Bark (on pallet lumber)
Also called: bark remnant, bark pocket
Bark is the outer layer of a tree trunk. ISPM 15 requires wood packaging to be made from debarked wood, allowing only small remnants: pieces under 3 cm wide of any length, or wider pieces with a surface area under 50 cm².
In depth: ISPM 15: the wood packaging standard for international shipping
Pallet parts sawn near the outside of a log can carry strips of bark along a waney edge. Bark can harbor insects, which is why the international standard for wood packaging, ISPM 15, limits it.
ISPM 15 limits
| Bark piece | Allowed? |
|---|---|
| Less than 3 cm (about 1.2 in) wide | Yes, any length |
| 3 cm or wider, total surface area under 50 cm² (about 7.75 in²) | Yes |
| 3 cm or wider, 50 cm² or more | No |
Wood used for ISPM 15 packaging must be debarked before or after treatment, within these tolerances.
Why it matters
A pallet with oversized bark can be rejected at an import border even if it carries a valid heat-treatment mark. Bark also sheds dirt and fibers onto products, which matters in food and pharmaceutical supply chains, and it holds moisture, which can encourage mold.
On a spec sheet
Bark is covered by the ISPM 15 requirement and the lumber grade. For export or clean products, state "debarked per ISPM 15" and, if needed, "no bark on exposed faces".
Related
- GlossaryDebarked lumberDebarked lumber is wood from which the bark has been removed. ISPM 15 requires all treated wood packaging to be made of debarked wood, allowing only small pieces of bark: under 3 cm wide of any length, or wider pieces with a surface area under 50 cm² each.
- GlossaryWhat is ISPM 15?ISPM 15 is the International Plant Protection Convention (IPPC) standard for wood packaging material in international trade. It requires pallets, crates and dunnage made of solid wood to be debarked, treated by an approved method such as heat treatment (56 °C core for 30 minutes), and marked with the IPPC mark.
- GlossaryWane (lumber defect)Wane is bark, or the absence of wood, on the edge or corner of a sawn piece, where the cut reached the outside of the log. Pallet lumber grades limit how wide and deep it can be.
- StandardsISPM 15: the wood packaging standard for international shippingISPM 15 is the IPPC standard requiring solid-wood packaging, including pallets and dunnage, to be debarked, treated (HT, DH, MB or SF) and marked before crossing a border. Plywood, OSB, presswood, wood 6 mm thick or less, and plastic, metal and paper pallets are exempt.
- GuidesHeat-treated pallets (HT): what they are, when you need them, and costA heat-treated (HT) pallet's wood core was held at 56 °C (133 °F) for 30 minutes under ISPM 15, then stamped with the IPPC mark and HT. Most countries require it on wood pallets crossing their border. It adds roughly $1–3 per pallet (2026 US estimate) and kills pests; it does not dry the wood.
More in Materials
- GlossaryCant (pallet lumber)A cant is a log that has been sawn flat on two or four sides. In the pallet industry it usually means the low-grade center of a hardwood log, left after grade lumber is cut from the outside, which is resawn into pallet parts.
- GlossaryComposite block (pallet)A composite block is a pallet block made from wood chips, particles or fibers bonded with resin under heat and pressure. It does not split like solid wood and, as processed wood, is exempt from ISPM 15 on its own.
- GlossaryCorrugated fiberboard (pallets and slip sheets)Corrugated fiberboard is a board made of a fluted paper medium glued between flat paper liners. It is used for boxes, and in pallet work for corrugated paper pallets, slip sheets, tier sheets and pallet runners.
- GlossaryCut stock (pallet components)Cut stock is lumber already sawn to the finished thickness, width and length of pallet parts, such as 5/8 × 3-1/2 × 40 in deckboards, ready for nailing. It is also called pallet stock or shook.
- GlossaryDouglas-fir (pallet lumber)Douglas-fir is a dense, strong softwood from western North America, also grown in Europe. It is species class 11 (Douglas-fir–larch) in the Uniform Standard and PDS, and class 33 in the European species list.
- GlossaryGalvanizing (steel pallets and fasteners)Galvanizing is coating steel with zinc to protect it from corrosion. Steel pallets are often hot-dip galvanized after fabrication, and galvanized nails, staples and hinges are used where wood pallets or collars see moisture.
Last reviewed 2026-09-24. 188 words.