The Sodium salt of Carboxymethyl Cellulose is generally referred to as CMC or Cellulose Gum. It is a water soluble cellulose ether produced by reacting alkali cellulose with the sodium salt of monochloroacetic acid.

CMC solutions in water as non Newtonian and pseudoplastic. CMC is available in various viscosities and is hot and cold water soluble. If CMC solutions are heated to high temperatures for long periods they will depolymerise and some viscosity degradation will occur. CMC solutions are also stable over a wide pH range but highly alkaline pH will degrade the viscosity. Highly substituted (DS > 0.7) CMC's show lesser degradation. CMC solution viscosities increase exponentially with concentration in water.

CMC is compatible in solutions with most other water soluble non-ionic and anionic polymers and gums, carbohydrates, salts, solvents and proteins.

Several salts have different effects on CMC solutions. The behaviours of CMC solutions to salts depend on the kind of salt, concentration, ph, temperature and even on the order of addition of CMC and salts to the solution.