The original post: /r/todayilearned by /u/zahrul3 on 2025-01-29 11:40:57.

Original Title: TIL metal or blood by itself doesn’t have a smell. The “metallic” smell of blood is instead derived from Fe2+ (iron) ions in metal/blood which react with fatty acids in sweat, forming 1-octen-3-one, which gives the characteristic “metallic” smell of metals and blood.