Potassium nitrate

E number E252INS 252CAS 7757-79-1

Listed as a preservative by Canada, Codex and the US.

Listed as preservatives (CA, US, Codex) · colours (US) · flavour enhancers (US) · colour retention agents (Codex) · flavouring agents and adjuvants (US)
Chemical structure of Potassium nitrate, from PubChem compound 24434
Structure from PubChem CID 24434 (National Library of Medicine, public domain). A depiction of one compound: where a listing covers a family, or a substance has no single structure, this page shows none.

Potassium nitrate, historically called saltpetre, is used in slow-cured meats and some cheeses, where it is gradually reduced to nitrite.

Where it is and isn’t permitted

Status of Potassium nitrate by jurisdiction. Every jurisdiction this site covers is listed, including those where the substance does not appear.
JurisdictionStatusScope and limitsCitation
Australia and New ZealandFood Standards Australia New ZealandPermitted, with conditions

3 food categories

highest permitted level 500 mg/kg

Show every food category
  • 1.6 Cheese and cheese products — 50 mg/kgCalculated as nitrate ion.
  • 8.2.4 Slow dried cured meat — 500 mg/kg
  • 8.3.1 Fermented, uncooked processed comminuted meat products — 500 mg/kg
Food Standards Code, Schedule 15, S15—5and 2 further provisionsretrieved 2026-10-17
CanadaHealth CanadaPermitted, with conditions

no numerical limit (good manufacturing practice)

5 permitted uses

Show every permitted use
  • In: Cover pickle or dry cure used in the curing of preserved meat or preserved meat by-product prepared by slow cure processes. Purpose: Preservative. Limit: Good manufacturing practice. If used singly or in combination with sodium nitrate, the total amount of such nitrate salts added to each batch of preserved meat or preserved meat by-product not to exceed 200 ppm, calculated prior to any smoking, cooking or fermentation. When potassium nitrate is included in the cover pickle or dry cure that is sold for use in preserved meat or preserved meat by-product, it must be packaged separately from any spice or seasoning. Amendment notices: NOM/ADM-0122. — Health Canada, List of Permitted Preservatives (List 11), item P.7(a)
  • In: Dry sausage, semi-dry sausage, preserved meat or preserved meat by-product prepared by slow cure processes. Purpose: Preservative. Limit: If used singly, the amount added to each batch of dry sausage, semi-dry sausage, preserved meat or preserved meat by-product not to exceed 200 ppm, calculated prior to any smoking, cooking or fermentation. If used in combination with sodium nitrate, the total combined amount added to each batch of dry sausage, semi-dry sausage, preserved meat or preserved meat by-product not to exceed 200 ppm, calculated prior to any smoking, cooking or fermentation. Amendment notices: NOM/ADM-0122. — Health Canada, List of Permitted Preservatives (List 11), item P.7(b)
  • In: Meat binder for dry sausage, semi-dry sausage, preserved meat or preserved meat by-product prepared by slow cure processes. Purpose: Preservative. Limit: Good manufacturing practice. If used singly or in combination with sodium nitrate, the total amount of such nitrate salts added to each batch of dry sausage, semi-dry sausage, preserved meat or preserved meat by-product not to exceed 200 ppm, calculated prior to any smoking, cooking or fermentation. When potassium nitrate is included in the meat binder that is sold for use in dry sausage, semi-dry sausage, preserved meat or preserved meat by-product, it must be packaged separately from any spice or seasoning. Amendment notices: NOM/ADM-0122. — Health Canada, List of Permitted Preservatives (List 11), item P.7(c)
  • In: Mold ripened cheese packed in hermetically sealed containers. Purpose: Preservative. Limit: If used singly, the amount not to exceed 200 ppm of the milk and milk products used to manufacture the cheese. If used in combination with sodium nitrate, the total combined amount not to exceed 200 ppm of the milk and milk products used to manufacture the cheese. In either case, the amount not to exceed 50 ppm in the finished cheese. — Health Canada, List of Permitted Preservatives (List 11), item P.7(d)
  • In: Ripened cheese, containing not more than 68% moisture on a fat free basis during manufacture of which the lactic acid fermentation and salting is completed later than 12 hours after coagulation of the curd by food enzymes and where the added salt is applied externally to the cheese as dry salt or in the form of brine. Purpose: Preservative. Limit: If used singly, the amount not to exceed 200 ppm of the milk and milk products used to manufacture the cheese. If used in combination with sodium nitrate, the total combined amount not to exceed 200 ppm of the milk and milk products used to manufacture the cheese. In either case, the amount not to exceed 50 ppm in the finished cheese. — Health Canada, List of Permitted Preservatives (List 11), item P.7(e)
Health Canada, List of Permitted Preservatives (List 11)and 4 further provisionsretrieved 2026-10-17
European UnionEuropean Commission / EFSAPermitted, with conditions

