I don't know if this is a generally known tip, but I discovered that the solvent used to clean up UPVC windows also does a great job on any foam that gets on skin.
Yes, I know, someone wasn't using gloves!
It works a treat and you just wash off with soapy water.
AFAIK the main solvent in the solvent based uPVC cleaners is Methyl isobutyl ketone. I am no chemist and I doubt that occasional exposure to it will be harmful, but as I said, I am no chemist.
I tend to use "decorators wipes" instead.
Oh, and yes, 75% of the time that I work with expanding foam, I will end up with some on my skin or in my hair (if I am using it under kitchen cupboards with wire wool to make the area mouse proof).
I never buy expanding foam without buying (or making sure that I already have) the aerosol can of cleaner as well.
BTW, be advised that the propellant used in expanding foam is VERY flammable. It is quite a heavy gas and thus lingers close to the floor until it evaporates off. There have been recorded cases of people receiving serious burns when using lots of the stuff in unventilated areas.
Keep the windows open, smoke outside and you will probably be fine.
