Sodium acid phosphate

INS 339(i)CAS 89140-32-9

Used as a preservative — Codex also lists it as acidity regulator, emulsifier, emulsifying salt, humectant, sequestrant, stabilizer, thickener.

Monosodium phosphate is an acidity regulator and buffer, and a component of some baking powders.

Where it is and isn’t permitted

Status of Sodium acid phosphate by jurisdiction. Every jurisdiction this site covers is listed, including those where the substance does not appear.
JurisdictionStatusScope and limitsCitation
United StatesFood and Drug AdministrationPermitted21 CFR 182.6085retrieved 2026-09-07
Codex AlimentariusCodex Alimentarius Commission / JECFAPermitted, with conditions

108 food categories

highest permitted level 44,000 mg/kg

Show every food category
  • 01.1.1 Fluid Milk (plain) — 1,500 mg/kg
  • 01.1.2 Other Fluid Milk (plain) — 2,200 mg/kg
  • 01.1.3 Fluid Buttermilk (plain) — 1,500 mg/kg
  • 01.1.4 Flavoured Fluid Milk Drinks — 1,500 mg/kg
  • 01.2 Fermented and renneted milk products (plain), — 1,000 mg/kg
  • 01.3.1 Condensed milk (plain) — 880 mg/kg
  • 01.3.2 Beverage whiteners — 13,000 mg/kg
  • 01.4 Cream (plain) and the like — 2,200 mg/kg
  • 01.5.1 Milk powder and cream powder (plain) — 4,400 mg/kg
  • 01.5.2 Milk and cream powder analogues — 4,400 mg/kg
  • 01.6.1 Unripened cheese — 4,400 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) — 1,500 mg/kg
  • 01.8.1 Liquid whey and whey products, excluding whey cheeses — 880 mg/kg
  • 01.8.2 Dried whey and whey products, excluding whey cheeses — 4,400 mg/kg
  • 02.2.1 Butter — 880 mg/kg
  • 02.2.2 Fat spreads, dairy fat spreads and blended spreads — 2,200 mg/kg
  • 02.3 Fat emulsions mainly of type oil-in-water, including mixed and/or flavoured products based on fat emulsions — 2,200 mg/kg
  • 02.4 Fat-based desserts excluding dairy-based dessert products of food category 01.7 — 1,500 mg/kg
  • 03.0 Edible ices, including sherbet and sorbet — 7,500 mg/kg
  • 04.1.2.10 Fermented fruit products — 2,200 mg/kg
  • 04.1.2.11 Fruit fillings for pastries — 1,500 mg/kg
  • 04.1.2.3 Fruit in vinegar, oil, or brine — 2,200 mg/kg
  • 04.1.2.6 Fruit-based spreads (e.g. chutney) excluding products of food category — 1,100 mg/kg
  • 04.1.2.7 Candied fruit — 10 mg/kg
  • 04.1.2.8 Fruit preparations, including pulp, purees, fruit toppings and coconut milk — 350 mg/kg
  • 04.1.2.9 Fruit-based desserts, incl. fruit-flavoured water-based desserts — 1,500 mg/kg
  • 04.2.1.2 Surface-treated fresh vegetables, (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), seaweeds and nuts and seeds — 1,760 mg/kg
  • 04.2.1.3 Peeled, cut or shredded fresh vegetables, (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), seaweeds and nuts and seeds — 5,600 mg/kg
  • 04.2.2.1 Frozen vegetables (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), seaweeds and nuts and seeds — 5,000 mg/kg
  • 04.2.2.2 Dried vegetables (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), seaweeds, and nuts and seeds — 5,000 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 — 2,200 mg/kg
  • 04.2.2.4 Canned or bottled (pasteurized) or retort pouch vegetables (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), and seaweeds — 2,200 mg/kg
  • 04.2.2.5 Vegetable (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), seaweed, and nut and seed purees and spreads (e.g. peanut butter) — 2,200 mg/kg
  • 04.2.2.6 Vegetable (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), seaweed, and nut and seed pulps and preparations (e.g. vegetable desserts and sauces, candied vegetables) other than food category 04.2.2.5 — 2,200 mg/kg
  • 04.2.2.7 Fermented vegetable (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera) and seaweed products, excluding fermented soybean products of food categories 06.8.6, 06.8.7, 12.9.1, — 2,200 mg/kg
  • 04.2.2.8 Cooked or fried vegetables (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), and seaweeds — 2,200 mg/kg
  • 05.1.1 Cocoa mixes (powders) and cocoa mass/cake — 1,100 mg/kg
  • 05.1.3 Cocoa-based spreads, incl. fillings — 880 mg/kg
  • 05.1.4 Cocoa and chocolate products — 1,100 mg/kg
  • 05.1.5 Imitation chocolate, chocolate substitute products — 2,200 mg/kg
  • 05.2 Confectionery including hard and soft candy, nougats, etc. other than food categories 05.1, 05.3, and 05.4 — 2,200 mg/kg
  • 05.3 Chewing gum — 44,000 mg/kg
  • 05.4 Decorations (e.g. for fine bakery wares), toppings (non-fruit), and sweet sauces — 1,500 mg/kg
  • 06.2.1 Flours — 2,500 mg/kg
  • 06.3 Breakfast cereals, including rolled oats — 2,200 mg/kg
  • 06.4.1 Fresh pastas and noodles and like products — 2,500 mg/kg
