PI-WIKI-MAT-02 · Material Science · reviewed 2026-10-26
Biocompatibility of Implant-Grade Metals in Body Jewelry
Critical numbers
ASTM F136 Ti: Oxygen max0.13 wt% [1]
ASTM F136 Ti: Iron max0.25 wt% [1]
ASTM F136 Ti: Aluminium5.5 – 6.5 wt% [1]
ASTM F136 Ti: Vanadium3.5 – 4.5 wt% [1]
ASTM F138 (316LVM): Nickel13.0 – 15.0 wt% [2]
ASTM F138 (316LVM): Carbon max0.03 wt% [2]
REACH Nickel Release Limit (piercing)≤ 0.2 µg/cm²/week (EN 1811); 0.5 for prolonged skin contact [5]
CoCr ASTM F1537: Chromium26.0 – 30.0 wt% [3]
CoCr ASTM F1537: Molybdenum5.0 – 7.0 wt% [3]
Gold minimum (initial piercing)18ct / 750 ‰
Surface roughness Ra target≤ 0.4 µm
Niobium purity minimum99.9% (ASTM B392)
Do not
- "Surgical steel" accepted without specification
- No ICP-MS certificates requested
- Mixing metal types in healing piercings
- Assuming CoCr is nickel-free
- Relying on colour as a metal identifier
- Storing jewelry in conditions that degrade passivation
Applicable standards
- European Union & UK — REACH Regulation 1907/2006, Annex XVII, Entry 27
- United States — ASTM F136-13(2021)
- ASEAN & Asia-Pacific — Thailand