E171 Colour

Titanium Dioxide

Written by the VitaWhat editorial team · Medically reviewed by Steve Davis · Last reviewed 24 July 2026 · Editorial policy

What it does

White colour/opacifier.

How it's made

Purified mineral titanium dioxide.

Titanium dioxide is a brilliant white pigment that was widely used to whiten and add opacity to foods such as icings, coatings, chewing gum and sweets. It is one of the whitest substances known and scatters light strongly, giving a clean, bright white.

It is manufactured from titanium-bearing minerals such as ilmenite or rutile. In the two main industrial routes, the ore is treated either with sulphuric acid (the sulphate process) or with chlorine (the chloride process) to separate the titanium, which is then converted to pure titanium dioxide and precipitated as extremely fine white particles.

The pigment is washed, dried and milled, and food grades are made to strict purity limits. It is worth noting that the EU withdrew approval for titanium dioxide as a food additive in 2022 over uncertainties about very fine (nano) particles, so its status now differs between regions; where still permitted it is a purified, tightly specified pigment.

Possible reactions

Banned as a food additive in the EU (2022) over genotoxicity concerns; still used elsewhere.

Sources & references

  1. UK Food Standards Agency — Food additives
  2. EFSA — Food additives

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