Isn't fire also a danger with plastic pallets? Generally, plastic fire is even worse than wood fire (in terms of heat and toxic substances generated). Wood burns, but it isn't instantly flammable and may in some circumstances withstand fire better than steel (though this is counter-intuitive).
You can add chemicals to plastic to make it resist fire, but those have other problems, often with toxicity.
Generally, if you have huge stacks of some unused material in a place, and it can catch fire, there is something wrong with the process. It would make sense that those pallets are worth some money so you can get rid of them easily. If not, should the local authorities control the amount of material stored if it can be a hazard?
You can add chemicals to plastic to make it resist fire, but those have other problems, often with toxicity.
Generally, if you have huge stacks of some unused material in a place, and it can catch fire, there is something wrong with the process. It would make sense that those pallets are worth some money so you can get rid of them easily. If not, should the local authorities control the amount of material stored if it can be a hazard?