Take the Quiz - Get 15% OFF your 1st Order
Search

Chapter 11: The supporting cast · Part 1: Polymers

Sodium carboxymethylcellulose (CMC)

No badge

Also called
cellulose gum, CMC, E466
Found in
laundry powder and liquid, dishwasher tablets

The worst fact: as a food additive, it changed people's gut. In a feeding trial, 7 people who ate 15 g a day for 11 days had modestly more tummy discomfort after meals than 9 people on the same diet without it, and less diverse gut bacteria. An earlier mouse study found low levels caused low-grade inflammation and obesity.

Why brands use it: it's an anti-redeposition agent: it holds lifted dirt in the wash water so it doesn't settle back on fabric. In dishwasher tablets it's listed as an enzyme stabiliser.

Take care if: no specific group. It has no Australian hazard classification, and the US EPA's Safer Choice list rates it a green circle ("verified to be of low concern").

Comes from: plant cellulose treated with alkali and monochloroacetic acid or its sodium salt.

Myth check: "It's a synthetic plastic": no. It's made from cellulose obtained "directly from strains of fibrous plant material", chemically modified so it dissolves in water.

Contaminants: nil. (Food grade allows up to 0.4% sodium glycolate, a by-product of the recipe.)

Fair to say: the UN's food additive committee (JECFA) set no limit on daily intake for modified celluloses, and a load of washing isn't something you eat. How well it breaks down in the environment depends on the grade.

Correct as of November 2026. What the badges mean

Sources

  • European Union. Regulation (EC) 1333/2008 Annex V; Regulation (EU) 231/2012 (food additive specifications); Regulation (EU) 2022/63 (E171); Regulation (EU) 1297/2014 (detergent capsules); Regulation (EC) 790/2009 and Delegated Regulation (EU) 2021/849 (borates); Regulation (EU) 109/2012; Regulation (EU) 2023/2055 (microplastics); Regulation (EU) 2024/1328 (D4, D5, D6); Regulation (EC) 1223/2009 (cosmetics) Annexes III and IV.
  • JECFA (FAO/WHO). Specifications and evaluations: titanium dioxide (2023), sodium carboxymethylcellulose, polyvinylpyrrolidone, Brilliant Blue FCF, tartrazine, Sunset Yellow FCF, D&C Red 33.
  • Danish EPA. Substances in household detergents (2019).
  • Chassaing B et al. Randomized controlled-feeding study of dietary emulsifier carboxymethylcellulose. Gastroenterology 2022.
  • Chassaing B et al. Dietary emulsifiers impact the mouse gut microbiota. Nature 2015;519:92-96.

The full source list is at the end of Chapter 11.