Top 5 Eco-Friendly Emulsifiers for Sustainable & COSMOS-Approved Formulations

Every cream, lotion, and milk you make is a quiet act of diplomacy: you're persuading oil and water — two things that genuinely do not want to mix — to live together in a stable, elegant texture. The emulsifier is the diplomat.

For a long time that job was done by ethoxylated (PEG-based) emulsifiers. They're cheap, forgiving, and effective — but they're made using ethylene oxide, and they're prohibited under the COSMOS standard. As formulators move toward greener, certifiable products, a new generation of plant-derived emulsifiers has stepped in. They're beautiful to work with once you understand them — but they are not drop-in swaps for the PEGs you may have learned on.

Here are five worth knowing, and how to actually formulate with them.

A note on HLB: HLB (Hydrophilic-Lipophilic Balance) is a rough guide to what an emulsifier "wants" to do — lower values (3–6) favour water-in-oil, higher values (8–18) favour oil-in-water. Treat it as a starting map, not a guarantee: many natural emulsifiers form liquid-crystal networks whose behaviour isn't fully captured by a single HLB number.

1. Cetearyl Olivate (& Sorbitan Olivate)

INCI: Cetearyl Olivate, Sorbitan Olivate

Best-known trade name: Olivem® 1000 · Type: O/W · Typical use: 2–5% · Approx. HLB: ~8–9 · ✅ COSMOS-approved

Derived from olive oil, this is one of the most popular natural emulsifiers for good reason: it forms a liquid-crystal structure that mimics skin's own lamellar lipids, giving a soft, cushiony, skin-like feel and useful occlusivity. It is beloved for facial creams and rich body lotions.

• Loves: moderate-to-high oil phases; gives a luxurious, velvety skin feel.
• Processing: hot process — heat both phases to ~70–75 °C before combining.
• Watch: can feel soapy or draggy if the oil phase is too low; benefits from a co-emulsifier or a small amount of gum (xanthan, sclerotium) for long-term stability, particularly in formulas containing electrolytes or high levels of actives.

2. Cetearyl Glucoside (& Cetearyl Alcohol)

INCI: Cetearyl Glucoside, Cetearyl Alcohol

Best-known trade name: Montanov® 68 · Type: O/W · Typical use: 1–5% · Approx. HLB: ~10–12 · ✅ COSMOS-approved

An alkyl polyglucoside (APG) emulsifier built from fatty alcohols (coconut- or palm-derived) and glucose. It also forms liquid crystals, produces glossy, stable emulsions, and tolerates a reasonably wide pH range. A reliable workhorse for lighter lotions and milks.

• Loves: medium oil phases; pairs well with a hydrocolloid gum for suspension of particles or pigments.
• Processing: hot process — heat both phases before combining.
• Watch: sourcing — the fatty alcohol component is typically palm-derived. If sustainable sourcing is central to your brand, ask for RSPO-certified or traceable palm documentation from your supplier.

3. Sucrose Stearate (Sucrose Esters)

INCI: Sucrose Stearate (grade-dependent; other sucrose ester INCIs available)

Best-known trade name: Sisterna® range · Type: O/W (grade-dependent) · Typical use: 1–5% · Approx. HLB: varies widely by ester grade (~3 to ~16) · ✅ COSMOS-approved

Made from sugar and vegetable fatty acids, sucrose esters are wonderfully gentle — a genuinely strong choice for sensitive-skin and baby-type products. Different grades carry very different HLB values, so you can blend a high- and low-HLB grade to dial in the emulsion type and stability you need.

• Loves: light, fresh lotions; fluid emulsions; blending grades for a tailored HLB target.
• Watch: can be less robust as a sole emulsifier — often performs best as part of a combined system, sometimes alongside a co-emulsifier or gum. Some grades are heat-sensitive; always follow the supplier's recommended process temperature and addition method.

