E466 SODIUM CARBOXYMETHYL CELLULOSE

E466 Sodium Carboxymethyl Cellulose is an anionic, water-soluble, high-molecular-weight polymer derived from natural cellulose by chemical modification, in which carboxymethyl groups (-CH₂-COOH) are introduced onto some of the hydroxyl groups of the glucopyranose monomers of the cellulose backbone, and which is commercially used in its sodium salt form (sodium CMC, NaCMC) as a versatile thickener, stabilizer, emulsifier, binder, water retention agent, film former, and suspending agent in food, pharmaceutical, cosmetic, and industrial applications.
E466 Sodium Carboxymethyl Cellulose is registered under E number E466 in the European Union, and under E469 when enzymatically hydrolyzed; it is approved as Generally Recognized as Safe (GRAS) by the US FDA, and has been assigned an acceptable daily intake (ADI) of 0–25 mg/kg body weight by the Joint FAO/WHO Expert Committee on Food Additives (JECFA), confirming its established safety for food use at commercially relevant levels.
E466 Sodium Carboxymethyl Cellulose was first synthesized in the early 20th century when German chemist Fritz Sturmann patented a process for producing CMC in 1918 by chemically modifying natural cellulose through the introduction of carboxymethyl groups, and it has since become one of the most widely used and commercially important hydrocolloids globally, alongside xanthan gum.

CAS Number: 9004-32-4
EC Number (ECHA): 100.120.377
E Number: E466 (standard); E469 (enzymatically hydrolyzed)
HS Code: 39123100
Chemical Name: Sodium carboxymethyl cellulose; Partial sodium salt of a carboxymethyl ether of cellulose
Molecular Formula: [C₆H₇O₂(OH)x(OCH₂COONa)y]n where x = 1.50–2.80; y = 0.20–1.50; x + y = 3.0; n ≥ 4
Representative Formula: C₆H₇O₂(OH)₂OCH₂COONa (single unit)
Molecular Weight: >17,000 Da (degree of polymerization ≥100); variable based on grade
ChEBI: CHEBI:85146
ChEMBL: ChEMBL1909054
UNII: 05JZI7B19X
CompTox Dashboard (EPA): DTXSID7040441
JECFA ADI: 0–25 mg/kg body weight/day
Degree of Substitution (DS): 0.20–1.50 (food grade); 0.4–1.5 typical food grade
Viscosity (1% solution): 25–50,000 mPa·s (grade-dependent)
Optimal pH for viscosity: 6.5–9.0

Synonyms: Sodium Carboxymethyl Cellulose, Carboxymethyl Cellulose, CMC, NaCMC, SCMC, Sodium CMC, Cellulose Gum, Carmellose, Carboxymethylcellulose Sodium, Sodium Carboxymethylcellulose, Carboxy Methyl Cellulose, Cellulose Carboxymethyl Ether, CMC Gum, Cellulose Gum E466, E466, INS 466, CAS 9004-32-4

E466 Sodium Carboxymethyl Cellulose is the partial sodium salt of a carboxymethyl ether of cellulose, in which the cellulose backbone (β-1,4-linked D-glucose units) is modified by substituting some hydroxyl groups with carboxymethyl groups (-OCH₂COO⁻Na⁺), yielding an anionic, ionically charged polymer with high water solubility, high viscosity at low concentrations, and a wide range of rheological behavior depending on the degree of substitution (DS) and degree of polymerization (DP).
E466 Sodium Carboxymethyl Cellulose is an anionic polysaccharide — unlike non-ionic methyl cellulose (E461) — meaning its carboxylate groups carry negative charges in aqueous solution, conferring ionic character that allows interaction with cations, proteins, and other charged species, and giving it unique functional behavior in formulations at varying pH, ionic strength, and temperature conditions.

