E252 / Preservatives
Potassium nitrate
Safety in brief
Safe
Recorded EatMatrix rating, not a new clinical review. The amount, your sensitivities and country rules still matter.
- Watch for
- No allergen or sensitivity is recorded for this ingredient here. Check the whole product label; this is not an allergen-free guarantee.
- Selected research
- The paper did not report a statistically significant diabetes association for potassium nitrate in its main results. This is not proof of no effect, and it does not answer other health or safety questions. Study details and limits.
- Our advice
- A diabetes result and a cancer result can differ. Neither the absence nor presence of one association settles all health effects of this nitrate.
What it is
Potassium nitrate, also known as saltpeter, is a curing agent occasionally used in meat preservation to inhibit bacterial growth and help maintain a pink color in cured products. Like sodium nitrate, it can be converted in the body into nitrite and, under high heat, into nitrosamines, compounds linked to increased cancer risk with regular high consumption of cured meats. It has much larger non-food uses as a fertilizer (supplying plants with nitrogen and potassium) and as an oxidizer in gunpowder and fireworks -- those applications are unrelated to its food use. Food use is regulated with maximum permitted levels.
Also appears on labels as: Potassium nitrate, KNO3, Saltpeter, Food grade potassium nitrate, E252, E 252, E-252, INS 252, Potassium(V) nitrate, Potassium nitrate powder, Potassium nitrate solution, Additivo alimentare E252.
Dietary information
- Vegan
- Yes
- Halal
- Yes
- Gluten-free
- Yes
- Allergens
- None recorded
Recorded ingredient information. Check the product label or certification: sources, other ingredients and cross-contact can vary.
Research & body effects
Newer sources to read for E252
- 2026 BMJ study of food additive preservatives and cancer incidence
Published January 7, 2026. A prospective observational study in the French NutriNet-Santé cohort; it includes this ingredient. Observational associations cannot by themselves establish that an additive causes a health outcome.
- BfR assessment of limitations in that study
Published March 17, 2026. The German risk-assessment institute discusses uncertainty in the findings. This assessment is separate from a country's rules on permitted food uses.
Bibliographic identity and the indexed study type checked October 4, 2026. The BMJ abstract and BfR communication were read; a complete review of the study's methods, supplements and the wider evidence remains pending. These links do not change EatMatrix's recorded rating.
What selected 2026 human research means for E252
Type 2 diabetes: what was found
The paper did not report a statistically significant diabetes association for potassium nitrate in its main results. This is not proof of no effect, and it does not answer other health or safety questions.
The French NutriNet-Santé analysis included 108,723 people and 1,131 new diagnoses, with a median follow-up of 8.05 years. Diets were recorded repeatedly, including food brands. Researchers estimated additive intake and adjusted for factors such as diet, body size and smoking. They did not randomly assign people to eat this additive.
EatMatrix’s reading
A diabetes result and a cancer result can differ. Neither the absence nor presence of one association settles all health effects of this nitrate.
These findings deserve follow-up. Estimated intake, other features of the foods people ate and differences between volunteers can still influence the results. Most participants were women; the results may not transfer directly to children or every country. A proposed mechanism from cells or animals is not a demonstrated mechanism in people eating ordinary food.
A useful next step when choosing food
Compare the whole food: its ingredients, fibre, salt, free sugars, saturated fat and how often you eat it. Choose a varied pattern with more minimally processed foods where practical. Removing one E number alone has not been shown by these studies to prevent diabetes or heart disease.
Selected abstract, main-text methods/results and funding checked . Funders include European and French public research bodies; the authors declare no competing interests. Supplementary tables could not be inspected here, so individual corrected estimates are not reproduced. Indexed records showed no linked correction or retraction in this check; that is not proof none exists. This is a selected editorial review, not a complete clinical or current-country-use assessment. It does not change EatMatrix’s recorded rating or country permissions.
Selected research on E252
How to read study types- Expert critiqueGerman risk institute (BfR) on the BMJ preservatives study
Points to chance findings from many tests, diet effects hard to separate (sulfites track wine, for example) and self-reported intake. Sees no reason to change EFSA’s assessments.