18 food categories

highest permitted level 270 mg/kg

Show every food category
  • 1.7.2 ripened cheese — 75 mg/kgPermitted as a member of Nitrates. ML = 75 mg/kg. only hard, semi-hard and semi-soft cheese Period of application: from 9 October 2026. Note: (30) In the cheese milk or equivalent level if added after removal of whey and addition of water (XA) The maximum amount that may be added during the manufacturing expressed as NO₃ ion. (XB) In case the residual amount from all sources for the product ready for marketing throughout the shelf-life of the product exceeds 35 mg/kg expressed as NO₃ ion, food business operators shall investigate the reason of this excess.
  • 1.7.2 ripened cheese — 110 mg/kgPermitted as a member of Nitrates. ML = 110 mg/kg. only traditional Swedish granular-eyed cheese from Gäsene ripened for a minimum of 11 months Period of application: until 9 October 2027. Note: (30) In the cheese milk or equivalent level if added after removal of whey and addition of water (XA) The maximum amount that may be added during the manufacturing expressed as NO₃ ion. (XB) In case the residual amount from all sources for the product ready for marketing throughout the shelf-life of the product exceeds 35 mg/kg expressed as NO₃ ion, food business operators shall investigate the reason of this excess.
  • 1.7.2 ripened cheese — 110 mg/kgPermitted as a member of Nitrates. ML = 110 mg/kg. only traditional Swedish Cheddar cheese from Kvibille ripened for a minimum of 4 months Period of application: until 9 October 2027. Note: (30) In the cheese milk or equivalent level if added after removal of whey and addition of water (XA) The maximum amount that may be added during the manufacturing expressed as NO₃ ion. (XB) In case the residual amount from all sources for the product ready for marketing throughout the shelf-life of the product exceeds 35 mg/kg expressed as NO₃ ion, food business operators shall investigate the reason of this excess.
  • 1.7.2 ripened cheese — 110 mg/kgPermitted as a member of Nitrates. ML = 110 mg/kg. only traditional Swedish granular-eyed cheese from Falköping ripened for a minimum of 12 months Period of application: until 9 October 2027. Note: (30) In the cheese milk or equivalent level if added after removal of whey and addition of water (XA) The maximum amount that may be added during the manufacturing expressed as NO₃ ion. (XB) In case the residual amount from all sources for the product ready for marketing throughout the shelf-life of the product exceeds 35 mg/kg expressed as NO₃ ion, food business operators shall investigate the reason of this excess.
  • 1.7.4 whey cheese — 75 mg/kgPermitted as a member of Nitrates. ML = 75 mg/kg. only cheese milk of hard, semi-hard and semi-soft cheese Period of application: from 9 October 2026. Note: (30) In the cheese milk or equivalent level if added after removal of whey and addition of water (XA) The maximum amount that may be added during the manufacturing expressed as NO₃ ion. (XB) In case the residual amount from all sources for the product ready for marketing throughout the shelf-life of the product exceeds 35 mg/kg expressed as NO₃ ion, food business operators shall investigate the reason of this excess.
  • 1.7.6 cheese products (excluding products falling in category 16) — 75 mg/kgPermitted as a member of Nitrates. ML = 75 mg/kg. only hard, semi-hard and semi-soft ripened products Period of application: from 9 October 2026. Note: (30) In the cheese milk or equivalent level if added after removal of whey and addition of water (XA) The maximum amount that may be added during the manufacturing expressed as NO₃ ion. (XB) In case the residual amount from all sources for the product ready for marketing throughout the shelf-life of the product exceeds 35 mg/kg expressed as NO₃ ion, food business operators shall investigate the reason of this excess.
  • 1.8 Dairy analogues, including beverage whiteners — 75 mg/kgPermitted as a member of Nitrates. ML = 75 mg/kg. only dairy-based cheese analogue Period of application: from 9 October 2025. Note: (30) In the cheese milk or equivalent level if added after removal of whey and addition of water (XA) The maximum amount that may be added during the manufacturing expressed as NO₃ ion. (XB) In case the residual amount from all sources for the product ready for marketing throughout the shelf-life of the product exceeds 35 mg/kg expressed as NO₃ ion, food business operators shall investigate the reason of this excess.
  • 8.3.1 Non-heat-treated processed meat — 110 mg/kgPermitted as a member of Nitrates. ML = 110 mg/kg. only large bacon primals and dry sausages without nitrites added Period of application: from 9 October 2025’;. Note 7: Maximum amount that may be added during the manufacturing, expressed as NaNO 2 or NaNO 3.
  • 8.3.4.1 Traditional immersion cured products (meat products cured by immersion in a curing solution containing nitrites and/or nitrates, salt and other components) — 150 mg/kgPermitted as a member of Nitrates. ML = 150 mg/kg. only Wiltshire bacon and similar products: Meat is injected with curing solution followed by immersion curing for 3 to 10 days. The immersion brine solution also includes microbiological starter cultures Period of application: from 9 October 2025. Note: (59) Nitrates may be present in some heat-treated meat products resulting from natural conversion of nitrites to nitrates in a low-acid environment (XI) The maximum residual amount from all sources for the product ready for marketing throughout the shelf-life of the product expressed as NO₃ ion.
