What is ISPM 15?
Also called: ISPM-15, ISPM No. 15, wood packaging export standard
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.
In depth: ISPM 15: the wood packaging standard for international shipping
ISPM 15 exists to stop wood-boring insects and nematodes moving between countries in packaging. Each country's national plant protection organization (NPPO) enforces it; in the US that is USDA APHIS, with the heat-treatment program run through agencies accredited by the American Lumber Standard Committee (ALSC).
Core requirements
| Requirement | Rule |
|---|---|
| Debarked lumber | Only small bark pieces allowed: under 3 cm wide, or over 3 cm wide with each piece under 50 cm² |
| Approved treatment | HT: 56 °C for 30 continuous minutes through the profile, including the core. DH: 60 °C for 1 continuous minute through the profile. MB or SF fumigation to a set schedule |
| Mark | The IPPC mark, preferably on at least two opposite sides |
| Exemptions | Wood 6 mm or less thick; processed wood (plywood, OSB, particleboard); plastic and other non-wood materials |
Why it matters for pallet design
Any solid-wood pallet that crosses a border (except where two countries agree otherwise) must comply, including pallets under imported machinery. Treatment adds cost, and repaired or remanufactured pallets must be re-treated. Non-wood and presswood pallets avoid it.
On a spec sheet or RFQ
State "ISPM 15, HT" (or DH), the number and position of marks, and whether you need a certificate or letter of compliance from the supplier. See the ISPM 15 standard page for the full rules.
Common confusions
Kiln drying alone is not ISPM 15 compliance. See KD-HT.
Frequently asked questions
Do plastic pallets need ISPM 15?
No. ISPM 15 covers solid wood packaging. Plastic, metal, paper and processed-wood materials such as plywood, OSB and presswood are exempt, as is wood 6 mm thick or less.
What treatments does ISPM 15 allow?
Four: heat treatment (HT), dielectric heating (DH), methyl bromide fumigation (MB) and sulphuryl fluoride fumigation (SF). The treatment code appears in the mark.
Does a repaired pallet need to be re-treated?
If up to about one third of components are replaced, the new parts must be treated and individually marked, or the whole pallet re-treated with old marks obliterated. If more than about one third are replaced, it counts as remanufactured and must be re-treated and re-marked.
Do I need ISPM 15 to ship between the US and Canada?
Canada and the US have not required ISPM 15 treatment for wood packaging moving between them, while Mexico does, according to Costco's supplier pallet policy. Confirm current rules with the national plant protection organization before shipping.
Related
- 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.
- GlossaryWhat is heat treatment (HT) for pallets?Heat treatment (HT) is the ISPM 15 method of heating wood packaging until the whole profile of the wood, including its core, reaches at least 56 °C for 30 continuous minutes. Treated pallets carry the IPPC mark with the code HT.
- GlossaryIPPC markThe IPPC mark is the stamp that shows wood packaging was treated under ISPM 15. It contains the IPPC symbol, a two-letter ISO country code, a producer or treatment provider code assigned by the national plant protection organization, and a treatment code (HT, DH, MB or SF), inside a border.
- TypesExport pallets: ISPM 15, container sizes and material choicesAn export pallet must meet ISPM 15 (heat-treated and marked wood, or an exempt material such as plastic, presswood, paper or metal), fit the container and the consignee's equipment, and usually be cheap enough to lose. Common choices are HT wood, 45 × 45 in or 1200 × 1000 mm footprints, and nestable plastic.
- GuidesPallet stamps and markings: HT, MB, DB, KD and what they meanMost wood pallet stamps are the ISPM 15 mark: IPPC wheat symbol, country code, facility number and treatment code. HT means heat-treated, DH dielectric heating, MB methyl bromide, SF sulfuryl fluoride. DB (debarked) and KD (kiln-dried) are older or separate marks. For reuse, pick HT and avoid MB.
More in Standards and compliance
- GlossaryCP palletCP pallets (chemical pallets) are a family of nine standardized wood block pallets, CP1 to CP9, developed for the European chemical and plastics industries. Each type has a defined size and construction for loads such as bagged polymer, drums and bulk containers.
- 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.
- GlossaryDielectric heating (DH)Dielectric heating (DH) is an ISPM 15 treatment that heats wood packaging with microwaves or radio waves until the entire profile of the wood, including its surface, reaches at least 60 °C for 1 continuous minute. Treated wood is marked with the code DH.
- GlossaryEPALEPAL (European Pallet Association e.V.) is the organization that licenses manufacturers and repairers of EPAL Euro pallets and other EPAL load carriers and controls their quality. The EPAL 1 Euro pallet is a 1200 × 800 × 144 mm block pallet used in open pallet exchange across Europe.
- GlossaryFSMA (Food Safety Modernization Act)FSMA is the US Food Safety Modernization Act of 2011. Under its Sanitary Transportation of Human and Animal Food rule (21 CFR Part 1, Subpart O), pallets are transportation equipment and must be designed and maintained so they are suitable and adequately cleanable, and do not make food unsafe.
- GlossaryGMAGMA stands for the Grocery Manufacturers Association (now the Consumer Brands Association), whose name became attached to the standard 48 × 40 in (1219 × 1016 mm) US grocery pallet: a partial four-way wood stringer pallet with three notched stringers, seven top and five bottom deckboards.
Last reviewed 2026-09-24. 248 words.