ISPM 15 does not apply to wood that has been processed so thoroughly that pests cannot survive in it, or that is too thin to shelter them. Plywood, particleboard, oriented strand board (OSB), veneer, wood 6 mm thick or less, sawdust, shavings, wood wool, heated wine and spirit barrels, and certain gift boxes are all outside the standard. Solid sawn wood of any thicker dimension is regulated, whatever it is called.
The principle behind the exemptions
ISPM 15, the international standard for wood packaging material (WPM), targets raw solid wood: material that was once part of a tree and could still harbor insects or nematodes inside. Where manufacturing has already killed or excluded those organisms, an additional ISPM 15 treatment gives no phytosanitary benefit, so the standard leaves such products out.
The exemptions are written into the scope of the standard itself and repeated in national rules. They are not exceptions that a customs officer can grant case by case, although officers may need to confirm that a product really is what it claims to be.
The list of exempt materials
Paraphrasing the 2009 standard, the following are not subject to ISPM 15:
| Exempt item | Why it is excluded | Practical example |
|---|---|---|
| Wood 6 mm or thinner | Too thin to hold wood-boring pests | Thin crates and veneer-type boxes |
| Processed wood material made with glue, heat and pressure, such as plywood, particleboard, OSB, veneer | Manufacturing process eliminates pests | Plywood boxes, OSB pallet decks |
| Sawdust, wood shavings, wood wool | Fragmented material | Cushioning and packing fill |
| Barrels for wine and spirits that were heated during manufacture | Heat during coopering | Oak casks |
| Gift boxes for wine, cigars and similar goods made from wood processed to be pest-free | Processing | Presentation boxes |
| Wood components permanently attached to freight vehicles and containers | Part of the vehicle, not packaging | Container floors and trailer beds |
National authorities publish equivalent lists. The US Animal and Plant Health Inspection Service (APHIS), for instance, names plywood, pressboard, oriented strand board, hardboard, parallel strand lumber, laminated veneer lumber and Masonite veneer, alongside plastic pallets, metal frames and synthetic foam, as materials it does not regulate as WPM. Australia lists thin wood of 6 mm or less, plywood, particleboard and sawdust as low-risk items.
Exempt pallet types
Several pallet families escape ISPM 15 because of their material:
- Plastic pallets. Not wood, so not regulated. See plastic pallets.
- Metal pallets. Steel and aluminium pallets are not wood; see metal pallets.
- Presswood or moulded wood pallets. Made from wood chips or fiber bonded under heat and pressure, they count as processed wood; see presswood pallets.
- Paper and corrugated pallets. Not wood in the solid sense; see paper and corrugated pallets.
- Plywood and OSB-based pallets and boxes. Exempt as processed wood panels, provided no solid sawn lumber is used in the construction.
The last condition is where many mistakes happen. A plywood box with solid-wood battens, a pallet with sawn stringers and OSB decks, or a crate with a solid-timber frame is not exempt. The solid parts are regulated, and the item needs a compliant treatment and mark.
Where exemptions stop
Four situations catch shippers who assume an item is exempt:
- Mixed construction. If any solid sawn component exceeds 6 mm and is not processed wood, the whole unit is treated as WPM for inspection purposes.
- Dunnage and bracing. Loose lumber used to block or brace cargo is WPM even if it is not part of a pallet. See dunnage rules.
- Reused wood from exempt items. Offcuts or boards salvaged from an exempt product and reused as packaging are solid wood once they are used as such and require treatment.
- Claims without proof. Processed panels should be identifiable as such. An unlabeled, painted or unusually glued assembly can be questioned at inspection, and the importer may need to show invoices or manufacturer data.
Because inspectors work visually, a product made from solid wood but disguised by paint or thin veneer faces particular scrutiny.
Thin wood: how the 6 mm limit works
The 6 mm threshold refers to the thickness of the wood piece. A crate made entirely from 5 mm slats qualifies. A crate with 5 mm slats and 20 mm solid-wood edge battens does not, because the battens are above the limit. For packaging components such as nail-strip cleats, check the thickness at the thickest point, not the average.
Country notes
The ISPM 15 exemption list is international, but some countries add conditions or enforce documentary checks. Intra-European Union trade and trade between the United States and Canada follow special arrangements rather than the treatment-and-mark rules; see the country overview. When shipping to a country with a high-risk profile for its forests, treating all solid wood as WPM is the safe default.
Frequently asked questions
Is plywood exempt from ISPM 15?
Yes. Plywood is processed wood made with glue, heat and pressure, and is outside the scope of the standard. Solid-wood parts attached to a plywood item are not exempt.
Are OSB pallets exempt?
OSB (oriented strand board) is exempt as a processed wood panel. A pallet is exempt only if its entire wood content is exempt; OSB decks on sawn-lumber stringers need treatment and a mark on the solid parts.
Do wooden boxes thinner than 6 mm need a mark?
No. Wood of 6 mm or less in thickness is exempt from ISPM 15, so a box made entirely of such wood needs no treatment or marking.
Does an exemption mean no inspection?
No. Customs and plant health officers can still inspect any consignment, and an item claimed as exempt may be examined to confirm that it is made of processed wood.
Sources
- ISPM 15: Regulation of wood packaging material in international trade (2009) — International Plant Protection Convention (FAO)
- Wood Packaging Material — USDA APHIS
- ISPM 15 import requirements for timber packaging — Australian Government Department of Agriculture, Fisheries and Forestry
- EU import requirements for wood packaging material, explained — Agrinfo.eu