The main application of titanium dioxide as a white color pigment is in the manufacture of paints, coatings, paper and plastics.
As a food additive E171, titanium dioxide is mainly used in sweets, fine bakery products, soups, broths and sauces, as well as salads, spreads and in products containing processed nuts. The pigment is particularly suitable for coloring foods and as a white glossy coating for sweets such as dragées or chewing gums, food supplements and pharmaceuticals.
Furthermore, titanium dioxide is used as a feed additive and, due to its coloring properties, as a white pigment in cosmetic products such as toothpaste and in tattooing products.
In sunscreens, tiny titanium dioxide particles in nanoform (particle size of 1-100 nanometers) serve as mineral light protection filters that reflect harmful UV radiation and thus protect the skin.
Titanium dioxide can be absorbed through the skin (dermal), through the respiratory tract (inhalation) and through the digestive tract (oral).
Absorption via the digestive tract
Via the consumption of foods containing the additive E171, titanium dioxide can be absorbed from the gastrointestinal tract even in small amounts. Since titanium dioxide is excreted from the body only very slowly, it can accumulate in organs. In the May 2021 risk assessment by the European Food Safety Authority (EFSA), genetic damage (genotoxicity) could not be ruled out, as it has been shown that titanium dioxide can cause DNA and chromosome damage. Thus, EFSA has concluded that the use of titanium dioxide as a food additive is no longer safe.
Absorption through the skin
Titanium dioxide is not absorbed through skin care products such as sunscreens. Thus, these sunscreens can be applied to the skin (including sunburn-damaged skin) without concern. There are currently no indications that the use of titanium dioxide in cosmetic products is harmful to the health of consumers.
Absorption via the respiratory tract
If titanium dioxide particles (from dusts and paints) are inhaled, they can penetrate deep into the lung tissue, where they can cause inflammation and lead to the formation of tumors. Thus, titanium dioxide is classified as possibly carcinogenic when inhaled. The use of titanium dioxide nanoparticles in sunscreens that can be absorbed into the lungs by inhalation (spray bottles) is not permitted and is regulated by EU Cosmetics Regulation (EC) No. 1223/2009.
Situation in Austria
Due to existing safety concerns, the European Commission issued a regulation in mid-January 2022 to ban the use of titanium dioxide as an additive in food . In order to allow a smooth transition and to ensure the food supply, a transition period of 6 months has been defined in this regulation, which will apply from February 7, 2022. After this transition period, the use of the additive titanium dioxide in food will be prohibited. Products manufactured using titanium dioxide before the end of the transition period may remain on the market until the expiration date or the best-before date.
As part of the official control, we are checking the titanium dioxide content in selected sugar confectionery and additive mixtures.
In addition, we conducted tests of sunscreens containing titanium dioxide nanoparticles in October 2020. We concluded that these tested sunscreens comply with the specific requirements of the EU Cosmetics Regulation (EC) No. 1223/2009 and that there is no reason for complaint. According to this regulation, the use of titanium dioxide in nanoform is subject to labeling and must be listed in the product's ingredients.
- In the case of pre-packaged goods, a label with the class designation "colorant" followed by the designation "titanium dioxide" or the E-number ("E 171") in the list of ingredients must be affixed to the packaging or container
- In the case of open goods (e.g. loose sugar confectionery), there is no obligation to label the colorant
- In skin care products and cosmetics, titanium oxide is listed in the list of ingredients under the designation "CI 77891
Regulation (EC) No. 1333/2008 applies to the use of titanium dioxide as a food additive. Titanium dioxide is approved for coloring selected foods according to the quantum satis principle (as much as necessary, as little as possible to achieve the technological effect). Currently, the Specification Regulation for Food Additives (EU) No. 231/2012 does not include specific particle size requirements for titanium dioxide.
