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Hydroxyethyl laurdimonium chloride (HELD or Hydroxyethyl laurdimonium chloride) is a cationic surfactant and conditioning agent belonging to the family of quaternary ammonium compounds.
It is widely used in personal care (hair conditioners, shampoos), textile and detergent formulations for its antistatic, softening, and deposition-enhancing properties.
CAS 2271-92-3
Common synonyms and identifiers:
Hydroxyethyl laurdimonium chloride
1-Dodecanaminium, N-(2-hydroxyethyl)-N,N-dimethyl-, chloride (IUPAC-derived)
Alkyl dimethyl ethanol ammonium chloride (lauryl) — generic
(C12)alkyl(hydroxyethyl)dimethylammonium chloride
Quaternary ammonium compounds, C12-18-alkyl(hydroxyethyl)dimethyl, chlorides (commercial mixtures)
Hydroxyethyl laurdimonium chloride (often abbreviated HELD or HY-Laurdimonium chloride in industry documentation) is a mono-hydroxyethyl substituted laurdimonium quaternary ammonium salt.
The substance combines a hydrophobic lauryl (C12) alkyl tail with a cationic quaternary ammonium center and a small hydrophilic hydroxyethyl group, giving it a balance between water dispersibility and substantive interaction with negatively charged substrates such as hair and fabrics.
It is used primarily as a hair-conditioning agent, antistatic agent, and fabric softener active. Commercial products are often sold either as relatively pure C12 lauryl homologs or as C12–C18 mixtures (designated generically as alkyl C12–18).
This distinction matters for physical properties and regulatory identifiers.
Molecular structure and physicochemical properties
Structure
The structural motif is a quaternary ammonium cation with three substituents: one long alkyl chain (lauryl — C12), two methyl groups, and an N-(2-hydroxyethyl) substituent that contains a terminal hydroxyl group. The counter-ion is chloride (Cl–).
The general formula for the lauryl homolog can be written as C12H25–N+(CH3)2–CH2CH2OH Cl–.
Molecular formula and weight (theoretical)
Empirical formula (lauryl homolog): C16H36ClNO (approximate — depends on exact alkyl chain definition and whether mixture present).
Molecular weight (approximate for pure lauryl homolog): ~289–315 g·mol⁻¹ (users should consult supplier spec for exact values).
Physical properties
Appearance: pale yellow to amber liquid or viscous liquid at room temperature (commercial grades vary).
Solubility: highly soluble and dispersible in water; soluble in alcohols and polar organic solvents to varying degrees.
pH: aqueous solutions typically mildly alkaline to neutral depending on concentration and impurities.
Surface activity: strong cationic surfactant, lowers surface/interfacial tension in aqueous systems; shows critical micelle concentration (CMC) behavior typical for long-chain quaternary ammonium salts.
Cloud point: may show temperature-dependent phase behavior when combined with nonionic surfactants; cloud point influenced by electrolytes and specific co-surfactants.
Chemical stability
Hydroxyethyl laurdimonium chloride is generally stable under neutral and mildly acidic or basic conditions.
Hydrolytic degradation can occur under strong alkaline or strongly acidic conditions, particularly at elevated temperatures, leading to dealkylation or Hofmann-type degradation products.
Oxidative agents (e.g., strong oxidizers) can affect long-term stability.
Synthesis and industrial manufacture
Typical synthetic route
Production typically follows two broad steps:
Alkylation of dimethylaminoethanol (or similar tertiary amine): A tertiary amine such as dimethylaminoethanol is quaternized by reaction with a lauryl halide (e.g., lauryl chloride) under controlled conditions to yield the quaternary ammonium salt.
For commercial C12–C18 mixtures, the corresponding fatty alkyl chlorides or oxides (from natural fatty alcohol derivatives) are used.
Neutralization and purification: The crude quaternary salt may be washed, neutralized, and formulated as an aqueous solution.
Purification may remove residual halide, unreacted alcohols, or tertiary amine.
Alternative routes include the use of alkyl epoxides (alkyl oxides) reacting with dimethylaminoethanol followed by protonation/quaternization to form the chloride salt.
Raw materials and feedstocks
Lauryl chloride or lauryl alcohol derivatives (fatty feedstock)
Dimethylaminoethanol (or analogs)
Chloride source (if alkyl epoxides used)
Solvent systems (water, alcohols)
Process considerations
Reaction temperature control to avoid side reactions (e.g., alkylation of unintended sites).
Stoichiometry management for complete quaternization while minimizing tertiary amine residues.
Removal of residual halides or chlorinated organics for cosmetic-grade materials.
Typical commercial specifications and grades
Commercial materials may be supplied as 25–80% active aqueous solutions. Typical specification parameters include:
Active matter (% w/w)
Appearance (clear to slightly hazy liquid)
pH (of 1% aqueous)
Specific gravity
Chloride content
Residual tertiary amine content
Microbial limits (for personal care applications)
Formulators choose grades (purity, chain distribution, viscosity) according to application: high-purity lauryl-only grades for specialty cosmetics; broader C12–C18 mixtures for industrial cleaners and fabric softeners.
