Indeed, and I'll add another thing: engine cleaner, like brake or carb cleaners, contains toluene, and quite often benzene and other aromatic solvents. They are amongst the strongest solvents you can find, but they also happen to be highly cancerigen. They should be avoided unless there's no other choice to get the job done.

As for cleaning with white spirit, I wouldn't do it because it's known to dissolve certain plastics, and also because it's runny enough that I'd worry about dripping some into a bearing. I think citrus-based cleaners, or those "bio engine cleaners", as well as soapy water are the way to go to make a bike shine safely.