Most cosmetic creams are oil-in-water (O/W), but the formulas that win in hot, humid climates are often the opposite: water-in-oil (W/O) or water-in-silicone (W/Si). In these architectures the water phase is dispersed inside a continuous oil or silicone film, giving longer wear, better sweat resistance and a drier after-feel. The ingredient that makes either system possible is the right silicone emulsifier. This guide walks through the Damongwz W408–W422 range, explains how to match each grade to a W/Si or W/O brief, and compares silicone emulsifiers with traditional polyol-ester alternatives.
W/Si vs W/O: what the architecture changes
Both W/Si and W/O put water droplets inside a non-aqueous continuous phase. The difference is the continuous phase itself.
| Feature | Water-in-silicone (W/Si) | Water-in-oil (W/O) |
|---|---|---|
| Continuous phase | Silicone (dimethicone, volatile silicone, phenyl silicone) | Oil (ester, hydrocarbon, vegetable oil, UV filter oil) |
| Skin feel | Very light, fast dry-down, powdery or silky | Richer, more occlusive, longer play-time |
| Sweat / water resistance | Excellent | Very good |
| Best applications | Long-wear foundation, primer, water-resistant sunscreen, makeup base | Sunscreen, rich night cream, dry-skin balm, colour cosmetic |
| Typical emulsifiers | Low-HLB PEG dimethicones: W410, W418 | Low-HLB silicone or polyol esters: W408, W411 |
The choice usually comes down to feel and claim. If the brief is "lightweight, dry-touch, survives sweat," start with W/Si. If it is "nourishing, high SPF, rich coverage," W/O is usually easier to formulate.
The W408–W422 range at a glance
Every grade in this range is a PEG- or PEG/PPG-modified dimethicone. The length and type of modification change the HLB and therefore the optimal emulsion type.
| Grade | INCI | HLB | System fit | Primary character |
|---|---|---|---|---|
| W408 | Lauryl PEG-8 Dimethicone | 3.0 | W/O primary | Strong W/O emulsifier; high molecular weight; excellent oil compatibility and pigment dispersion |
| W410 | PEG-10 Dimethicone | 4.2 | W/Si primary / W/O auxiliary | Lightweight, stable W/Si film; good spread and fast dry-down |
| W411 | Cetyl PEG/PPG-10/1 Dimethicone | 3.0 | W/O primary | Broad oil compatibility (hydrocarbon, vegetable, ester, UV filters); strong pigment dispersion |
| W412 | PEG-12 Dimethicone | 12.2 | Co-emulsifier / water-phase additive | Water-soluble; adds gloss, slip and foam boost; reduces tack |
| W418 | Bis-PEG/PPG-18/18 Dimethicone | 2.7 | W/Si primary / W/O auxiliary | Creates a distinct water-break effect; very light, powdery after-feel |
| W422 | Bis-PEG-12 Dimethicone | 14.7 | Co-emulsifier / water-phase additive | Easily disperses in water; transparent; hydrating, lightweight, conditioning |
See full COA notes and sample specs on the Silicone Emulsifiers category page.
How to pick an emulsifier by system and feel
| Product goal | Lead emulsifier | Co-modifier | Why this pair |
|---|---|---|---|
| Ultra-light W/Si foundation | W410 | W412 1–2% | W410 builds the W/Si structure; W412 adds gloss and reduces powderiness. |
| Water-resistant sunscreen (W/Si) | W410 or W418 | W422 1–2% | W418 gives a dry, water-break feel; W422 improves water-phase solubility and spread. |
| Velvety primer / makeup base | W410 | — | Low HLB gives a tight, powdery film that layers well under colour. |
| Rich W/O sunscreen | W408 or W411 | — | Low HLB and broad oil compatibility handle high UV-filter loads. |
| Long-wear colour cosmetic | W411 | W412 0.5–1% | W411 disperses pigments strongly; a touch of W412 improves flow and wetting. |
| Glossy serum / body spray | — | W412 or W422 2–4% | High-HLB grades disperse in water and add a silky, non-tacky sheen. |
Building a basic W/Si foundation or sunscreen
- Silicone phase (external, 25–40%). Blend volatile dimethicone or methyl trimethicone with any pigments, UV filters or elastomer powders. This phase will form the continuous film on skin.
- Primary emulsifier (2–5%). Add W410 (or W418 for a drier feel) to the silicone phase and disperse evenly.
- Water phase (internal, 40–60%). Combine water, glycerin, butylene glycol, preservatives and any water-soluble actives. Keep electrolytes low.
- Emulsify. Add the water phase slowly to the silicone/emulsifier blend while homogenising at medium–high shear. Continue until droplet size is fine and uniform.
- Finish. Cool below 40°C and add heat-sensitive actives, fragrance or additional W412/W422 for gloss.
Building a basic W/O sunscreen or colour cosmetic
- Oil phase (external, 30–50%). Combine UV filters, esters, hydrocarbons or vegetable oils with pigments. Heat if needed to dissolve solid UV filters.
- Primary emulsifier (2–4%). Add W408 or W411 to the oil phase. W411 is usually the safer default when the oil phase is complex (multiple UV filters + pigments).
- Water phase (internal, 40–60%). Mix water, glycerin, preservatives and any water-soluble actives. Heat to match the oil phase temperature if a hot process is used.
- Emulsify. Add the water phase to the oil phase under high shear. W/O emulsions generally need stronger homogenisation than O/W to achieve a fine internal droplet size.
- Stabilise. Add a small amount of W12 wax, fumed silica or magnesium sulphate if the emulsion is soft or shows syneresis.
For humid markets, test at 45°C and 75% RH for at least four weeks, plus a freeze-thaw cycle. W/O formulas can look stable in the lab but separate under thermal stress if the water droplets are too large.
Silicone emulsifiers vs traditional polyol-ester emulsifiers
| Attribute | Silicone emulsifier (W408–W422) | Traditional polyol-ester emulsifier |
|---|---|---|
| Film feel | Lighter, silkier, faster dry-down | Often richer, waxier, slower absorption |
| Water resistance | Excellent (especially W/Si) | Moderate; needs additional film former |
| Pigment / UV filter dispersion | Very good with low-HLB grades | Good; depends on oil polarity match |
| Cost | Higher per kilo | Usually lower |
| Best claim fit | Long-wear, sweat-proof, lightweight, silky | Hydrating, nourishing, cost-sensitive |
Many premium Southeast Asian and Middle Eastern brands use both: a silicone emulsifier as the primary architecture for performance, and a small amount of traditional emulsifier or co-surfactant to control cost and sensory.
Three mistakes that break silicone emulsions
- Adding the emulsifier to the wrong phase. Low-HLB W/Si and W/O emulsifiers must be pre-dispersed in the oil or silicone phase before water is introduced. Dumping them into water causes immediate inversion or separation.
- Ignoring HLB matching. W410 (HLB 4.2) works for W/Si because the continuous silicone phase is hydrophobic. W412 (HLB 12.2) is too hydrophilic to stabilise W/Si on its own. Match the emulsifier HLB to the system.
- Overloading electrolytes. Salt, magnesium sulphate and some preservatives can collapse W/Si emulsions. Add electrolytes last, at the lowest effective level, and run stability tests.
For the water-dispersible PEG-12 grades (W412 / W422) used as silicone surfactants in clear serums, hair care and rinse-off systems, see our water-dispersible silicone surfactant guide.
FAQ
What is the difference between W/Si and W/O emulsions?
Both place water droplets inside a non-aqueous continuous phase. In W/Si the continuous phase is silicone, giving a very light, fast-drying, sweat-resistant film ideal for long-wear makeup and water-resistant sunscreen. In W/O the continuous phase is oil, giving a richer, more occlusive feel better suited to nourishing sunscreens and dry-skin products.
Can W410 be used as the only emulsifier in a W/Si formula?
Yes, W410 is designed as a primary W/Si emulsifier at typical use levels of 2–5%. Many formulators also add 0.5–2% of W412 or W422 to adjust gloss, spread or water-phase compatibility, but W410 alone can stabilise a straightforward W/Si foundation or sunscreen.
Why choose a silicone emulsifier over a traditional polyol-ester emulsifier?
Silicone emulsifiers create lighter, silkier films with better sweat and water resistance than most traditional polyol-ester emulsifiers. They also disperse pigments and UV filters well in silicone- or oil-continuous systems. The trade-off is a higher raw-material cost, so they are most common in premium long-wear, sun-care and colour-cosmetic lines.
Which grade is best for a waterproof sunscreen?
For a W/Si waterproof sunscreen, start with W410 or W418 as the primary emulsifier. W418 gives a drier, more distinct water-break feel, while W410 is more forgiving and produces a silkier film. Add 1–2% W422 if the formula needs extra water-phase solubility and spread.