# Heat treated pallets and ISPM 15

Most countries only accept <b>solid wood pallets and crates that meet ISPM 15</b>: the wood is heat treated (core at least <b>56 °C for 30 minutes</b>) or fumigated, then stamped with the IPPC mark, country code, producer number and treatment code such as <b>HT</b>. Plastic, plywood, OSB and presswood pallets are exempt.

## Key takeaways

- ISPM 15 applies to solid wood packaging over 6 mm thick: pallets, crates, dunnage.
- HT = heat treated to 56 °C core for 30 minutes; MB = methyl bromide (being phased out).
- The stamp must show the IPPC logo, country code, producer number and treatment.
- Non-compliant wood can be refused, treated or destroyed at the importer's cost.

## What ISPM 15 is

ISPM 15 is an international standard from the International Plant Protection Convention (IPPC) that stops wood-boring pests travelling in packaging. Most trading countries, including the US, Canada, the EU, the UK, China and Australia, require it for imports.


## What must be treated

- Pallets, skids, crates, boxes and cable drums made of solid wood.
- Dunnage: wood used to brace or block cargo in containers.
- Wood packaging that has been repaired or reused must still carry valid marks.


## What is exempt

- Processed wood: plywood, OSB, particle board, fibreboard and presswood pallets.
- Wood 6 mm thick or less, and shavings, sawdust or wood wool.
- Plastic, metal and paper pallets.
- Barrels for wine and spirits that were heated in manufacture.


## Reading the ISPM 15 stamp

| Part of the mark | Meaning |
|---|---|
| IPPC wheat-ear logo | The mark is an official ISPM 15 mark |
| Country code, e.g. CN, US, DE | Country where the wood was treated |
| Producer or treatment number | The registered company that treated or made it |
| HT | Heat treatment, core 56 °C for 30 minutes |
| MB | Methyl bromide fumigation, restricted or banned in many countries |
| DH | Dielectric heating, an approved alternative |


> The mark must be legible and permanent, on at least two opposite sides of the pallet or crate. A handwritten 'HT' does not count.


## If wood packaging is not compliant

Customs or plant health officers can order the packaging to be treated, removed and destroyed, or the whole shipment re-exported, and the importer pays. Live insects can trigger an inspection of later shipments from the same exporter.


## Practical tips

- Ask your pallet supplier for stamped HT pallets for any export, even if the destination seems relaxed.
- Check dunnage and bracing timber too; it is often forgotten.
- Consider plastic or presswood pallets for air freight: lighter and exempt.
- Mention compliant wood packaging on the packing list if the buyer asks.

[Choose a pallet footprint](https://cartonmath.com/pallet-sizes/): EUR, UK, US, Asia and Australian pallet sizes.

## Sources

- [IPPC: International Standards for Phytosanitary Measures (ISPM 15)](https://www.ippc.int/en/core-activities/standards-setting/ispms/)

## FAQ

**What does HT mean on a pallet?**
Heat treated: the wood was heated until its core reached at least 56 °C for 30 minutes under ISPM 15.

**Do plastic pallets need ISPM 15?**
No. ISPM 15 applies to solid wood packaging; plastic, metal and processed wood such as plywood are exempt.

**Do I need heat treated pallets for export?**
For most countries yes, if the pallets are solid wood. Untreated pallets can be refused or destroyed.

**What is the difference between HT and MB pallets?**
HT pallets are heat treated; MB pallets were fumigated with methyl bromide, which many countries restrict or ban.

Source page: https://cartonmath.com/guides/heat-treated-pallets-ispm-15/
Updated: 2026-10-06
Publisher: CartonMath (https://cartonmath.com)