Heat-treated pallets (HT): what they are, when you need them, and cost

"Heat-treated" is the most requested option on export pallet quotes and one of the most misunderstood. It is a phytosanitary treatment defined by an international standard, it is proven only by a stamp, and it has nothing to do with how dry or clean the pallet is.

#What does heat-treated mean on a pallet?

A heat-treated pallet is one whose wood has been heated so that the core of the thickest piece reaches at least 56 °C (133 °F) for at least 30 continuous minutes. That is the heat treatment schedule in ISPM 15, the international standard for wood packaging material. The heat kills wood-boring insects and nematodes that could otherwise travel between countries in pallets and crates.

After treatment, an authorized facility applies the IPPC mark: the IPPC wheat-ear symbol, a country code, a facility number and the treatment code HT. Without the mark, the pallet is not compliant, whatever treatment it actually received.

#ISPM 15 treatment options

All ISPM 15 wood must also be made from debarked lumber. Small bark pieces are allowed: less than 3 cm (1.2 in) wide of any length, or wider pieces under 50 cm² (7.75 in²) in area.

#Heat-treated vs kiln-dried

HT and kiln drying (KD) are different things.

A kiln schedule usually exceeds the HT schedule, so kiln-dried lumber from a certified mill often carries a KD-HT stamp. But a pallet built from green wood and then heat-treated is an HT pallet that is still wet. See heat-treated vs kiln-dried and pallet lumber moisture.

#When do you need heat-treated pallets?

You need ISPM 15-compliant (in practice, HT) pallets whenever solid-wood pallets cross a border into a country that enforces ISPM 15. Most trading countries do.

Costco's pallet policy is a useful example of a retailer applying the rule: it does not require HT within Canada, the US or Mexico or at the Canada–US border, but requires HT pallets at the Mexico–US border and for overseas imports and exports, with the ISPM 15 mark on both long sides. See Costco pallet requirements.

#Reading the HT stamp

A typical US HT mark reads, inside a border:

• IPPC symbol (wheat ear) on the left
• US: ISO country code
• Facility number: assigned under an accredited agency program
• HT: treatment code
• Often the agency logo and, in some marks, "DB" (debarked), which older marks included and current ISPM 15 no longer requires as a separate code

In the US the program is run by the American Lumber Standard Committee (ALSC), which accredits inspection agencies that license treatment facilities. The mark must be legible, permanent and not hand-drawn, and should appear on at least two opposite sides of the pallet. Full details are in pallet stamps and markings.

#How much does heat treatment cost?

Heat treatment typically adds about $1–3 per pallet to a new wood pallet (2026 US estimate). The price depends on:

• Volume. Treating a full kiln is cheaper per pallet than a small batch.
• Pallet size and mass. Thick blocks and stringers take longer to reach core temperature.
• Whether the lumber was already KD-HT. A pallet built entirely from KD-HT stock still needs to be marked by a certified facility; costs vary by program.
• Recycled pallets. Used pallets must be re-treated after repair, which adds handling.

Pooled pallets can also be ordered HT. PECO, for example, lists heat treatment as an extra-charge option with a longer delivery window, and CHEP supplies HT pallets for export programs.

#Heat-treated crates, dunnage and bracing

ISPM 15 covers all solid-wood packaging, not only pallets. Crates, skids, blocking, bracing and dunnage in a container also need treatment and the mark. A shipment on HT pallets can still be held at the border because of untreated wooden bracing.

#Who can heat-treat and mark pallets?

Only facilities authorized under a national program may apply the ISPM 15 mark. In the US, those are pallet manufacturers, recyclers and lumber mills licensed by an ALSC-accredited inspection agency. The agency audits the facility's kilns, temperature records and marking practices. A pallet shop that is not in a program can buy HT lumber or have pallets treated by a licensed facility, but it cannot mark pallets itself. When you choose a supplier for export pallets, ask for its program and facility number.

#Rules for reused and repaired HT pallets

• An intact HT pallet can be reused for export without re-treatment.
• A repaired or remanufactured pallet (any new or replaced solid-wood component) must be re-treated as a whole and re-marked, and old marks must be obliterated. See pallet repair.
• A pallet with a new board but the old stamp is not compliant.

#Are heat-treated pallets safe for reuse and DIY?

HT uses heat only, no chemicals, so HT-marked pallets are the preferred choice for reuse. Two cautions:

• Avoid pallets marked MB. Methyl bromide is a toxic fumigant, and while residue on old pallets is unlikely to be significant, there is no reason to take the risk indoors, near food or in firewood.
• An HT stamp tells you nothing about spills. A pallet that carried chemicals can be contaminated whatever its stamp. See free pallets.

#Specifying it for a quote

Add these fields to your RFQ:

• ISPM 15 treatment: HT (or DH); MB not accepted
• Mark location: two opposite sides minimum; both long sides if the customer requires it (Costco does), or all four sides
• Certificate or letter of compliance required with each shipment: yes or no
• Moisture target, stated separately (for example KD19)
• Destination countries

Every wood template in the designer, such as the export-ready block pallet, has an ISPM 15 option that prints on the drawing sheet. For the full export picture, see export pallets.