  • 8.3.4.1 Traditional immersion cured products (meat products cured by immersion in a curing solution containing nitrites and/or nitrates, salt and other components) — 150 mg/kgPermitted as a member of Nitrates. ML = 150 mg/kg. only Wiltshire ham and similar products: Meat is injected with curing solution followed by immersion curing for 3 to 10 days. The immersion brine solution also includes microbiological starter cultures Period of application: from 9 October 2025. Note: (59) Nitrates may be present in some heat-treated meat products resulting from natural conversion of nitrites to nitrates in a low-acid environment (XI) The maximum residual amount from all sources for the product ready for marketing throughout the shelf-life of the product expressed as NO₃ ion.
  • 8.3.4.1 Traditional immersion cured products (meat products cured by immersion in a curing solution containing nitrites and/or nitrates, salt and other components) — 150 mg/kgPermitted as a member of Nitrates. ML = 150 mg/kg. only entremeada, entrecosto, chispe, orelheira e cabeça (salgados), toucinho fumado and similar products: Immersion cured for 3 to 5 days. Product is not heat-treated and has a high water activity Period of application: from 9 October 2025. Note: (59) Nitrates may be present in some heat-treated meat products resulting from natural conversion of nitrites to nitrates in a low-acid environment (XI) The maximum residual amount from all sources for the product ready for marketing throughout the shelf-life of the product expressed as NO₃ ion.
  • 8.3.4.1 Traditional immersion cured products (meat products cured by immersion in a curing solution containing nitrites and/or nitrates, salt and other components) — 7 mg/kgPermitted as a member of Nitrates. ML = 7 mg/kg. only cured tongue : Immersion cured for at least 4 days and pre-cooked Period of application: from 9 October 2025. Note: (59) Nitrates may be present in some heat-treated meat products resulting from natural conversion of nitrites to nitrates in a low-acid environment (XI) The maximum residual amount from all sources for the product ready for marketing throughout the shelf-life of the product expressed as NO₃ ion.
  • 8.3.4.1 Traditional immersion cured products (meat products cured by immersion in a curing solution containing nitrites and/or nitrates, salt and other components) — 180 mg/kgPermitted as a member of Nitrates. ML = 180 mg/kg. only kylmâsavustettu poronliha/kallrökt renkött : Meat is injected with curing solution followed by immersion curing. Curing time is 14 to 21 days followed by maturation in cold-smoke for 4 to 5 weeks Period of application: from 9 October 2025. Note: (XA) The maximum amount that may be added during the manufacturing expressed as NO₃ ion. (XK) In case the residual amount from all sources for the product ready for marketing throughout the shelf-life of the product exceeds 95 mg/kg expressed as NO₃ ion, food business operators shall investigate the reason of this excess.
  • 8.3.4.1 Traditional immersion cured products (meat products cured by immersion in a curing solution containing nitrites and/or nitrates, salt and other components) — 180 mg/kgPermitted as a member of Nitrates. ML = 180 mg/kg. only bacon, filet de bacon and similar products: Immersion cured for 4 to 5 days at 5 to 7 °C, matured for typically 24 to 40 hours at 22 °C, possibly smoked for 24 hrs at 20 to 25 °C and stored for 3 to 6 weeks at 12 to 14 °C Period of application: from 9 October 2025. Note: (40) Without added nitrites (59) Nitrates may be present in some heat-treated meat products resulting from natural conversion of nitrites to nitrates in a low-acid environment (XA) The maximum amount that may be added during the manufacturing expressed as NO₃ ion. (XK) In case the residual amount from all sources for the product ready for marketing throughout the shelf-life of the product exceeds 95 mg/kg expressed as NO₃ ion, food business operators shall investigate the reason of this excess.
  • 8.3.4.1 Traditional immersion cured products (meat products cured by immersion in a curing solution containing nitrites and/or nitrates, salt and other components) — 150 mg/kgPermitted as a member of Nitrates. ML = 150 mg/kg. only Rohschinken, nassgepökelt and similar products: Curing time depending on the shape and weight of meat pieces for approximately 2 days/kg followed by stabilisation/maturation Period of application: from 9 October 2025. Note: (XI) The maximum residual amount from all sources for the product ready for marketing throughout the shelf-life of the product expressed as NO₃ ion.
  • 8.3.4.2 Traditional dry-cured products (dry curing process involves dry application of curing mixture containing nitrites and/or nitrates, salt and other components to the surface of the meat followed by a period of stabilisation/maturation) — 150 mg/kgPermitted as a member of Nitrates. ML = 150 mg/kg. only dry cured bacon and similar products: Dry curing followed by maturation for at least 4 days Period of application: from 9 October 2025. Note 39: Maximum residual amount, residue level at the end of the production process, expressed as NaNO 2 or NaNO 3.
  • 8.3.4.3 Other traditional and traditionally cured products (including immersion and dry cured processes used in combination or where nitrite and/or nitrate is included in a compound product or where the curing solution is injected into the product prior to cooking) — 150 mg/kgPermitted as a member of Nitrates. ML = 150 mg/kg. only Rohschinken, trocken-/nassgepökelt and similar products: Dry curing and immersion curing used in combination (without injection of curing solution). Curing time depending on the shape and weight of meat pieces for approximately 14 to 35 days followed by stabilisation/ maturation Period of application: from 9 October 2025. Note 7: Maximum amount that may be added during the manufacturing, expressed as NaNO 2 or NaNO 3.
  • 9.2 Processed fish and fishery products including molluscs and crustaceans — 270 mg/kgPermitted as a member of Nitrates. ML = 270 mg/kg. only pickled herring and sprat Period of application: from 9 October 2025’;.
Regulation (EC) No 1333/2008, Annex IIand 17 further provisionsretrieved 2026-10-18
Great BritainFood Standards Agency / Food Standards ScotlandPermitted, with conditions

