I checked a few of the pallets where I work; they're heat treated, no chemical treatment. But! While I'd feel safe using the pallets used to ship corrugate bundles, the pallets used to ship the sketchy drums of mystery chemicals look identical and end up in the same trailers headed off to some pallet recycler.
Also, dust from certain species of wood can be quite bad for you. If I didn't know the origin and history of a piece of wood, I'd likely avoid working with it.
I checked a few of the pallets where I work; they're heat treated, no chemical treatment. But! While I'd feel safe using the pallets used to ship corrugate bundles, the pallets used to ship the sketchy drums of mystery chemicals look identical and end up in the same trailers headed off to some pallet recycler.
I keep forgetting to check the CHEP pallets.