Reading the ISPM 15 stamp, mark by mark
The ISPM 15 stamp is a mark of five parts: the IPPC symbol, a country code, a producer number, a treatment code such as HT, and sometimes DB. HT means the wood core reached at least 56 °C and held it for 30 minutes.
Mark by mark
| Part | Looks like | Says |
|---|---|---|
| IPPC symbol | A small wheat ear | Treated under the international standard |
| Country code | US | The country whose programme applied the mark |
| Producer number | Digits | Who applied it, so the mark can be traced |
| Treatment code | HT or MB | Heat treated, or methyl bromide fumigated |
| DB | Letters | Debarked |
What the standard requires
ISPM 15 regulates wood packaging material in international trade. It requires the wood to be debarked and heat treated to a core temperature of at least 56 °C for 30 minutes (or fumigated) and marked. Remaining bark must be under 3 cm wide, or if wider, under 50 square cm in surface area.
When a shipment out of Jacksonville needs it
Any pallet in an export container leaving Blount Island, Dames Point or Talleyrand does. A truck from Jacksonville to Orlando does not, because it is domestic. A pallet used inside a container going to another country, even with goods bound for a US-owned warehouse overseas, counts as international.
Some countries add rules of their own. Canada, for instance, has a separate policy on wood packaging from the continental United States that is exempt from CFIA policy D-98-08 pending a phased move to full ISPM 15 (CFIA). Check with the carrier or the importer.
How to check a pallet in your hands
- Find the stamp on a stringer or block, not only on a deck board.
- Read the treatment code: HT or MB.
- Check the mark is sharp and not painted over.
- Look at the wood: bark or active insects mean it should not ship.
Jacksonville Pallet does not stamp or certify pallets. It explains the mark so the heat-treated pallets request names what the box needs. Related: export pallets and HT and mould.
Common problems at the dock gate
| What the loader finds | What it means | What to do |
|---|---|---|
| Stamp only on one deck board | The mark may have come from a replaced board, not the whole pallet | Look for the mark on the stringer or block |
| Stamp smudged or painted over | A checker cannot read it | Swap the pallet |
| MB instead of HT | Fumigated rather than heat treated | Check the destination accepts MB |
| No stamp but clean new wood | Not treated; looks are not a mark | Do not load |
| Mixed stamped and unstamped pallets | A partial load fails whole | Sort before stuffing |
A Jacksonville example
A freight forwarder stuffing a 40 ft box at a Northside warehouse has a stack of 48x40 pallets that were repaired last month. One deck board on each was replaced with untreated lumber. The original stamp is on the stringer, but the replacement board is not heat treated. A careful loader sorts these out or sends them for re-treatment through an authorised facility. The mark certifies the wood it was applied to.
Why the standard exists
Wood packaging crosses borders with whatever insects live in the wood. ISPM 15 is the international answer: treat the wood so that pests do not travel. That is why a pallet in a container out of JAXPORT is regulated while the same pallet on a truck to Atlanta is not.
Questions
What does HT mean on a pallet?
Heat treatment. The wood core reached at least 56 °C for 30 minutes.
Is DB required?
Wood must be debarked before treatment. DB shows on some stamps.
Can a pallet be re-stamped?
Treatment and marking come from an authorised facility. Ask the facility, not a dock.
Where is the stamp on a pallet?
On the stringers or blocks, and often on two sides.
Keep reading
Sources, reviewed 12 November 2026: ISPM 15 (Wikipedia).