  • 06.4.2 Dried pastas and noodles and like products — 900 mg/kg
  • 06.4.3 Pre-cooked pastas and noodles and like products — 2,500 mg/kg
  • 06.5 Cereal and starch based desserts (e.g. rice pudding, tapioca pudding) — 7,000 mg/kg
  • 06.6 Batters (e.g. for breading or batters for fish or poultry) — 5,600 mg/kg
  • 06.8.1 Soybean-based beverages — 1,300 mg/kg
  • 06.8.3 Soybean curd (tofu) — 100 mg/kg
  • 07.1.1.2 Soda breads — 9,300 mg/kg
  • 07.1.2 Crackers, excluding sweet crackers — 9,300 mg/kg
  • 07.1.3 Other ordinary bakery products (e.g. bagels, pita, English muffins) — 9,300 mg/kg
  • 07.1.4 Bread-type products, including bread stuffing and bread crumbs — 9,300 mg/kg
  • 07.1.5 Steamed breads and buns — 9,300 mg/kg
  • 07.1.6 Mixes for bread and ordinary bakery wares — 9,300 mg/kg
  • 07.2 Fine bakery wares (sweet, salty, savoury) and mixes — 9,300 mg/kg
  • 08.2.1 Non-heat treated processed meat, poultry, and game products in whole pieces or cuts — 2,200 mg/kg
  • 08.2.2 Heat-treated processed meat, poultry, and game products in whole pieces or cuts — 1,320 mg/kg
  • 08.2.3 Frozen processed meat, poultry and game products in whole pieces or cuts — 2,200 mg/kg
  • 08.3 Processed comminuted meat, poultry, and game products — 2,200 mg/kg
  • 08.4 Edible casings (e.g. sausage casings) — 1,100 mg/kg
  • 09.2.1 Frozen fish, fish fillets, and fish products, including molluscs, crustaceans, and echinoderms — 2,200 mg/kg
  • 09.2.2 Frozen battered fish, fish fillets and fish products, including molluscs, crustaceans, and echinoderms — 2,200 mg/kg
  • 09.2.3 Frozen minced and creamed fish products, including molluscs, crustaceans, and echinoderms — 2,200 mg/kg
  • 09.2.4.1 Cooked fish and fish products — 2,200 mg/kg
  • 09.2.4.2 Cooked molluscs, crustaceans, and echinoderms — 2,200 mg/kg
  • 09.2.5 Smoked, dried, fermented, and/or salted fish and fish products, including molluscs, crustaceans, and echinoderms — 2,200 mg/kg
  • 09.3.1 Fish and fish products, including molluscs, crustaceans, and echinoderms, marinated and/or in jelly — 2,200 mg/kg
  • 09.3.2 Fish and fish products, including molluscs, crustaceans and echinoderms, pickled and/or in brine — 2,200 mg/kg
  • 09.3.3 Salmon substitutes, caviar and other fish roe products — 2,200 mg/kg
  • 09.3.4 Semi-preserved fish and fish products, including molluscs, crustaceans and echinoderms (e.g. fish paste), excluding products of food categories 09.3.1 - 09.3.3 — 2,200 mg/kg
  • 09.4 Fully preserved, including canned or fermented fish and fish products, including molluscs, crustaceans, and echinoderms — 2,200 mg/kg
  • 10.2.1 Liquid egg products — 4,400 mg/kg
  • 10.2.2 Frozen egg products — 1,290 mg/kg
  • 10.3 Preserved eggs, including alkaline, salted, and canned eggs — 1,000 mg/kg
  • 10.4 Egg-based desserts (e.g. custard) — 1,400 mg/kg
  • 11.1.2 Powdered sugar, powdered dextrose — 6,600 mg/kg
  • 11.4 Other sugars and syrups (e.g. xylose, maple syrup, sugar toppings) — 1,320 mg/kg
  • 11.6 Table-top sweeteners, including those containing high-intensity sweeteners — 1,000 mg/kg
  • 12.1.1 Salt — 8,800 mg/kg
  • 12.1.2 Salt substitutes — 4,400 mg/kg
  • 12.2.2 Seasonings and condiments — 2,200 mg/kg
  • 12.5 Soups and broths — 1,500 mg/kg
  • 12.6 Sauces and like products — 2,200 mg/kg
  • 12.9 Soybean-based seasonings and condiments — 1,200 mg/kg
  • 13.1.1 Infant formulae — 450 mg/kg
  • 13.1.3 Formulae for special medical purposes for infants — 450 mg/kg
  • 13.2 Complementary foods for infants and young children — 4,400 mg/kg
  • 13.3 Dietetic foods intended for special medical purposes (excluding products of food category 13.1) — 2,200 mg/kg
  • 13.4 Dietetic formulae for slimming purposes and weight reduction — 2,200 mg/kg
  • 13.5 Dietetic foods (e.g. supplementary foods for dietary use) excluding products of food categories — 2,200 mg/kg
  • 13.6 Food supplements — 2,200 mg/kg
  • 14.1.2.1 Fruit juice — 1,000 mg/kg
  • 14.1.2.3 Concentrates for fruit juice — 1,000 mg/kg
  • 14.1.3.1 Fruit nectar — 1,000 mg/kg
  • 14.1.3.3 Concentrates for fruit nectar — 1,000 mg/kg
  • 14.1.3.4 Concentrates for vegetable nectar — 1,000 mg/kg
  • 14.1.4 Water-based flavoured drinks, including "sport," “energy,” or "electrolyte" drinks and particulated drinks — 1,000 mg/kg
  • 14.1.5 Coffee, coffee substitutes, tea, herbal infusions, and other hot cereal and grain beverages, excluding cocoa — 300 mg/kg
  • 14.2.2 Cider and perry — 880 mg/kg
  • 14.2.5 Mead — 440 mg/kg
  • 14.2.6 Distilled spirituous beverages containing more than 15% alcohol — 440 mg/kg
  • 15.0 Ready-to-eat savouries — 2,200 mg/kg
CXS 192-1995 Table One, INS 339(i)and 107 further provisionsretrieved 2026-09-07