E466 Sodium Carboxymethyl Cellulose has a DS typically between 0.4 and 1.5 for food-grade applications; DS <0.3 yields alkali-soluble material only; DS >0.4 yields water-soluble material; DS approaching 0.7 gives the most easily dissolved grades; and DS >1.5 provides improved stability in acidic and alkaline environments due to more complete substitution of the reactive hydroxyl groups.
E466 Sodium Carboxymethyl Cellulose is not metabolized by the human body and is excreted essentially unchanged in the feces (100% fecal recovery), making it non-caloric at typical use levels; however, at high dietary concentrations it may alter gut microbiota composition and cause gastrointestinal discomfort — the subject of ongoing research into its effects on inflammation and inflammatory bowel disease.

Uses of E466 Sodium Carboxymethyl Cellulose:
E466 Sodium Carboxymethyl Cellulose is used in ice cream and frozen desserts to control ice crystal formation and growth during freezing and storage, providing a smoother and creamier texture, improving overrun (air entrainment), stabilizing emulsions, and preventing syneresis and ingredient separation.
E466 Sodium Carboxymethyl Cellulose is used in bakery products (breads, cakes, pastries, muffins, gluten-free products) to improve dough handling, increase loaf volume, create a finer and softer crumb structure, retain moisture, extend shelf life, improve release from molds, and mimic some gluten properties in gluten-free formulations.

E466 Sodium Carboxymethyl Cellulose is used in dairy products (yogurt, cottage cheese, cheese, dairy desserts) as a thickener, stabilizer, and texturizer, preventing ingredient separation, improving mouthfeel, and preventing syneresis (liquid separation from gel).
E466 Sodium Carboxymethyl Cellulose is used in beverages (fruit juices, soft drinks, dairy drinks, instant drink mixes) to provide body and mouthfeel, prevent sedimentation of particles, create stable cloudiness, improve dispersibility, and prevent clumping.

E466 Sodium Carboxymethyl Cellulose is used in sauces, dressings, ketchups, gravies, and condiments as an effective thickener and emulsion stabilizer providing smooth, consistent texture, preventing oil-water separation, and enabling formulation of low-fat or reduced-calorie versions by replacing fat in the thickened water phase.
E466 Sodium Carboxymethyl Cellulose is used in processed meats (sausages, hot dogs, deli meats, meatballs, meat analogues) to improve water-holding capacity, reduce cooking loss, improve binding properties, enhance juiciness and tenderness, and prevent product disintegration during cooking.

E466 Sodium Carboxymethyl Cellulose is used in confectionery (candies, chewing gums, jellies, fillings, glazes) to modify texture, prevent moisture migration, prevent sugar crystallization, and as an edible film for coating confections.
E466 Sodium Carboxymethyl Cellulose is used in pet food as its largest single volume application, absorbed by dry pet food formulations that form their own gravy when warm water is added.

E466 Sodium Carboxymethyl Cellulose is used in toothpaste to enable complete mixing of liquid and solid raw materials and to provide proper viscosity, brightness, smoothness, molding, and flow properties in the formulation.
E466 Sodium Carboxymethyl Cellulose is used in laundry detergents as a soil suspension polymer designed to deposit onto cotton and other cellulosic fabrics, creating a negatively charged barrier that prevents redeposition of soils onto fabric during washing.

E466 Sodium Carboxymethyl Cellulose is used in pharmaceutical applications as a tablet binder, film coating agent, suspending agent in liquid medicines, lubricant in capsule formulations, controlled-release matrix, artificial tears and eye drops for dry eye treatment, and in veterinary medicine to prevent bowel adhesions in abdominal surgeries in horses.
E466 Sodium Carboxymethyl Cellulose is used in cosmetics and personal care products (shampoos, conditioners, face masks, skin creams, sunscreens) as a viscosity modifier, film former, binder, emulsion stabilizer, and moisture retention agent; approximately 25% of shampoos and conditioners use CMC for conditioning and detangling effects.

E466 Sodium Carboxymethyl Cellulose is used in the oil drilling industry as a drilling mud additive where it acts as a viscosity modifier, water retention agent, wellbore protection agent, and filtration loss reducer in drilling fluids, with ultra-high viscosity grades used in fracturing fluids to carry fillers into oil wells.
E466 Sodium Carboxymethyl Cellulose is used in textiles as a thickening agent in printing pastes (2–3%), fabric finishing agent, non-woven fabric binder, yarn sizing agent (1–3%), and alternative to synthetic thickeners in dyeing and printing.