- Observational studyBMJ study of preservatives and cancer in 105,260 French adults
Linked higher intake of potassium nitrate with overall and breast cancer. It observed diets and cannot show the additive caused the cancers. 11 of the 17 preservatives studied showed no link.
- Observational studyPreservatives and type 2 diabetes in 108,723 French participants
No statistically significant type 2 diabetes association for potassium nitrate was reported in the main results. A null result does not establish safety for every use or outcome; this was an observational cohort.
- Regulator reviewEFSA re-evaluation of sodium and potassium nitrate
Kept the safe daily limit of 3.7 mg per kg of body weight. Nitrate from additives is under 5% of the nitrate people get from food.
Publisher amendment:
Earlier source summaries checked ; latest additions checked . See the detailed research section for what was read and the remaining limits. This is a selection of sources, not a complete literature review. Authority assessments apply to the uses and places they cover.
Health notes from our ingredient record
- In the body and during food processing, nitrate can convert to nitrite and then to nitrosamines, some of which are linked to increased cancer risk with regular high consumption of cured meats.
- High levels in drinking water (from agricultural runoff, not food additive use) pose a particular risk to infants by reducing blood oxygen-carrying capacity (methemoglobinemia, 'blue baby syndrome').
- Dietary nitrate from vegetables (e.g., leafy greens, beets) is generally considered to have a different, often favorable, health profile compared with nitrate/nitrite added to cured meats.
Other references from our ingredient record
These links come from the original ingredient record. They are separate from the source reviews above and have not all been checked for the exact ingredient, amount consumed or claim. Dates are shown newest first.
- Re‐evaluation of sodium nitrate (E 251) and potassium nitrate (E 252) as food additives — EFSA Panel on Food Additives, EFSA Journal (2017). Official EFSA scientific opinion (bibliographic reference, imported 2026-10-13). It covers the additive as a group assessment and is not an individual human study; read the opinion for its findings.
Country rules
Country checks for E252
Permission depends on the market, type of food, amount and conditions. A scientific opinion or an E-number alone does not establish a legal use. These checks are separate from the stored EatMatrix rating.
Compare all eight markets and their sources
| Market | What is checked |
|---|---|
| European Union | Regulation (EC) 1333/2008, Annex II Part B, version , contains the exact code E252: Potassium nitrate. Listing alone does not allow every food use. Part E food categories, limits, specifications and applicable later acts still need a product-specific check. Source read: . |
| Great Britain | The FSA register record for E252 (Potassium nitrate) lists “Authorised” in England, Scotland and Wales. Register updated: 01 April 2025; record checked: . Food-specific conditions and specifications still need a separate legal check. |
| United States | Selected US conditions for Potassium nitrate Official federal text current through ; read . Food uses, limits and exceptionsA specific FDA fish use Potassium nitrate is listed as a curing agent for cod roe at no more than 200 ppm in the finished roe. Do not transfer this cod-roe provision to another fish or to sodium nitrate. USDA cured-meat and poultry conditions The curing-agent table includes sodium and potassium nitrite/nitrate, with process-specific amounts. Nitrites and nitrates may not be used in the listed baby, junior or toddler foods. The stated finished-product ceiling is 200 ppm nitrite calculated as sodium nitrite, with separate bacon rules. It is not the same as an ingoing curing amount or a personal intake limit. No nitrate curing of bacon USDA expressly prohibits nitrates in curing bacon. Nitrite permissions and nitrate permissions must not be treated as interchangeable. EatMatrix’s reading: a legal use condition answers where and how an ingredient may be used. It is not a test of your product, a personal safe intake or a claim that the ingredient benefits your body. Match the named substance, food and amount. Other federal provisions, food standards, state rules and later changes may also apply; this is a selected source review, not a complete product-compliance decision. |
| Northern Ireland | Review pending. Check the applicable EU rules and territory arrangements; the GB register alone does not establish this status. FSA guidance is a starting source, not a verified permission for this entry. |
| Canada | Named food-use records located. Health Canada lists the preparations below for specified foods and purposes. This is conditional permission for those uses, not approval of every product or a personal safety verdict. Only the named records and conditions below were located. Exact composition and specifications still need matching. Source tables captured . List publication dates are shown separately. Good Manufacturing Practice (GMP) is a condition of use, not an unlimited amount or a recommended intake. Food and Drug Regulations B.16.003 requires the listed source, purpose, amount and other conditions to match. The official consolidation read was current to 21 September 2026; product specifications and applicable later changes still need checking. Read 5 listed food-use conditionsPotassium NitrateHealth Canada: List of Permitted Preservatives. List published ; item P.7.
