ALKYL ETHER CARBOXYLIC ACIDS

Alkyl ether carboxylic acids (AEC, also known as ether carboxylates, polyoxyethylene alkyl ether carboxylic acids, or alkoxylate acetic acids) are a unique class of anionic-nonionic ("crypto-anionic") surfactants characterised by a three-part molecular architecture: a lipophilic alkyl chain (C₅–C₂₂, typically C₁₀–C₁₈), a hydrophilic polyoxyethylene (EO) or oxyethylene-oxypropylene (EO-PO) alkoxylate spacer, and a terminal carboxylic acid group (-CH₂-COOH) that is pH-switchable between non-ionic (low pH) and anionic (alkaline pH) character — expressed by the general formula R²-(OC₂H₄)ₙ-O-CH₂-COOH where R² = C₅–C₂₂ alkyl and n = 1–12 (typically 2–6); they are produced by carboxymethylation of fatty alcohol ethoxylates with sodium monochloroacetate (chloroacetate route) or by catalytic oxidation of fatty alcohol ethoxylates, and are commercially available in free acid, alkali metal salt (sodium, potassium), or alkanolamine salt form with the free acid dominating the market.
Alkyl ether carboxylic acids are used across a wide and growing range of applications: personal care (shampoos, shower gels, facial cleansers, mild skin care) as mild, low-irritation co-surfactants; industrial metalworking fluids (metalworking fluids, hydraulic fluids, treatment fluids) as low-IFT lubricants and emulsifiers; oilfield operations (water-based drilling muds, enhanced oil recovery, well stimulation) exploiting their ultra-low interfacial tension under high-temperature and high-salinity conditions; industrial cleaning; construction (concrete admixtures, superplasticisers); textile processing; and as carboxymethylation starting materials for the synthesis of alkyl ether carboxylic acid taurides (AEC taurides) — a high-performance class of mild, hard-water-stable anionic surfactants for cosmetic and technical cleaning preparations.
Alkyl ether carboxylic acids are generally regarded as low to moderate hazard: they are not classified as carcinogens, CMR substances, or SVHC; free acid forms are mild skin and eye irritants; they are generally biodegradable; they show outstanding hardwater tolerance and lime-soap dispersing capability; they carry no GHS acute toxicity classification for the majority of commercial grades; performance and safety profile varies significantly with alkyl chain length and degree of ethoxylation — formulation-specific SDS should be consulted.

General Formula: R²-(OC₂H₄)ₙ-O-CH₂-COOH
R² = C₅–C₂₂ alkyl (typically C₁₀–C₁₈)
n = 1–12 (typically 2–6)
Product Form: Free acid / Sodium salt / Potassium salt / Alkanolamine salt

Synonyms: Alkyl ether carboxylic acid, AEC, Ether carboxylate, Ether carboxylic acid, Polyoxyethylene alkyl ether carboxylic acid, Alkoxylate acetic acid, Alkyl polyethoxy carboxylic acid, Alkyl EO carboxylate, Crypto-anionic surfactant, AEC surfactant, Akypo (trade name, Chem-Y), Marlowet 4543 (trade name, Hüls), Sandopan D-LW (trade name, Sandoz), Carboxymethylated fatty alcohol ethoxylate

Alkyl Ether Carboxylic Acids form a family of anionic surfactants containing an alkyl chain, ether units and a terminal carboxylic acid group.
The general structure of Alkyl Ether Carboxylic Acids can be represented as R–(OCH₂CH₂)ₙ–O–CH₂–COOH.

Alkyl Ether Carboxylic Acids combine the surface activity of ethoxylated alcohols with the reactivity of carboxylic acids.
The molecular properties of Alkyl Ether Carboxylic Acids vary according to alkyl-chain length and the number of ether units.

Commercial Alkyl Ether Carboxylic Acids may appear as clear liquids, viscous fluids or soft pastes.
Product concentration, chain distribution and temperature influence the physical form of Alkyl Ether Carboxylic Acids.

Alkyl Ether Carboxylic Acids develop an anionic character when their carboxylic acid groups undergo neutralization.
Sodium, potassium and amine salts can be prepared from Alkyl Ether Carboxylic Acids.