4. Sodium Stearoyl Lactylate (SSL)

INCI: Sodium Stearoyl Lactylate

Type: O/W · Typical use: 0.5–3% (most effective as a co-emulsifier) · Approx. HLB: ~8–10 · ✅ COSMOS-approved

Derived from lactic acid and stearic acid, SSL is an anionic emulsifier that punches above its weight, particularly as a co-emulsifier that boosts the stability of a primary system. It contributes light, elegant textures and is naturally derived and readily biodegradable.

• Loves: partnering with a primary emulsifier; light lotions and sprayable emulsions.
• Watch: being anionic, it can be sensitive to low pH and incompatible with cationic ingredients (e.g. certain conditioning agents such as behentrimonium chloride) — always check compatibility before finalising your formula.

5. Polyglyceryl Esters

INCI examples: Polyglyceryl-3 Dicitrate/Stearate, Polyglyceryl-4 Caprate, Polyglyceryl-6 Distearate

Type: O/W or W/O depending on grade · Typical use: 1–5% · ✅ COSMOS-approved (grade and supplier dependent — always verify)

This is a whole family rather than a single ingredient, built from plant-derived glycerine and fatty acids. There are grades for O/W and W/O emulsions, cold-processable options, and solubiliser-type grades suited to micellar waters and mists — making polyglyceryl esters one of the most versatile green toolkits available to the modern formulator.

• Loves: versatility — depending on the grade, you can build sprayable lotions, W/O sunscreens, or elegant cold-process emulsions.
• Watch: grades are not interchangeable. HLB, emulsion type, recommended use level, and processing method all vary significantly between grades and suppliers. This is the ingredient family that most rewards careful reading of the supplier's technical data sheet and starting formulas before you begin.

Honourable mentions

• Lecithin / Hydrogenated Lecithin (e.g. Emulmetik™; INCI: Lecithin / Hydrogenated Lecithin) — phospholipid emulsifiers with excellent skin affinity, but native lecithin is prone to oxidation and odour development; hydrogenated grades offer improved stability. Sourcing (soy vs. sunflower) is worth considering for allergen and sustainability reasons.
• Cetearyl Wheat Straw Glycosides & Cetearyl Alcohol — an APG emulsifier using non-food-crop agricultural by-product as feedstock, which is a positive sustainability story. Note the wheat-derived origin if you are catering to any gluten-sensitive marketing positioning, even though cosmetic products are not ingested.

A few honest formulating truths

• Green emulsifiers are more demanding than PEGs. Many rely on liquid-crystal networks that require an adequate fatty phase, correct processing temperature, good high-shear mixing, and often a hydrocolloid gum (xanthan, sclerotium gum) as a stability co-pilot. Expect to iterate — this is normal and not a sign you have chosen the wrong emulsifier.
• Stability testing is non-negotiable. Run freeze-thaw cycles and hold samples at elevated temperature (40–45 °C) for a minimum of several weeks. Check appearance, pH, viscosity, and odour over time. A cream that looks perfect on day one can separate at week six.
• "Natural" does not automatically mean COSMOS-approved. COSMOS certification applies to a specific raw material from a specific supplier, verified through their documentation — not to an ingredient category in the abstract. Always confirm the exact grade's certification status directly with your supplier and your certifier before making any on-pack claims.
• Palm and coconut sourcing matters. Several of these emulsifiers use palm- or coconut-derived fatty alcohols and fatty acids. If responsible sourcing is part of your brand promise, request RSPO certification or equivalent supply-chain traceability documentation.
• Gentle does not mean irritant-free for everyone. Even mild, well-tolerated emulsifiers can cause a reaction in some individuals. Always recommend patch testing of finished products, and ensure your safety assessor reviews the full formula before launch.

Quick reference

*Grade-dependent — always check the supplier TDS. Verify COSMOS status for the specific grade and supplier.

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This article is educational and is not a substitute for the manufacturer's technical data sheet, your own stability and safety testing, or a qualified cosmetic safety assessor's review. Always verify use levels, processing conditions, and regulatory or certification status against the supplier's current documentation and the applicable regulations for your target market.