There is a growth I think called Bracket Fungus on a the trunk of a Sycamore tree. Is this fungus poisonous to humans?
Is Bracket Fungus Poisonous
Some old herbals list bracket fungi as useful in treating certain diseases; however, more modern sources list them as poisonous. Be that as it may, they are certainly not edible. But if you mean, can you be poisoned by handling or brushing agains one, I wouldn't think so. Gloves are recommended if you're planning to mess with one, however. Here's some more information: https://www.gardeningknowhow.com/ornamental/fungus-lichen/tree-bracket-fungus.htm