Yes, it has been approved as a safe ingredient by the U.S. Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA), as well as Joint FAO/WHO Expert Committee on Food Additives (JECFA).


Metabolism

Potassium sorbate is the salt of unsaturated fatty acids that participate in fat metabolism and finally metabolized into water and CO2 in the human body. (10)

FDA
It is generally recognized as safe (GRAS) as a chemical preservative when used in accordance with good manufacturing practice. (11)

How much to use
Approved with the following concentration (12):

Cheeses < 0.3%
Fruit Butter & Art Sw Jelly & Preserves < 0.1%
Margarine & Oleomargarine < 0.1% or 0.2% total in combination w/other preservatives
EFSA
Potassium sorbate (E202) is listed in Commission Regulation (EU) No 231/2012 as an authorised food additive and categorized in “Additives other than colours and sweeteners” (13).

Approved uses
The following food list may contain with potassium sorbate at the maximum use levels ranging from 20 to 6,000 mg/kg (14):

Cheese of unripened ripened, whey or processed
Spreads, beverage whiteners
Jam, jellies and marmalades
potato dough and pre-fried potato slices
Chewing gum
Toppings
Pre-cooked or processed cereals
Bread, fine bakery wares
Meat products
Seasonings and condiments
Fruit juices, beer Cider and perry
Aromatised wines

http://www.chinafooding.com/Potassium_Sorbate