Steel, Titanium, and Niobium

ASTM F-138 stainless steel, ASTM F-136 titanium, Niobium
Surely you have heard many body jewelry companies make a fuss over the materials their products are made of. In fact, organizations like the Association of Professional Piercers (APP) even maintain standards on acceptable materials for both new and healed piercings. There are all sorts of coined terms companies throw around when describing their jewelry, but what does it all really mean?
With a multitude of different materials used in body jewelry nowadays: metals, woods, plastics, glass, porcelain, stones (the list could go on); it’s difficult to keep track of it all. What can be autoclaved? Which could induce an allergic reaction? Which tends to harbor bacteria? Let’s take a look at a few specific metals: ASTM F-138 stainless steel, ASTM F-136 titanium, and Niobium. Let’s find out what all those numbers stand for and where those industry standards come from.
ASTM stands for American Society for Testing and Materials and their standards are used around the world to improve product quality, enhance safety, facilitate market access and trade, and build consumer confidence. Their criteria for an implant grade rating is based on the presence or lack of presence of certain elements. If the ASTM has not rated the metal that is going into your fresh piercing, you probably don’t want it there.
Stainless steel is the most common material used in body jewelry in the United States today. Allergic reactions, when they occur, are rarely due to the stainless steel but from other factors (most commonly from mechanical irritation or harsh cleaning products). Some people, however do have allergies to the nickel found in the metal. Polishing the steel to a mirror finish results in a protective layer of chromium oxide that helps keep the nickel content trapped inside. Stainless Steel consists of a variety of alloys and many of them are used for body jewelry, but only a few specific grades are proven biocompatible: steel that is ASTM F-138 is one of them. What this all means is steel that is ASTM F-138 compliant is steel that has passed the criteria for implantation.
Titanium is another common metal considered suitable for body jewelry; in fact all 38 alloys are compliant for implant. Though there are many commercially used grades of the material, the only one recommended for use in piercing jewelry by the APP is Titanium (Ti6Al4V ELI) that is ASTM F136 compliant, which is widely used in our industry as it best meets our needs. Because of its nickel free content, titanium rarely induces an allergic reaction in its wearers and because it is highly resistant to corrosion, it is less likely than other materials to react with body fluids. Being a lightweight metal (around 60% the weight of stainless steel given the same volume), makes titanium quite appealing for a piece of body jewelry, especially when you are looking to wear larger sizes. Aesthetically titanium has another draw; it can be anodized in several brilliant colors.
Niobium is a metal that actually resembles titanium in certain aspects, one of which being that it does not react with body fluids. Heavier, and more expensive to produce than titanium, you won’t find as much body jewelry created with the metal. One thing to watch out for with Niobium is if it is not as pure as possible, it can lead to allergic reactions to the material. Niobium is another metal that can be anodized for colors similar to those produced with titanium. I am sure you noticed that Niobium lacks a rating from the ASTM, this is because Niobium is elemental; nothing is added to the metal, which eliminates the need for a rating, and this is part of the reason it is so biocompatible.
Yikes, that sure is a lot of information! Hopefully we were able to clear a little bit up about the differences between a few metals that are well used in body jewelry and give you a better understanding of what is good for your piercing and why. If you have further questions or things you are still unsure about, you should always ask your piercer. Being well informed about what you are putting into your body is never a bad thing and can save you a major headache later!