E466 Sodium Carboxymethyl Cellulose is used in paper production as a sizing agent, reinforcing agent, dispersant, and wet additive to improve paper surface strength, smoothness, printability, and retention.
E466 Sodium Carboxymethyl Cellulose is used in lithium ion battery manufacturing as an electrode binder (particularly for graphite anodes), processable from water — avoiding the toxic n-methylpyrrolidone (NMP) solvent required for the traditional PVDF binder — and often used in conjunction with styrene-butadiene rubber (SBR) for silicon-containing anodes requiring extra flexibility.

E466 Sodium Carboxymethyl Cellulose is used in wine production to achieve tartrate or cold stability, inhibiting tartrate crystal nucleation and growth more stably than metatartaric acid, and reducing energy usage compared to conventional cold stabilization processes.
E466 Sodium Carboxymethyl Cellulose is used in research and biotechnology as a substrate for endoglucanase enzyme assays (highly specific for endo-acting cellulases), as a binder for cation-exchange resins in protein purification by ion-exchange chromatography (insoluble CMC grades), as a dispersant for carbon nanotubes in aqueous media, in ice packs to form a eutectic mixture with lower freezing point, and in conservation-restoration as an adhesive or fixative.

Benefits or Advantages of E466 Sodium Carboxymethyl Cellulose:
E466 Sodium Carboxymethyl Cellulose provides exceptional thickening power at very low concentrations (typically 0.1–1.0%), significantly reducing the amount needed compared to natural thickeners such as starch, agar, or gelatin, and enabling cost-effective formulation with precise viscosity control.
E466 Sodium Carboxymethyl Cellulose is non-toxic, non-allergenic in the vast majority of individuals, and has been confirmed safe for human consumption by the FDA, EFSA, JECFA, and regulatory authorities worldwide, with extensive toxicological data showing no carcinogenicity, mutagenicity, teratogenicity, or reproductive toxicity.

E466 Sodium Carboxymethyl Cellulose is vegan, gluten-free, halal, and kosher, derived from plant-based cellulose (cotton linters or wood pulp) without use of animal matter, making it suitable for all major dietary and religious requirements.
E466 Sodium Carboxymethyl Cellulose demonstrates high salt and alkali resistance, allowing it to replace guar gum in high-electrolyte applications, and maintains viscosity and stability across a wide pH range (6.5–9.0 optimal), a wide temperature range, and in the presence of diverse food ingredients.

E466 Sodium Carboxymethyl Cellulose has excellent water-binding capacity, providing superior moisture retention in baked goods, processed meats, and frozen foods — reducing cooking loss, extending shelf life, and preventing dryness and staling.
E466 Sodium Carboxymethyl Cellulose forms a transparent colloidal solution in water with good clarity, stability, and resistance to light degradation, making it suitable for clear beverages, transparent gel applications, and visual clarity-sensitive products.

Features of E466 Sodium Carboxymethyl Cellulose:
E466 Sodium Carboxymethyl Cellulose is a slightly hygroscopic white or slightly yellowish or greyish, odorless and tasteless, granular or fibrous powder that forms a clear to slightly opalescent viscous colloidal solution in both cold and hot water, and is insoluble in methanol, ethanol, acetone, chloroform, and benzene.
E466 Sodium Carboxymethyl Cellulose has a viscosity of 25–50,000 mPa·s in 1% aqueous solution (grade-dependent), with viscosity reaching its maximum at pH 6.5–9.0, beginning to decrease below pH 6, forming gel below pH 2.5, and also decreasing above pH 9 — with viscosity reduction accelerating above pH 11.5.

E466 Sodium Carboxymethyl Cellulose exhibits viscosity that decreases with increasing temperature (thermoreversible in low to moderate ranges) but shows permanent viscosity reduction above a critical temperature; presence of inorganic salts increases viscosity; higher DS value reduces the temperature sensitivity of viscosity.
E466 Sodium Carboxymethyl Cellulose is available in technical grade (~60% CMC + ~40% sodium chloride and sodium glycolate, used in detergents), semi-purified grade (used in paper applications), and food/pharmaceutical pure grade (salts removed), confirming that different grades have distinct purity and application profiles.

