Tuesday, February 17, 2009

Nickel named Allergen of 2008

You may wonder why that watch you purchased leaves you with bright red itchy welts around your wrist, the answer may lie in the Nickel content of your watch case and band. More common ,but not exclusively, found in cheap watches, Nickel is used as it is inexpensive durable and lustrous. Gold (yellow & white), silver, sterling silver, silver plate, palladium, chrome and cobalt often contain nickel.

What is Nickel?

Nickel is a transition metal naturally found in the earth's crust. It is a chemical element. Its chemical symbol is Ni and Atomic Number 28. It is located between cobalt and copper on the periodic table. Its raw appearance is lustrous, metallic and silvery with a gold tinge which takes a high polish. It is a 4.00 on the Mohs Scale of Hardness. Primary Nickel is obtained from mining its ore and from nickel matte. Large production sites include Sudbury Region in Canada which produces 30% of all Nickel, and in many locations in Russia. Nickel is also found in large quantities in nickel-iron meteorites as well as close to the earths core. Closer to the crust it is not as abundant ranking only 24th in order of abundance. Nickel is corrosion resistant, thus used in alloys, as plating in a large variety of applications including watches and jewelry as well as our Nickel coin which is comprised of 75% copper and 25% nickel.

Nickel is not a new transition metal. It has been in use since 3500 B.C. in the form of an alloy. It was only in 1751 that Axel Fredrik Cronstedt, a Swedish chemist, who at first mistook this Nickel's ore for a copper mineral, classified Nickel as a chemical element. In 1890, Nickel was introduced as cast metal and steel alloys in order to improve its mechanical attributes. Over 100 years ago, stainless steel was invented. 40% to 50% of all Nickel produced goes into stainless steel.

Nickel in Watches

In watches, Nickel is primarily used in stainless steel in the production of water-resistant cases. In addition "nickel silver"an alloy of nickel, copper and zinc has been in use for the past 150 years in the production of plates and bridges in high end timepieces replacing the use of brass. Antique cheap watches used nickel silver to replace real silver before the introduction of stainless steel. Nickel is used to electroplate brass watch parts such as bridges and plates to prevent oxidation. Just a thin layer of Nickel can lend a metallic sheen to the watch components. Nickel is also used in the crafting of pendulum rods and balance springs. Invar, a ferronickel comprising of 36% nickel with an ultra low coefficient of expansion, as well as Elinavar is a variation of Invar, coined by Charles-Edouard Guillaume (1861-1938) , a Swiss who worked for the International Bureau of Weights and Measures, whose thermo-elastic coefficient is zero between -60º and + 70º and in 1920 received a Nobel Prize in physics for discovering anomalies in nickel-steel alloys. Invar and Elinavar is used in precision pendulum rods, watch balance springs, geodetic baselines, length standards, thermostats and other devices where high precision is vital. Guillaume's total compensating balance spring for high precision watches and chronometers was perfected by incorporating the Elinvar hair spring in the movement of the luxury timepiece.

Allergies and Nickel

An allergy is a disorder of the immune system. Allergic reactions occur as a result of allergens which in our case is Nickel. The allergic reactions occur at varying degrees of seriousness some life threatening others a minor irritation. Statistically 10% of healthy people are prone to one kind of allergy or another. There is a vast amount of information about different levels of allergy's, allergens, manifestations of allergies and so on. For the purposes of this article we need not delve into great depth, but rather skim the surface and utilize the relevant information in regard to nickel as an allergen.

A Nickel Allergy is a very common form of Allergic Contact Dermatitis (ACD). A rash develops after direct contact with nickel and may have the following characteristics:

Rash or bumps on skin, Itching which can be severe, redness or changes in skin color, Dry patches of skin that can resemble a burn, blisters and draining fluid in sever cases, Sweating aggravates condition. (Source: MayoClinic.com)

redness, itching, hives and/or cracks.

  • An individual must be in direct contact with a bracelet, band or watch case containing Nickel creating an allergic reaction.

  • Nickel liberates easily from the alloy and onto the skin in the form of cations, or positively charged particles creating an allergic reaction.

  • The positive ions must be transferred via a fluid which serves as an electrolyte. This fluid is quite often sweat, but may also be water from the sea or swimming pool.

