172 Iron Oxide

Posted 25 Oct 2023
172 Iron Oxide

What is Iron Dioxide, and where is it used? Iron oxide (E172) is a versatile food additive with multiple purposes in the food industry [1-3]. It serves as both a preservative and a colourant, enhancing the visual appeal and ensuring the preservation and stability of food products.

Iron oxide is a naturally occurring compound that exists in different forms, including red (Fe2O3), yellow (Fe2O3·H2O), and black (Fe3O4) [4]. These forms of iron oxide have unique characteristics and applications while sharing similar properties that make them suitable for use in food products.

Common applications of iron oxide in food include:

  • Colour Enhancement: Iron oxide is widely used as a food colourant, providing vibrant hues ranging from red and yellow to brown and black [1-4]. This allows food manufacturers to achieve desired visual effects in various products, including confectioneries, baked goods, cereals, sauces, and beverages.

  • Preservation and Stability: Acting as a preservative, iron oxide inhibits the growth of microorganisms in food products, extending their shelf life [1-3]. It is utilised in processed meats, sauces, dressings, and other items to prevent spoilage and maintain freshness, thereby contributing to the overall quality and safety of the food.

Purported Health Implications

  • Iron Supplementation: Iron oxide, being a source of iron, can provide a dietary supplement of this essential mineral [5]. Iron plays a vital role in the body, contributing to the production of red blood cells and oxygen transportation. However, it's important to note that iron oxide's contribution to iron intake is minimal compared to other dietary sources such as meat, legumes, and leafy green vegetables.

  • Antioxidant Properties: Iron oxide, particularly the red form (Fe2O3), exhibits antioxidant properties due to its iron content [6-7]. Antioxidants help protect cells from oxidative stress caused by harmful free radicals, potentially reducing the risk of chronic diseases. However, it's important to obtain antioxidants from a balanced diet rich in fruits, vegetables, and whole grains, rather than relying solely on iron oxide as a source.

Recommendations for Safe Consumption

Iron oxide (E172) has undergone rigorous safety evaluations by regulatory authorities, including Food Standards Australia New Zealand (FSANZ), the European Food Safety Authority (EFSA) and the U.S. Food and Drug Administration (FDA) [8-10]. These assessments have concluded that iron oxide is safe for consumption within the approved limits.

The acceptable daily intake (ADI) of iron oxide varies depending on the specific form (red, yellow, or black) and the country's regulatory standards [8-10]. It is crucial for food manufacturers to adhere to these guidelines and use iron oxide within the permitted levels to ensure consumer safety.


  1. Cichello SA. Oxygen absorbers in food preservation: a review. Journal of food science and technology. 2015 Apr;52:1889-95.

  2. Dey S, Nagababu BH. Applications of food color and bio-preservatives in the food and its effect on the human health. Food Chemistry Advances. 2022 Oct 1;1:100019.

  3. Shahbazi Y, Shavisi N. Current advancements in applications of chitosan based nano-metal oxides as food preservative materials. Nanomedicine Research Journal. 2019 Sep 1;4(3):122-9. Lehto S, Buchweitz M, Klimm A, Straßburger R, Bechtold C, Ulberth F. Comparison of food colour regulations in the EU and the US: a review of current provisions. Food Additives & Contaminants: Part A. 2017 Mar 4;34(3):335-55.

  4. Pfaff G. Iron oxide pigments. Physical Sciences Reviews. 2021 Apr 23;6(10):535-48.

  5. Mazgaj R, Lipiński P, Szudzik M, Jończy A, Kopeć Z, Stankiewicz AM, Kamyczek M, Swinkels D, Żelazowska B, Starzyński RR. Comparative evaluation of sucrosomial iron and iron oxide nanoparticles as oral supplements in iron deficiency anemia in piglets. International Journal of Molecular Sciences. 2021 Sep 14;22(18):9930.

  6. Góral D, Marczuk A, Góral-Kowalczyk M, Koval I, Andrejko D. Application of Iron Nanoparticle-Based Materials in the Food Industry. Materials. 2023 Jan 12;16(2):780.

  7. Silva MM, Reboredo FH, Lidon FC. Food Colour Additives. Foods. 2022 Jan 28;11(3).

  8. Food additives -alphabetical list Food additives -alphabetical list [Internet]. 2019. Available from: https://www.foodstandards.gov.au/consumer/additives/additiveoverview/Documents/Food%20additives%20-%20alphabetical%20May%202019.pdf 

  9. Scientific Opinion on the re-evaluation of iron oxides and hydroxides (E 172) as food additives | EFSA [Internet]. www.efsa.europa.eu. Available from: https://www.efsa.europa.eu/en/efsajournal/pub/4317

  10. Center for Food Safety and Applied Nutrition. Summary of Color Additives for Use in the United States [Internet]. U.S. Food and Drug Administration. 2019. Available from: https://www.fda.gov/industry/color-additive-inventories/summary-color-additives-use-united-states-foods-drugs-cosmetics-and-medical-devices


We do our best to source robust information from a number of credible sources.  There is, however, a large amount of information on various aspects of nutritional elements along with  claims in terms of their contribution to helping in body health which may contradict the above.