Thanks for your help, blakenoah. I have further questions.

The crates which were sent to us from Japan utilized both heat treated wood with the official stamps and were also fumigated because of the solid lumber feet and supports.

To reuse these crates, would I have to have them re-fumigated? And is it safe for me or other staff to work with recently fumigated crates? If methyl bromide kills bugs, is it safe for me to be working around?