Analytical methods and quality control
Identification
Nuclear Magnetic Resonance (NMR): 1H and 13C NMR provide structural confirmation.
The hydroxyethyl methylene and hydroxyl signals are diagnostic.
Infrared Spectroscopy (FTIR): Characteristic quaternary ammonium bands and C–H stretching modes of the alkyl chain.
Quantification
Titration: Chloride content via argentometric titration; active quaternary nitrogen via titration methods.
Chromatography: GC (after derivatization) or HPLC methods to analyze alkyl chain distribution and detect impurities.
Mass Spectrometry: LC–MS for molecular weight confirmation and trace impurities.
Purity and impurity profiling
Residual tertiary amine
Unreacted alkyl halide or alcohol
Free chloride and inorganic salts
Microbial contaminants (for cosmetic grades)
Mechanism of action in conditioning and antistatic systems
Substantivity
Cationic quaternary ammonium compounds bind strongly to negatively charged surfaces (hair keratin, fabric fibers) through electrostatic interactions.
The long alkyl chain provides hydrophobic interaction and film formation, leading to improved lubricity, reduced friction, and antistatic behavior.
Hair conditioning
Deposition of a thin, lubricious layer on hair scales reduces combing force, increases shine, and imparts softness.
The hydroxyethyl group increases water compatibility and may favor better deposition from aqueous rinse-off systems.
Compatibility with other surfactants
Cationic quats are often incompatible with anionic surfactants in concentrated form due to ionic pairing and precipitation.
However, hydroxyethyl substitution and controlled formulation strategies (e.g., using dilution sequences, adding electrolytes, or using amphoteric co-surfactants) permit coexistence in many practical shampoo and rinse-off formulations.
SAFETY INFORMATION ABOUT HYDROXYETHYL LAURDIMONIUM CHLORIDE
First aid measures:
Description of first aid measures:
General advice:
Consult a physician.
Show this safety data sheet to the doctor in attendance.
Move out of dangerous area:
If inhaled:
If breathed in, move person into fresh air.
If not breathing, give artificial respiration.
Consult a physician.
In case of skin contact:
Take off contaminated clothing and shoes immediately.
Wash off with soap and plenty of water.
Consult a physician.
In case of eye contact:
Rinse thoroughly with plenty of water for at least 15 minutes and consult a physician.
Continue rinsing eyes during transport to hospital.
If swallowed:
Do NOT induce vomiting.
Never give anything by mouth to an unconscious person.
Rinse mouth with water.
Consult a physician.
Firefighting measures:
Extinguishing media:
Suitable extinguishing media:
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Special hazards arising from the substance or mixture
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas
Advice for firefighters:
Wear self-contained breathing apparatus for firefighting if necessary.
Accidental release measures:
Personal precautions, protective equipment and emergency procedures
Use personal protective equipment.
Avoid breathing vapours, mist or gas.
Evacuate personnel to safe areas.
Environmental precautions:
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
Methods and materials for containment and cleaning up:
Soak up with inert absorbent material and dispose of as hazardous waste.
Keep in suitable, closed containers for disposal.
Handling and storage:
Precautions for safe handling:
Avoid inhalation of vapour or mist.
Conditions for safe storage, including any incompatibilities:
Keep container tightly closed in a dry and well-ventilated place.
Containers which are opened must be carefully resealed and kept upright to prevent leakage.
Storage class (TRGS 510): 8A: Combustible, corrosive hazardous materials
Exposure controls/personal protection:
Control parameters:
Components with workplace control parameters
Contains no substances with occupational exposure limit values.
Exposure controls:
Appropriate engineering controls:
Handle in accordance with good industrial hygiene and safety practice.
Wash hands before breaks and at the end of workday.
Personal protective equipment:
Eye/face protection:
Tightly fitting safety goggles.
Faceshield (8-inch minimum).
Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).
Skin protection:
Handle with gloves.
Gloves must be inspected prior to use.
Use proper glove
removal technique (without touching glove's outer surface) to avoid skin contact with this product.
Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices.
Wash and dry hands.
Full contact:
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
Splash contact
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
It should not be construed as offering an approval for any specific use scenario.
Body Protection:
Complete suit protecting against chemicals, The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.
Respiratory protection:
Where risk assessment shows air-purifying respirators are appropriate use a fullface respirator with multi-purpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls.
If the respirator is the sole means of protection, use a full-face supplied air respirator.
Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).
Control of environmental exposure
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
Stability and reactivity:
Chemical stability:
Stable under recommended storage conditions.
Incompatible materials:
Strong oxidizing agents:
Hazardous decomposition products:
Hazardous decomposition products formed under fire conditions.
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas.
Disposal considerations:
Waste treatment methods:
Product:
Offer surplus and non-recyclable solutions to a licensed disposal company.
Contact a licensed professional waste disposal service to dispose of this material.
Contaminated packaging:
Dispose of as unused product
