can you compost treated pallets?
No — a pallet stamped MB was fumigated with methyl bromide, and any pallet may have soaked up whatever leaked on it in transit.
which bins can take it?
- hot pile no
- cold pile no
- worm bin no
- bokashi no
- tumbler no
- curbside no
why?
Pallets pass through fumigation chambers, warehouse pest treatment, and cargo spills before anyone offers them free on the curb. The IPPC stamp burned into the stringer tells part of the story: HT means heat treated with nothing but hot air, while MB means methyl bromide, a fumigant the US has phased out but which still arrives on imported stock. Pesticide residue and spilled industrial liquids soak into softwood and cannot be washed back out, so they ride straight into finished compost.
watch out for
- An unmarked pallet is a coin flip — plenty of domestic one-way pallets are untreated softwood, but nothing on the boards records what spilled on them in a warehouse.
- Blue, red, and brown branded pallets are leased property that the rental pools want back; they are not free lumber to break apart.
- Stained, oily, or sour-smelling boards are a no even with an HT stamp, because the stamp only certifies the pest treatment.
what to do instead
Return leased pallets to the retailer, list plain ones free locally, or drop them at a wood-waste transfer station that grinds clean lumber. If a pallet is stamped HT, unpainted, and unstained, it is just kiln-dried softwood — those boards can be chipped for a slow brown or reused for projects.
often confused with
- Untreated Wood — Heat-treated pallet boards are ordinary lumber; it is the MB fumigation stamp and unknown cargo residue that make pallets a no.
quick answers
How do I read the stamp on a pallet?
Look on the outer stringer for a shield-shaped IPPC mark. HT is heat treatment, KD is kiln dried, DB is debarked — all fine. MB is methyl bromide, and that pallet should not become a garden bed, a chicken coop, or firewood.
Can I use free pallets to build a compost bin?
Only HT-stamped ones, and even then expect three to five years before the slats rot out at ground contact. Set them on gravel or bricks rather than bare soil to buy an extra season.