Quick Search

PRODUCTS

STEARETH-21

CAS Number: 9005-00-9
EC Number: 500-017-8
Molecular Formula: C20H41O2
Molecular Weight: 313.5383

Waxy compound that is a derivative of the fatty alcohol stearyl alcohol
Functions as a surfactant and solubilizing agent

Helps keep ingredients together in an emulsion
Deemed safe by the independent Cosmetic Ingredient Review panel

Steareth-21 is a surfactant composed of polyethylene glycol polymer and stearyl alcohol.

A waxy solid material that helps oil and water to mix together, aka emulsifier. 
Steareth-21 is super similar to Steareth-20 with just a little more ethoxylation and thus a little more water solubility. 
Steareth-21 works very well when combined with mostly oil-soluble emulsifiers such as Steareth-2 and the two together can form exceptionally stable emulsions. 

Steareth-21 is a waxy compound that functions as a surfactant, emulsifier and solubilizing agent, all of which helps create optimal aesthetics for skin care formulations. 
Steareth-21 is often combined with other steareth ingredients, such as steareth-2, for an improved sensory profile.

Steareth ingredients are prepared by interacting with the chemical intermediate gas ethylene oxide with stearyl alcohol, a process which forms an entirely new stable compound. 
The number that comes after (for instance, 21) indicates the average number of ethylene oxide units used in the preparation.

In 2012, the independent Cosmetic Ingredient Review panel ruled that steareth-21 is safe as used in cosmetics in amounts up to 7%.
There have been concerns about the safety of steareth ingredients because toxic 1,4-dioxane, a by-product of ethoxylation, can be produced; however, this is eliminated through purification processes.

Steareth-21 is a polyethylene glycol ether made from stearic acid. 
Steareth-21 is used as an emulsifier in cosmetics and personal care products, including makeup, lotions, personal cleanliness products and deodorants, as well as suntan, fragrance, skin, eye and hair care products. 

The Steareths are "prepared by reacting ethylene oxide with stearyl alcohol where the numerical value in the name corresponds to the average number of units of ethylene oxide. 
Therefore, Steareth-21 is prepared using an average of 21 units of ethylene oxide reacted with stearyl alcohol, and is relatively liquid compared to higher Steareth values, which become waxy solids.

Steareth-21 is a polyethylene glycol ether obtained from stearic acid.
Steareth-21 is a synthetic cleansing agent & emulsifier used in skin care & hair care products.

Steareth-21 is also used as a solubilizing agent. 
Steareth-21 is a non-ionic emulsifier. 

A waxy solid material that helps oil and water to mix together.
Steareth-21 is considered safe to be used on skin & hair when present in Steareth-21 formulations.

In this research, birefringent emulsions stabilized with Steareth-2 and Steareth-21 were studied. 
Some authors attributed to them a liquid-crystalline structure, although the microphotographs presented by them as an evidence of such structure actually suggest the presence of solid crystals instead of liquid crystals. 

The purposes of this paper are to determine the true cause of the birefringence of this type of emulsions and to study how the composition of the oily phase influences the stability and the bire- fringence. 
Six emulsions stabilized with a mixture of Steareth-2 and Steareth-21 were prepared, each one with a different emollient. 

Four of them were birefringent while two were isotropic. 
The observed birefrin- gence would be due to the presence of solid crystals and not of liquid-crystals. 

These solid crystals could be originated by the interaction between both emulsifiers, either between themselves, with stearic acid or cetyl alcohol presents in the formulations, or even because of the insolubility of stearic acid or cetyl alcohol in emollient oil. 
Moreover, the isotropic emulsions showed greater viscosity than the birefringent ones. 
This result is accorded to the fact that the birefringence is not related to the presence of a liquid-crys- talline interphase, because this type of interphase leads to an increase of viscosity.

Steareth-21 Emulsifier, commonly used in underarm products. 
Due to Steareth-21 special characteristics, good electrolyte resistance and good texture, not sticky.

Steareth-21 is a polyethylene glycol ether made from stearic acid. 
Steareth-21 is used as an emulsifier in cosmetics and personal care products, including makeup, lotions, personal cleanliness products.

Steareth-21 is a chemical compound consisting of the polymer of polyethylene glycol and stearic alcohol.
Steareth-21 appears as white granular flakes.

Acts as a non-ionic surfactant and emulsifier. 
Can be used individually, or in combination with a variety of other hydrophobic emulsifi ers to cover a wide range of oil in water and water in oil emulsions.

Function in Steareth-21:
O/W emulsifier, component enabling the formation of an emulsion. 

Emulsion is a physicochemical form that is created by combining (mixing) the water phase with the oil phase. 
Examples of cosmetic emulsions are creams, lotions, lotions. 

A substance that stabilizes foam and improves the quality of foam in a mixture with anionic surfactants. 
Steareth-21 acts as a rheology modifier (i.e. improves the consistency causing an increase in viscosity) in washing preparations containing anionic surfactants, thanks to the formation of the so-called mixed micelles.

Cosmetic action of Steareth-21:
Washing substance, removes impurities from the surface of the hair and skin. 
The moisturizing substance facilitates the contact of the cleaned surface with the washing solution, which facilitates the removal of impurities from the surface of the skin and hair.

