CETEARETH-2 PHOSPHATE

Ceteareth-2 Phosphate is often used together with stronger surfactants to moderate skin feel or reduce irritation, by balancing cleansing strength vs gentleness.
Ceteareth-2 Phosphate is used in rinse-off products to help remove oils, dirt, sebum.
Ceteareth-2 Phosphate helps lather or at least spread of product.

CAS Number: 106233-09-4 
EC Number: 500-295-0
Formula    C9H8N3O2

Molecular Nature: Mixture of mono- and diesters of phosphoric acid with ethoxylated fatty alcohols (cetyl and stearyl, ~2 EO units)
Base alcohols: Cetyl alcohol (C₁₆H₃₄O), Stearyl alcohol (C₁₈H₃₈O)
Ethoxylation (~2 EO units): Adds –(CH₂CH₂O)₂– groups to the fatty alcohol
Phosphate esterification: Reaction with phosphoric acid (H₃PO₄) produces mono- and diesters

Molecular formulas (examples in the mixture):
Ceteth-2 phosphate: C₂₀H₄₃O₆P
Steareth-2 phosphate: C₂₂H₄₇O₆P

Molecular Weight (approximate range):
Ceteth-2 phosphate: ~410–430 g/mol
Steareth-2 phosphate: ~440–460 g/mol

SYNONYMS:
C16-18 alcohols, ethoxylated, phosphates (2 mol EO average), Ceteareth-2 phosphate, C16-18 alcohols, ethoxylated, phosphates (2 mol EO average molar ratio), Ceteareth-2 phosphate, C16-18 alcohols, ethoxylated, phosphates (2 EO),

Ceteareth-2 Phosphate is a phosphate ester derivative of ethoxylated cetearyl alcohol (which itself is a mixture of cetyl and stearyl alcohols).
The “2” refers to approximately 2 ethylene oxide (EO) units on average.

Because of the phosphate group, Ceteareth-2 Phosphate combines features of a non-ionic ethoxylated surfactant and some anionic/cationic (depending on pH) properties—though generally used as surfactant/emulsifier.

Ceteareth-2 Phosphate can change solubility or wetting behavior vs non-phosphated ceteareths.
Ceteareth-2 Phosphate is a polyethylene glycol ether of Cetearyl Alcohol (q.v.).

USES and APPLICATIONS of CETEARETH-2 PHOSPHATE:
Beyond standard cleansing and emulsifying, here are more specific or nuanced ways Ceteareth-2 Phosphate is used.
Shampoos, Shower Gels, Soaps: Ceteareth-2 Phosphate is used in rinse-off products to help remove oils, dirt, sebum.

Ceteareth-2 Phosphate helps lather or at least spread of product.
Skin Cleansers uses of Ceteareth-2 Phosphate: Facial or body washes where milder surfactants are desired.
Phosphated version can allow gentler cleansers with decent cleansing ability.

Emulsion Stabilizer in Cosmetic Creams/Lotions: When formulating creams or lotions that have both oil and water phases, Ceteareth-2 Phosphate helps stabilize the emulsion, especially when there are mild actives or botanicals.
Paired with Other Surfactants / Emollients: Ceteareth-2 Phosphate is often used together with stronger surfactants to moderate skin feel or reduce irritation, by balancing cleansing strength vs gentleness.

Product Texture / Feel Enhancer: Ceteareth-2 Phosphate helps improve spreadability of wash-off products, helps the feel of cream washes or cleansing lotions to be smoother (less “tight” or “strip-like”).
Ceteareth-2 Phosphate is used in skin care products, moisturizers, hair conditioners, sunscreens / sun protection products, indoor tanning / suntan products, and hair dyes, colors, and tints.

Because of its ethoxylation degree (24 EO units), Ceteareth-2 Phosphate tends toward stronger solubilizing capacity and better performance in formulations needing to dissolve or disperse lipophilic actives in aqueous phases.
Ceteareth-2 Phosphate works as an emulsifier: Ceteareth-2 Phosphate helps stabilize oil-in-water emulsions and reduce surface tension between oil-water phases.