Chemical Properties of E466 Sodium Carboxymethyl Cellulose:
E466 Sodium Carboxymethyl Cellulose consists of anhydroglucose units linked by β-1,4-glycosidic bonds, with carboxymethyl groups (-OCH₂COO⁻Na⁺) randomly distributed along the cellulose backbone; the general formula is [C₆H₇O₂(OH)x(OCH₂COONa)y]n where x + y = 3.0, with DS (y) between 0.20 and 1.50 for food grade.
E466 Sodium Carboxymethyl Cellulose is synthesized by the alkali-catalyzed reaction of cellulose with chloroacetic acid (or sodium monochloroacetate), introducing polar carboxyl groups that render the cellulose water-soluble and chemically reactive: Cell-OH + NaOH → Cell·O⁻Na⁺ + H₂O; then Cell·O⁻Na⁺ + ClCH₂COO⁻Na⁺ → Cell-OCH₂COO⁻Na⁺ + NaCl.

E466 Sodium Carboxymethyl Cellulose is relatively stable across a wide pH range; resistant to degradation by bright light; insoluble in vegetable and animal fats; and incompatible with concentrated strong acids (precipitates CMC free acid), certain metal cations (Ca²⁺, Fe³⁺ can cross-link and gel CMC), and strong oxidizing agents.
E466 Sodium Carboxymethyl Cellulose is a green, safe, and biodegradable functional polymer material that can replace guar gum, gelatin, agar, sodium alginate, and pectin in numerous food and industrial applications, with the functional properties determined by DS, degree of polymerization (DP), solution concentration, pH, temperature, and presence of electrolytes.

Production of E466 Sodium Carboxymethyl Cellulose:
E466 Sodium Carboxymethyl Cellulose is produced industrially from purified cellulose (cotton linters or softwood wood pulp, chosen for high cellulose content and low impurities) by a two-step process: alkalinization — treating cellulose with aqueous NaOH (5–50%) to form alkali cellulose; etherification — reacting alkali cellulose with sodium monochloroacetate (up to 30%) in an alcohol-water medium at 50–75°C under controlled temperature and stirring to achieve the target DS.
E466 Sodium Carboxymethyl Cellulose production yields approximately 60% CMC and 40% salts (sodium chloride and sodium glycolate) in the initial reaction; a further purification process removes these salts to produce pure CMC for food and pharmaceutical applications; an intermediate semi-purified grade retains some salt content for paper applications.

E466 Sodium Carboxymethyl Cellulose quality and properties are controlled by adjusting the ratio of reactants, temperature, reaction time, and use of organic solvents (such as isopropanol) during etherification, which determine DS, DP, molecular weight, viscosity grade, and solubility behavior.
E466 Sodium Carboxymethyl Cellulose is available from major producers worldwide in food grade (FCC), pharmaceutical grade (USP/NF/EP), and industrial/technical grade in standard grades of low viscosity (25–100 mPa·s), medium viscosity (100–5,000 mPa·s), and high viscosity (5,000–50,000 mPa·s) at 1% aqueous solution.

Material Safety Data Sheet (MSDS) of E466 Sodium Carboxymethyl Cellulose:

Handling of E466 Sodium Carboxymethyl Cellulose:
E466 Sodium Carboxymethyl Cellulose should be handled in accordance with good industrial hygiene and safety practices and in compliance with the applicable Safety Data Sheet.
E466 Sodium Carboxymethyl Cellulose handling requires avoiding generation and inhalation of dust and avoiding skin and eye contact with powder, though the substance is considered non-toxic and hypoallergenic.

SDS of E466 Sodium Carboxymethyl Cellulose:

Stability and Reactivity of E466 Sodium Carboxymethyl Cellulose:

Chemical stability:
E466 Sodium Carboxymethyl Cellulose is stable under normal storage conditions in sealed containers at ambient temperature protected from moisture.

