Heat Treating Wood for International Shipping
How do I go about getting information about heat treating wood for international shipping?
(United States) The general requirement for heat sterilization is to heat the interior of the wood configuration (center of the middle board in the stack) to 133 degrees Fahrenheit for a period of at least 30 minutes. The most common method to do this is with high humidity heat (steam) rather than dry heat, because when using dry heat, the water being released by the wood as it dries helps to cool the wood, causing the process to take much longer. Using steam becomes more cost-effective because it takes much less time to heat the interior to 133 degrees. This is explained in part in a publication found here: http://www.fpl.fs.fed.us/documnts/pdf2006/fpl_2006_simpson002.pdf
For more information, check the USDA Forest Products Laboratory website at www.fpl.fs.fed.us
and search for "heat sterilization" and "international trade."
(Great Britain) There is the timber kiln drying standard ISPM 15 referred to by many in the timber trade simply as 56/30. This is a process of bringing the temperature of the wood inside the kiln to 56º C (~133º F) and holding it for 30 minutes, which completely kills any fungus present; it allows the seller of the wood to mark it with the ISPM 15 mark indicating compliance with the standard. Here is one place to start reading up on the subject, http://www.forestry.gov.uk/pdf/infonotepurchasedhtdbrev110504.pdf/$FILE/infonotepurchasedhtdbrev110504.pdf
This article originally appeared in the Woodworker's Journal eZine.
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