Titanium dioxide - Optical brightener with health risk

Titanium dioxide is a colour pigment that has the highest opacity of all white pigments. It is chemically stable and is considered non-toxic.

In medicine, it is used as a pure optical colouring agent with the INCI (International Nomenclature of Cosmetic Ingredients) designation CI 77891 for tablets, creams, cosmetics as well as in Sun creams used as a mineral UV filter.

As a colouring Food additive E171 It is added to sweets, chewing gum, toothpaste, mozzarella and as a white pigment in confectionery and coatings. 90 % of titanium dioxide is used in the industrial sector for the production of paints, lacquers, paper and plastics.

Titanium dioxide is formed from titanium, the fourth most common metal in the world. When it reacts with oxygen, titanium dioxide (TiO2) is formed. Since pure titanium hardly occurs on earth, it has to be extracted from titanium iron ore in an energy-intensive and cost-intensive way. The production process therefore leads to the emission of greenhouse gases and is climate-relevant. In Germany alone, about 550,000 tonnes of titanium dioxide are produced each year. produced as microparticles (particles above 100 nm) or nanoparticles (particles below 100 nm). This corresponds to a total share of 10 % in the global market. Nano titanium dioxides are among the most frequently produced nanoparticles

Absorption of titanium dioxide through the skin

2010 saw the arrival of a Study concluded that the uptake of nanoparticles by the skin is determined by the particle size and that this depends on the health status of the skin. For the uptake of titanium dioxide particles by Tattoos However, it has not yet been possible to make a statement on this issue.

Absorption of titanium dioxide via the gastrointestinal tract

In a Study of the University Hospital Zurich In 2016, it was shown in a mouse model that titanium dioxide (nano) particles as food additive E171 below 100 nm led to an increase in further inflammation and damage to the intestinal mucosa in mice with inflammatory bowel disease. The Zurich scientists therefore recommended that patients with intestinal inflammation avoid foods containing titanium dioxide. French researchers also showed in rats in 2017 that the ingestion of E171 in nanoparticle form Cause intestinal inflammation can and continues to damage the immune system.

To carcinogenic potential of titanium dioxide (nano)particles after oral exposure, no suitable studies are available so far. However, since titanium dioxide takes a long time to degrade in tissues, it has the potential to accumulate, leading to the assumption that tumours may develop as a result of the accumulation. The Database of the European Chemicals Agency (ECHA) therefore lists titanium dioxide as a possible carcinogenic substance.

At present, according to Federal Institute for Risk Assessment (BfR) not assess whether the assessment of the European Food Safety Authority (EFSA) on E171 is also transferable to titanium dioxide particles (CI 77891) in toothpaste as cosmetic products and has therefore recommended further investigations.

Uptake of titanium dioxide via the lungs

The Scientific Committee on Consumer Safety (SCCS) states that the use of titanium dioxide in powder form in topical preparations, based on current data and the possible classification of titanium dioxide according to the CLP Regulation as Carcinogen category 2 (inhalation) is not safe for general consumers if inhaled.

In sun creams, titanium dioxide (nano) particles are added as mineral UV protection to prevent the whitening effect. Already defined nanoparticle forms that could lead to exposure to the lungs are not permitted here. However, a final assessment of exposure to nanoparticles and the resulting necessary amendment to the EU Cosmetics Regulation is still pending. As of 9 September 2021 solid and liquid cosmetic products as well as sprays containing at least 1% titanium dioxide must be separately labelled with warnings throughout the EU. However, there is no ban.

Ban on titanium dioxide in food in Europe

Since 6 May 2021, the EFSA no longer considers the use of titanium dioxide as a food additive to be safe, as it is not possible to disprove the possible genotoxic effect of titanium dioxide (nano)particles after reviewing more than 200 in vitro and in vivo studies on animals relevant to the topic. Nor do the studies allow any conclusion to be drawn on a correlation between certain properties of titanium dioxide (nano)particles (size, composition) and the outcome of the genotoxicity studies. It is not possible to define an acceptable daily intake level. The French Food Safety Agency also ANSES criticises that there is a lack of data to declare the substance as clearly harmless.

As a consequence, France was the first EU member to ban titanium dioxide as a food additive from 1 January 2020. Switzerland will follow with a ban at the end of 2021. However, titanium dioxide will continue to be permitted in products such as cosmetics, sunscreen or medicines.

Conclusion

Titanium dioxide is an additive that is not essential and bears no relation to the potential risks. It is used solely to increase the visual appeal of a product and is thus merely a marketing tool.

For health and climate-related reasons, it is therefore recommended that titanium dioxide should not be added to medicines, skin care creams and foodstuffs.

Update 16.10.2021:

On 08.10.2021, the EU member states agreed to the European Commission's proposal to allow the use of ban titanium dioxide (E171) as an additive in food from 2022.

 Update 04.02.2022:

The European Union (EU) has issued the ban on the use of titanium dioxide as a food additive (E171). It comes into force from 7 February 2022 and is binding from 7 August 2022. Manufacturers will be required to replace titanium dioxide in medicines with excipients within the next three years. Before 1 April 2024, the European Medicines Agency (EMA) carry out a further assessment of titanium dioxide.