the qualities of steel for surgical implants. The only quality recommended for use by the Association of Professional Piercers is steel that is certified to meet ASTM or ISO standards for surgical implant applications. "Surgical Steel is made of a variety of alloys. Many of them are used for body jewelry, but only a few specific grades are proven biocompatible" Titanium Titanium body jewelry is often manufactured in either commercially pure grades 1 to 4, grade 5 TI6AL4V alloy or grade 23 Ti6AL4V ELI alloy. The only quality recommended for use by the Association of Professional Piercers is Titanium that is certified to meet ASTM or ISO standards for surgical implant applications. "Look for implant certified titanium (Ti6Al4V ELI) that is ASTM F136 compliant or ISO 5832-3 compliant, or commercially pure titanium that is ASTM F67 compliant.". Pure and alloyed qualities have long been used for both piercings and surgical implants, and very few long-term allergies and other complications have been reported, though as with any material they could arise after prolonged contact with the human body. Ti6Al4V ELI alloy contains aluminum and vanadium. When the EU Nickel Directive came into force - high nickel bearing alloys were restricted from use in primary (new) piercings. Because of its virtually 'Nickel Free' content Titanium has become one of the preferred materials used in piercing jewellery within the borders of the EU. Titanium jewellery is lightweight (around 60% the weight of stainless steel given the same volume), it is highly corrosion resistant and less likely to react with body fluids, is not magnetic, it can be anodized to create a layer of colored oxide on the surface. Common colors are yellow, blue, purple, green, and rainbow. Titanium can be sterilized in an autoclave. Niobium Niobium is a metal resembling titanium, but it is softer and heavier. When using niobium in a piercing jewelry it has to be as pure as possible, the threshold value being 99.9% niobium. This is sometimes called "999 Niobium". Impurities in low quality material can lead to allergies. Pure niobium doesn't react to body fluids, oxygen or cleaning agents. It can safely be autoclaved. It is allowed in healing piercings by the EU nickel law. Niobium can be heat treated to obtain a permanently dim black surface. A Septum retainer in black niobium is practically invisible. The selection of niobium jewelry is much smaller than that of titanium