Uses of Sodium Alginate

Updated February 21, 2017

Sodium alginate is a product of alginic acid, which is found in brown algae. This is the sodium salt of alginic acid. This sodium salt is extracted as a gum from the cell wall of the algae. This compound is useful because it can absorb large amounts of water, up to 300 times its weight. It has many uses in a range of industries.

Dental Impressions

A powdered version of sodium alginate is used to create dental impressions. When mixed with water, the resulting material is stretchable but will also hold its form. This gum is packed into a dental tray and then is bitten into. Molds of the teeth are then made from the impression.

Indigestion tablets

Sodium alginate is used in a type of indigestion tablet. The alginate will form a protective coating around the walls of the oesophagus and stomach. This protective coating gets rid of the discomfort of having too much acid in the stomach. Some indigestion tablets will contain alginates and antacids.

Reactive Dye

Sodium alginate is a thickener added to reactive dye for good consistency. Thickeners can also help hold the dye to the fabric and increase the brightness of the colour.

Food Additive

Sodium alginate is used as a food additive as a thickener, stabiliser, emulsifier and bulking agent. It is typically found in gel-like substances. This product is also added to dehydrated products because of its ability to quickly absorb water. Sodium alginate is added to milk products, cheese products, fat spreads, dried vegetables, processed fruit, canned vegetables, breakfast cereals, starch-based products, fish products, and more.


Sodium alginate is used as a chelator for pulling radioactive heavy metals from the body. This chemical helps mobilise and absorb the heavy metal and get it out of the body. Chelation can be done slowly or quickly. Fast chelation can cause severe reactions in the body.

Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author

Liz Tomas began writing professionally in 2004. Her work has appeared in the "American Journal of Enology and Viticulture," "BMC Genomics" and "PLoS Biology." She holds a Master of Science in food science from Cornell University and a Bachelor of Science in biochemistry from the University of New Hampshire. She is pursuing her Ph.D. in oenology at Lincoln University.