The pH of a formulation influences the ionization and surface activity of Alkyl Ether Carboxylic Acids.
Neutralization generally improves the water dispersibility of Alkyl Ether Carboxylic Acids.

Alkyl Ether Carboxylic Acids reduce surface tension and promote effective wetting of solid surfaces.
The ether groups help Alkyl Ether Carboxylic Acids maintain useful performance in aqueous formulations.

Good compatibility with hard water represents an important advantage of Alkyl Ether Carboxylic Acids.
Calcium and magnesium ions affect Alkyl Ether Carboxylic Acids less severely than many conventional soaps.

Alkyl Ether Carboxylic Acids can provide detergency while maintaining a relatively mild formulation profile.
Personal-care manufacturers use Alkyl Ether Carboxylic Acids in products designed for gentle cleansing.

Shampoos, facial cleansers and body washes may contain Alkyl Ether Carboxylic Acids as primary or secondary surfactants.
Alkyl Ether Carboxylic Acids can support stable foam and comfortable skin feel in cleansing formulations.

Household cleaners use Alkyl Ether Carboxylic Acids to improve wetting, soil removal and rinsing.
Alkyl Ether Carboxylic Acids can complement nonionic and other anionic surfactants in multipurpose cleaners.

Dishwashing formulations may employ Alkyl Ether Carboxylic Acids to balance cleaning performance and foam behavior.
The formulation flexibility of Alkyl Ether Carboxylic Acids supports their use in concentrated cleaning products.

Industrial cleaners incorporate Alkyl Ether Carboxylic Acids for degreasing and surface-wetting applications.
Alkyl Ether Carboxylic Acids can assist the removal of oily deposits from metal and hard surfaces.

Metalworking fluids may use Alkyl Ether Carboxylic Acids as emulsifying and lubricity-supporting components.
The polar and nonpolar regions of Alkyl Ether Carboxylic Acids help stabilize oil-in-water systems.

Textile-processing formulations use Alkyl Ether Carboxylic Acids as wetting, scouring or emulsifying agents.
Alkyl Ether Carboxylic Acids can promote uniform penetration of treatment baths into textile fibers.

Leather-processing products may contain Alkyl Ether Carboxylic Acids to improve wetting and emulsification.
Alkyl Ether Carboxylic Acids can help distribute oils and processing auxiliaries more evenly across leather surfaces.

Agrochemical formulations use Alkyl Ether Carboxylic Acids as wetting agents, dispersants or emulsifiers.
Alkyl Ether Carboxylic Acids can improve the spreading of liquid formulations over plant surfaces.

Emulsion polymerization systems may incorporate Alkyl Ether Carboxylic Acids as stabilizing surfactants.
Alkyl Ether Carboxylic Acids help control particle formation and dispersion stability in selected polymer emulsions.

Manufacturers commonly prepare Alkyl Ether Carboxylic Acids from ethoxylated fatty alcohols.
Carboxymethylation introduces the terminal carboxylic acid functionality into Alkyl Ether Carboxylic Acids.

Fatty alcohol selection determines the hydrophobic chain distribution of Alkyl Ether Carboxylic Acids.
The ethoxylation level controls the hydrophilic balance and water compatibility of Alkyl Ether Carboxylic Acids.

Formulators select Alkyl Ether Carboxylic Acids according to required foam, wetting and emulsification performance.
Combining Alkyl Ether Carboxylic Acids with other surfactants can produce synergistic cleaning effects.

Active-matter content, acid value, pH and color represent important quality parameters for Alkyl Ether Carboxylic Acids.
Chromatographic and titration methods can support the quality control of Alkyl Ether Carboxylic Acids.

