Hi Carpenter, I agree with you that in the light of all the other environmentally unsound things that we all do, MDF emissions are minute. However, if one can eliminate this bad thing from one's home environment, then why not eliminate it? Every little helps and if I can do this small thing, then I will do it. As we will also be trying to have an eco friendly heating system, using sustainable wood windows, doors, floors and ecofriendly insulation, then it would seem silly to have a kitchen emitting gases, ( however miniscule), which can't really be recycled without emitting dioxins. The old kitchen that is in the house is already recycled in that it came from another house and i would hope to pass on at least some of it to someone else. It is a solid wood kitchen so it can be burnt. I'll have to check the carcasses though. I get your point about that being a waste of good wood to use it for carcasses. However, if we are talking about cheap renewable pine then why not use it? If there is a cheaper and entirely safe alternative, we'll have a look at that too.
On the landfill question, you are right people throw out perfectly good wood items and that is very wrong, of course they should be used as a a heat source. However, if the wood is treated in some way I really couldn't say whether the chemicals released into the atmosphere would be less hazardous than if it was allowed to rot in landfill. I imagine with the technology involved in modern incineration that emissions can be reduced to very low levels but without further research I couldn't say.
Thanks for your helpful replies.