Heat Treated (HT) Wood is widely used in the Packaging and Crating Industry. Heat Treatment is an effort to prevent the introduction of non-native pest’s species into native ecosystems. Non-native pest species that live in wood can threaten native forest ecosystems, since a natural predator will often not exist for an introduced pest species.
In order for wood to be certified as heat treated, the wood must have been placed in a closed chamber and heated to a temperature of 56 degrees Celsius for a minimum of 30 minutes.
You can also read more here if you want to buy heat treated wooden pallets.
This combination is considered adequate to destroy any pests in the wood. Methods of heat treatment include kiln drying and chemical pressure impregnation (including steam heating, hot water heating and dry heating).
For customs purposes, heat-treated wood must be certified with certain types of permanent markings. These marking must be present on at least two sides of the wooden article. A wooden crate or packaging material can be considered non-compliant with heat treatment rules under three categories, unmarked, inappropriately marked or infested. If a package is found to be in violation of heat treatment rules under any of these categories, the material can be subject to re-export at the cost of the importer.