YenzoWhat is E338 (phosphoric acid)?
Appendix 1 of Circular 24/2019/TT-BYT lists the functions of phosphoric acid as acidity regulator, antioxidant and sequestrant.
E338Phosphoric acid
E338 is phosphoric acid (orthophosphoric acid). In food it adds sourness and adjusts acidity, and it also binds metal ions and supports antioxidants.
- Code
- E338 · INS 338
In Vietnam✓ PermittedOn the list of permitted additives — Circular 24/2019, Appendix 1
Risk level on the Yenzo Scalelow?Based on EFSA's scientific assessment, 2019
EFSA (2019) found that intake in children can exceed the ADI. On the Yenzo Scale this finding does not raise the risk level by itself.
How much a day stays within the ADI?EFSA 2019 (group ADI for phosphates, as phosphorus): 40 mg/kg bw per day
about 2.6 g a daythat is 2,600 mg
How E338 appears on labels
IngredientsIllustrative example
Wheat flour, vegetable oil, salt, sugar, acidity regulator (338), dried onion and garlic, pepper, natural colour (160a).
acidity regulator (338)acidity regulator 338E338INS 338axit phosphoricacid phosphoricaxit orthophosphoricphosphoric acid
Phosphoric acid in food
Flavoured drinksLiquid milkUnripened cheeseEdible ices and fruit icesCocoa and chocolate productsSweets and confectioneryProcessed meat and poultry, not heat-treatedCooked fish productsCanned and bottled vegetables
Questions about phosphoric acid
Is phosphoric acid harmful?
In 2019 EFSA set a group ADI of 40 mg/kg body weight per day, expressed as phosphorus, for the phosphate additives (E338–E341, E343, E450–E452). EFSA noted that in one estimated scenario intake by infants, toddlers and other children exceeded this ADI.
Is Phosphoric acid permitted in Vietnam?
Yes. Phosphoric acid (INS 338) is listed in Appendix 1 of Circular 24/2019/TT-BYT, the list of additives permitted in food.
Can children and pregnant women have E338?
In the EU, additives may not be used in foods for infants and young children unless Annex II of Regulation (EC) No 1333/2008 provides for it. Annex II lists E338 in categories 13.1.1 (infant formulae), 13.1.2 (follow-on formulae), 13.1.3 (processed cereal-based foods and baby foods, only for pH adjustment) and 13.1.5.1 (dietary foods for infants for special medical purposes and special formulae for infants) (only for pH adjustment). The Regulation has no separate provision for pregnant women. If you have a particular health condition, ask a doctor.
Other acidity regulators
E335Sodium tartratesvery lowE336Potassium tartratesvery lowE337Sodium potassium tartratevery lowE339Sodium phosphateslowE340Potassium phosphateslowE341Calcium phosphateslow
See all acidity regulators →Updated 21 October 2026
Sources (3)
- Re‐evaluation of phosphoric acid–phosphates – di‐, tri‐ and polyphosphates (E 338–341, E 343, E 450–452) as food additives and the safety of proposed extension of use
- Thông tư 24/2019/TT-BYT (văn bản hợp nhất 09/VBHN-BYT), Phụ lục 2A: nhóm thực phẩm được phép dùng INS 338
- Regulation (EC) No 1333/2008 on food additives (consolidated text of 18.08.2026): Article 16 and Annex II, Part E, category 13.1 (foods for infants and young children)