The process of treating the heat treated lumber for export is necessary for the export of any type of wood from the US to other countries in the world. This is a law that came into effect years ago to prevent the spread of harmful pests, especially the pinewood nematode, and a type of Asian beetle. Treating the wood prior to shipping will kill any insects and their larvae before it ever leaves this country. The process of treating the wood was agreed upon at an international convention whose membership focuses on plant protection. The law is called the ISPM 15 which stands for International Standards for Phytosanitary Measures, Publication 15.
The way heat treated lumber for export is prepared is quite simple. The wood that is designated for export is placed into a special chamber that is heated until the wood core has reached a temperature of fifty-six degrees Celsius. The wood has to remain at that temperature for at least one half hour before it can be removed and cooled. Only then will it receive the ISPM 15 stamp that is necessary for export. It is not only straight wood planks that need to be treated. Wood wedges or dunnage needs to get the same treatment if it is to be exported.