PEG-100 Stearate- ▸ O/W emulsifier: Stabilizes oil-in-water creams and lotions.
- ▸ Co-emulsifier: Provides the hydrophilic partner in emulsifier pairs.
- ▸ Emulsion stabilizer: Improves emulsion stability and texture.
A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.
Request SDS →PEG-100 Stearate (CAS 9004-99-3) is the polyethylene glycol (100 EO) monoester of stearic acid — a hydrophilic, nonionic oil-in-water (O/W) emulsifier widely used across personal care and cosmetics. With a high ethylene-oxide content, it carries a high HLB (~18.8) and almost never works alone. Formulators reach for it as the hydrophilic half of the classic Glyceryl Stearate (and) PEG-100 Stearate self-emulsifying base, where it is paired with low-HLB glyceryl stearate to build stable, easy-to-process O/W creams and lotions.
What PEG-100 Stearate does in a formulation
PEG-100 Stearate is built by esterifying stearic acid, a C18 fatty acid, with polyethylene glycol of roughly 100 ethylene-oxide units. That long EO chain is what makes it strongly water-loving. On its own it is too hydrophilic to emulsify a typical oil phase, so its job is to supply hydrophilic character to a balanced emulsifier system — it pulls the overall HLB up toward the level an O/W emulsion needs.
Pair it with glyceryl stearate (HLB ~3.8) and the combined blend lands near HLB 11, a practical target for emulsifying the non-polar oils and waxes common in skin-care. The two-emulsifier approach is more forgiving than a single surfactant: it tolerates a wider oil-phase range and tends to produce smoother, more stable emulsions. The trade-off is that you are committing to a fixed glyceryl-to-PEG ratio, so if your oil phase is unusually polar or unusually heavy you may still need to adjust co-emulsifiers or stabilizers rather than rely on the pair alone.
Applications
Primary O/W emulsifier and co-emulsifier
The dominant use is as the workhorse emulsifier for lotions, creams, and milks. As the Glyceryl Stearate (and) PEG-100 Stearate system it functions as a self-emulsifying (SE) base — add it to the oil phase, combine the phases hot, and it builds the emulsion with straightforward processing. This is why it is one of the most reached-for O/W systems in cosmetic labs: predictable, easy to scale, and stable across a useful pH window, which makes it a common choice for formulas that include acidic actives such as AHAs and BHAs.
Solubilizer for oils and fragrance
Because of its high hydrophilicity, PEG-100 Stearate also helps carry small amounts of oil-soluble material — light oils, emollient esters, and fragrance — into the water phase. Formulators use it to keep these components evenly dispersed rather than separating out over shelf life.
Texture and viscosity contribution
Beyond emulsifying, the stearate backbone contributes body and a characteristic smooth, cushioned skin-feel. In the SE blend it supports viscosity build without heavily thickening the formula, which gives formulators room to dial in rheology with the rest of the system rather than fighting an over-thick base.
Forms and grades
PEG-100 Stearate and the glyceryl stearate / PEG-100 stearate SE blend are typically supplied as solid flakes, pastilles, or pellets that melt into the oil phase during processing. Two procurement paths are common: the pre-blended Glyceryl Stearate (and) PEG-100 Stearate SE emulsifier, bought as a single ingredient for drop-in formulating, or standalone PEG-100 Stearate for labs that prefer to build and tune their own emulsifier ratio. Confirm INCI composition, blend ratio where applicable, and grade specifics against the supplier’s technical data sheet and Certificate of Analysis for each lot.
Handling
Store in a cool, dry place in closed containers and handle per the Safety Data Sheet, which governs PPE, storage, and incompatibilities. The SDS and CoA are the authoritative source for handling and specification — review them before formulation and scale-up.
Source PEG-100 Stearate in bulk
RawSource sources PEG-100 Stearate (CAS 9004-99-3), and the complete Glyceryl Stearate (and) PEG-100 Stearate self-emulsifying emulsifier system, in bulk for personal-care and cosmetic manufacturers. Tell us your target volume, packaging, and ship-to location and we will return a quote. Request a quote to get started.
Reviewed and updated July 2026 by the RawSource technical team.
PEG-100 Stearate is a hydrophilic, nonionic polyethylene glycol ester of stearic acid (CAS 9004-99-3), used with glyceryl stearate as the standard oil-in-water emulsifier pair in creams and lotions.
PEG-100 Stearate: key figures for buyers
- 1,844 cosmetic formulations reported using PEG-100 Stearate in 2023 use data, up from 424 formulations in 2002, per the CIR Safety Assessment of PEG Stearates (2024 re-review).
- 6% maximum reported use concentration for PEG-100 Stearate in the 2023 survey, down from the 25% ceiling reported in 2002 (CIR, 2024).
- “Safe as cosmetic ingredients in the present practices of concentration and use”: the Expert Panel conclusion covering PEG-100 Stearate, first published in 1983 and re-affirmed in the re-review published in 2005 (Cosmetic Ingredient Review).