Uses of Alkyl Ether Carboxylic Acids:
Alkyl ether carboxylic acids are used in personal care formulations — shampoos, shower gels, bubble baths, facial cleansers, hand soaps, and liquid cleansers — as mild, low-irritation anionic surfactants and co-surfactants; they exhibit significantly lower skin and mucous membrane irritation than conventional anionic surfactants (alkyl sulfates, alkyl ether sulfates), making them preferred in mild, daily-use, baby, and sensitive-skin formulations; they function as foaming agents, wetting agents, and emulsifiers, and can reduce the irritating power of sodium lauryl sulfate (SLS) and sodium laureth sulfate (SLES) when used as co-surfactants.
Alkyl ether carboxylic acids — particularly grades with alkyl chains longer than C₁₆ and low degrees of ethoxylation (n = 2–3) — are increasingly used in industrial metalworking and machining fluids as W/O emulsifiers, extreme-pressure lubricant additives, and corrosion inhibitors; their stability under extreme temperature and pH conditions, combined with their ultra-low interfacial tension capability, makes them particularly valuable in water-based and semi-synthetic cutting fluids, hydraulic fluids, and specialty treatment fluids used in metal forming, grinding, and rolling operations.
Alkyl ether carboxylic acids are used in oilfield operations including water-based drilling muds (as viscosifiers, emulsifiers, and shale inhibitors), enhanced crude oil recovery (EOR) by chemical flooding where their ultra-low IFT (achievable under high-temperature and high-salinity conditions characteristic of reservoir environments) reduces residual oil saturation, and well stimulation (acid stimulation) where their pH-switchable character enables controlled behaviour in acidic and alkaline downhole environments.
Alkyl ether carboxylic acids serve as the key starting material for the synthesis of alkyl ether carboxylic acid taurides (AEC taurides, formula R²-(OC₂H₄)ₙ-O-CH₂-CO-NR¹-C₂H₄-SO₃M, where R¹ = H or C₁–C₄ alkyl, M = H, Na, K, Ca/2, or Mg/2) — a class of surfactants with excellent foaming power in both soft and hard water, outstanding lime-soap dispersing capability, and superior skin and eye mucous membrane compatibility compared with conventional anionic surfactants; N-methyl taurides of lauryl ether carboxylic acids are particularly preferred; synthesis proceeds via acid chloride formation (with SOCl₂, PCl₃, or phosgene) followed by Schotten-Baumann condensation with aqueous taurine solutions.
Alkyl ether carboxylic acids are used in industrial cleaning formulations — alkaline industrial degreasers, process cleaners, bottle washers, and CIP (clean-in-place) systems — where their outstanding hardwater tolerance and lime-soap dispersing capability maintain performance in high-hardness water without precipitation or loss of activity; they are compatible with both anionic and nonionic co-surfactants and with alkali (sodium hydroxide, potassium hydroxide) in concentrated alkaline systems.
Alkyl ether carboxylic acids are used in the textile industry for scouring, dyeing, and finishing auxiliaries; in concrete and construction as superplasticisers and concrete admixtures (exploiting their surface-wetting, dispersing, and rheology-modifying properties); and in agricultural formulations as emulsifiers, wetting agents, and adjuvants for pesticide and herbicide formulations.
Alkyl ether citrates — produced by esterification of fatty alcohol ethoxylates with one or two carboxylic groups of citric acid — are a specialised sub-class of alkyl ether carboxylic acids used as mild co-surfactants in personal care formulations, where they reduce the irritating power of lauryl sulfates and lauryl ether sulfates and are particularly well suited for eye, baby, and sensitive-skin applications.

Benefits and Advantages of Alkyl Ether Carboxylic Acids:
The pH-switchable ionic character of alkyl ether carboxylic acids — behaving as nonionic surfactants under acidic conditions and as fully anionic surfactants under alkaline conditions — is a unique structural feature enabling application across both acidic and alkaline systems from a single surfactant molecule; this dual character allows formulation chemists to design systems with controlled foaming, wetting, and emulsifying behaviour that changes predictably with pH — a functionality not available from purely anionic or purely nonionic surfactants.
Alkyl ether carboxylic acids show outstanding hardwater tolerance and lime-soap dispersing capability under harsh application environments (high salinity, elevated temperature, concentrated alkalinity) that typically degrade the performance of conventional soaps, alkyl sulfates, alkyl ether sulfates, and alkylbenzene sulfonates; this property is structurally rooted in the polyoxyethylene spacer between the alkyl chain and the carboxylate head group, which maintains hydration and prevents calcium/magnesium salt precipitation even in very hard water.
Alkyl ether carboxylic acids are significantly milder to skin, hair, and eye mucous membranes than conventional anionic surfactants such as SLS, SLES, LABS, and alkane sulfonates; this superior mildness — quantified by Zein number, rabbit eye Draize test, and human patch test — enables their use in products designed for daily use, infant skin, and sensitive or compromised skin barriers without the barrier disruption associated with stronger anionic surfactants.
The combination of ultra-low interfacial tension capability (achievable at ppm concentrations under reservoir temperature and salinity conditions), pH-switchable ionicity, hardwater stability, and biodegradability positions alkyl ether carboxylic acids as preferred surfactant technology for chemically enhanced oil recovery (EOR) and next-generation water-based drilling fluid formulations, where environmental, performance, and regulatory requirements are increasingly stringent.

