Metals: Common contamination

Top contamination sources and how they break sorting or end markets.

What to know

Acceptance and processing depend on local equipment, contamination rates, and end-market requirements. Treat this page as a decision framework.

Do this

• Keep items empty and dry.
• Separate mixed components when feasible.
• Store clean material to preserve grade.

Avoid this

• Food residue, liquids, and mixed laminates.
• Small pieces that fall through screens.
• Tanglers (bags, cords) where relevant.

Questions to ask locally

• Does the program accept this material by shape or by resin/type?
• Are caps/lids left on or removed?
• Is drop-off preferred over curbside?

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