Reactivity:
No dangerous reaction is expected under normal conditions of use.
E466 Sodium Carboxymethyl Cellulose may form gels or precipitate in the presence of concentrated divalent or trivalent cations (Ca²⁺, Fe³⁺); may undergo viscosity reduction under extreme pH (<2 or >12) or elevated temperature.

Conditions to avoid:
High concentrations of divalent cations (calcium, magnesium, iron).
Extreme pH conditions below 2 or above 12 (accelerated hydrolysis and viscosity loss).
Prolonged elevated temperature (permanent viscosity reduction).
Moisture during storage (hygroscopic; may clump).

Incompatible materials:
Concentrated strong acids (precipitate CMC as free acid).
Strong oxidizing agents.
High concentrations of calcium, iron, and other multivalent cations.

Hazardous decomposition products:
Carbon monoxide (CO).
Carbon dioxide (CO2).
Acrid smoke and irritating organic fumes (under high-temperature decomposition or fire).

Handling and Storage of E466 Sodium Carboxymethyl Cellulose:

Handling:
Handle in accordance with good industrial hygiene and safety practices.
Avoid inhalation of dust; use respiratory protection where dust generation cannot be avoided.
Wear eye protection where dust may be generated.
Wash hands thoroughly after handling.
Pre-blend with dry ingredients before adding to liquid systems to prevent clumping.

Storage:
Store at ambient temperature in a cool, dry, well-ventilated area.
Keep in tightly sealed original containers; E466 Sodium Carboxymethyl Cellulose is slightly hygroscopic and may absorb moisture and clump.
Stable under recommended storage conditions.

First Aid Measures of E466 Sodium Carboxymethyl Cellulose:

Inhalation:
Move affected person to fresh air.
Dust may cause mechanical respiratory irritation; seek medical advice if symptoms persist.

Skin contact:
Wash affected skin with soap and water.
Rare severe allergic reactions have been reported; seek medical advice immediately if hives, itching, swelling, or other allergic symptoms occur.

Eye contact:
Rinse immediately with plenty of clean water for at least 15 minutes.
Seek medical attention if irritation persists.

Ingestion:
E466 Sodium Carboxymethyl Cellulose is practically non-toxic at food use levels.
Rinse mouth with water; drink adequate water.
Seek medical advice if large amounts are ingested or if gastrointestinal discomfort occurs.

Firefighting Measures of E466 Sodium Carboxymethyl Cellulose:

Suitable extinguishing media:
Water spray, foam, dry chemical powder, or carbon dioxide.

Specific hazards:
E466 Sodium Carboxymethyl Cellulose is combustible in dry powder form.
Thermal decomposition emits acrid smoke and irritating organic fumes.

Protective equipment for firefighters:
Wear self-contained breathing apparatus (SCBA) and full protective clothing.

Firefighting instructions:
Cool exposed containers with water spray.
Prevent contaminated firefighting water from entering drains or waterways.

Accidental Release Measures of E466 Sodium Carboxymethyl Cellulose:

Personal precautions:
Avoid inhalation of dust; use appropriate respiratory protection.
Wet spilled powder creates a slipping hazard.

Environmental precautions:
E466 Sodium Carboxymethyl Cellulose is of low environmental concern (biodegradable); prevent large quantities from entering drains or waterways.

Methods for cleaning up:
Sweep or vacuum dry spilled material into labeled waste containers; avoid creating dust.
Dispose according to local regulations.

Exposure Controls / Personal Protective Equipment of E466 Sodium Carboxymethyl Cellulose:

Engineering controls:
Provide adequate local exhaust ventilation where dust is generated.

Eye protection:
Wear safety glasses or goggles where dust generation is possible.

Hand protection:
Gloves recommended for prolonged handling; rare skin sensitization reported.

Respiratory protection:
Wear a dust respirator (NIOSH-approved) where dust cannot be avoided.

Hygiene measures:
Wash hands thoroughly after handling E466 Sodium Carboxymethyl Cellulose and before eating, drinking, or smoking.

