Potassium sorbate is the potassium salt of sorbic acid, chemical formula C6H7KO2. Its primary use is as a food preservative (E number 202). Potassium sorbate is effective in a variety of applications including food, wine, and personal care products.

Potassium sorbate is produced by neutralizing potassium hydroxide with sorbic acid, an unsaturated carboxylic acid that occurs naturally in some berries. The colorless salt is very soluble in water.

Potassium sorbate is used to inhibit molds and yeasts in many foods, such as cheese, wine, yogurt, dried meats, apple cider, soft drinks and fruit drinks, and baked goods. It can also be found in the ingredients list of many dried fruit products. In addition, herbal dietary supplement products generally contain potassium sorbate, which acts to prevent mold and microbes and to increase shelf life, and is used in quantities at which there are no known adverse health effects, over short periods of time.

Also, it is used in many personal care products to inhibit the development of microorganisms for shelf stability. Some manufacturers are using this preservative as a replacement for parabens.

It has no noticeable flavor at normal usage levels. The preservative efficiency of potassium sorbate is particularly effective in foods with a pH rating up to 6.5.

Typical usage concentration 0.15-0.3% (if used alone) or 0.1-0.2% (if used in combination with other preservatives).

Typical intake usage rates of potassium sorbate are 0.025% to 0.1%, which in a 100g serving yields intake of 25 mg to 100 mg. Acceptable daily intakes for human is 12.5 mg/kg, or 875 mg daily for an average adult (150 lbs or 70 kg), according to FAO/World Health Organization Expert Committee on Food Additives.

It is completely dissolvable in water. Certificate of Analysis is available upon request.

Toxicology
A very mild and naturally inspired preservative. The U.S. Food and Drug Administration has found no evidence demonstrating that potassium sorbate would be a hazard when used at current levels or at levels that might reasonably be expected to be consumed in the future.
Potassium sorbate exhibits low toxicity with LD50 (rat, oral) of 4.92 g/kg, similar to that of table salt.
A skin, eye and respiratory irritant, although some research implies it has a long term safety record and non-toxic profile.

Reference
wikipedia
livestrong