A.
Although native metals are fluorine-free, common surface treatments and machining processes introduce high-risk PFAS chemistry:
- Hard Chrome Plating: PFOS or 6:2 FTS are standard mist suppressants used in electroplating baths to control hazardous fumes, leaving persistent trace residues on metal surfaces.
- Functional Coatings: High-end metallic housings or fasteners often utilize fluorinated topcoats to achieve anti-fingerprint (AF), anti-smudge (AS), hydrophobic, or low-friction properties.
- Machining Residues: Industrial cutting fluids and lubricants containing PTFE powders or fluorinated surfactants can remain on metal parts if post-machining cleaning is insufficient.
- Professional recommendation: Because surface finishes and process residues are primary vectors for contamination, metal hardware destined for regulated markets must undergo targeted extractive testing to ensure market access.