Identifiers of E466 Sodium Carboxymethyl Cellulose:
E Number: E466 (standard); E469 (enzymatically hydrolyzed)
CAS Number: 9004-32-4
EC Number (ECHA): 100.120.377
HS Code: 39123100
Chemical Name: Sodium carboxymethyl cellulose; Cellulose gum
Molecular Formula: [C₆H₇O₂(OH)x(OCH₂COONa)y]n
ChEBI: CHEBI:85146
ChEMBL: ChEMBL1909054
UNII: 05JZI7B19X
CompTox (EPA): DTXSID7040441
JECFA ADI: 0–25 mg/kg body weight/day
US FDA: GRAS; food additive and food contact substance
EU: Approved food additive E466 under Regulation (EC) No 1333/2008; specifications in Commission Regulation (EU) No 231/2012 (updated 2013)
GHS Classification: Not classified as hazardous
Halal: Yes
Kosher: Yes
Vegan: Yes
Gluten-free: Yes (FDA confirmed)
Ionic character: Anionic

Properties of E466 Sodium Carboxymethyl Cellulose:
Physical state: Solid (powder)
Appearance: Slightly hygroscopic white or slightly yellowish or greyish, odorless and tasteless, granular or fibrous powder
Odor: Odorless
Taste: Tasteless
Molecular weight: >17,000 Da (variable; grade-dependent; DP ≥100)
Degree of substitution (DS): 0.20–1.50 (food grade: 0.4–1.5)
Boiling point: 527–528°C (representative unit)
Viscosity (1% aqueous solution): 25–50,000 mPa·s (grade-dependent)
Optimal viscosity pH: 6.5–9.0
Solubility in cold water: Excellent; forms viscous colloidal solution
Solubility in hot water: Excellent (dissolves in both hot and cold water)
Solubility in organic solvents: Insoluble in methanol, ethanol, acetone, chloroform, benzene
pH stability: 6.5–9.0 (optimal); functional 4–11; limited outside this range
Temperature effect: Viscosity decreases with increasing temperature; permanent viscosity loss at elevated temperatures
Salt/alkali resistance: High (can replace guar gum in high-electrolyte systems)
Light stability: Resistant to degradation by bright light
GHS Classification: Not classified
JECFA ADI: 0–25 mg/kg body weight/day

Specifications of E466 Sodium Carboxymethyl Cellulose — Food Grade:
Appearance: White or slightly yellowish, odorless, tasteless powder
DS (carboxymethyl groups per anhydroglucose unit): 0.20–1.50
Molecular weight: >17,000 Da (DP ≥100)
Viscosity (1% solution): 25–50,000 mPa·s (grade-dependent)
pH (1% solution): 6.5–8.0 (aqueous solutions neutral to slightly alkaline)
Loss on drying: ≤10% (105°C, 3h)
Degree of substitution: 0.20–1.50
Sulphated ash: ≤10.0%
Chloride (as NaCl): ≤1.0%
Sodium glycolate: ≤0.4%
Sodium content: 6.5–9.5%
Arsenic: ≤3 mg/kg (EU); ≤1 mg/kg (some specifications)
Lead: ≤2 mg/kg
Mercury: ≤1 mg/kg
Cadmium: ≤1 mg/kg
Heavy metals (as Pb): ≤10–20 ppm
GHS: Not classified
Storage: Ambient temperature, cool dry place, tightly sealed containers; slightly hygroscopic

Names of E466 Sodium Carboxymethyl Cellulose:
E466
Sodium Carboxymethyl Cellulose
Carboxymethyl Cellulose
CMC
NaCMC
SCMC
Sodium CMC
Cellulose Gum
Carmellose
Carboxymethylcellulose Sodium
Carboxy Methyl Cellulose
Sodium Carboxymethylcellulose
Cellulose Carboxymethyl Ether
CMC Gum
Cellulose Gum E466
INS 466
E469 (enzymatically hydrolyzed form)
CAS 9004-32-4
HS 39123100
Walocel (conservation/restoration)
Klucel (conservation/restoration)