I googled it and got this:
http://www.doityourself.com/stry/3-health-effects-of-freon-exposure
...and other sites. A snippet:
When Freon gases are in very high concentration, they can cause dizziness, asphyxia and loss of coordination and concentration. They may cause irritation, particularly with regard to sensitive skin (skin rashes, dermatitis, etc.), but the good news is that Freon has no long term effects on health. Freon is not a mutagen, teratogen or carcinogen, and it does not affect the liver.
>> Freon has no long term effects on health. Freon is not a mutagen, teratogen or carcinogen, and it does not affect the liver.
“Ask your doctor if Freon is right for you.”