If you have read any of our sustainability reporting, you have seen the reference to "EPA WARM." If you have read any other packaging or recycling company's sustainability reporting, you have also seen it. Almost nobody explains it. Here is a plain-English walkthrough.
What WARM is
WARM stands for Waste Reduction Model. It is a life-cycle assessment framework published by the US Environmental Protection Agency. The model estimates the greenhouse-gas-equivalent emissions, energy use, and economic impact of different end-of-life choices for waste streams.
For corrugated cardboard specifically, WARM provides emission factors for landfilling, recycling, composting, combustion, and source reduction. Source reduction is the relevant one for reused-box programs: it estimates the emissions avoided by not producing the box in the first place.
What the numbers actually look like
Per ton of corrugated cardboard, the WARM source-reduction factor (most recent revision) is approximately:
- Greenhouse gas emissions avoided: ~3.1 metric tons of CO₂-eq per ton of corrugate not made.
- Energy avoided: ~33 million BTU per ton.
For an 18-pound triple-wall Gaylord box, that works out to roughly 11.4 lbs of CO₂-equivalent avoided per box reused vs newly manufactured. This is the source of the number you have seen across our website.
What WARM does not do
WARM is a high-quality framework with real limitations.
It does not account for transportation emissions associated with reuse vs new procurement. A reused box has a transportation footprint to get it back to the user; a new box has a transportation footprint to get it from the mill to the user. Whichever wins depends on geography.
It does not account for reconditioning energy. The labor and energy to inspect, repair, and re-issue a used box is a small but non-zero footprint.
It does not account for landfill avoidance separately. If your alternative to reuse is landfilling rather than recycling, the carbon math gets even better, but WARM does not double-count that.
How we use it
For headline numbers — the "11.4 lbs avoided per box" you see in our marketing — we use WARM source-reduction factors with a small downward adjustment for our reconditioning footprint. We round conservatively.
For per-customer closed-loop reports, we use a more granular calculation that includes route-specific transport emissions and our actual measured reconditioning energy. The numbers there are slightly lower than the WARM headline but more defensible to a customer's sustainability auditor.
Should you trust WARM?
Yes, within its acknowledged limitations. It is the most widely accepted North American framework for waste-stream emissions accounting. The EPA updates it periodically. The factors are sourced from industry-association life-cycle assessments and validated against independent academic work.
What you should be skeptical of is sustainability claims that cite WARM without describing the boundary conditions of the calculation. WARM done well is honest. WARM done quickly can flatter any number you want.