Features of Alkyl Ether Carboxylic Acids:
The physicochemical properties of alkyl ether carboxylic acids are highly tuneable across a broad performance space by independent variation of three structural parameters: (1) alkyl chain length (R² = C₅–C₂₂): longer chains increase lipophilicity, reduce CMC, increase emulsifying power for oils, and shift performance toward W/O emulsification; shorter chains increase water solubility and foaming in aqueous systems; (2) degree of ethoxylation (n = 1–12): increasing n increases hydrophilicity, water solubility, hardwater tolerance, and milder skin character, while reducing foaming and emulsifying power for oil; (3) head group form (free acid vs sodium/potassium/alkanolamine salt): the free acid behaves as a nonionic surfactant below its pKa (~3.5–5.0 for the carboxylate group, shifted from typical carboxylic acid pKa by the EO chain) and as a fully anionic surfactant above pH 7.
Alkyl ether carboxylic acids are characterised by: very good foaming performance in soft water; good to excellent lime-soap dispersing power; low to medium foaming at neutral to acidic pH; good wetting and surface-tension reduction; lubrication; corrosion inhibition; emulsification and emulsion stabilisation; ultra-low IFT capability under EOR-relevant conditions; compatibility with anionic, nonionic, cationic, and amphoteric surfactants; low skin and mucous membrane irritation; and general biodegradability meeting OECD 301/302 criteria for most commercial chain lengths.
Alkyl ether carboxylic acids are marketed in multiple physical forms: liquid (aqueous solution, 20–40% active) for easy dosing in personal care and industrial formulations; concentrated paste (60–70% active); and dry powder (spray-dried sodium salt) for high-active-content applications; viscosity of aqueous grades varies from low-viscosity solutions to high-viscosity pastes depending on chain length, ethoxylation, and concentration; in the free acid form, many commercial grades are clear to slightly hazy viscous liquids at room temperature.
Regulatory position: modern alkyl ether carboxylic acid grades are free of 1,4-dioxane (a key regulatory concern with ethoxylated surfactants under EPA/FDA regulation) when produced by controlled catalytic oxidation routes or by the chloroacetate route under properly controlled conditions; the 1,4-dioxane issue has significantly reduced use of ethoxylated anionic surfactants (including AECs) in personal care markets in recent years, driving reformulation toward non-ethoxylated alternatives or AEC grades with demonstrably low 1,4-dioxane content (≤1 ppm, COSMOS standard).

