Wood pallets under IBCs were the default for thirty years. They are increasingly not. The reasons are operational, regulatory, and contractual, and most of them are not about wood being a bad material — they are about wood being a fussy material in a hardened logistics environment.
Operational
Wood absorbs moisture, dries unevenly, develops splinters, harbors pests, and warps under load. None of these are dealbreakers for a single warehouse cycle. All of them are dealbreakers for a returnable fleet that cycles 8–12 times.
Composite is dimensionally stable. It does not warp, swell, or splinter. A composite pallet that gets rained on is identical to a composite pallet that did not. A wood pallet that got rained on, dried, and got rained on again is sometimes a different pallet than the one it started as.
Regulatory
International shipments require heat-treated (HT) wood stamps under ISPM 15. The stamp adds about $1.50 per pallet. Composite has no equivalent requirement because it is not phytosanitary.
For food applications, the FDA is increasingly skeptical of wood pallets in direct contact with food-grade containers, even though wood itself is not formally prohibited. Several major food retailers have unofficially adopted composite-only policies.
Contractual
Most third-party logistics contracts now write composite into the spec by default for IBC moves. A wood pallet under an IBC will sometimes get refused at a dock for no other reason than the contract says composite.
When wood still makes sense
Repair shops. Repurposing projects. One-time intra-facility moves. There is nothing wrong with wood for the wrong application; there is just a long list of applications that have moved on.