Most wood pallets carry a stamp on a stringer or block. Some are mill marks or company logos and mean nothing to you. One of them, the ISPM 15 mark, records how and where the wood was treated. This page explains how to read it. It is a guide to reading stamps, not a certification statement about any particular pallet.
Where to look
Turn the pallet on its side. If you find a mark on only one side, or it is smudged past reading, treat the pallet as unmarked.
The ISPM 15 mark
ISPM 15 is the standard for solid wood packaging, administered through the IPPC. Its purpose is to stop pests such as wood boring beetles traveling in raw wood packaging. A compliant mark has four parts:
| Part | What it means |
|---|---|
| IPPC symbol | The wheat ear logo. Shows the mark is an ISPM 15 mark. |
| Country code | Two letter ISO code of the country where the wood was treated, for example US. |
| Producer number | The unique number issued to the treatment provider or manufacturer. |
| Treatment code | How the wood was treated. HT, MB, DH or SF. |
A worked example: a stamp reading the wheat symbol, then US, then a number, then HT says the wood was heat treated by a registered facility in the United States, and the number identifies that facility.
The treatment codes
HT means heat treatment. The wood core was heated to a minimum of 56°C (133°F) for at least 30 minutes. This is the common treatment in the United States and the one most buyers mean when they ask for "stamped" pallets.
MB means methyl bromide fumigation. Many countries have restricted or phased it out, and HT is the usual alternative.
DH means dielectric heating, a newer heat method recognized in the ISPM 15 text.
SF means sulfuryl fluoride fumigation, the newest of the four treatment codes.
DUN is not a treatment code: it marks solid wood used as dunnage, the loose blocking and bracing inside a container, rather than a pallet or crate.
KD, and marks that are not ISPM 15
KD means kiln dried. It is a moisture control step for lumber, not an ISPM 15 treatment code on its own, although kiln drying to the required temperature at a registered facility can double as heat treatment and you will often see HT and KD together. You will also see mill marks, grade stamps, recycler marks and company logos that have nothing to do with ISPM 15. Pressure treated lumber, the green tinted kind used outdoors, is a chemical treatment for rot and is not an ISPM 15 treatment either; it is rarely used for pallets.
What is exempt
Processed wood such as plywood, OSB, particle board and glued veneer is exempt from ISPM 15 because the manufacturing process already deals with pests. Pallets built from those materials do not need the mark.
When the stamp matters, and when it does not
For domestic shipping the stamp is not required, and most pallets moving around Georgia are unstamped and fine. If the receiving end has handed you a written requirement, forward it with your order and we will confirm the stock against it.
A used pallet with a stamp is still a used pallet. The mark shows the wood was treated when the pallet was made, not that it has been inspected since. A repaired pallet is a special case: if a replacement board is untreated wood, the pallet as a whole no longer qualifies, and it should be re-treated and re-marked. Ask any supplier what their repaired heat treated stock has been through before you rely on it.
We stock heat treated pallets for buyers who need HT stock, and every heat treated pallet we supply carries the ISPM 15 stamp; see the heat treated pallets page for what we hold.
Tell us the quantity and what the receiving end has asked for: request a quote.