Yesterday, a reader alerted us to the possible dangers of wooden shipping pallets, especially found ones that are so great for d-i-y projects.
When we read that even new wood pallets could be subject to chemical treatments, we did some research to figure out how we can happily keep making things out of wood pallets, which we view as a sort of Lego for grownups: the perfect building block. So here is the best info we have on navigating found pallets (with some additional info woven in just this morning), plus a great source of pure wood pallets.
We discovered that the shipping pallets you find at the dump or on the street could be problematic. They could
a) have been exposed to potentially toxic bacteria from food, animals, or drug residues from whatever they were used for etc.
b) be made from pressure-treated wood, a chemical heat-treating process sometimes used to make them more durable and prevents insect infestation (used mainly for international shipments). That makes them something you probably don’t want inside the house unless you seal them to prevent possible exposure to the chemicals. Heat-treated pallets “bears the initials HT near theIPPC logo (the regulatory agency that oversees international pallets); the problem is that pressure-treating is only one of the kinds of heat treatments allowable; it will not be indicated by the stamp). If you happen to know what pressure-treated wood looks like, you can just avoid this wood.
c) have been fumigated with potentially toxic insecticides to prevent insect infestation (for pallets that have been shipped internationally). Pallets fumigated with methyl bromide bear the initials MB near the IPPC logo. As of March 19, 2010, the use of Methyl Bromide has been phased out.
There’s no way for us to gauge how great the dangers really are, although they don’t seem that dire to us. The gist, like just about everything these days: use found pallets according to your own good judgement and comfort level. Reading our Projects Consultant Nina Saltman‘s comments, below, should allay some fears as well.
If you’re nervous about using found pallets, you can buy chemical-free wood pallets at Uline,”the Shipping Supply Specialist”, whose mail-order catalogue we find endlessly inspiring. They sell pallets made from new wood (from a non-coniferus northern hardwood, such as oak, elm, maple, or cottonwood) or recycled wood (a mix of any of these woods). If you want to prevent any kind of insect activity, you can buy the pallets heat-treated, which means they’ve been heated to a certain temperature – without chemicals.
Now, here’s what Nina Saltman had to say about the matter:
“I am not an expert on pallets, but this is what I DO know…mostly from having worked in warehousing (previous lifetime), and receiving pallets: Most common pallets that I am familiar with are NOT pressure treated, or treated in any way. They are usually C-grade lumber material with many flaws (known as checks, pits, and knots). They are often very rough lumber. There are those pallets that I have seen, that are much heavier duty, that are thicker dimensioned lumber, and in some cases have been pressure treated. Pressure treated should not be confused with fire treated. There are many different ways of treating lumber. The link following is “simplified pressure treated 101″. http://www.naturalhandyman.com/iip/infxtra/infpre.html
So then the next question is whether you can seal it etc. The short answer is Yes. The longer answer is that often times pressure treated lumber has these little hatch marks all along the wood surface. It is not especially good looking, and is hard, if not impossible to fill, sand out, or disguise. That being said you can paint, seal stain etc. pressure treated like any other type, it just may look darker, as the pressure treating usually darkens the wood already…I do not think that short term, occasional handling of pressure-treated wood is a problem. If I handle treated lumber for any length of time, or project, I usually wear gloves and wash my hands before I eat. I would not recommend treated lumber near food, but do not think of it as a hazard for general building useage. I used it on the foundation, and deck framing lumber for our shed, for instance.”
Click here to read about the pallet house above, designed as disaster relief (what about those pallets?)
Related posts: PS: Some Possible Dangers of Wood Shipping Pallets