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ISPM 15: Buying Dunnage with Stamp

If your company ships its products overseas then you probably know all about ISPM 15, the heat treatment of wood, and that exporters face consequences for non-compliant wood products.  If you're asking yourself "Why do I need to heat treat wood?" you need to read this other Valley Box article.


In a nutshell, Heat treatment (HT) is a non-chemical process to prevent the international transport and spread of disease and insects that could negatively affect plants or ecosystems. The process involves heating the wood material until its core reaches 56 °C or 132.8°F for at least 30 minutes. This method of thermal treatment goes beyond the surface to kill any living organisms along with improve resistance to rot and fungus.


The Heat Treatment Program was developed in order for the American Lumber Standard Committee to implement a quality control program for the official labeling of heat treated wood material with an ISPM 15 mark. The measure applies to many wood packaging materials but excludes products made from alternative materials such as OSB, hardboard, and plywood.

Companies who export their products overseas sometimes require loose lumber, otherwise known as dunnage. It's used in conjunction with the wood shipping crate to restrict the movement of the internal products or to keep the crate static during transit. Generally dunnage is just reused pieces of lumber, however if a customs official inspects the inside of the crate, each piece of dunnage must bear the ISMP 15 heat treatment stamp.

Options to source dunnage with ISPM 15 heat treatment

Valley Box Company

Unfortunately, packaging manufacturers are not legally allowed to sell loose lumber featuring their permitted "ISPM 15 HT" stampHowever, Valley Box can sell lumber stamped “ISPM15 HT DUN” indicating dunnage that's been heat treated. There are a few key things to keep in mind:

  • HT Dunnage can only be used for internal blocking and bracing, not exterior additions to the wood crate.
  • HT Dunnage ISMP 15 identification numbers must match any other wood used in the construction of the wood crate.
  • ISMP 15 identification numbers can be mixed only when dunnage is used to block and brace the wood crate inside a shipping container and is not a part of the construction.
(619) 449-2882

Package Research Laboratory

The United States Department of Agriculture recommends contacting one of the inspection agencies under the Heat Treatment Programs to get information on obtaining officially marked dunnage. Check out Package Research Laboratory they have friendly inspection agents located throughout the United States.
(973) 627-4405

More Inspection Agencies

For a list of inspection agencies and contact information, visit the American Lumber Standard Committee website. Currently there are 19 accredited independent third-party agencies with operations of these agencies extending to approximately 5,300 facilities. They have a convenient contact list on their site.
(301) 972-1700.

Topics: Wood, Tips

Valley Box Company

Written by Valley Box Company

Valley Box demonstrates what is possible beyond just the typical wooden crate. This specialty crating manufacturer works with a wide variety of materials from wood to plastic, corrugated, metals and more. Discover how to take specialty crating to the next level.