FUNCTION(S) of CETEARETH-2 PHOSPHATE IN COSMETIC PRODUCTS:
*CLEANSING
Ceteareth-2 Phosphate cleans skin, hair or teeth

*SURFACTANT - CLEANSING
Surface-active agent to clean skin, hair and / or teeth

*SURFACTANT - EMULSIFYING
Ceteareth-2 Phosphate allows the formation of finely dispersed mixtures of oil and water (emulsions)

FUNCTIONS (INCI) of CETEARETH-2 PHOSPHATE:
*Cleansing : 
Ceteareth-2 Phosphate helps to keep a clean surface

*Emulsifying : 
Ceteareth-2 Phosphate promotes the formation of intimate mixtures between immiscible liquids by modifying the interfacial tension (water and oil)

*Surfactant : 
Ceteareth-2 Phosphate reduces the surface tension of cosmetics and contributes to the even distribution of the product when it is used

BENEFITS & CHARACTERISTICS of CETEARETH-2 PHOSPHATE:
Ceteareth-2 Phosphate is good ability to stabilize emulsions, giving smoother texture in creams/lotions etc.
Ceteareth-2 Phosphate enhances the feel / spreadability of cosmetic and personal-care products: helps ingredients distribute uniformly.

Because of its level of ethoxylation, Ceteareth-2 Phosphate provides a balance: sufficiently hydrophilic to mix with water, yet retaining some lipophilic compatibility to interact well with oils/emollients.
Ceteareth-2 Phosphate helps with cleansing: reduces interfacial tension so oils, dirt etc. can be removed when rinsed.

ADDITIONAL BENEFITS & CHARACTERISTICS of CETEARETH-2 PHOSPHATE:
Here are some deeper or less obvious benefits / traits of Ceteareth-2 Phosphate:

Characteristic / Benefit 
*Mildness / Reduced 
Irritation Because the EO chain is small (≈2), and the phosphate ester can help buffer or moderate surfactant action, Ceteareth-2 Phosphate is often less harsh than higher EO non-ionic surfactants or strong anionic surfactants.
Useful for sensitive skin formulations.

*Good Wetting & Spreading 
Ceteareth-2 Phosphate helps the formulation wet skin or hair surfaces more effectively, which can improve cleansing or dispersion of other ingredients.

*Moderate Foaming Potential 
While not primarily a foamer, in combination with other surfactants or under certain formulation pH it can contribute to or support foam.
Good for personal care cleansers.

*Emulsion Stability 
Ceteareth-2 Phosphate helps stabilize emulsions (oil/water) at low surfactant levels, helping reduce separation or “breaking” over time.
Helps with shelf stability.

*Cosmetic Acceptability 
Ceteareth-2 Phosphate helps produce a feel that consumers like: smooth, non-sticky, balanced (not too heavy oily, not too drying) especially in wash-off or daily use products.

*Formulation Flexibility 
Due to its dual nature (fatty alcohol backbone + phosphate + light EO), formulators can use Ceteareth-2 Phosphate in a wide pH range, with variety of co-emulsifiers, oils, or mild actives.

PHYSICAL & CHEMICAL PROPERTIES of CETEARETH-2 PHOSPHATE:
Ceteareth-2 Phosphate is an ethoxylated fatty alcohol (cetyl/stearyl base) with an average of 24 ethylene oxide units.

*Appearance: 
Ceteareth-2 Phosphate is typically waxy solid / flakes, white to off-white.

*Solubility: 
Ceteareth-2 Phosphate is dispersible in water when warmed and with agitation; more readily soluble in compatible non-ionic solvents or oils.

*Function in formulation: 
Ceteareth-2 Phosphate acts as a non-ionic surfactant, emulsifier, cleansing agent in cosmetics and personal care products.

WHAT IS IT?
Ceteareths (Ceteareth-2, Ceteareth-3, Ceteareth-4, Ceteareth-5, Ceteareth-6, Ceteareth-7, Ceteareth-8, Ceteareth-9, Ceteareth-10, Ceteareth-11, Ceteareth-12, Ceteareth-13, Ceteareth-14, Ceteareth-15, Ceteareth-16, Ceteareth-17, Ceteareth-18, Ceteareth-20, Ceteareth-22, Ceteareth-23, Ceteareth-24, Ceteareth-25, Ceteareth-27, Ceteareth-28, Ceteareth-29, Ceteareth-30, Ceteareth-33, Ceteareth-34, Ceteareth-40, Ceteareth-50, Ceteareth-55, Ceteareth-60, Ceteareth-80, Ceteareth-100) are liquids to waxy solids.

In cosmetics and personal care products, Ceteareth ingredients are used in skin care products, moisturizers, hair conditioners, suntan and indoor tanning products and hair dyes, colors, and tints.

WHY IS IT USED?
Ceteareth-2 to -18, and Ceteareth-22, help to form emulsions by reducing the surface tension of the substances to be emulsified.
Ceteareth-22 is also used to decrease the thickness of liquid cosmetics and personal care products.
Ceteareth-20 to -40 help other ingredients to dissolve in a solvent in which they would not normally dissolve, and along with Ceteareths-50 to -100, clean the skin and hair by helping water to mix with oil and dirt so that these substances can be rinsed away.

