Can all pallet wood be used for indoor projects?

A lot of pallet wood is full of chemicals

There are two main things to look 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

It depends on how they are treated. If with chemicals, no, that would give off chemicals into the air which would not be good.

https://www.1001pallets.com/pallet-safety/

NO! Some of the older ones will be the kind of pressure-treated wood that off-gasses poison.

http://www.instructables.com/id/How-to-determine-if-a-wood-pallet-is-safe-for-use/

https://www.1001pallets.com/pallet-safety/

There are other links where you can read up on the safety of pallet wood. One issue you need to be careful about is wood that has carried certain food products as there have been reports of E.coli on the wood. I would think this would be covered in one of the links I provided for you above. Good luck!!

Pallet wood is rough sawn and made for constrution/industrial site purposes to move goods with. They can be found in scrap yards. If you want your home to look like Sanford and Son, go ahead and use it.

I would worry about anything that may have spilled onto the pallet during its first life. As long as they look clean I would say that you are good to go.