Potassium Sorbate
In plain terms
The potassium salt of sorbic acid, a food-grade preservative used as a gentler paraben alternative. Your body clears it like a fatty acid with no buildup; the only catch is a rare sensitivity to sorbic acid.
What the evidence shows
Potassium sorbate is the potassium salt of sorbic acid, a preservative that started in the kitchen and moved into skincare as a gentler stand-in for parabens and formaldehyde releasers. Its job is to hold back mold and yeast in water-based products. The safety record is long and dull in the best way: regulators rate it safe for food, your body handles it like a fatty acid and clears it to water and carbon dioxide without storing any, and it does not build up. Toxicity tests come back practically clean, and irritation is minor even at concentrations far above what any product would use. The one caveat worth naming is that sorbic acid, which potassium sorbate becomes on contact with water, is a rare skin sensitizer. A small share of people can react to it, more often in leave-on products or on already-irritated skin, but the rates in testing sit below one percent, which is why it does not carry the allergen flag that stronger sensitizers do. It also works best in slightly acidic formulas and is usually paired with another preservative to cover bacteria. For most people, in most products, it is one of the cleaner preservatives on the shelf.
On the label
Listed as potassium sorbate or E202. It is one of the gentler preservatives and a common paraben alternative; the only group to watch is people who react to sorbic acid, usually in leave-on products or on broken skin.