Operations · 7 min read

Contamination 101 — what’s salvageable, what isn’t.

Not every used box can be reused. Some should be baled, some should be recycled, and a few — rare cases — genuinely belong in hazardous waste. Here's our field guide.

Tell us what you have, or what you need. A human reads every request and replies within one business day — no chatbots, no phone calls.

Salvageable with effort.

  • Label residue. Almost always fixable with a putty knife and a heat gun. Our grade B allows minor residue.
  • Sharpie and ink stamps. Doesn’t affect structure. Fine for grade B or C.
  • Tape marks and adhesive. Gets covered by new tape on re-tape. Not a problem.
  • Dust and general warehouse grime. Air blower and a broom at Zone B. Not a problem.
  • Light grain or bulk food residue (dry).Vacuumed out and surfaces wiped down. Fine for non-food reuse.

Bale, don’t reuse.

  • Oil and grease stains. Structurally ruins the fiber bond. Gets baled and sold as low-grade OCC.
  • Wax coatings. Old produce boxes often have wax impregnation. Cannot be re-pulped or reused for any other application. These go to a specialty recycler.
  • Water damage. Wet corrugated delaminates and loses structural integrity. Gets baled while still damp.
  • Heavy printing ink. Not a salvage issue but makes the box ugly for grade A/B resale. Often gets baled.
  • Mold. Almost never reusable. Baled immediately and stored separately until outbound pickup.

Do not touch — call somebody else.

  • Hazmat placards and residues. We turn these trucks around. Hazmat requires a licensed disposal chain.
  • Biological waste. Same. We’re not a biohazard disposal company.
  • Heavy metal contamination. Goes to specialty hazardous handlers.
  • Anything that came from a lab. Even if it looks fine. We don’t risk it.

What to do with a questionable load.

When you’re not sure if a batch is salvageable, send us photos and a quick description through the form at the top of this page. We’ll tell you which of the four categories above it falls into and quote accordingly — pickup fee for bale-only loads, pickup credit for reusable loads, or “please call a hazmat specialist” for the rare third option.

Contamination 101 — Salvageable and Unsalvageable Used Corrugated Boxes by Denver Eco Boxes