Heat-treated pallets
A heat-treated pallet has had its wood core held at 56 °C or hotter for at least 30 minutes and carries the HT code and the IPPC mark. If your crate crosses a border, the stamp is the first thing to look for.
What the stamp tells you
ISPM 15 is the international standard that regulates wood packaging in international trade. A compliant pallet carries a stamp with the IPPC mark, a country code, the producer’s number and a treatment code. HT means heat treated. Wood packaging must also be debarked before heat treatment or fumigation. The stamp guide reads each part.
| Part | What it is |
|---|---|
| IPPC mark | The standard’s symbol |
| Country code | Where the pallet was treated |
| Producer number | Who treated it |
| HT | Heat treated, core at 56 °C for 30 minutes |
Who needs one
Shippers sending wood crates or pallets overseas usually do. Biotech, electronics and equipment makers on the I-270 corridor and near Dulles ship small recurring batches this way. See pallets for biotech and pharma. Wood packaging going to Canada from the continental United States is currently exempt from the CFIA policy D-98-08 pending a phased move to full ISPM 15, so check the destination before you assume either way.
Heat treatment is not mold treatment
HT does not make wood immune to mold. Heat-treated pallets loaded into trailer vans while still hot are susceptible to mold. Wood with moisture content below 20% will not support mold, mildew, decay or fungus. If your goods are food or pharma, ask about moisture as well as the stamp.
What to tell us
- Size and count. Custom sizes are common for export crates.
- The destination country, so you know what to look for.
- New or used. A used pallet can carry an HT stamp if it was treated.
- How often. A one-time crate and a weekly export flow are planned differently.
We do not state a price or a lead time on this page. Both depend on the build and the count.
Checking a stamp when it arrives
Read the mark on the end block or the side of the deckboard. It should show the IPPC symbol, a country code, a producer number and the treatment code. If any part is missing or smudged beyond reading, ask before you ship on it. A pallet that fails inspection at the port holds up a container.
Who should ask for heat treatment
- Exporters, whose container shipments need the ISPM 15 mark.
- Manufacturers whose customers abroad require it.
- Shippers sending crates overseas, even from a small plant.
- Anyone unsure whether the destination country enforces the rule; ask the carrier first.
Domestic shippers do not need the stamp. If your freight never leaves the United States, plain pallets are fine.
Heat treatment and cost
Treated wood costs more than untreated because the kiln time and the inspection are extra. If you only need a few for a one-off shipment, tell us the count and the destination. A small lot of treated pallets is a different quote from a trailer.
Paperwork that travels with the load
An exporter may need a certificate or a statement from the pallet supplier, and the carrier may ask for it. Tell us what your carrier or customer requires, and we say what we can provide with the pallets.
Reading a stamp at the dock
Turn a pallet on its side and look at the end block or stringer. A clear mark with a country code, a producer code and the letters HT is what a receiving clerk looks for. A smeared, painted-over or missing mark is reason to hold the pallet aside.
What the treatment is
Heat treatment brings the core of the wood to at least 56 degrees Celsius for a minimum of 30 minutes. Wood must also be debarked first, and the rule for remaining bark is narrow: under 3 centimeters wide, or if wider, under 50 square centimeters of surface. The mark on the pallet says the treatment was done under a program that checks it.
Heat treatment does not make wood immune to mold. A pallet loaded into a van while still hot can grow mold, so storage and drying still matter after the treatment.
What an exporter should ask for
- The mark on every pallet, legible on both sides.
- The country the pallets are headed to, since destination rules differ.
- The container or crate shipment date, so supply can be planned before it.
- Whether the mark must survive repairs, which affects what can be supplied.
What a stamp does not tell you
A stamp proves the wood was treated under a program that checks it. It does not tell you about size, load capacity or repair. A heat-treated pallet can still be cracked or damp, so look at the boards as well as the mark. Mold can grow on heat-treated pallets that go into a van while still hot, because the treatment does not make wood immune.
Planning ahead of a shipment
Exporters tend to know their ship date well before they know their pallet count. Tell us the date and a rough range of pallets as early as you can. Supply is easier to plan for a container that is a few weeks out than for one that leaves in a day or two.
Canada and other destinations
Wood packaging moving from the continental United States into Canada is currently exempt from the Canadian agency’s separate policy while a phased move to full ISPM 15 implementation proceeds. Other countries have their own rules, and some change. Ask your carrier or your customer what the destination requires before you order, and tell us what you learn.
Storage after treatment
Keep treated pallets dry and ventilated. Moisture below 20 percent will not support mold, mildew, decay or fungus, and a stack with space between rows dries faster than a tight block. Stacking treated and untreated pallets together risks mixing them, so keep the groups visibly apart and identify them before loading.
Mixing treated and untreated in one order
An order may include both: treated pallets for the export leg and ordinary ones for domestic freight. Name the split in the request, so the marked pallets are kept apart from the others on the truck and the paperwork reflects which is which.
Send the count
Questions
- What does HT mean on a pallet?
- Heat treated. The wood core reached at least 56 °C and stayed there for at least 30 minutes, as ISPM 15 requires.
- Do pallets need to be heat treated for export?
- Most export shipments of wood packaging need an ISPM 15 treatment and stamp. Check the destination country’s rule.