobalt, which can be an allergen for some skin types.
In jewellery its mostly alloyed with carbon which makes it even harder. This is tungsten carbide. One big advantage is tungsten carbide jewellery is very scratch resistant. Some Tungsten Carbide could be alloyed with Cobalt too, so best check the composition when buying.
A down side is that Tungsten Carbide jewellery contains approx 15% nickel as a binder.
One myth is Tungsten Carbide rings cant be removed in an emergency. Whilst this was probably true many years ago its not any more but should still only be done by a professional.
Brass is a Copper and Zinc alloy. Sounding bad already right. Well yes, the Copper content will have the reaction stated above, turning skin green. Brass is mainly used as a base metal is it plates easily. Unfortunately when this plating wears thin it can case a reaction.
There is no 100% certain rule as everyone's body chemistry is different. When going through the skin we would recommend the metals less likely to cause a reaction: Titanium, Niobium and Tantalum, and the purer grades the better. Then the alloys, Platinum and Palladium, reactions start to become more common as we get to Stainless Steel and 18k Gold.
You can limit the likelihood of a reaction, but only by being informed about the materials used to make the pieces you buy and then trying it. That way you can build the knowledge of your bodies reactions, and if your still uncertain we offer a 100 days no worries guarantee for complete peace of mind.