And if so how they are dangerous and how dangerous they are. I'd really appreciate it if I could get a definite answer that doesn't rely on having to be believed or not.

---- If some things below sound odd it's because I copied and pasted it from a yahoo answers post I made that wasn't getting any answers. ----

I've googled and found a lot of Q&A on this but nobody that cites scientific sources and where everyone has a different opinion from "It can cause respiratory problems." to "It's fatal." to "It's just an annoying smell."

My technician says it's O.K. and no worse than smelling a bit of bug spray, my doctor says he has no idea, the technician checked everything and said he fixed it but he didn't.

I really need to know the cold hard facts on this because I have pre-existing respiratory problems and right now I have the flu.

BTW I'm of course talking about that oil smell that comes out sometimes when the furnace kicks on.

I think I just figured out why there is no definite answer on this question. Like every Q&A place there are categories and while as with every question I ever post I typically get 4-5 answers real quick and then no more, I cannot expect anyone who knows biology to know anything about furnace oil fumes while also I can not expect anybody who knows about furnace oil fumes to know anything about biology.