Preservatives in skincare — what they do

Preservatives keep water-based formulas safe from microbial growth. Modern, well-tolerated systems are why your essence stays safe for months.

18 preservatives in the K-beauty INCI decoder

• Benzoic Acid — A preservative that helps prevent the growth of mold and bacteria to keep a product safe.
• Benzyl Alcohol — A naturally occurring preservative and solvent that helps protect a product from spoilage.
• Butylparaben — A preservative that helps guard a formula against bacteria and mold over its shelf life.
• Chlorphenesin — A preservative that helps protect a product from microbial growth so it keeps fresh through use.
• Dehydroacetic Acid — A preservative that helps keep a product free of microbes so it stays fresh and safe.
• Diazolidinyl Urea — A preservative that helps keep a product free of microbes to maintain freshness.
• DMDM Hydantoin — A preservative that helps prevent bacterial growth so a product stays safe to use.
• Ethylhexylglycerin — A gentle preservative booster that supports other preservatives while also softening and conditioning the skin.
• Ethylparaben — A preservative that helps keep a product stable and safe by limiting bacterial growth.
• Imidazolidinyl Urea — A preservative that helps protect water-based products from bacterial contamination.
• Methylchloroisothiazolinone — A potent preservative (used with methylisothiazolinone) effective at very low levels; restricted to rinse-off products due to allergy risk.
• Methylisothiazolinone — A potent preservative used in very small amounts, mainly in rinse-off products; a frequent contact allergen now restricted in leave-on products.
• Methylparaben — A long-established preservative that helps keep a product free from bacteria and fungus.
• Phenoxyethanol — A widely used preservative that helps keep a product free of bacteria and mold so it stays safe to use over time.
• Potassium Sorbate — A mild food-grade preservative that helps stop yeast and mold from growing in a product.
• Propylparaben — A preservative from the paraben family that helps protect a formula from microbial spoilage.
• Sodium Benzoate — A gentle preservative that helps keep a formula stable and free from bacteria during its shelf life.
• Sorbic Acid — A gentle preservative that helps protect a formula against yeast and mold.

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✍️ Written & reviewed by the KoreaPlus Editorial team — dermatologist-informed, cosmetic-science researched & source-cited. Last reviewed: 2026-08-08.

General educational information using cosmetic structure-function wording — not medical advice. Always patch-test new actives. © KoreaPlus.