Pallet wood mulch: where most 'recycled' pallets go
Most wood pallets that EPA counts as recycled are chipped, mainly into mulch or animal bedding (EPA Facts and Figures, 2018 data). WARM gives this no emissions credit: dimensional lumber has no composting factor (WARM v16 Exhibit 12-3, 'NA'), so the Pallet Fate Report counts grinding toward diversion with zero CO2e.
How much goes to mulch
EPA estimated 3.1 million tons of wood pallet recycling in 2018, describing it as 'usually by chipping for uses such as mulch or bedding material' and excluding wood burned for fuel (EPA, containers and packaging). That is the source of the often-quoted recycling figure; see why 27% and 95% are both quoted.
What makes it safe
- Clean, unpainted, untreated wood. Ask the grinder whether painted and treated pallets are screened out before grinding.
- Metal removed. Ask whether nails are pulled by magnet after grinding.
- Dye, if used, is applied to the chips; the colour says nothing about the source wood.
Why WARM gives it no credit
WARM's wood chapter lists composting as 'NA' for dimensional lumber (EPA WARM v16, Exhibit 12-3). The model has no factor for grinding wood into mulch. Using a compost or yard-trimmings factor instead would mix materials, so the Pallet Fate Report shows grinding as diverted tons with a CO2e of zero and says why.
In a scope 3 inventory, EPA's Hub Table 9 also has no recycled or composted factor for dimensional lumber, so ground wood cannot be costed from that table either (EPA Hub 2025). Report the tonnage and say it is not quantified.
Sources
- Containers and Packaging: Product-Specific Data (wood packaging, 1960–2018) U.S. EPA. Accessed October 27, 2026. Page last updated October 19, 2026; latest data year 2018.
- Documentation for Greenhouse Gas Emission and Energy Factors Used in WARM, Version 16: Construction Materials Chapters, ch. 12 Wood Products (EPA-530-R-23-020) U.S. EPA. Accessed October 27, 2026. Exhibits 12-3 (p. 12-3), 12-9, 12-13, 12-15 and 12-16 (p. 12-10).
- GHG Emission Factors Hub 2025, Table 9 (Scope 3 Category 5 and Category 12) U.S. EPA Center for Corporate Climate Leadership. Accessed October 27, 2026. The 2025 Hub is the latest listed on the Hub page on the access date.