Propylene glycol alginate

E number E405INS 405CAS 9005-37-2

Used as an emulsifier — Codex also lists it as bulking agent, carrier, foaming agent, gelling.

Propylene glycol alginate is an alginate modified to survive acid, which makes it the thickener of choice for salad dressings and for stabilising beer foam.

Where it is and isn’t permitted

Status of Propylene glycol alginate by jurisdiction. Every jurisdiction this site covers is listed, including those where the substance does not appear.
JurisdictionStatusScope and limitsCitation
United StatesFood and Drug AdministrationPermitted, with conditions21 CFR 172.858retrieved 2026-09-07
Codex AlimentariusCodex Alimentarius Commission / JECFAPermitted, with conditions

55 food categories

highest permitted level 20,000 mg/kg

Show every food category
  • 01.1.2 Other Fluid Milk (plain) — 1,300 mg/kg
  • 01.1.4 Flavoured Fluid Milk Drinks — 1,300 mg/kg
  • 01.2.1.1 Fermented milks (plain), not heat-treated after fermentation — 5,000 mg/kg
  • 01.2.1.2 Fermented milks (plain), heat-treated after fermentation — 5,000 mg/kg
  • 01.3.2 Beverage whiteners — 5,000 mg/kg
  • 01.4.2 Sterilized and UHT creams, whipping and whipped creams, and reduced fat creams (plain) — 5,000 mg/kg
  • 01.4.3 Clotted cream (plain) — 5,000 mg/kg
  • 01.4.4 Cream analogues — 2,500 mg/kg
  • 01.6.1 Unripened cheese — 5,000 mg/kg
  • 01.6.2.3 Cheese powder (for reconstitution; e.g. for cheese sauces) — 16,000 mg/kg
  • 01.6.4 Processed cheese — 9,000 mg/kg
  • 01.6.5 Cheese analogues — 9,000 mg/kg
  • 01.7 Dairy-based desserts (e.g. pudding, fruit or flavoured yoghurt) — 6,000 mg/kg
  • 02.2.2 Fat spreads, dairy fat spreads and blended spreads — 3,000 mg/kg
  • 02.3 Fat emulsions mainly of type oil-in-water, including mixed and/or flavoured products based on fat emulsions — 3,000 mg/kg
  • 03.0 Edible ices, including sherbet and sorbet — 10,000 mg/kg
  • 04.1.2.11 Fruit fillings for pastries — 5,000 mg/kg
  • 04.1.2.5 — 5,000 mg/kg
  • 04.1.2.8 Fruit preparations, including pulp, purees, fruit toppings and coconut milk — 5,000 mg/kg
  • 04.1.2.9 Fruit-based desserts, incl. fruit-flavoured water-based desserts — 6,000 mg/kg
  • 04.2.2.3 Vegetables (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), and seaweeds in vinegar, oil, brine, or soybean sauce — 6,000 mg/kg
  • 05.1.2 Cocoa mixes (syrups) — 10,000 mg/kg
  • 05.1.3 Cocoa-based spreads, incl. fillings — 10,000 mg/kg
  • 05.2 Confectionery including hard and soft candy, nougats, etc. other than food categories 05.1, 05.3, and 05.4 — 5,000 mg/kg
  • 05.3 Chewing gum — 5,000 mg/kg
  • 05.4 Decorations (e.g. for fine bakery wares), toppings (non-fruit), and sweet sauces — 5,000 mg/kg
  • 06.4.1 Fresh pastas and noodles and like products — 10,000 mg/kg
  • 06.4.2 Dried pastas and noodles and like products — 5,000 mg/kg
  • 06.4.3 Pre-cooked pastas and noodles and like products — 5,000 mg/kg
  • 06.8.1 Soybean-based beverages — 10,000 mg/kg
  • 07.1.1.1 Yeast-leavened breads and specialty breads — 4,000 mg/kg
  • 07.1.2 Crackers, excluding sweet crackers — 2,000 mg/kg
  • 07.1.5 Steamed breads and buns — 500 mg/kg
  • 07.1.6 Mixes for bread and ordinary bakery wares — 20,000 mg/kg
  • 07.2.1 Cakes, cookies and pies (e.g. fruit-filled or custard types) — 3,000 mg/kg
  • 07.2.2 Other fine bakery products (e.g. doughnuts, sweet rolls, scones, and muffins) — 2,000 mg/kg
  • 07.2.3 Mixes for fine bakery wares (e.g. cakes, pancakes) — 10,000 mg/kg
  • 08.3 Processed comminuted meat, poultry, and game products — 3,000 mg/kg
  • 10.2.1 Liquid egg products — 10,000 mg/kg
  • 10.2.2 Frozen egg products — 10,000 mg/kg
  • 10.4 Egg-based desserts (e.g. custard) — 3,000 mg/kg
  • 11.4 Other sugars and syrups (e.g. xylose, maple syrup, sugar toppings) — 10,000 mg/kg
  • 12.5.1 Ready-to-eat soups and broths, including canned, bottled, and frozen — 10,000 mg/kg
  • 12.6.1 Emulsified sauces and dips (e.g. mayonnaise, salad dressing, onion dips) — 8,000 mg/kg
  • 12.6.2 Non-emulsified sauces (e.g. ketchup, cheese sauce, cream sauce, brown gravy) — 8,000 mg/kg
  • 12.6.3 Mixes for sauces and gravies — 8,000 mg/kg
  • 13.3 Dietetic foods intended for special medical purposes (excluding products of food category 13.1) — 1,200 mg/kg
  • 13.4 Dietetic formulae for slimming purposes and weight reduction — 1,200 mg/kg
  • 13.6 Food supplements — 1,000 mg/kg
  • 14.1.4.1 Carbonated water-based flavoured drinks — 500 mg/kg
  • 14.1.4.2 Non-carbonated water-based flavoured drinks, including punches and ades — 500 mg/kg
  • 14.1.4.3 Concentrates (liquid or solid) for water-based flavoured drinks — 500 mg/kg
  • 14.1.5 Coffee, coffee substitutes, tea, herbal infusions, and other hot cereal and grain beverages, excluding cocoa — 500 mg/kg
  • 14.2.1 Beer and malt beverages — 500 mg/kg
  • 15.1 Snacks - potato, cereal, flour or starch based (from roots and tubers, pulses and legumes) — 3,000 mg/kg
CXS 192-1995 Table One, INS 405and 54 further provisionsretrieved 2026-09-07

What it is made from

Made by reacting seaweed alginate with propylene oxide. The alginate is of plant origin; the propylene oxide is petroleum-derived.

  • Vegan
  • Vegetarian
CAS registry number
9005-37-2

Every name it appears under

7 recorded names. A label may use any of them.

E number

  • E405

INS number

  • 405

CAS registry number

  • 9005-37-2

As it appears in regulation

  • Propylene glycol alginate

Other names

  • E 405
  • Propane-1, 2-diol alginate
  • PROPYLENE GLYCOL ALGINATE

Hazard reference values

Values set by assessing bodies. A body that has not set a value is not listed here.
TypeValuePopulationAssessed byOpinion
ADI55 mg/kg bw/dayconsumersEFSA ANS2018

Evidence and how bodies read it

Studies, and the differing conclusions regulators drew from them, are curated by hand rather than machine-read, and none has been written for this substance yet.

Sources for this page

  • ecfr retrieved 2026-09-07
  • gsfa retrieved 2026-09-07

Full licence terms and publisher details on Sources. How this page is built and updated: Method.

Machine-readable:/api/v1/additives/propylene-glycol-alginate.json