Chemical Properties of Alkyl Ether Carboxylic Acids:
Alkyl ether carboxylic acids are produced commercially by two principal routes: (1) carboxymethylation of fatty alcohol ethoxylates (FAEO) with sodium monochloroacetate (ClCH₂COONa) under alkaline conditions: FAEO-OH + ClCH₂COONa → FAEO-O-CH₂-COONa + NaCl, followed by acidification to give the free acid form; this is the dominant commercial route due to its simplicity and cost-effectiveness; (2) catalytic oxidation of fatty alcohol ethoxylates with oxygen using palladium, platinum, or gold catalysts — this route avoids sodium chloride by-product and produces higher-purity AECs with no 1,4-dioxane, but is more capital-intensive; and (3) reaction of fatty alcohol ethoxylates with acrylates or glycolic acid derivatives (minor routes for specialty AECs).
Key reactions of alkyl ether carboxylic acids: (1) in acid media (pH < pKa ~3.5–5), the carboxylate head group is protonated → nonionic behaviour (low foaming, low IFT); (2) in alkaline media (pH > 7), the carboxylate is deprotonated → fully anionic → high foaming, high detergency, excellent lime-soap dispersing; (3) neutralisation with NaOH, KOH, or alkanolamines (monoethanolamine, triethanolamine) → sodium, potassium, or alkanolamine carboxylate salts; (4) reaction with thionyl chloride (SOCl₂), phosphorus trichloride (PCl₃), or phosgene (COCl₂) → corresponding acid chloride (AEC-Cl) — key intermediate for synthesis of AEC taurides by Schotten-Baumann condensation with taurine (H₂N-CH₂-CH₂-SO₃H) or N-methyltaurine.
Alkyl ether carboxylic acids are compatible with all major classes of co-surfactants (anionic, nonionic, cationic at low levels, amphoteric); they are stable to alkaline hydrolysis under normal application conditions; they show slow acid hydrolysis of the ether linkages under strongly acidic conditions at elevated temperature; they are not volatile and not flammable under ambient conditions; they are readily biodegradable (OECD 301/302) and do not bioaccumulate.
Commercial trade names and standards: Akypo® series (Chem-Y/KAO), Marlowet® 4543 (Evonik/Hüls), Sandopan® D-LW (Clariant/Sandoz), Rewoderm® (Evonik), Jordapon® (Solvay); these products differ in alkyl chain distribution, degree of ethoxylation, active content, and physical form; product selection requires matching the structure to the application requirements (chain length for lipophilicity, n for hydrophilicity, form for handling).

Production of Alkyl Ether Carboxylic Acids:
The dominant commercial production route is carboxymethylation: fatty alcohol ethoxylates (prepared by ethoxylation of C₁₂–C₁₈ fatty alcohols derived from palm, palm kernel, or coconut oil) are reacted with sodium monochloroacetate (NaMCA) in the presence of an alkali catalyst (NaOH) at 60–90°C; the etherification produces sodium AEC salt directly; this is then either sold as the sodium salt, further saponified/neutralised, acidified to give the free acid form, or purified; key quality parameters include active content (by GC or titration), 1,4-dioxane content (ppb/ppm level, GC-MS), residual NaCl, and glycolate by-product levels.
Commercial alkyl ether carboxylic acids are available in: free acid form (25–40% active in water or as 100% active viscous liquid); sodium salt form (20–40% active aqueous solution); and powder/granule (spray-dried sodium salt, ≥85% active); typical specification limits: active matter ≥98% (anhydrous basis or as declared); pH of 1% solution: 5.5–7.0 (sodium salt) or 1.5–3.5 (free acid); colour (APHA or Lovibond): ≤50–100; heavy metal content per COSMOS or ECOCERT specifications; 1,4-dioxane ≤1 ppm (COSMOS cosmetic standard); packaging: 20–200 kg drums, IBC, bulk tanker.

Alkyl Ether Carboxylic Acid Material Safety Data Sheet (MSDS):

Handling of Alkyl Ether Carboxylic Acids:
Alkyl ether carboxylic acids in free acid form (pH < 3.5) are mildly acidic and can cause mild skin and eye irritation on prolonged or repeated contact; wear appropriate PPE (gloves, eye protection) for routine handling; avoid inhaling aerosols or mists; use in well-ventilated areas; standard chemical handling practices are sufficient for most industrial and laboratory operations.
Sodium salt forms (aqueous solutions, pH 5.5–7.5) are mild to non-irritating under brief contact and present very low acute hazard; standard industrial hygiene practices apply; concentrated alkaline solutions (pH >10) may cause more significant skin and eye irritation — treat as mildly caustic.

Alkyl Ether Carboxylic Acid SDS:

Stability and Reactivity of Alkyl Ether Carboxylic Acids:

Chemical stability:
Alkyl ether carboxylic acids are chemically stable under normal ambient storage conditions.
They undergo slow ether linkage hydrolysis under strongly acidic conditions (pH < 1) at elevated temperatures; they are stable to alkaline hydrolysis under normal application conditions; they are not oxidisers and do not polymerise.

