Measures against nickel allergy
Since the number of people complaining of metal allergy symptoms is increasing in recent years, we have described countermeasures and cautions for nickel, which is the top cause of metal allergy.
Daio Seisakusho has been handling more metal products than before, but since the number of people who are complaining of metal allergy symptoms is increasing in recent years, nickel-free is one of the causes of metal allergy. We will continue to promote productization to create products that are kind to people.
What is metal allergy?
Metal allergy is called allergic contact dermatitis, and when the metal used in daily sundries and accessories comes into contact with the human body, the metal that is slightly ionized by sweat and the like melts out and When it enters and exceeds the tolerated capacity of the person, it is judged as a foreign substance by the action of immunity, causes a rejection reaction (sensitization), and causes inflammation such as red swelling, rash, or itchiness of the skin. is.
In particular, be careful as accessory piercings that open the earlobe and touch the skin are often troublesome. The same applies to necklaces, bracelets, rings, etc. that come into direct contact with the skin.
In addition, it is relatively hard to develop in winter, but it is easy to develop in summer when it is easy to sweat.Since sweat is acidic and there are metals that are weak against acid, the combination of metal worn on It is thought that one of the reasons is that it is easily ionized by the chlorine ions inside and melts out.
What are metals that are prone to metal allergies?
What kind of metal can cause metal allergy (allergic contact dermatitis)?
It means whether sweat is a metal that is weak against acid and easily dissolves.
Nickel is generally the most common cause of metal allergies (allergic contact dermatitis).
One of the reasons is that nickel is weak against acid and chlorine ions in sweat have a strong effect of dissolving nickel.
Another reason is that nickel itself is very often used in the case where it is contained in the matrix of the industrial product (material itself) or used on the surface (plating etc.). In our products as well, nickel-plated silver key chains and mobile phone strap parts are used.
It seems that some people often say that they are allergic to gold (K18) or silver (SV925), but in that case, it is rare that they are allergic to gold and silver, It is highly possible that the auxiliary materials added for industrial reasons, such as increasing the workability and hardness, contain metals that may cause metal allergies. Of course, even gold and silver may have metal allergies, so please be careful.
Legal regulations, etc.
Although there are no legal regulations in Japan yet, in the EU, products that come into direct and long-term skin contact with nickel have a release amount of 0.5 μg/cm XNUMX.2/ There are laws such as not exceeding a week, the European Directive restricting the use of Nickel (EC Directive European Directive Annex 94/27/EC), and the manufacture and import of products that do not comply with this It is prohibited.
1) Insert into the ear or other parts of the human body, whether or not they are immediately removed, while the wound created by piercing the body to pierce the body does not epithelize Nickel shall not be used in the post assembly.
However, this excludes cases where the post assembly is made of a uniform material and nickel is less than 0.05% of the total mass.
2) In the following products, which are expected to come into direct and long-term contact with the skin, if the release of nickel from the skin-contacting parts of these products is 0.5 μg/cm2Above, nickel shall not be used in these products.
- Necklace bracelet chain anklet ring
- Watch case band stop
- Rivet Rivet Button Fastener Zipper When metal marks are used on clothing
3) The products listed in 2) above are covered with a non-nickel coating, which is 2 μg/cm per week for at least 0.5 years of normal use.2Nickel shall not be used in these products unless a sufficient release of nickel that does not exceed the limit can be secured.
Furthermore, the products of 1), 2), and 3) shall not be placed on the market unless they meet the requirements of each section.
What is nickel
Nickel has a risk of causing allergies, but it is also a metal often used in products familiar to everyone.
Most of our everyday items are key chains and cell phone straps, so most of the silver-colored metal parts are nickel-plated on the surface.Stainless steel used in tableware and kitchens, as well as metals such as white copper of 50 yen, 100 yen, 500 yen coin High proportion of nickel is used.
Nickel plating is widely used for metal miscellaneous goods, but for accessories and accessory parts that often come into direct contact with the skin, nickel-free plating (nickel-free plating) that has a color and luster like nickel is also used. ..
Recently, many shops are now lined with "nickel-free plating" so that people who are prone to metal allergies can safely select products.
Nickel-free plating is a plating that has the same luster and corrosion resistance as nickel plating without using nickel, mainly for the purpose of preventing allergies to nickel contained in metal accessories.
There are many people who confuse nickel-free plating with plating for meter reading devices, so I would like to touch on plating for meter reading devices as well.
For the problem of sewing needles mixed in clothing and other sewing products, we use a needle detector to inspect the presence of needles at the factory. At this time, if there is iron or nickel attached to the magnet, it will react with the meter, so it is necessary to make accessories such as buttons and metal fittings that do not have magnetism.
Plating for needle detectors is electroless nickel plating that does not have magnetism so that it will not react with the needle detectors.
Please refer to the above PDF document for nickel-free plating and plating compatible with the meter.
To prevent metal allergies
To prevent metal allergies,
1) Take an allergic reaction test (patch test) at the hospital and do not wear any metal that may cause allergies.
2) Gold, silver, platinum, and other precious metals are metals that are less susceptible to metal allergies. Please select products that do not use alloys such as nickel or plating.
3) Chlorine ions in sweat have a strong effect of dissolving metals, so it is also important to wipe off when sweating.