SCIENTIFIC FACTS
Ceteareths are made from cetearyl alcohol, which is a mixture of cetyl and stearyl alcohol, and ethylene oxide.
The numerical value represents the average number of molecules of ethylene oxide added to generate the specific Ceteareth ingredient.
For example, Ceteareth-2 is made by reacting Cetearyl Alcohol with an average of 2 molecules of ethylene oxide.

PHYSICAL and CHEMICAL PROPERTIES of CETEARETH-2 PHOSPHATE:
Product: Ceteareth-2 phosphate
CAS: 106233-09-4
Formula: C9H8N3O2
Class: Specialty Chemicals
Function: Surfactant, Emulsifier, Acid, Stabilizer
Industry: Cosmetic
Appearance: White to off-white waxy solid or paste
Odor: Bland or characteristic odor
Solubility: Soluble in water; forms stable emulsions
pH Stability: Stable in a broad pH range; hydrolyzes under highly acidic or basic conditions

HLB (Hydrophilic-Lipophilic Balance): Approximately 4.9
Flash Point: >100°C
Density: ~1.020 g/mL at 60°C
Melting Point: ~45°C
Boiling Point: Not available
Water Solubility: Approximately 11 mg/L at 25°C
Cloud Point: Low (specific values depend on formulation and concentration)
Foaming Behavior: Low foaming
Compatibility: Compatible with organic and hydrocarbon solvents; low freezing point
Applications: Emulsifier, penetrant, detergent, used in industrial cleaning, household detergents, and textile auxiliaries

Appearance: White to off-white solid, waxy flakes or powder
Chemical Family: Nonionic/anionic surfactant (phosphate ester)
Stability: Stable under normal storage and handling conditions; good hydrolytic stability
HLB Value: ~ 10–12 (suitable for O/W emulsions)
Reactivity: Stable with most cosmetic ingredients; may hydrolyze under strong acidic or basic conditions
Biodegradability: Considered readily biodegradable
Odor: Mild, characteristic

Solubility: Dispersible in water; soluble in alcohols; compatible with oils in emulsions
pH (1% solution): Typically 4.0 – 6.0
Melting Point: ~ 45 – 55 °C (varies slightly with supplier)
Boiling Point: Not applicable (decomposes before boiling)
Density: ~ 0.9 – 1.0 g/cm³
Flash Point: > 100 °C (estimated, not highly flammable)
Formulation Behavior: Functions as an oil-in-water (O/W) emulsifier and stabilizer

FIRST AID MEASURES of CETEARETH-2 PHOSPHATE:
-Description of first-aid measures
*General advice:
Show this material safety data sheet to the doctor in attendance.
*If inhaled:
After inhalation: 
Fresh air.
*In case of skin contact: 
Take off immediately all contaminated clothing. 
Rinse skin with
water/ shower.
*In case of eye contact:
After eye contact: 
Rinse out with plenty of water. 
Call in ophthalmologist. 
Remove contact lenses.
*If swallowed:
After swallowing: 
Immediately make victim drink water (two glasses at most). 
Consult a physician.
-Indication of any immediate medical attention and special treatment needed.
No data available

ACCIDENTAL RELEASE MEASURES of CETEARETH-2 PHOSPHATE:
-Environmental precautions:
Do not let product enter drains.
-Methods and materials for containment and cleaning up:
Cover drains. 
Collect, bind, and pump off spills. 
Observe possible material restrictions. 
Take up dry. 
Dispose of properly. 
Clean up affected area.

FIRE FIGHTING MEASURES of CETEARETH-2 PHOSPHATE:
-Extinguishing media:
*Suitable extinguishing media:
Carbon dioxide (CO2) 
Foam 
Dry powder
*Unsuitable extinguishing media:
For this substance/mixture no limitations of extinguishing agents are given.
-Further information:
Prevent fire extinguishing water from contaminating surface water or the ground water system.

EXPOSURE CONTROLS/PERSONAL PROTECTION of CETEARETH-2 PHOSPHATE:
-Control parameters:
--Ingredients with workplace control parameters:
-Exposure controls:
--Personal protective equipment:
*Eye/face protection:
Use equipment for eye protection. 
Safety glasses
*Body Protection:
protective clothing
*Respiratory protection:
Recommended Filter type: Filter A 
-Control of environmental exposure:
Do not let product enter drains.

HANDLING and STORAGE of CETEARETH-2 PHOSPHATE:
-Conditions for safe storage, including any incompatibilities:
*Storage conditions:
Tightly closed. 
Dry.

STABILITY and REACTIVITY of CETEARETH-2 PHOSPHATE:
-Chemical stability:
The product is chemically stable under standard ambient conditions (room temperature).
-Possibility of hazardous reactions:
No data available