Relatively few materials are safe for wear in a fresh piercing, as the jewelry must withstand the heat and pressure of autoclave sterilization. Another crucial factor is biocompatibility: it must be well tolerated by the body and local tissues to avoid healing complications, allergy, irritation, and infection. Finally, the human body is a harsh host, so only highly corrosion-resistant materials fare well in the flesh.

For wear in initial piercings, the Association of Professional Piercers accepts jewelry that meets implantation standards for materials and quality by the American (now International) Society for Testing and Materials (ASTM) and/or the International Standards Organization (ISO). Examples with their numbered designation codes and the other APP-approved materials are listed below. See www.safepiercing.org for updates.
 

Due to space constraints, all of the details were not included in the book. See below for the expanded list from the Association of Professional Piercers.