We have a 1915 house that we've lived in for two months. The house has been well cared for and kept up to high standards by the previous owner in the last 20 years. A couple of years ago the whole house was insulated with some kind of spray foam (the inspector said it was the "best kind" but I don't know what. It's yellow.).

The attic has a very strong smell. It's a kind of sweet chemical smell. It almost makes my throat burn to be up there for too long and I can taste it in my mouth when I leave. The entire peaked roof is insulated with exposed spray foam. I have assumed the smell was from the foam, but I have no experience with it and now I'm not so sure. Does spray foam insulation smell? Or could this be some old animal smell? I know animal urine can smell sweet but it's not a maple syrup smell like I've heard others describe. It had a definite chemical edge.

I'm almost certain there wasn't an uncontrolled rodent infestation in the last 20 years; there were probably occasional mice like in any old house but the previous owners were incredibly meticulous and they wouldn't have let something overtake the attic.

Any thoughts? Thanks!