What the Hell Are Heat Treated Pallets?

Heat Treated Wood Pallet

If you are wondering what heat-treated pallets you are not alone. You may have heard about heat treated wood pallets but never stopped to ask what the difference is between heat treated pallets and plain old pallets.

In many areas of the world heat treated crates, heat treated wooden pallets, and other wooden shipping containers are mandatory. One word describes why heat-treated pallets are a necessity. Phytosanitary. It is a big word that basically means, we do not want insects and wood disease to spread from one country to another.

ISPM15 Sertified

History of HT Pallet

Pallets have been circulating around the globe since the second world war in the 1940’s. They became a supply chain staple to help troops receive supplies during the war, and they just took off. Since that time there have been several attempts at improving the wooden pallet, but nothing has really changed, except for the fact that heat treating pallets have become a standard.

Heat treating is a relatively new standard that North America and the EU, as well as Australia and other countries have adopted to keep disease, insects and plant life safe around the globe. International Plant Protection Convention (IPPC) came up with the phytosanitary process to help keep eco-systems safe.

The goal is to keep risks down that eco-systems will be affected by palletized goods moving from one country to another. The regulations of the ISPM 15 affects all wood type packaging not just pallets. For example, crates, dunnage, pallets, boxes, anything made of wood that is thicker than 6mm must be heat treated to enter certain countries.

ISPM 15 was not adopted until 2002. The ISPM 15 has been revised a few times over the years, including in 2009. The most recent revision states that wood must be debarked before heat treatment. Australia held out for an additional year after the revision to comply because they argued that it would be undue stress on pallet manufacturers. In 2010 they adopted the new requirement.

The “wheat stamp” is used to identify pallets and other wooden conveyances as ht or heat treated. Custom agents will look for the stamp to ensure that the container or conveyance is allowed into the country.

The heat-treated pallet stamp is an identifying mark that assures the receiving country that the pallet has been treated and is safe to enter. It is a good plan that seems to be working very well.

Why is Heat Treating Pallets Important?

One insect that is ready to lay larvae can take down an entire eco-system. That seems like it is hard to believe but it has happened many times in world history. Introducing an invasive species can cause a tremendous amount of damage to an eco-system.

There have been many cases of “hitchhikers” (insects) are not visible to the naked eye because they borrow into the wood and start hatching just in time to get to their new country. A good example of invasive insects affecting an eco-system is the woolly adelgid, an aphid like insect that is infesting Hemlock trees up and down the east coast of the United States.

This little aphid is hard to see with the naked eye. It originates in south east Asia and is thought to have arrived via a pallets in the early 2000’s before ISPM 15 was passed. One little bug certainly could not cause thousands of miles of trees to die, but it is happening.

It is estimated that over 5000 Hemlock trees have already fallen because of one tiny invasive insect. Some of the trees were old growth and hundreds of years old. There is a snowball affect because there are specific species of birds that only make their home in Hemlock trees. When there are not enough trees for them to nest in, they stop nesting. One insect that is not native to the region can have devastating effects on the entire eco-system.

The problem with invasive species is that they are not part of the natural eco-system where there is a checks and balance of sorts. In its natural environment this tiny bug would have plenty of predators to keep its population down, but in an environment that it is not normally found there are so few predators that the bug is able to thrive.

One aphid is not a problem but millions of them are. Heat treated pallets ensure that the tiniest of the insect world never gets to cross the boarders into territories where they can thrive beyond natural limits.


Not Every Country Wanted to Come on Board

Pallets are largely standardized by the communities that use them. For example, what is standard in North America may not be standard in Asia. The goal for international standardization has been a goal that has been slow to reach.

When the talk of pest and disease control for pallets was first initiated at the UN there were a lot of countries that dragged their feet to get on board with the idea. They cited economic hardship on the manufacturer and were afraid it would cause trade problems among countries.

Those that are pro international standardization brought up some valid points like the fact that if pallets are standardized and a universal agreement is reached to treat pallets for pests and disease than it would speed up trade processes through customs.

Even with the known threat that invasive species from fungus to insects can have on an eco-system many in the industry were rallying against the idea of being required to treat their pallets to prevent the spread of infestation of invasive species.

Eventually even the countries that were dragging their feet to commit to this small part of standardizing pallets agreed. Ultimately those countries that are not on board with the ISPM 15 standards are not big international trade players or they too would be forced into adopting the regulations.

Heat Treating

What Countries Require ISPM 15 Compliance?