The European Food Safety Authority (EFSA) published an evaluation of titanium dioxide as an additive in 2016 as part of its re-evaluation program. Based on the scientific studies available at the time, there was no evidence of health concerns for consumers. However, EFSA noted in its opinion that there was little technical data to characterize E171. In 2016, the nano content was assumed to be less than 3.2%. EFSA recommended in the assessment that more data be collected to characterize E171. Only by collecting technical data from industry has it been shown that up to 50% of TiO2 particles are smaller than 100 nm and 1% are smaller than 30 nm.
French researchers found adverse effects on the immune system of rats (intestinal inflammation and precancerous lesions) when titanium dioxide was ingested orally on a regular basis in a study published in 2017 on the possible effects of the food additive E171. The French Agency for Food, Environment and Health (ANSES), which was in charge of reviewing the studies, stated in a statement that most of the studies on TiO2 were not consistent; furthermore, it was difficult to compare the results. Nevertheless, by 2020, French authorities were the only EU country to ban the addition of E171 in food due to health concerns.
EFSA was asked to re-evaluate the additive by the European Commission in March 2020. For this evaluation, an animal study (extended generation study EOGRT study) was conducted and due to the latest findings on nano content, this time studies on titanium dioxide nanoparticles were also considered. Thus, a wider range of more than 10,000 scientific studies was used in this assessment compared to 2016. In addition, the guidance document published by EFSA in 2018 on the risk assessment of the application of nanoscience and nanotechnologies in the food and feed chain was used to assess the studies.
E171 can be absorbed by the intestine in small amounts (probably 0.5% of the dose) when ingested orally and distributed in the different organs. TiO2 nanoparticles have an estimated absorption of about 1% and can be accumulated in the body and have a half-life of 200-450 days. Due to the different particle size distribution of E171 (5-50% <100nm), the exposure of nanoparticles by E171 cannot be estimated.
In the extended generation study, there was no evidence of general toxic effect of E171, only decreased antigen-induced IgM levels were observed. Intestinal inflammation and precancerous lesions were not observed. However, the EFSA Panel concluded that the study design has deficiencies to exclude an immunotoxic effect of E171, therefore the development of precancerous lesions in the intestine by E171 cannot be completely excluded. Both the EOGRT study and the scientific studies consulted show no adverse health effects in general toxicity and organ toxicity at doses of 1000 mg/kg bw/day E171 and 100 mg/kg bw/day TiO2 nanoparticles (>30nm). There was also no evidence of adverse effects of E171 in reproductive and developmental studies. For TiO2 nanoparticles (<100nm), there was evidence of a potential neurotoxic effect that may have adverse effects, but the study results were inconclusive.
Considering all available in vitro and in vivo studies, the suspicion of genotoxicity could not be excluded, as it has been shown that TiO2 particles can lead to DNA strand breaks and damage to chromosomes. A suspicion of gene mutation could not be established. Due to the poor data situation, potential carcinogenicity could not be evaluated. Most genotoxic effects were recorded for TiO2 nanoparticles, but in a few studies genotoxic effects could also be observed for TiO2 particles larger than 100 nm. It was therefore not possible for the EFSA Panel to assign genotoxicity with a specific physicochemical property such as particle size (< or > 100nm), shape (anatase or rutile) or status of agglomeration. Furthermore, the genotoxic mode of action of TiO2 nanoparticles could not be clearly elucidated. Therefore, the EFSA Panel was also unable to establish a safe threshold regarding particle size and concludes that the use of titanium dioxide as an additive is not safe.
There are no known acute adverse health effects from oral ingestion of E171, which would lead to an immediate ban. The EFSA Panel was unable to derive an Acceptable Daily Intake (ADI) in their assessment due to suspected genotoxicity and therefore the safety of the additive could not be substantiated. In order to ensure the supply chain and avoid food wastage, if E171 is banned, it is appropriate to provide food manufacturers with a transition period to discontinue the use of this additive in food and to replace it if necessary.
A possible alternative for the use of titanium dioxide is the approved food colorant calcium carbonate (E170) or not coloring the food.
Last updated: 16.08.2023