I worked at a pallet mill none of the wood was treated

You actually CAN know where they’ve been and what they’ve been used for, if you just pay attention to what industry they have been used in, and if you look them over carefully before you bring them home.

As far as wood treatment, there are codes on the side that will tell you what has or has not been used to prepare the wood before it was put together as a pallet. Look at the codes. If there are no codes, though, avoid the pallet altogether, as with THOSE you have no idea of knowing how they have been pre-treated.

“… the main one to watch out for is MB. It means it was treated with Methyl Bromide.
If you don’t see an IPPC logo then you know not to use it. While a pallet may be perfectly safe without the logo, it could also mean it was treated with chemicals.”
(source: https://www.instructables.com/id/How-to-determine-if-a-wood-pallet-is-safe-for-use/?ALLSTEPS)

“There are two main things to watch for on the stamp:

The IPPC Logo: if you don’t see it, don’t use it! Even if a pallet may be perfectly safe without this logo, it could also mean that it was treated with chemicals!
The treatment code : [HT] = Heat treatment / [MB] = Methyl Bromide / [DB] = Debarked / [KD] = Kiln Dried.
The IPPC logo is for the International Plant Protection Convention (IPPC) pallets that are used and shipped internationally. These pallets are required to be made of a material that will not carry invasive insect species or plant disease through different countries. To meet the IPPC standards, a pallet can not be made of raw wood that has not been treated, in other terms, all pallets are treated. These pallets must be treated by one of the following methods, and the treatment will be under the supervision of an official agency approved to do this. Without this stamp, the pallet may be safe or not, so you should only use pallets whose source can be traced for a safe use.”
(source: https://www.1001pallets.com/pallet-safety/)

One final thing, if people are not careful, they can get used pallets that have chemicals spilled on them, and that can endanger people, pets, and livestock. Depending on the usage of the pallets (whether for building storage buildings or making raised gardening beds), it could be either a small hindrance or a huge problem. If there is ANY chance dangerous toxins could be on used pallets, pass on them. If there’s a chance there may be potentially very dangerous chemicals, and they cannot be sealed up with primer and paint, it’s just not worth the chance, in my opinion.

Hi Debra, Thank you so much for following along. We are glad you enjoyed it.