Hi!
I also have allergy to potassium sorbate.
If I include it on my creams, it makes the skin become red skin for about 15min, if I don't include it, then nothing happens. I tried it many times, and it happens at the recommended 0.3% and even at 0.05%. I also have a similar irritation (but not as much) if I use 0.5% sodium benzoate. I guess these salts (and their acids counterparts) are very irritant for the skin.
I found that at least 2 other people, out of 20 that tried my lotion, that had these same allergies. 10% is a very high percentage of irritation!
Now, I use 15% of organic alcohol in my lotions to preserve them. It works against bacteria and fungi (I tested them with lab equipment) and it does not dry or irritate the skin at all. It must be at least 15%.