The stainless steel used in manufacturing the watch cases releases varying amounts of nickel from the alloy depending on the nature of the alloy and the proportions of the individual components. Stainless Steel used for medical purposes releases virtually no nickel; however, cheap costume jewelry especially custom-made jewelry from artists like those found in flea markets have a high content of nickel. Nickel content is easily tested with dimethylglyxime (DMG) method. A simple spot test using the DMG solution can determine if the watch case, band or jewelry contains nickel. Young adults and teens, particularly girls aged 10-15 are susceptible to nickel allergies in jewelry for ear or other piercings as cheap jewelry targeted at that age group ,for some reason contain high nickel content (for further information see The San Francisco earring study, published online in the Journal of the American academy of Dermatology by Dermatologist Howard I.Maibach, MD, FAAD, professor of Dermatology at the University of California, San Francisco.) Belt buckles also contain Nickel causing reactions in that contact area.

In regard to the liberation of nickel ions is the condition of the metal surface in contact with the skin. Corroded case backs become rough or porous and attract the electrolyte fluid, most often perspiration, and become active zones for producing the allergenic cations which in turn generates higher concentrations of metal ions as the metal corrodes. Bi color watches made of alternating bands of gold and steel can cause reactions in people with sensitive skin. Gold and stainless steel have differing electric potentials which accelerates the transfer of ions in the sweat. This increase in galvanic corrosion leads to a greater risk of allergy. An increase in the corrosion rate causes an increase in the risk of an allergic reaction. Corrosion often occurs at the at the joint of two different metals are soldered together.The small cavity created as a result of the corrosion becomes an ideal area for more corrosion.

Solutions to the Nickel Allergy

a) Avoidance. An excellent alternative for those who are extremely allergic to Nickel.

  • One must look for jewelry and wristwatches labeled "nickel-free" or "hypoallergenic"
  • Avoid gold plated watches which have been worn over a long period of time. With time, the thin layer of gold wears off exposing the skin to the underlying metal containing high nickel levels.
  • Wear only titanium, platinum, rose gold (which has a high percentage of copper rather than nickel), and PVD or any synthetic materials like those found in Swatch watches. White gold often contains nickel exceeding the acceptable levels of nickel sensitivity.
  • Immediately discontinue wearing the wristwatch or other jewelry if any itching or redness occurs at the contact site.
  • If you know you have been previously diagnosed with a nickel allergy you may use a 1% hydro cortisone cream or ointment which can be purchased over-the-counter, or home remedies which have been prescribed by your doctor in the past to treat nickel-induced dermatitis.
  • If symptoms worsen or do not improve within three to five days after avoiding contact with the timepiece or jewelry consult a dermatologist. (Source: American Academy of Dermatology)
  • If you are not sure what the rash could be, consult your doctor.
  • Seek emergency care if the rash develops blisters or drains fluid (Source: mayoclinic.com)

b) Watch wearing precautions for people who have mild nickel sensitivity include:

  • One should remove ones watch before bedtime thereby lowering the amount of contact between skin and metal.
  • Regularly wipe the watch case and bracelet with a clean, dry cloth. A slightly damp cloth can be used if the watch is water resistant to eliminate the accumulation of nickle ions which can irritate the skin.
  • After heavy perspiration, any watch model no matter the nickel content should be removed from the wrist and carefully washed. With this practice the risk of a nickel allergy or a nickel sensitivity can be greatly reduced.

Currently there are no Federal Standards in regard to the definition of the term "hypoallergenic" or nickel free. Nickel free can mean only the top plating is nickel free but the base metal may contain nickel. Nickel allergies has raised concerns in the European community, which has begun the drafting of a legislation controlling the use of nickel especially in products that come in direct contact with the skin. On June 27, 1989, Denmark was the first to sign such a legislation which prohibits the import and production of products that liberate quantities of nickel higher than 0.5 micrograms/cm2 over a period of one week. In the early 1990's the European Union Nickel Directive was passed in an effort to decrease the widespread Nickel exposure in consumer and occupational products in Europe. This directive seems to be working and the Nickel products containing a high Nickel content has been reduced. No such regulation exists in the United States leaving millions of of people at risk for dermatitis Many high end watch making companies are monitoring the levels of nickel in their products, using materials such as titanium and PVD. Newly imposed regulations will only enhance the sale of wristwatches as customers will rest assured that the use of nickel has been reduced and monitored.

In the interim ,if you know you are allergic to Nickel, do research on the watch you wish to buy. Many of the watch brand websites have allergy information posted which can be quite helpful.