What is E172 and How is it Made?
E172 is the E number designation for a group of food colorants known as iron oxides and hydroxides. These are inorganic mineral compounds composed of iron and oxygen. While these pigments occur naturally as ochre and umber earths, the versions used in food production are typically synthesized under controlled conditions. This industrial process ensures a high level of purity, consistency, and stability, which are essential for food-grade ingredients. The specific chemical composition and manufacturing process determine the final color, resulting in distinct variants of E172.
The Different Shades of E172
The E172 food coloring is not a single compound but a category that includes several color variants:
- E172(i) – Black Iron Oxide: The deepest, darkest shade in the family.
- E172(ii) – Red Iron Oxide: A vibrant red pigment.
- E172(iii) – Yellow Iron Oxide: Provides a bright yellow hue.
Food manufacturers can blend these pigments to achieve a wide spectrum of earthy shades, including brown and orange, making E172 a versatile and popular colorant in the industry.
Common Foods Containing E172
This food additive is used in a surprisingly wide array of products to restore color lost during processing or to enhance their visual appeal. You can find E172 in:
- Confectionery: Used in cakes, sweets, and lozenges.
- Processed Meats: Added to sausage casings, meat pies, salmon, and prawns to provide a reddish color.
- Cheeses: Used to color the rinds of certain cheeses.
- Fruits and Vegetables: Employed to recolor green olives to black.
- Snacks and Desserts: Found in fine bakery wares and certain cereal and starch-based desserts.
- Pharmaceuticals and Supplements: Used for coloring medicine tablets and capsules.
E172 Safety Profile and Regulatory Status
Regulatory bodies worldwide, including the European Food Safety Authority (EFSA) and the U.S. Food and Drug Administration (FDA), have evaluated and approved E172 for use as a food additive, provided it is used within regulated limits. One of the reasons for its approval is that the iron oxides are poorly absorbed by the intestinal mucosa and are almost completely excreted again, minimizing systemic exposure to the body.
However, the safety profile is not without nuance. A 2015 EFSA re-evaluation of E172 noted limitations in the available toxicological data, especially concerning the potential genotoxicity of nanoparticles present in some preparations. While the panel did not find definitive evidence of harm, they concluded that a sufficient safety assessment was not possible based on the data available at the time. Concerns have also been raised about potential aluminum contamination in some dye batches.
Comparison with E171 (Titanium Dioxide)
E172 is often mentioned in discussions alongside E171, another mineral-based food additive. While both are inorganic pigments, their uses and regulatory statuses can differ significantly.
| Feature | E172 (Iron Oxides) | E171 (Titanium Dioxide) |
|---|---|---|
| Function | Provides a range of yellow, red, brown, and black colors to foods. | Primarily used as a white pigment to provide brightness and opacity. |
| EU Status (Food Use) | Remains permitted in the EU and many other regions for food coloring. | Banned as a food additive in the EU since 2022 due to potential genotoxicity concerns related to nanoparticles. |
| US Status (Food Use) | Continues to be permitted by the FDA for use in food. | Continues to be permitted by the FDA for use in food, unlike its status in the EU. |
| Primary Concern | Concerns related to nanoparticle content and potential aluminum contamination. | Nanoparticle concerns led to the EU ban, despite continued use elsewhere. |
| Overall Stability | High stability to heat and light, making it very versatile. | Very stable, but regulatory action highlights unresolved health questions. |
Natural Alternatives to E172
For consumers and manufacturers looking to avoid artificial or mineral-based colorants, several natural alternatives exist:
- For Red Hues: Beetroot juice and pomegranate juice can provide a vibrant red color.
- For Yellow/Orange Hues: Turmeric powder, carrot juice, and saffron are excellent options.
- For Black/Brown Hues: While not a perfect match for all iron oxide shades, vegetable carbon (E153) can be used to achieve a black color, while natural ingredients like caramel coloring (E150) can provide brown tones.
Conclusion
E172, the E number for iron oxides and hydroxides, serves as a versatile and stable food colorant, responsible for creating a wide palette of earthy tones in countless food products. Although it is approved by major regulatory bodies and is generally considered safe for consumption within specified limits, specific concerns regarding potential nanoparticle content and past limitations in toxicological data have led to closer scrutiny. For many consumers, the low intestinal absorption offers reassurance, while others may opt for products using natural coloring agents. Regardless of the choice, awareness of E172 and its place in the modern food supply is essential for making informed dietary decisions.
