By Matt McConnell, Executive Relationship Manager
When it comes to treating pallets, kiln drying and heat treatment are often confused because both involve heat. However, these processes serve distinct purposes and are not interchangeable. Understanding their differences is essential for businesses that rely on pallets for domestic or international shipping.
What is Heat Treatment?
Think of heat treatment as total sterilization. The primary goal is to eliminate all living organisms in the wood, similar to pasteurization in the food industry.
Why is Heat Treatment Necessary?
- Prevents the spread of pests and diseases: Untreated lumber can harbor invasive pests such as the Emerald Ash Borer and the Asian Longhorned Beetle. If left unchecked, these pests can hitch a ride on pallets and spread to new regions, causing severe ecological and economic damage.
- Meets international shipping regulations: To prevent the spread of invasive species, the International Standards for Phytosanitary Measures No. 15 (ISPM 15) requires that all pallets used for exporting goods be heat-treated. The ISPM 15 stamp, typically applied as an ink stamp, stencil, or brand, certifies compliance with this global standard.
- Reduces pallet weight: Heat treatment removes enough moisture from the wood to make it lighter, reducing shipping costs.
- Improves durability: Heat-treated pallets are stronger, making them more reusable and recyclable, which contributes to waste reduction.
What is Kiln Drying?
Kiln drying is a process that removes moisture from lumber to prevent warping, cracking, and shrinkage. Unlike heat treatment, kiln drying is primarily about improving the wood’s stability rather than eliminating pests.
Key Benefits of Kiln Drying
- Prevents wood damage: Excess moisture can cause wood to twist, crack, or shrink. Drying it in a kiln helps maintain its integrity.
- Reduces weight for shipping: Lower moisture content makes the wood lighter, cutting down transportation costs.
- Enhances durability: Kiln-dried wood is more weather-resistant and less likely to split under stress.
- Minimizes discoloration: Kiln drying prevents mold and staining, making it ideal for industries using moisture-sensitive materials such as paper and cardboard.
Does Kiln Drying Kill Pests?
No. While kiln drying removes some pests, it does not reach the lethal temperature of 133°F, which is required to kill wood-boring insects. This is why kiln drying alone does not meet ISPM 15 export requirements.
Do All Pallets Need to Be Heat Treated?
No. Only pallets used for international shipments require heat treatment under ISPM 15 regulations.
- Domestic use: Pallets that remain in the U.S. do not need to be heat treated.
- Export use: Any pallet used for international shipping must be heat treated and stamped with the ISPM 15 mark.
A Warning About Methyl Bromide (MB) Treatment
Pallets marked with MB were treated with methyl bromide, a chemical once used for pest control. However, the U.S. banned methyl bromide treatment in 2005 due to its harmful effects on the ozone layer.
⚠ If you find a pallet with an MB stamp, do not use it for personal projects or burn it. Instead, contact a licensed waste handler for safe disposal.
Why Understanding the Difference Matters
For businesses dealing with custom pallets, knowing the difference between kiln drying and heat treatment is critical.
- Kiln drying reduces moisture content, making wood more stable and resistant to damage.
- Heat treatment sterilizes wood, ensuring compliance with international shipping regulations.
Both processes contribute to the production of high-quality, sustainable pallet solutions.
How Can Ongweoweh Help?
Ongweoweh has been a leader in the pallet industry since 1978. With our extensive supplier network, we can help you find the right pallet solution for your business needs. Need pallets? Have questions? Contact us today to get started.