If you are an exporter or you have a business that you are trying to take global it is important that you know which countries are going to expect that you will ship your goods on a heat-treated pallet. Each of the following countries not only expect that you will send your goods on heat treated pallets but are participants in the ISPM 15. The country name and the date that they joined the standardization efforts are as follows (note that countries that do not have a date next to the name were original adopters of the ISPM 15 in 2002):

  • Algeria April 2017
  • Argentina: June 2006
  • Australia: Sept 2004; Complete Adoption: July 2010
  • Bolivia: July 2005
  • Brazil: June 2005
  • Bulgaria: Jan 2006
  • Canada: Sept 2005 (US-Canada exemption)
  • Chile: June 2005
  • China: Jan 2006
  • Colombia: Sept 2005
  • Costa Rica: Mar 2006
  • Cuba: Oct 2008
  • Dominican Republic: July 2006
  • Ecuador: Sept 2005
  • Egypt: Oct 2005
  • European Union: Mar 2005
  • Austria
  • Belgium
  • Bulgaria
  • Croatia
  • Cyprus
  • Czech Republic
  • Denmark
  • Estonia
  • Finland
  • France
  • Germany
  • Greece
  • Hungary
  • Ireland
  • Italy
  • Latvia
  • Lithuania
  • Luxembourg
  • Malta
  • Netherlands
  • Poland
  • Portugal
  • Romania
  • Slovakia
  • Slovenia
  • Spain
  • Sweden
  • United Kingdom.
  • Guatemala: Sept 2005
  • Honduras: Feb 2006
  • India: Nov 2004
  • Indonesia: Sept 2009
  • Israel: June 2009
  • Jamaica: January 2011
  • Japan: Apr 2007
  • Jordan: Nov 2005
  • Kenya: Jan 2006
  • Lebanon: Mar 2006
  • Malaysia: Jan 2010
  • Mexico: Sept 2005
  • New Zealand: April 2003
  • Nicaragua: Feb 2006
  • Nigeria: Sept 2004
  • Norway: July 2008
  • Oman: Dec 2006
  • Paraguay: June 2005
  • Peru: Mar 2005
  • Philippines: June 2005
  • Serbia: June 2005
  • Seychelles: Mar 2006
  • South Africa: Jan 2005
  • South Korea: June 2005
  • Sri Lanka: Mar 2004
  • Switzerland: Mar 2005
  • Syria: April 2006
  • Thailand: February 2010
  • Taiwan: Jan 2009
  • Ethiopia 2006
  • Trinidad & Tobago: July 2010
  • Turkey: Jan 2006
  • United States: Sep 2005
  • Ukraine: Oct 2005
  • Venezuela: June 2005
  • Vietnam: June 2005

As you can see most of the large trade hubs require that pallets are heat treated. There are also specific guidelines for how that treatment is carried out. Heat treated pallets are largely preferred over chemically treated pallets.

What is the Heat Treatment Process?

Large kilns are used to heat treat wood for pallet manufacturers. The wood is debarked and placed in the kiln until it reaches an internal temperature of 140 degrees Fahrenheit for a minimum of 30 minutes. The pallet wood is then stamped with an internationally recognizable seal assuring the ht process has been completed.

The process will kill off any disease, insect or insect larvae and make the pallet safe for shipping. It is a simple effective process of keeping invasive insects from other countries.

Added Benefit

There is an added benefit of this kiln drying process that benefits the user. Soft woods that are often used in the construction of pallets get stronger when they are heat treated. Heat treatment removes much of the moisture from the wood and strengthens the fibers.

Not only is heat treating pallets good for the eco-systems around the globe they are also good for the user.

What Does NOT Need To be Treated

There are some wooden conveyances that do not need to be treated including:

  • Packaging material that is less than 6 mm thick
  • Packaging that is wholly made of processed wood like particle board
  • Veneer boards that have been made using glue, pressure and heat
  • Wooden barrels for wine and grain alcohol that has been heat treated during the process
  • Wood shavings, sawdust or wood wool
  • Wood parts that are permanently attached to containers and freight vehicles

Heat treated wooden pallets are always necessary. Other wood shipping materials are typically smaller and have come into some type of contact with a heating process anyway.

Treatment Codes

Chemical Treatment Is an Option but Not A Widely Accepted One

Under the ISPM15 guidelines, there really is no mandatory statement that says the heat treatment is the only acceptable way to treat pallets, but it is the favored way. Another option is chemical treatment. Fumigation either via a container or a tent is another option, however, it comes with some down sides.

It is usually more expensive to chemically treat pallets. There is also the risk of chemical residue left on the pallets that can make some buyers weary. Chemicals can stay in the wood for years to come even after treatment to remove it. Of course, chemical treatment is also dangerous for the people that work with them.

In both processes, container fumigation, and tent fumigation, the process is similar. Pallets are placed either in a container or a tent and fumigated with pesticide and fungicide. It is an easier process for the manufacturer although a more expensive process.

Unfortunately, fumigation does not make the pallet boards stronger. It does meet the requirements of ISPM 15, but it also limits the recyclability and the repurposing of the pallets. Chemical residue can be a permanent fixture in pallets that are treated this way and can make them unable to be used for repurposing safely.

ISPM15 Pallets for Export

The Moral of the Story

Heat treated pallets are not only better for the environment they are better for the user. They are stronger, safer, and affordable. They make getting through customs easier and ensure that your business is always in compliance.

Heat treating is superior to chemical treating because it helps to strengthen the wood and of course chemical residue is a non-issue. Once a pallet is heat treated it never expires. That means you can use a ht pallet repeatedly without ever having to worry about treating it again.

If you use pallets in your enterprise, it is best to get familiar with the ht mark on your pallets, so you know exactly what your supplier is shipping you. Understanding the value of ht pallets is an important first step in doing business internationally.

Heat treating is an important first step in coming to an international agreement on the standardization of pallets and making sure that international trade does not put to much stress on the eco-systems.