I feel as if I’ve spent about a month collecting and chopping up pallets. I haven’t a clue how much firewood I’m going to need, so I’ve probably erred on the side of caution (I hope I have!). I must have collected at least 30 of the things, most of which came from one firm in Harlesden.
At one time, the roof was piled four pallets high along its entire length, and I had to stay put until I’d chopped enough of them up to allow me to see where I was going. While I was doing this, a woman cycling along the towpath stopped and asked me whether it was ok to burn pallets. She was under the impression that they were treated with something nasty that makes them give off poisonous fumes. I didn’t know whether she was right or wrong but I thought I’d better check.
What I found out is that pallets have to be treated to ensure that they cannot carry insects or plant diseases to other countries. Usually this involves heat treatment but some pallets, mostly from the USA, have been treated with a chemical called bromomethane, also known as methyl bromide. This is a seriously nasty chemical that damages various parts of the body, may be carcinogenic and attacks the ozone layer for good measure. Apparently it has now been phased out, but some pallets are still in use. My haul included only one such pallet, and I was able to weed it out before it found its way on to the fire (but after I’d spent a fair amount of time chopping it up).
Fortunately, they are usually quite easy to spot. Pallets from outside Europe have a stamp on them that describes how they have been treated. The stamp usually looks something like this:
The logo on the left is made up of the letters IPPC, which stands for International Plant Protection Convention, and HT means that it has been heat treated. Pallets that have been fumigated with methyl bromide will have MB instead. The one I found was clearly labelled, but not in a position where it was easy to spot. Not all countries use this exact stamp, but all those from outside Europe should have either HT or MB stamped on them.
I don't know whether this is news to anyone. I certainly wasn't aware of it until recently, so I hope this is useful to anyone thinking of using pallets as part of their firewood supply.