How to read the HT stamp on a pallet

BOX 01The four parts, left to right

1. The IPPC logo. A stylized wheat ear identifies the mark as an ISPM 15 treatment mark.
2. The country code. Two letters for the country where the wood was treated.
3. The producer and region number. It identifies who treated the wood, so a receiving country can trace it.
4. The treatment code. HT means heat treatment: the core of the wood reached at least 56 °C for at least 30 minutes.

BOX 02Where it sits and what to reject

The mark is burned or stamped on the wood, usually on a block or a stringer, where it can be read after the pallet is loaded. Reject a pallet where the mark is smudged, painted over, partly sanded or missing, or where a repaired board has no mark of its own. A pallet repaired after treatment should be treated and marked again.

Heat treatment does not stop mold. Heat-treated pallets loaded into trailers while still hot are susceptible to mold per Pallet Enterprise, so check for it too.

BOX 03Reading the drawing

The drawing shows the parts of a mark; the number in it belongs to no real producer. For the rules behind it see ISPM 15 for exporters, and for the product page, heat-treated pallets.

BOX 04Common ways a stamp goes wrong

Four faults come up: a stamp that is too faint to read, a stamp on only one side of the pallet, a stamp that has been painted over and a stamp from a pallet whose wood has been repaired with unmarked boards. The last is the hardest to spot.

If the pallet has been repaired, the new boards need to be treated and marked too, or the whole pallet needs re-marking. A pallet with a stamp on the stringer and plain, unmarked deck boards is a doubtful one. When in doubt, ask the receiver at the destination.

BOX 05A stamp is a record, not a guarantee

The stamp shows that someone claimed the pallet was treated. It does not prove that the treatment happened or that the wood was untouched afterward. Inspectors check the stamp against the producer's registration; they do not test the wood.

For a buyer, the practical consequence is to buy from a source you can trace. A pallet with a clear mark from a producer you can name is a better bet than one whose mark you cannot read. Keep the paperwork if you have it.

BOX 06A practice run

Pick one pallet from a pile and find the stamp. Read the logo, the country code, the producer number and the treatment letters in turn. If you can read all four, the stamp is complete. If one is missing, the pallet is doubtful. Do this for a handful from each stack.

BOX 07Where stamps are faint

Stamps are faintest on dark, weathered wood and on boards that have been planed. If a stamp is hard to read, try a different light angle or wet the spot slightly. If it remains unreadable, treat the board as unmarked.