Functions of Steareth-21:
Cleaning agent: Helps keep a surface clean

Emulsifying agent: Promotes the formation of intimate mixtures between immiscible liquids by modifying the interfacial tension (water and oil)

Surfactant: Reduces the surface tension of cosmetics and contributes to the even distribution of the product during use

Application of Steareth-21:
A nonionic emulsifier, suitable to obtain O/W cream and lotions, also can be used as stabilizer for skin care.
Excellent emulsify ability, suitable for emulsification of mineral oil(eg: white oil),nature oil, stearyl and etc.

Can obtain a steady system when used alone.
Steady property,can uses in high density electrolytical system.
Vegetable based,low irritation.

Uses of Steareth-21:
Steareth-21 as surfactant is used for skin and hair-cleaning purposes and as emulsifier and solubilizing agent in Hair Care products, Hair Colorants and Developers. 
Steareth-21 helps to keep the product stable over time and is also a "wash-out" component in Developers and Hair Colorants, means Steareth-21 helps to remove all residues after a Hair Color application.

Steareth-21 is classified as:
Cleansing
Emulsifying
Surfactant

Storage of Steareth-21:
Can be stored at room temperature But close the bottle tightly And sealed from direct sunlight or heat, Steareth-21 is at least 2 years old

Keep in dry and cool conditions, Resist freezing and light.
Period of validity: One year. (<35°C)

Safety Measures/Side Effects of Steareth-21:
Steareth-21 is considered a low hazard ingredient. 

There are some concerns regarding the contamination of Steareth-21 with small amounts of 1,4-dioxane, a by-product of ethoxylation and a known toxin. 
However, this contamination can be controlled through purification and is not considered a likely hazard in cosmetics or personal care products.

Security of Steareth-21:

Safety of the ingredient of Steareth-21:
Steareth-21 is safe for use in cosmetic products. 
Cosmetic Ingredient Review: In a 2012 report, CIR experts recognized Steareth-21 (belonging to the group of PEG alkyl esters) as a safe ingredient in cosmetic products. 

CIR stipulates that the preparations should be formulated so as not to be irritating. 
Steareth ingredients can increase the penetration of other ingredients through the skin, so care should be taken when formulating cosmetic products with ingredients whose safety rating is based on no permeation. 
This evaluation is also intended to consider future PEG alkyl ether cosmetic ingredients that differ from those listed here only in the number of ethylene glycol repeating units.

Pure Substance Safety of Steareth-21:
Not classified as a dangerous substance according to chemical regulations.

Physical and Chemical Properties of Steareth-21:
Appearance: White to ivory white flake.
Odor: Characteristic odor
melt point: 42.0~46.0
Acid Value(mgKOH/g): ≤1.0
Hydroxyl Value(mgKOH/g): 43.0~53.0
water Content(%): ≤1.0

Assay: 95.00 to 100.00 % 
Food Chemicals Codex Listed: No
Boiling Point: 413.00 to  414.00 °C. @ 760.00 mm Hg (est)
Flash Point: > 200.00 °F. TCC ( > 93.33 °C. )
logP (o/w): 7.966 (est)
Soluble in: water, 0.01014 mg/L @ 25 °C (est)

Chem/IUPAC Name of Steareth-21:
brij 721
brij S721
cromul EM1207

Synonmys of Steareth-21:
hetoxol STA-21
lipocol S-21
2-octadecoxyethanol (peg-21)
peg-21 stearyl ether
poly(oxy-1,2-ethanediyl), .alpha.-octadecyl-.omega.-hydroxy- (21 mol EO average molar ratio)
polyethylene glycol (21) stearyl ether
polyoxyethylene (21) stearyl alcohol ether
polyoxyethylene (21) stearyl ether
2-(Octadecyloxy)ethanol
2136-72-3
2-Octadecoxyethanol
9005-00-9
Ethanol, 2-(octadecyloxy)-
Ethylene glycol monooctadecyl ether
POE (10) stearyl alcohol ether
2-(octadecyloxy)ethan-1-ol
Steareth-20
Steareth-21
Ethanol,2-(octadecyloxy)-
2-Octadecyloxyethanol
3-Oxahenicosane-1-ol
2-(octadecyloxy) ethanol
2-(octadecyloxy)-ethanol
6-Tetrachloro-2-picoline
DSSTox_CID_9299
C18-alcohol polyethoxylate
AMTGC009
DSSTox_RID_78754
DSSTox_GSID_29299
Polyoxyl stearyl ether (NF)
SCHEMBL490673
Ethoxylated Stearyl Alcohols 2
Polyoxyethylene(100) stearate
CHEMBL3181944
Ethoxylated Stearyl Alcohols 20
a,a,a,6-Tetrachloro-2-picoline
Polyethylene glycol stearyl ether
DTXSID60858842
DTXSID70891669
AMY36496
C20H42O2
EINECS 218-374-0
Tox21_202772
MFCD00043351
ZINC56898840
AKOS015839820
AS-2008
HEXADECANOIC-7,7,8,8-D4ACID
NCGC00260319-01
CAS-9005-00-9
DB-066492
BB 0256761
CS-0318307
FT-0682442
D08975
F20467

  • Share !
E-NEWSLETTER