9 food categories

highest permitted level 500 mg/kg or mg/l

Show every food category
  • 1.7.2 Ripened cheese — 150 mg/kg or mg/lPermitted as a member of E 251–252: Nitrates. ML = 150. only hard, semi-hard and semi-soft cheese. Note (30): In the cheese milk or equivalent level if added after removal of whey and addition of water.
  • 1.7.4 Whey cheese — 150 mg/kg or mg/lPermitted as a member of E 251–252: Nitrates. ML = 150. only cheese milk of hard, semi-hard and semi-soft cheese. Note (30): In the cheese milk or equivalent level if added after removal of whey and addition of water.
  • 1.7.6 Cheese products (excluding products falling in category 16) — 150 mg/kg or mg/lPermitted as a member of E 251–252: Nitrates. ML = 150. only hard, semi-hard and semi-soft ripened products. Note (30): In the cheese milk or equivalent level if added after removal of whey and addition of water.
  • 1.8 Dairy analogues, including beverage whiteners — 150 mg/kg or mg/lPermitted as a member of E 251–252: Nitrates. ML = 150. only dairy-based cheese analogue. Note (30): In the cheese milk or equivalent level if added after removal of whey and addition of water.
  • 8.3.1 Non-heat-treated meat products — 150 mg/kg or mg/lPermitted as a member of E 251–252: Nitrates. ML = 150. Note (7): Maximum amount that may be added during the manufacturing, expressed as NaNO 2 or NaNO 3.
  • 8.3.4.1 Traditional immersion cured products (Meat products cured by immersion in a curing solution containing nitrites and/or nitrates, salt and other components) — several limitsPermitted as a member of E 251–252: Nitrates. (1) ML 250: only Wiltshire bacon and similar products : Meat is injected with curing solution followed by immersion curing for 3 to 10 days. The immersion brine solution also includes microbiological starter cultures; (2) ML 250: only Wiltshire ham and similar products : Meat is injected with curing solution followed by immersion curing for 3 to 10 days. The immersion brine solution also includes microbiological starter cultures; (3) ML 250: only Entremeada, entrecosto, chispe, orelheira e cabeca (salgados), toucinho fumado and similar products : Immersion cured for 3 to 5 days. Product is not heat-treated and has a high water activity; (4) ML 10: only cured tongue : Immersion cured for at least 4 days and pre-cooked; (5) ML 300: only kylmâsavustettu poronliha/kallrökt renkött : Meat is injected with curing solution followed by immersion curing. Curing time is 14 to 21 days followed by maturation in cold-smoke for 4 to 5 weeks; (6) ML 250: only bacon, filet de bacon and similar products : Immersion cured for 4 to 5 days at 5 to 7 °C, matured for typically 24 to 40 hours at 22 °C, possibly smoked for 24 hrs at 20 to 25 °C and stored for 3 to 6 weeks at 12 to 14 °C.; (7) ML 250: only rohschinken, nassgepökelt and similar products : Curing time depending on the shape and weight of meat pieces for approximately 2 days/kg followed by stabilisation/maturation. Note (39): Maximum residual amount, residue level at the end of the production process, expressed as NaNO 2 or NaNO 3. Note (59): Nitrates may be present in some heat-treated meat products resulting from natural conversion of nitrites to nitrates in a low-acid environment. Note (7): Maximum added amount, expressed as NaNO 2 or NaNO 3. Note (40): Without added nitrites.
  • 8.3.4.2 Traditional dry cured products. (Dry curing process involves dry application of curing mixture containing nitrites and/or nitrates, salt and other components to the surface of the meat followed by a period of stabilisation/maturation) — 250 mg/kg or mg/lPermitted as a member of E 251–252: Nitrates. (1) ML 250: only dry cured bacon and similar products : Dry curing followed by maturation for at least 4 days; (2) ML 250: only dry cured ham and similar products : Dry curing followed by maturation for at least 4 days; (3) ML 250: only jamon curado, paleta curada, lomo embuchado y cecina and similar products : Dry curing with a stabilisation period of at least 10 days and a maturation period of more than 45 days; (4) ML 250: only presunto, presunto da pa and paio do lombo and similar products : Dry cured for 10 to 15 days followed by a 30 to 45-day stabilisation period and a maturation period of at least 2 months; (5) ML 250: only jambon sec, jambon sel and other similar dried cured products : Dry cured for 3 days + 1 day/kg followed by a 1-week post-salting period and an ageing/ripening period of 45 days to 18 months; (6) ML 250: only rohschinken, trockengepökelt and similar products : Curing time depending on the shape and weight of meat pieces for approximately 10 to 14 days followed by stabilisation/maturation. Note (39): Maximum residual amount, residue level at the end of the production process, expressed as NaNO 2 or NaNO 3. Note (59): Nitrates may be present in some heat-treated meat products resulting from natural conversion of nitrites to nitrates in a low-acid environment. Note (40): Without added nitrites.
  • 8.3.4.3 Other traditionally cured products. (Immersion and dry cured processes used in combination or where nitrite and/or nitrate is included in a compound product or where the curing solution is injected into the product prior to cooking) — several limitsPermitted as a member of E 251–252: Nitrates. (1) ML 250: only rohschinken, trocken-/nasgepökelt and similar products : Dry curing and immersion curing used in combination (without injection of curing solution). Curing time depending on the shape and weight of meat pieces for approximately 14 to 35 days followed by stabilisation/maturation; (2) ML 10: only jellied veal and brisket : Injection of curing solution followed, after a minimum of 2 days, by cooking in boiling water for up to 3 hours; (3) ML 300: only rohwürste (salami and kantwurst) : Product has a minimum 4-week maturation period and a water/protein ratio of less than 1,7; (4) ML 250: only Salchichon y chorizo traducionales de larga curacion and similar products : Maturation period of at least 30 days; (5) ML 250: only saucissons sec and similar products : raw fermented dried sausage without added nitrites. Product is fermented at temperatures in the range of 18 to 22 °C or lower (10 to 12 °C) and then has a minimum ageing/ripening period of 3 weeks. Product has a water/protein ratio of less than 1,7. Note (39): Maximum residual amount, residue level at the end of the production process, expressed as NaNO 2 or NaNO 3. Note (59): Nitrates may be present in some heat-treated meat products resulting from natural conversion of nitrites to nitrates in a low-acid environment. Note (40): Without added nitrites. Note (7): Maximum added amount, expressed as NaNO 2 or NaNO 3.
  • 9.2 Processed fish and fishery products including mollusks and crustaceans — 500 mg/kg or mg/lPermitted as a member of E 251–252: Nitrates. ML = 500. only pickled herring and sprat.
Assimilated Regulation (EC) No 1333/2008, Annex II (as at 28 June 2024)and 8 further provisionsretrieved 2026-10-18
JapanConsumer Affairs AgencyPermitted, with conditions
Designated additive: Appended Table 1, item 214, 硝酸カリウム (“Potassium Nitrate” in the unofficial English translation). …

