Some chemicals, we don't have enough info on one way or another. The less exposure to anything the better. You can drink hydrochloric acid if it is diluted enough, ammonia under your sink is less harmful than anhydrous (refrigerant) ammonia because it is diluted. I would recommend looking up the MSDS for any refrigerant you work with to see what information is known and what precautions to take. It is not a bad idea to error on the side of caution.
Also, it seems like politics has some influence on MSDS data so don't take it as gospel. Last time I looked at the one for gasoline, (or was it diesel) it said there wasn't enough information to determine whether it is a carcinogen (which I find hard to believe there is not enough info.) But it is probably best to limit exposure as much as possible. No reason to wash your face with it.
Here is the DuPont MSDS page for refrigerants. All the other manufaturers have them as well, this was just easy for me to find: