Cooling Agent WS-10: The Gentle, Persistent Cool for Skin and Mouth

WS-10 stands apart in the WS range because it is the line’s liquid workhorse, and its cooling behaves differently from the crystalline grades. Because WS-10 acts across the entire oral mucosa and on the skin at once, it delivers a gentle, persistent cool rather than a sharp, localized one. Consequently, formulators use it where a soft, lingering freshness matters more than a hard burst. This post explains why WS-10 cools gently yet persistently, where that profile fits, and how to build solvent-free systems around it.

Why WS-10 cools gently yet persistently

WS-10 (Menthoxypropanediol, CAS 87061-04-9, FEMA 3784) is a colorless, low-viscosity liquid with virtually no aroma and very low volatility. First, its cooling reaches the whole oral mucosa and the skin simultaneously, so the sensation spreads instead of landing in one spot. Next, at roughly 4.5 times the strength of menthol, it stays gentle — with no bitterness, burning or numbness. In addition, its two hydroxyl groups give it better water compatibility than most WS coolants, while purity holds at ≥99% (GC). Most importantly, because the cool is persistent yet soft, products feel refreshing without turning clinical.

Where a gentle persistent cool fits

The broad, soft profile suits products that touch skin and mouth alike. For example, skin creams, lotions, after-sun and shaving products gain a calm, lasting cool that never stings. Meanwhile, toothpaste, mouthwash and lozenges keep a fresh feel without a medicinal edge. Furthermore, beverages, dairy and confectionery use the same gentle cool at low doses (around 10 mg/kg). Beyond these, shampoos, body washes and pharmaceutical plasters rely on the same mucosa-and-skin action. In every case, WS-10 supplies comfort rather than shock.

How to build solvent-free systems with WS-10

Start by adding WS-10 directly to the oil phase, or pre-dissolve it in PG or ethanol before dosing. Because it is a liquid, this step needs no crystal dispersion and keeps batches uniform. Next, blend WS-10 with WS-3 or WS-23, or with menthyl lactate, to extend and shape the cooling curve. As a result, you build layered, longer-lasting systems without added solvent. Therefore, request a sample and COA to set the dose for your base, and review our applications guide for starting points by category.