Designated additive: Appended Table 1, item 214, 硝酸カリウム (“Potassium Nitrate” in the unofficial English translation). Standards for use — Specifications and Standards for Foods, Food Additives, etc. (MHW Notification No. 370 of 1959), Part II (Food Additives), F (Standards for use), entry 硝酸カリウム: (1) [may be used only in the foods stated] “硝酸カリウムは、チーズ、清酒、食肉製品及び鯨肉ベーコン以外の食品に使用してはならない。” (2) [sets maximum levels of use for the foods stated; limits how much may remain in the foods stated] “硝酸カリウムの使用量は、硝酸カリウムとして、チーズにあっては原料に供する乳1Lにつき0.20g以下、清酒にあっては酒母1Lにつき0.10g以下でなければならない。また、硝酸カリウムは、亜硝酸根として、食肉製品及び鯨肉ベーコンにあってはその1kgにつき0.070g以上残存しないように使用しなければならない。” The Japanese is the standard as published. There is no official English translation of the Notification; the English in square brackets is this site’s description of what each sentence does, not a translation of the foods or the levels. Compositional specifications for this additive, in the same Notification, are not imported and are not shown here; nor are the general rules in F 添加物一般, which apply to every additive.

Regulations for Enforcement of the Food Sanitation Act (MHW Ordinance No. 23 of 1948), Appended Table 1retrieved 2026-10-18
South KoreaMinistry of Food and Drug SafetyPermitted, with conditions
Designated food additive: Standards and Specifications for Food Additives, Part III, 1. …

Designated food additive: Standards and Specifications for Food Additives, Part III, 1. 일반식품첨가물 (general food additives), 질산칼륨 (“Potassium Nitrate”, the English the Code prints beside it). Main use (주용도) of 질산칼륨: 발색제, 보존료. Standard for use (사용기준) of 질산칼륨: (1) [may be used only in the foods listed; sets a limit on the amount used] “질산칼륨은 아래의 식품에 한하여 사용하여야 한다. 질산칼륨의 사용량은 아질산이온으로서 아래의 기준 이상 남지 아니하도록 사용하여야 한다. 1. 식육가공품(식육추출가공품 제외), 기타 동물성가공식품(기타식육이 함유된 제품에 한함)：0.07g/kg 2. 치즈류 : 0.05g/kg 3. 대구알염장품：0.2g/kg” The Korean is the standard as published. There is no official English translation of the current Code (the English version on MFDS’s website is the 2020 edition and has no legal effect); the English in square brackets is this site’s description of what each sentence does, not a translation of the foods or the levels. Compositional specifications (Part IV) are not imported, nor are the general standards in Part II, which apply to every additive.