EatMatrix reading: match the exact preparation and food first. A manufacturing limit is not an acceptable daily intake (ADI). A label without the amount cannot establish exposure, and an unlisted name here does not establish a ban. |
| Australia | Review pending. Food Standards Code permissions and conditions need an additive-specific check. FSANZ food-additive rules is a starting source, not a verified permission for this entry. |
| New Zealand | Review pending. Food Standards Code permissions and conditions need an additive-specific check. FSANZ food-additive rules is a starting source, not a verified permission for this entry. |
| Japan | Review pending. The relevant list, identity and use standards need an additive-specific check. CAA food-additive lists is a starting source, not a verified permission for this entry. |
Sources & review status
Check what each source covers: an authority’s conclusion, a research finding and a country’s legal permission answer different questions.
What this guide covers
- Selected research
- 4 source summaries, with publication dates and study types. Several publications may describe the same study population.
- Official assessment reference
- EFSA opinion located for E252. Identity and code coverage checked; full findings review pending.
- Original ingredient record
- 1 research link; newest recorded date: . Sources added separately to this guide are not included in this count.
This guide brings together our ingredient record and the dated sources shown here. Missing information describes a gap in this guide; it does not mean an ingredient is untested, safe or harmful. This is not a complete review of every study, preparation or current country rule. The amount in a product and how it is used still matter.
How to read the ratings, research and country checksAgency labels recorded by EatMatrix
These are imported database classifications, not verified current statements from each authority. Use the dated official sources below for their actual scope and conclusions.
| Authority | Database label |
|---|---|
| FDA | Safe |
| WHO | Safe |
| EFSA | Safe |
| FSANZ | Safe |
| Japan | Safe |
| UK FSA | Safe |
| Health Canada | Safe |
An official EFSA assessment for E252
An official scientific opinion covering E252 exists. A missing research link or rating in our database does not mean this additive has never been assessed. This reference identifies the document; it does not replace a review of its findings, later research or current food-use rules.
EFSA: Re-evaluation of sodium nitrate (E251) and potassium nitrate (E252)
- Published
- Publisher amendment
- Codes covered by this reference
- E251, E252
- Source type
- EFSA scientific opinion, not an individual human trial
EatMatrix checked this reference’s identity and code coverage on . The full evidence review, an exhaustive check for subsequent publications and corrections, and market-specific permissions remain pending. This does not change the recorded EatMatrix rating above.
Database updated: . What does an E number mean on a food label?
Common questions
Frequently asked questions
What is EatMatrix's recorded rating for E252?
The recorded EatMatrix rating for E252 (Potassium nitrate) is “Safe”. It is calculated from labels stored in our ingredient database. These labels are not verified current regulator decisions or country permissions. A database update date is not a scientific review date.
Is E252 vegan, halal or gluten-free?
According to our ingredient data for Potassium nitrate — vegan: yes, vegetarian: yes, halal: yes, kosher: yes, gluten-free: yes, dairy-free: yes. Manufacturing sources can vary between products; check the label if it matters to you.
What is E252 and why is it used?
Potassium nitrate, also known as saltpeter, is a curing agent occasionally used in meat preservation to inhibit bacterial growth and help maintain a pink color in cured products. Like sodium nitrate, it can be converted in the body into nitrite and, under high heat, into nitrosamines, compounds linked to increased cancer risk with regular high consumption of cured meats. It has much larger non-food uses as a fertilizer (supplying plants with nitrogen and potassium) and as an oxidizer in gunpowder and fireworks -- those applications are unrelated to its food use. Food use is regulated with maximum permitted levels.
Does E252 contain allergens?
No known allergens are recorded for Potassium nitrate.
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This page shows information and classifications recorded in our ingredient database. Current scientific and market-specific verification remains pending as described above. It is general information, not medical advice.