Not sure what you mean. We used dried ivy stems as kindling for getting the fire going with no obvious ill effects. If you mean throwing the whole green leaved stuff on a bonfire then sorry, no idea, we forgot to leave a space for a bonfire when we designed the garden.

I can't see why burning ivy would cause you to get sick...

Ingestion of Hedera is supposed to be emetic and purgative though there are far too few cases reported to be able to gauge what amount would cause poisoning.

The literature is almost all about contact dermatitis.

I know nothing about the effects from burning so it, clearly, hasn't been written up by anyone.

I wonder if your neighbours may have ingested plant material from their hands when building the bonfire.

But, it seems to me, since you can't know what nasties may be in the smoke of any bonfire, the important thing is to make sure you're not going to be in the smoke before you light it.

I often have to burn ivy when I have a bonfire, as we had loads of it on the ground. It's not easy to burn when it's green, but catches light eventually when the heat from the bonfire has dried it enough. It burns then without problems that I'm aware of.

Thanks very much. It sounds as though it's safe to have the ivy bonfire but maybe I'll wait until my neighbours are away!

That would be thoughtful of you - no point in upsetting them when you can avoid it.

How long does it take to dry live ivy out on a bonfire