Standards and Specifications for Food Additives (식품첨가물의 기준 및 규격), MFDS Notification, Part III (Standards for use, by item)retrieved 2026-10-18
United StatesFood and Drug AdministrationPermitted, with conditions21 CFR 172.160retrieved 2026-10-17
Codex AlimentariusCodex Alimentarius Commission / JECFAPermitted, with conditions

1 food category

highest permitted level 35 mg/kg

Note 30 As residual NO3 ion.

Note 464 For use in products conforming to the Standards for Cheddar (CXS 263-1966), Danbo (CXS 264-1966) Edam (CXS 265-1966), Gouda (CXS 266-1966), Havarti (CXS 267-1966), Samsø (CXS 268-1966), Emmental (CXS 269-1967), Tilsiter (CXS 270-1968), Saint-Paulin (CXS 271-1968) and Provolone (CXS 272-1968) only as preservatives.

Note XS208 Excluding products conforming to the Standard for Cheese in Brine (CODEX STAN 208-1999).

Note XS274 Excluding products conforming to the Standard for Coulommiers (CXS 274-1969).

Note XS276 Excluding products conforming to the Standard for Camembert (CXS 276-1973).

Note XS277 Excluding products conforming to the Standard for Brie (CXS 277-1973).

Note XS278 Excluding products conforming to the Standard for Extra Hard Grating Cheese (CXS 278-1978).

CXS 192-1995 Table One, INS 252, food category 01.6.2retrieved 2026-09-07

How much is permitted

A listing usually limits the quantity as well as the food. Only one of the forms that takes is a figure: quantum satis and good manufacturing practice permit the amount the technological effect requires and no more, which is a limit rather than the absence of one. Figures below are the range across every food category this page is listed in, and categories differ between regulators — see how much is permitted.

Australia and New Zealand50 mg/kg – 500 mg/kg3 numeric limit
Canada—2 GMP, 3 no quantity stated
European Union7 mg/kg – 270 mg/kg18 numeric limit
Great Britain150 mg/kg – 500 mg/kg7 numeric limit, 2 several limits
Japan—1 no quantity stated
South Korea—1 no quantity stated
United States—1 no quantity stated
Codex Alimentarius35 mg/kg1 numeric limit

Regulatory changes

What the weekly comparison of the imported lists has seen move. No dated act has been written up for this additive; the status panel above shows where the rules stand now.

Differences the refresh found

Each import is compared with the one before. These are the differences seen, dated by when the comparison ran — not by when they took legal effect, which the lists do not say. Nothing here is interpreted; the provisions and their citations are in the panel above.

  1. · European Union

    European Union: 6 provisions added, 3 provisions removed.

    • Removed 1.7.2 ripened cheese — 150 mg/kg
    • 1.7.4 whey cheese: 150 mg/kg → 75 mg/kg
    • 1.7.6 cheese products (excluding products falling in category 16): 150 mg/kg → 75 mg/kg
    • Added 1.7.2 ripened cheese — 110 mg/kg
    • Added 1.7.2 ripened cheese — 110 mg/kg
    • Added 1.7.2 ripened cheese — 110 mg/kg
    • Added 1.7.2 ripened cheese — 75 mg/kg

What it is made from

Mined or manufactured by neutralising nitric acid with a potassium base.

  • Vegan
  • Vegetarian

Compare other additives on the dietary indexes.

CAS registry number
7757-79-1
InChIKey
FGIUAXJPYTZDNR-UHFFFAOYSA-N
PubChem
CID 24434

The two specifications, compared

The European Union sets identity and purity by regulation; JECFA publishes its own through FAO, advisory until a country adopts it. Both documents are below in full. These are the parameters each puts a number on.

ParameterEuropean UnionJECFA
Assayno less than 99 %no less than 99 %
Loss on dryingno more than 1 %no more than 1 %
Leadno more than 0.1 mg/kgno more than 2 mg/kg
Arsenicno more than 0.1 mg/kg—
Mercuryno more than 0.1 mg/kg—

One parameter differs between the two documents. A difference is not a disagreement about safety: the two are revised on their own cycles, and an assay or a drying loss can be measured against a different preparation of the substance, which is why only the contaminant ceilings are marked. Within the EU the EU's figure is the one that binds.

How the EU defines it

The legal specification an additive must meet to be sold as this E number in the EU — what it is, how it may be made, and the purity it must reach. From Commission Regulation (EU) No 231/2012.

E 252 Potassium nitrate

Synonyms: Chile saltpetre; Cubic or soda nitre

Assay, identification and purity criteria

Description and assay

Einecs
231-818-8
Chemical name
Potassium nitrate
Chemical formula
KNO₃
Molecular weight
101,11
Assay
Content not less than 99 % on the anhydrous basis
Description
White crystalline powder or transparent prisms having a cooling, saline, pungent taste

Identification

Test for nitrate
Passes test
Test for potassium
Passes test
pH
4,5-8,5 (5 % solution)

Purity criteria

Loss on drying
Not more than 1 % (105 °C, 4 hours)
Nitrites
Not more than 20 mg/kg expressed as KNO₂
Arsenic
Not more than 0,1 mg/kg
Lead
Not more than 0,1 mg/kg
Mercury
Not more than 0,1 mg/kg

Commission Regulation (EU) No 231/2012, Annex, E 252

How JECFA defines it

The international specification for identity and purity, prepared by the Joint FAO/WHO Expert Committee on Food Additives and published by FAO. It is a different document from any above, written by a different body and revised on its own cycle; it is advisory, and a country adopts it or does not.

INS 252 Potassium Nitrate

Synonyms: INS No. 252

Assay, identification and purity criteria

Description and assay

Specification history
Prepared at the 44th JECFA (1995), published in FNP 52 Add 3 (1995) superseding specifications prepared at the 27th JECFA (1983), published in FNP 28 (1983) and in FNP 52 (1992). Metals and arsenic specifications revised at the 63rd JECFA (2004). An ADI of 0-3.7 mg/kg bw was established at the 44th JECFA (1995). Nitrate should not be used for infants below 3 months.
Chemical names
Potassium nitrate
C.A.S. number
7757-79-1
Chemical formula
KNO 3
Formula weight
101.11
Assay
Not less than 99.0% on the dried basis Colourless, odourless, transparent prisms, or white granular or crystalline powder
FUNCTIONAL USES
Antimicrobial preservative, colour fixative
METHOD OF ASSAY
Weigh accurately about 0.4 g of the sample previously dried at 105º for 4 h and dissolve in about 300 ml of water in a 500 ml round flask. Add 3 g of a f f ( ) powder of Devarda's alloy and 15 ml of sodium hydroxide solution (2 in 5), and connect with a spray-preventing device and condenser to the flask. Allow to stand for 2 h. Transfer 50 ml of 0.1N sulfuric acid to a receptacle, and use this to collect 250 ml of the distillate, and titrate the excess sulfuric acid with 0.1N sodium hydroxide, using 3 drops of methyl red/methylene blue TS as the indicator. Perform a blank test in the same manner as the sample to make any necessary correction. Each ml of 0.1N sulfuric acid is equivalent to 10.11 mg of KNO 3 .

Identification

Solubility (Vol. 4)
Soluble in water; slightly soluble in ethanol
Test for potassium (Vol. 4)
Passes test
Test for nitrate (Vol. 4)
Passes test

Purity criteria

Loss on drying (Vol. 4)
Not more than 1% (105 o , 4 h)
Nitrite
Not more than 20 mg/kg See description under TESTS
Lead (Vol. 4)
Not more than 2 mg/kg Determine using an atomic absorption technique appropriate to the specified level. The selection of sample size and method of sample preparation may be based on the principles of the method described in Volume 4, “Instrumental Methods.”
Test: Nitrite
Principle: A spectrophotometric determination using a reaction between nitrite, sufanilamide and N-(1-naphthyl) ethylenediamine dihydrochloride to produce a pink coloured complex which is measured by its absorbance at 540 nm. Reagents - Sulfanilamide Solution: Dissolve 2 g of sulfanilamide in 1000 ml dilute hydrochloric acid TS. - Coupling reagent: Dissolve 0.2 g of N-(1-naphthyl)-ethylene- diamine dihydrochloride in water and dilute to 100 ml. Keep the reagent in a brown bottle in a refrigerator. - Nitrite standard: Dissolve 0.750 g of sodium nitrite (previously dried for 4 h over silica gel) in water and dilute to 1000 ml (500 μg nitrite/ml). Dilute 10 ml of this stock solution to 100 ml with water (50 μg nitrite/ml). Finally dilute 10 ml of this preparation to 1000 ml with water (0.5 μg nitrite/ml). Procedure Standard curve: Pipette into 100 ml volumetric flasks 0, 5, 10, 20 and 50 ml of nitrite standard (corresponding to 0, 2.5, 5, 10 and 25 μg of nitrite) and dilute to about 80 ml with water. Add to each of the flasks 10 ml of sulfanilamide solution and mix. After 3 min add 1 ml of coupling reagent, dilute to mark with water, mix and let stand for 15 min. Measure the absorbance of the solutions against water at 540 nm using 10 mm cuvettes. Draw a standard curve with the absorbance as a function of amount of nitrite (it shall be a straight line). Sample: Accurately weigh about 1 g of the sample to the nearest 0.001 g. Dissolve in water and dilute to 100 ml. Pipette 20 ml into a 100 ml volumetric flask and dilute to about 80 ml with water. Add 10 ml of sulfanilamide solution and mix. After 3 min add 1 ml of coupling reagent, dilute to mark with water, mix and let stand for 15 min. Measure the absorbance of the solution against water at 540 nm using 10 mm cuvettes. Read on the standard curve the amount of nitrite corresponding to the actual absorbance. Calculation where A = Amount of nitrite read from the standard curve (μg) W = Weight of sample (g)

FAO JECFA Monograph 1 (2006)