- 1:1 blend ratio on record for Glyceryl Stearate/PEG-100 Stearate, registered under UNII RD25J5V947 and CAS 84750-06-1 (FDA Global Substance Registration System, accessed July 2026).
- 344.2 index points in May 2026 (preliminary) for the US producer price index, surface-active agent manufacturing, up 2.0% from 337.5 in May 2025 (BLS series PCU325613325613).
Regulatory & registration requirements
- TSCA (US):
- REACH (EU): Not determined from public registry
- EC number: 618-405-1
TSCA Inventory flag XU: a substance exempt from reporting under the Chemical Data Reporting Rule (40 CFR 711) (EPA flag legend).
Source: EPA TSCA Inventory (July 2025 release) · ECHA CHEM — retrieved 2026-07-12
Frequently Asked Questions
What is PEG-100 stearate?
PEG-100 Stearate (CAS 9004-99-3) is a nonionic surfactant — the polyethylene glycol (100 EO) monoester of stearic acid. It is a hydrophilic, high-HLB oil-in-water emulsifier used in creams, lotions, and related personal-care formulations, most often as the hydrophilic partner in an emulsifier pair.
What is glyceryl stearate and PEG-100 stearate used for?
Glyceryl Stearate (and) PEG-100 Stearate is the classic self-emulsifying O/W base in cosmetics. The two are bought together as one emulsifier blend: glyceryl stearate is the low-HLB lipophilic partner and PEG-100 stearate is the high-HLB hydrophilic partner, and together they land near HLB 11 to emulsify the oils and waxes in lotions and creams. The pair is valued for easy processing and stable emulsions across a useful pH range, including acidic formulas with AHAs or BHAs.
What is PEG-100 stearate made from?
It is produced by esterifying stearic acid, a C18 fatty acid, with polyethylene glycol of about 100 ethylene-oxide units. The long EO chain makes it strongly hydrophilic, which is why it is commonly paired with a lipophilic co-emulsifier such as glyceryl stearate.
Is PEG-100 stearate water soluble?
The high ethylene-oxide content (100 EO) makes PEG-100 Stearate strongly hydrophilic, so it disperses and solubilizes well in water and serves as the hydrophilic partner in O/W emulsifier pairs. Exact solubility behavior depends on the formulation; consult the technical data sheet.
How is bulk PEG-100 stearate supplied?
PEG-100 Stearate and the glyceryl stearate / PEG-100 stearate SE blend are typically supplied as flakes, pastilles, or pellets in bulk industrial packaging such as drums and totes. CoA and SDS are provided per lot; contact RawSource with your volume and destination for available pack sizes.
What is the cost of bulk PEG-100 stearate?
Bulk pricing varies with volume, packaging, blend versus standalone grade, and destination. Request a quote from RawSource with your target quantity and ship-to location for current landed pricing.
Is glyceryl stearate and PEG-100 stearate natural?
No. The ethoxylated half of the pair makes the blend synthetic. CIR documents PEG stearate manufacture by esterification of stearic acid with polyethylene glycol, or by direct ethoxylation of stearic acid, a process whose reactants include ethylene oxide. PEG ingredients therefore sit outside natural-origin positioning even when the stearic acid feedstock is plant-sourced. Buyers building certified natural lines should confirm ingredient eligibility with their certifier before specifying this system.
Is PEG-100 stearate safe for skin?
The Cosmetic Ingredient Review Expert Panel concluded that PEG-100 Stearate and nine related PEG stearates are “safe as cosmetic ingredients in the present practices of concentration and use.” That finding was first published in 1983 and re-affirmed in the Panel’s re-review published in 2005. CIR’s 2024 re-review reports 1,844 formulations using PEG-100 Stearate in 2023 at concentrations up to 6%. Qualify each lot against its SDS and CoA, and run your own product safety assessment as your quality system requires.
What is the trade name for glyceryl stearate and PEG-100 stearate?
The blend sells under many trade names, most carrying the number 165. FDA’s Global Substance Registration System lists Arlacel 165, Tego Care 165, Simulsol 165, Lipomulse 165, Ritapro 165, and Protachem GMS-165 among the names registered for Glyceryl Stearate/PEG-100 Stearate (UNII RD25J5V947). Specifications can differ between producers, so qualify an alternate grade against its technical data sheet and Certificate of Analysis rather than the trade name.
What is the INCI name for glyceryl stearate and PEG-100 stearate?
On raw-material documentation the blend is declared as Glyceryl Stearate (and) PEG-100 Stearate, the INCI names of its two components. Finished-product ingredient lists carry each component separately. FDA’s Global Substance Registration System records the 1:1 combination as Glyceryl Stearate/PEG-100 Stearate, with UNII RD25J5V947 and CAS 84750-06-1 assigned to the blend itself. Confirm the declared composition on each supplier’s documentation before regulatory filing.
What is the REACH and TSCA regulatory status of PEG-100 Stearate?
PEG-100 Stearate (CAS 9004-99-3) is listed as Active on the U.S. EPA TSCA Inventory; its REACH registration status is not determined from the public ECHA registry.