@ MrSnuggles
When thinking of oil fumes from a chemical standpoint it is a valid question, really. "Oil" is a mix of several hydrocarbons, each with its own ignition point. Oil can evapourate, thus "oil vapour" (or, mostly "fuel vapour" in aviation world) and it can burn, thus "oil smoke" but it is hard to define "oil fume" chemically.
Water is not described in the term "water fumes" either. You'd prefer "water vapour" or maybe "mist" or "fog" ;-)
About organophosphates, there is to my knowledge no real time detector but as it is a quite sticky family of compounds, I would suggest bringing a sterile cotton swab into the cockpit. Remove it from its protection layers when starting the flight and put it into a test tube when the flight is over (or when you had enough...) and send it to the closest agricultural lab to analyze. They have a vast experience with organophosphates within the agricultural industry so it is inexpensive but might be scary when you get your results back...
Don't ask if you don't want the answer and so on...
Agree 99%, except it is easy to define a fume