Order protocol
Sleep & recovery Whole topic
Hormones & energy Whole topic
Metabolism & nutrition Whole topic
Brain & mind Whole topic
Longevity & body Whole topic
Women & family Whole topic
Basics & environment Whole topic
Biohacking & technology Whole topic
Fénix Methode

Tired of generic advice? A protocol built on your numbers.

Order protocol
All articles Every article is based on a chapter of the book NAVRHNUTÝ and peer-reviewed studies.
Biohacker score2 minutes – find out where your body holds you back Results checkNormal vs. optimal for your blood values Biological ageHow old your body is – from 9 blood values CalculatorsBMI, waist, protein, sleep, caffeine, VO2max Daily helperDaily routines, light, sleep and breathing on your phone My stackCheck supplements & medication + daily plan ChallengesSmall daily habits with reminders Fitness testVO2max, fitness age, strength and balance at home Biological twinAll your data in a 3D body What to get testedPrintable list of blood tests Sample protocolSee what you get E-numbers & sugarsWhat is on the label and what to avoid Online advisorAnswers to common questions about body and results SupplementsForms, timing and combination check RecipesMeals without hidden sugars or needless additives GlossaryBiohacking explained from A to Z Gift voucherGive health – the protocol or the book
← Back to the E-number overview
E249Avoid

Potassium nitrite

Group: Preservatives · in the book

Harm level4 of 5Better avoid

In plain words

It is a curing salt that gives meat its pink colour and typical flavour and protects it from dangerous bacteria. You find it in ham, salami, sausages and other cured meats, though E250 is used more often.

Where you find it: ham, salami, frankfurters, bacon

Our recommendation

Avoid it where you can and eat cured meats only occasionally; choose nitrite-free products and do not give them to young children.

Possible risks and effects

  • Carcinogenic nitrosamines can form during cooking and in the stomach.
  • Regular eating of processed meat raises the risk of colorectal cancer.
  • At high doses methaemoglobinaemia; young children are especially sensitive.

For experts

Potassium nitrite (KNO2) reacts in meat with myoglobin to form stable pink nitrosylmyoglobin and effectively inhibits Clostridium botulinum. In 2017 EFSA set an ADI of 0.07 mg/kg body weight per day (as nitrite ion); although added nitrites make up only a minor part of total exposure, they can contribute to nitrosamine formation. The International Agency for Research on Cancer (IARC) classified processed meat as a Group 1 carcinogen in 2015, and in 2023 the EU adopted lower maximum permitted levels of nitrites and nitrates.

Check another E-number

More from this group

E211Sodium benzoateE250Sodium nitriteE210Benzoic acidE220Sulphur dioxideE223Sodium metabisulphiteE224Potassium metabisulphiteE251Sodium nitrateE252Potassium nitrate

This information is educational and based on EFSA assessments and available studies; it does not replace medical advice. With allergies, intolerances or illness, follow your doctor’s advice.