Every name it appears under

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

E number

  • E252

INS number

  • 252

CAS registry number

  • 7757-79-1

As it appears in regulation

  • Potassium nitrate

Other names

  • Attitude Adult Fluoride-free-Sensitive-Spearmint
  • Caswell No. 697
  • CCRIS 3667
  • Collo-Bo
  • Dr. Sheffield Sensitive Care
  • E 252
  • EPA Pesticide Chemical Code 076103
  • European Pharmacopoeia Reagent Conc.
  • HSDB 1227
  • INS NO.252
  • INS-252
  • Jason Total Protection Sensitive
  • Kali nitricum
  • Kalii nitras
  • Kaliumnitrat
  • Kiss My Face Sensitive
  • Kiss My Face Sensitive Fluoride-Free Whitening-Citrus Mint
  • KNO3
  • Niter
  • Nitrate of potash
  • Nitre
  • Nitric acid potassium salt (1:1)
  • Nitric acid, potassium salt
  • Nitrogen and oxygen isotopes in nitrate, NIST(R) RM 8568
  • Potassium nitrate
  • Potassium nitrate (JAN/USP)
  • Potassium nitrate (KNO3)
  • Potassium Nitrate ACS grade
  • Potassium Nitrate Standard Solution
  • Potassium nitrate(DOT)
  • Potassium nitrate, 99.99% trace metals basis
  • Potassium nitrate, 99.999% trace metals basis
  • Potassium nitrate, ACS reagent, >=99.0%
  • Potassium nitrate, anhydrous, 99.99% trace metals basis
  • Potassium nitrate, AR, >=99.5%
  • Potassium nitrate, BioUltra, >=99.5% (T)
  • Potassium nitrate, BioXtra, >=99.0%
  • Potassium nitrate, cell culture tested
  • Potassium nitrate, JIS special grade, >=99.0%
  • Potassium nitrate, LR, >=99.5%
  • Potassium nitrate, NIST(R) SRM(R) 193
  • Potassium nitrate, p.a., 99%
  • Potassium nitrate, Puratronic(R)
  • Potassium nitrate, ReagentPlus(R), >=99.0%
  • Potassium nitrate, SAJ first grade, >=99.0%
  • Potassium Nitrate, Trace metals grade 99.99%
  • Potassium standard for AAS, ready-to-use, in nitric acid
  • Potassium-nitrate
  • Salt peter
  • Salt peter (VAN)
  • Saltpeter
  • saltpetre
  • Schmidts
  • Schmidts WONDERMINT TOOTH AND MOUTH
  • Sensitive Teeth
  • Sensitive Tooth Paste
  • Sensodyne (TN)
  • SprinJene Natural Sensitivity and Gum
  • Vicknite

Systematic names

  • potassium nitrate

The EU re-evaluation programme

Every additive authorised in the EU before 20 January 2009 was put back through EFSA by Commission Regulation (EU) No 257/2010, and this one is named in it. What the Regulation required is below; whether the opinion has since been published is not something this site records.

  • To be evaluated by 31 December 2015. Named in Annex II, Part II, point 1 as “Potassium nitrate”, among the additives given priority within its class.

Hazard reference values

EFSA and JECFA have both set an acceptable daily intake for Potassium nitrate, and they agree: 3.7 mg/kg bw/day. An acceptable daily intake is a reference value set by a committee, not a threshold above which harm begins. See where the two committees differ.

Values set by assessing bodies. A body that has not set a value is not listed here.
TypeValuePopulationAssessed byOpinion
ADI3.7 mg/kg bw/dayconsumersEFSA ANS2017
ADI3.7 mg/kg bw/day—JECFA1995

Evidence and how bodies read it

What assessing bodies concluded

Each conclusion is paraphrased in the body's own framing, from the published opinion linked beneath it. Where bodies differ, both stand; this site does not adjudicate between them or add a view of its own.

  1. EFSA 2017

    The ANS Panel found no genotoxicity or carcinogenicity for sodium and potassium nitrate (E 251, E 252) and, despite uncertainty, concluded there was insufficient evidence to withdraw the SCF's ADI of 3.7 mg/kg bw/day. Additive use contributed less than 5% of total nitrate exposure and did not exceed the ADI, but exposure from all dietary sources combined would exceed it in all age groups.

    Source document

Common questions

Assembled from what is above, in the words the questions are usually asked in. Each answer is the same statement the relevant section makes, with the same citations behind it.

What is E 252?
E 252 is Potassium nitrate. Potassium nitrate, historically called saltpetre, is used in slow-cured meats and some cheeses, where it is gradually reduced to nitrite.
What is Potassium nitrate used for in food?
It is listed as a preservative — the role Canada, Codex and the US assign it. This page shows every function each regulator records, with the citation for each.
Where is Potassium nitrate permitted?
Of the seven regulators this site reads, Australia and New Zealand, Canada, the EU, Great Britain, Japan, South Korea, the US and the Codex standard permit it. Each permission is for named foods at named levels, not a blanket one; the table on this page gives them with citations.
Is Potassium nitrate vegan?
Yes. Potassium nitrate is not derived from animals, and is suitable for vegetarians. This page says what it is made from and how.

Sources for this page

  • anz retrieved 2026-10-17
  • ca retrieved 2026-10-17
  • eu retrieved 2026-10-18
  • gb retrieved 2026-10-18
  • jp retrieved 2026-10-18
  • kr retrieved 2026-10-18
  • ecfr retrieved 2026-10-17
  • gsfa retrieved 2026-09-07
  • euspecs retrieved 2026-10-18
  • jecfaspecs retrieved 2026-09-23

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