Reactivity:
Alkyl ether carboxylic acids are not reactive under normal ambient conditions; they do not present explosion, fire, or polymerisation hazards.
The free acid form reacts with strong alkalis (NaOH, KOH) to form the corresponding carboxylate salt with heat evolution; this is a controlled, commercially useful reaction used in product neutralisation.

Conditions to avoid:
Strong acids (pH < 1) at elevated temperatures — risk of ether linkage hydrolysis.
Strong oxidising agents — not compatible with concentrated peroxides or halogens.
Temperatures above 80°C for extended periods in aqueous solution — potential for slow degradation.
Mixing concentrated free acid form with strong alkali without controlled addition — exothermic neutralisation.

Incompatible materials:
Concentrated strong acids (HCl, H₂SO₄, HNO₃) at elevated temperature.
Strong oxidising agents (concentrated H₂O₂, permanganate, bleach at high concentrations).
Cationic surfactants at high concentrations — may form insoluble complexes (formulation-dependent).

Hazardous decomposition products:
No hazardous decomposition products under normal handling conditions.
At very high temperatures (>200°C): decomposition to carbon dioxide, acetic acid derivatives, and formaldehyde traces possible.

Handling and Storage of Alkyl Ether Carboxylic Acids:

Handling:
Wear chemical-resistant gloves and safety glasses for routine handling of free acid form.
Use in well-ventilated areas; avoid generating mists or aerosols.
For aqueous salt solutions: standard industrial hygiene practices are sufficient.
Wash hands after handling; do not eat, drink, or smoke in work areas.

Storage:
Store in tightly closed containers in a cool (5–35°C), dry, well-ventilated area.
Protect from freezing (freezing may cause phase separation in some formulations — gentle warming restores homogeneity).
Keep away from strong acids, strong oxidising agents, and cationic surfactants at high concentrations.
Shelf life: typically 12–24 months under recommended storage conditions.
Packaging: 20–200 kg drums (HDPE or steel); 1,000 L IBC; bulk road/rail tanker.

First Aid Measures for Alkyl Ether Carboxylic Acids:

Inhalation:
Move to fresh air; if aerosol exposure causes respiratory irritation, consult a physician.
Under normal handling conditions, vapour/aerosol exposure is minimal.

Skin contact:
Rinse with water; wash with soap and water; remove contaminated clothing.
Free acid form may cause mild irritation on prolonged contact; seek medical advice if irritation persists.

Eye contact:
Irrigate with plenty of water for at least 15 minutes; seek medical advice if irritation persists.
Free acid form may cause more significant eye irritation than salt forms; treat promptly.

Ingestion:
Rinse the mouth with water; seek medical advice; alkyl ether carboxylic acids have low acute oral toxicity.

Firefighting Measures for Alkyl Ether Carboxylic Acids:

Suitable extinguishing media:
Water spray, CO₂, dry chemical, or foam suitable for alcohol or aqueous-phase fires.

Specific hazards:
Alkyl ether carboxylic acids in aqueous solution are not flammable; concentrated/anhydrous grades may be combustible at elevated temperatures — check product-specific SDS for flash point data.

Protective equipment for firefighters:
Standard firefighting equipment; SCBA if significant smoke is present.

Accidental Release Measures for Alkyl Ether Carboxylic Acids:

Personal precautions:
Wear gloves and eye protection; contain spill to prevent slip hazard; ventilate area.

Environmental precautions:
Alkyl ether carboxylic acids are generally biodegradable; prevent large quantities from entering water courses; notify authorities per local regulations for large spills.

Clean-up methods:
Absorb with inert absorbent material; collect in closed containers; dispose per applicable regulations; wash residue area with water.

Exposure Controls / Personal Protective Equipment for Alkyl Ether Carboxylic Acids:

Engineering controls: Good general ventilation; local exhaust for aerosol generation; standard industrial practice.
Eye protection: Safety glasses or goggles.
Hand protection: Nitrile or neoprene gloves for prolonged contact with free acid form.
Respiratory protection: Not required under normal handling conditions.

