Polysorbate 80

Overview

Polysorbate 80 is a non-ionic surfactant made by reacting sorbitol (a sugar alcohol) with oleic acid (the main fatty acid in olive oil) and then ethoxylating the result with about 20 ethylene-oxide units. The resulting molecule has a fat-loving tail (oleate) and a water-loving head (the ethoxylated sorbitan), which lets it bridge oil and water.

It is one of the workhorses of cosmetic and pharmaceutical formulation — used in everything from facial mists to ice cream to vaccine adjuvants. In DIY cosmetics it is the standard tool for dissolving oils and oleoresins (heavy carrier oils, oil-soluble vitamins, oleoresin-form ROE) into water-based products.

Cosmetic-grade Polysorbate 80 is a clear-to-amber viscous liquid with a faint fatty smell. It is less skin-mild than Polysorbate 20 but stronger at dissolving heavier oils, which is the central trade-off when choosing between the two.

What it does in a formula

Primary role: solubilizer for oil-soluble materials in water-based products. The general rule is to use 1-3x the weight of the oil you want to solubilize. For a 0.5% essential-oil load you might use 1-1.5% Polysorbate 80; for a heavier 1% oleoresin you might use 2-3%.

Secondary roles: stabilizes emulsions when paired with a primary emulsifier (rarely used as a sole emulsifier in DIY because it gives weak, watery emulsions), and acts as a mild co-surfactant in cleansing systems.

It is one of the few materials that can dissolve heavy oleoresin-form ingredients like rosemary antioxidant (ROE) or vitamin-E concentrates into a water-rich product.

How to use

The technique is straightforward but easy to get wrong:

1. Weigh the oil-soluble ingredient (fragrance, essential oil, ROE, oil-soluble vitamin) into a small bowl
2. Add Polysorbate 80 at 1-3x the weight of the oil
3. Stir until you get a clear, uniform liquid (sometimes 30 seconds, sometimes a minute or two)
4. Add the combined oil+Polysorbate 80 to the water phase of the formula
5. Stir thoroughly

If you reverse the order — adding Polysorbate 80 to water first, then trying to add the oil — you usually get an opaque, milky dispersion instead of a clear solubilization. Pre-mix is the rule.

Usage range:

• Light fragrance solubilizing in water: 0.5-1.5%
• Essential oils in mists and toners: 1-2%
• Oleoresins (ROE, vitamin E in oil): 2-3%
• Heavy carrier oils in clear gels: 3-5%
• Mineral oil or silicone solubilizing: 3-5%

pH range: stable across the full cosmetic pH range.

Best for / Worst for

Best for: clear toners, mists, and serums containing fragrance or essential oils; ROE solubilization for oxidation protection of clear products; vitamin E delivery in water-based formulas; mosquito sprays and bug repellents (it dissolves heavier essential oils that Polysorbate 20 struggles with); cleansing oils that need to rinse with water.

Worst for: fragrance-only solubilizing in skincare (Polysorbate 20 is gentler and works for fragrance), sensitive-skin face products (PS80 has a slightly stronger irritation profile than PS20), products that need to stay sticky-free at very low usage (PS80 leaves more residue than PS20).

Common pitfalls

Wrong ratio. Using equal parts oil and Polysorbate 80 (1:1) is often not enough for heavier oils. Test small batches — start at 2:1 (PS80 to oil) and adjust down once you see a clear solution.

Wrong order. Pre-mix the oil and Polysorbate 80 first. Adding them separately to water leaves a hazy dispersion that does not feel solubilized.

Using it where Polysorbate 20 would be gentler. For light fragrance (under 0.5%) or for facial mist applications, PS20 is the better choice. Save PS80 for heavier loads.

Forgetting it has a faint smell. The oleate base has a mild fatty smell. Not unpleasant, but noticeable in unfragranced products.

Using it as a sole emulsifier. It is too weak. Pair with a real emulsifier (Olivem 1000, Montanov 68, BTMS-50, etc.) for actual emulsions.

Substitutes

• Polysorbate 20 — gentler, lighter, better for fragrance solubilizing and sensitive-skin formulas.
• PEG-40 Hydrogenated Castor Oil — also called Cremophor RH40; strong solubilizer for heavy oils in clear formulations.
• Caprylyl/Capryl Glucoside (also Polyglyceryl-10 Caprylate/Caprate) — natural-positioning solubilizer; weaker but ECOCERT-friendly.
• Olive Squalane + Tween blends — natural-positioning custom solubilizers.
• Decyl Glucoside — natural surfactant with some solubilizing power.