Drying to ISPM 15 Specs

Wood for foreign-bound pallets and crating needs to be heat-treated according to International Standards for Phytosanitary Measures (ISPM) criteria. There's a strict standard and a verification requirement, so it's not a casual undertaking. August 29, 2006

I have a Nyle 4000 kiln, and my customer wants fir beams dried to ISPM 15 specs 150 degree core temp for 30 min. Can my kiln do this? How long will it stay in the kiln to get core at 150 degree F? This is for shipping overseas.

Forum Responses
(Sawing and Drying Forum)
From Professor Gene Wengert, forum technical advisor:
ISPM requires that the wood temperature throughout be 56 degrees C (133 F) for 30 minutes, and not 150 F.

To obtain certification, which includes the ability to stamp every piece as heat treated, you need to pay a certification agency. They will come and certify the kiln controls. You will also need to have a record of temperature, so a thermometer is not enough... you need a chart. Your equipment will be checked once a month randomly for compliance.

One agency that does this is the NHLA. They charge around $250 per month and also travel expenses. In other words, this is not something that is done casually, but is a very intense and rigorous program intended to prevent the spread of disease.

The kiln unit you are asking about is the same as the Nyle L-200 and the compressor goes to 120 F maximum. It is not designed to meet the heat treating standards, obviously.

From contributor D:
I have the same kiln and routinely take it to 175 degrees when setting the pitch in Doug fir. Of course, the compressor isn't working, but the heater will get the temperature up there once the wood is dry.

From contributor L:
Yes, contributor D is right, you can heat the lumber to sterilize with an L200 (or DH4000), but the refrigeration system must be off when you do it. 175F is pushing it. We (Nyle) usually tell people to keep it under 160F.

Gene is right about the certification and it is probably not economic to do unless you are doing a lot of it. NHLA does allow you to turn in the stamp months you don't need it, but many of the agencies don't, so once in, you are all the way in and it will run $4000-5000 a year just to be certified. Also, you will need a recorder to keep a paper chart of each load.