The Blue pallets you see in the UK and all around the world are supposedly owned by GKN, they introduced them in the UK in the late 70,s. and where tightly controlled at first any delivery made on Chep (blue} pallet had to be replaced with another blue pallet if this was not possible, there used to be some documentation that had to be completed, and periodically someone from GKN Chep would visit and do an audit, to ensure they knew where the pallets were, that fell by the wayside quite quickly although they are still trying to control the use of them while they will burn some are treated with Methyl Bromide, they carry the stamp MB next to the word Chep { commonwealth handling pool } If my memory serves me, and definitely are not suitable to burn on a barbecue, the other issue with them and with all pallets, while they have a fairly long lifespan there is no way of telling what they have come into contact with during their previous usage, so my advise would be to steer clear of pallets of any type for use on a barbecue.