What it is made from

Made by partially neutralising phosphoric acid with sodium.

  • Vegan
  • Vegetarian
CAS registry number
89140-32-9
InChIKey
AJPJDKMHJJGVTQ-UHFFFAOYSA-M
PubChem
CID 23672064

Every name it appears under

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

INS number

  • 339(i)

CAS registry number

  • 7558-80-7
  • 89140-32-9

As it appears in regulation

  • Sodium acid phosphate

Other names

  • Acid sodium phosphate
  • Anhydrous sodium dihydrogen phosphate
  • H2NaO4P
  • HSDB 738
  • INS NO.339(I)
  • INS-339(I)
  • Ionosol B
  • Ionosol Mb
  • Ionosol T
  • KH7I04HPUU
  • Monobasic sodium phosphate
  • Monosodium dihydrogen monophosphate
  • Monosodium dihydrogen orthophosphate
  • Monosodium dihydrogen phosphate
  • Monosodium hydrogen phosphate
  • Monosodium monophosphate
  • Monosodium orthophosphate
  • Monosodium phosphate
  • Monosodium phosphate, anhydrous
  • Monosorb XP-4
  • NaH2PO4
  • natriumdihydrogen-phosphate
  • phosphoric acid, monosodium salt, anhydrous
  • Phosphoric acid, sodium salt
  • Phosphoric acid, sodium salt (1:1)
  • Phosphoric acid, xsodium salt
  • Primary sodium phosphate
  • Sodium acid phosphate
  • sodium biphosphate
  • Sodium biphosphate anhydrous
  • Sodium dihydngen phoshate anhydrous
  • Sodium dihydrogen monophosphate
  • Sodium dihydrogen orthophosphate
  • SODIUM DIHYDROGEN PHOSPHATE
  • Sodium dihydrogen phosphate (1:2:1)
  • Sodium dihydrogen phosphate (NaH2PO4)
  • Sodium dihydrogen phosphate, anhydrous
  • sodium dihydrogen-phosphate
  • Sodium dihydrogenorthophosphate
  • sodium dihydrogenphoshate
  • sodium dihydrogenphospate
  • sodium dihydrogenphosphat
  • sodium dihydrogenphosphate
  • Sodium monobasic phosphate (NaH2PO4)
  • Sodium orthophosphate monobasic
  • Sodium orthophosphate, primary
  • Sodium phosphate (Na(H2PO4))
  • Sodium phosphate (NaH2PO4)
  • sodium phosphate mono-basic
  • Sodium phosphate monobasic (anhydrate)
  • Sodium phosphate monobasic, AR
  • Sodium phosphate, monobasic
  • Sodium phosphate, monobasic (USP)
  • SODIUM PHOSPHATE, MONOBASIC ANHYDROUS
  • Sodium primary phosphate
  • Sodium salt of phosphoric acid
  • sodiumdihydrogen phosphate
  • sodiumdihydrogenphosphate

Hazard reference values

No reference value for this substance in the sources we hold.

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/sodium-acid-phosphate.json