Alkyl Ether Carboxylic Acid Identifiers:
General Formula: R²-(OC₂H₄)ₙ-O-CH₂-COOH
R²: C₅–C₂₂ alkyl (typically C₁₀–C₁₈)
n: 1–12 (typically 2–6)
Common CAS (laureth-n carboxylic acid series): e.g., 27306-79-2 (laureth-3 carboxylic acid), 33939-64-9 (laureth-5 carboxylic acid)
Salt forms: sodium, potassium, alkanolamine (MEA, TEA)
GHS Classification: Typically not classified (aqueous salt forms); mild irritant (free acid form, product-specific)
Form: Free acid / Sodium salt / Potassium salt / Powder
Active Content: 25–40% (aqueous grades); ≥85% (powder/granule)
pH: 1.5–3.5 (free acid, 1% solution); 5.5–7.0 (sodium salt, 1% solution)
Biodegradability: Readily biodegradable (OECD 301/302)
1,4-Dioxane: ≤1 ppm (COSMOS standard; product-specific)
Regulatory: COSMOS/ECOCERT compatible (grade-dependent); REACH registered; compliant with EU and US personal care and industrial regulations

Properties of Alkyl Ether Carboxylic Acids:
Physical state: Liquid (aqueous solution) or powder (sodium salt)
Appearance: Clear to slightly hazy liquid (free acid); colourless to pale yellow aqueous solution (sodium salt); white powder (spray-dried sodium salt)
Odour: Mild, characteristic
Ionic character: pH-dependent — nonionic (<pH ~4), anionic (>pH ~7); "crypto-anionic"
Foaming: Low to medium (pH-dependent; excellent in alkaline conditions)
IFT: Ultra-low achievable under EOR-relevant conditions
Hardwater tolerance: Outstanding
Lime-soap dispersing: Excellent
Skin mildness: Significantly milder than SLS/SLES
Biodegradability: Readily biodegradable (OECD 301/302)
pH stability range: Stable pH 2–14 (no ether hydrolysis under normal conditions)
Temperature stability: Stable to 80°C+ in aqueous solution
Compatibility: Anionic, nonionic, cationic (limited), amphoteric surfactants; alkaline systems
Storage: 5–35°C; protect from freezing; tightly closed

Alkyl Ether Carboxylic Acid Properties — Specifications:
Product name: Alkyl ether carboxylic acid (AEC) — grade dependent on R², n, and salt form
General formula: R²-(OC₂H₄)ₙ-O-CH₂-COOH / R²-(OC₂H₄)ₙ-O-CH₂-COONa
Alkyl chain: C₁₀–C₁₈ (typical commercial grades)
Degree of ethoxylation (n): 2–6 (typical commercial grades)
Active matter: ≥98% (anhydrous); 25–40% (aqueous grades)
1,4-Dioxane: ≤1 ppm (COSMOS); product-specific
pH (1% solution, sodium salt): 5.5–7.0
Colour (APHA): ≤50–100
Cloud point: Low (hardwater-stable)
Biodegradability: OECD 301/302 pass
GHS: Not classified (typical aqueous salt grades); mild irritant (free acid)
Shelf life: 12–24 months
Storage: 5–35°C; protect from freezing; tightly closed
Packaging: 20–200 kg HDPE/steel drums; 1,000 L IBC; bulk tanker
Documents: TDS, SDS, CoA, and 1,4-dioxane analysis report available on request

Names of Alkyl Ether Carboxylic Acids:
Alkyl ether carboxylic acid
Alkyl ether carboxylic acids
AEC
Ether carboxylate
Ether carboxylic acid
Polyoxyethylene alkyl ether carboxylic acid
Alkoxylate acetic acid
Alkyl polyethoxy carboxylic acid
Alkyl EO carboxylate
Crypto-anionic surfactant
Carboxymethylated fatty alcohol ethoxylate
Alkyl ether carboxylate
Laureth carboxylic acid
Sodium laureth carboxylate
Akypo (trade name, KAO/Chem-Y)
Marlowet 4543 (trade name, Evonik)
Sandopan D-LW (trade name, Clariant)
Rewoderm (trade name, Evonik)
Jordapon (trade name, Solvay)
AEC tauride precursor
Alkylether citrate (speciality sub-class, citric acid-based)