Is Titanium Dioxide dangerous for your Skin?
Titanium Dioxide, and in particular in nanoparticulate form, has been much talked about in recent years. Studies have multiplied to understand its impact on our body but also on the environment. And this has led to various modifications in the regulation of its use, in food and in cosmetics. But it may still be a little confusing for you. You are probably wondering what is the impact of the form [nano] on your health? or is it possible to use sunscreens containing Titanium Dioxide?
The different uses of Titanium Dioxide:
Often criticized for its potential toxicity, titanium dioxide (TiO2) comes in the form of a white powder, which is however very widely used. They are found in paints as well as in medicines, food or cosmetic products…
It has different functions and can serve as:
White coloring: both in food (additive: E171), and in cosmetics (example: toothpaste), where it appears in this case in the list of INCI ingredients under the codification: CI 77891
Opacifying agent: as in makeup powders for example, foundations or covering creams…
UV absorbent: it is used in many sun protection products. It is a very effective UV filter, especially to protect against UV B.
For use as a UV filter, it must appear in the INCI under the name: Titanium dioxide.
It is therefore an interesting ingredient on several levels, but which presents, in certain cases, a certain dangerousness. The fact that Titanium Dioxide exists in several aspects, complicates things and creates confusion and generalizations. Indeed, its physicochemical properties can vary and thus influence its toxicity, according in particular to:
its size: micrometric or nanometric
its shape: spherical, elongated, fibrous …
the presence of a coating which modifies the surface of the particles (coating of titanium).
Let’s try to get a little clearer, especially when it comes to cosmetics.
What are the 2 main criticisms made of Titanium Dioxide?
He is accused of being:
Carcinogenic by inhalation: Indeed, it has been classified by the IARC (International Center for Research on Cancer) as being able to be carcinogenic for humans due to its danger to the lungs in the event of inhalation of particles.
This is why it is officially classified as a category 2 carcinogen by inhalation, since it is likely to cause lung cancer. Since the pathogenicity of TiO2 in the lungs is linked to the inhalation of respirable titanium dioxide particles, this classification applies only to the substance, or to mixtures in powder form containing at least 1% of titanium dioxide, with particles ≤ 10 μm in diameter. This classification therefore mainly concerns people who regularly work in contact with this raw material, in an environment where Titanium Dioxide is present in high concentrations in the form of dust.
However, in cosmetics, droplets containing titanium dioxide can be inhaled at the time of use. This is why, the use of Titanium Dioxide in [nano] form is prohibited in sunscreen products in spray form.
Widely used in medicines, in some toothpastes, lipsticks and in many food products, titanium dioxide is ingested in these cases. Depending on the product, it is used in various concentrations, in different shapes and sizes, which makes it very difficult to quantify its impact on human health. We know that with Nano forms, the risk of penetration of these fine particles (less than 100 nanometers) into the body is greater, and that they could prove to be toxic to the organism.
INRA (National Institute of Agronomic Research) published in 2016 a study showing that chronic exposure to titanium dioxide (in nanoparticulate form) in rats is likely to cause precancerous lesions of the intestine and immune system disorders. However, studies of the toxicity of titanium dioxide in humans remain inconclusive and it is difficult to assess it precisely yet.
Therefore, the precautionary principle is recommended.
Thus, the ANSES (National Agency for Food, Environmental and Occupational Health Safety) assessed the safety of TiO2 as a food additive (E171). She concluded that the most recent studies do not “confirm or deny the carcinogenic potential”.
Due to the “lack of scientific data, […], ANSES” does not have new elements allowing to remove the uncertainties on the safety of the additive E171 “.
This has led to the suspension of the marketing of foodstuffs containing titanium dioxide, since January 1, 2020.
As it stands, this measure only concerns food and is not applicable to products such as toothpaste or lipsticks, where part of it can be swallowed.
As a precaution, Titanium Dioxide, especially in the nano form, should be avoided when used in toothpaste and lipsticks.
What is the interest of Titanium Dioxide as a Sun Protector?
Titanium Dioxide is a very interesting ingredient for formulating sun protection products, because it absorbs UV and reflects the sun’s rays. It is qualified as a mineral screen and is authorized in organic cosmetics.
Its safety as a sunscreen has been evaluated by the SCCNFP (Scientific Committee on Cosmetic Products and Non-Food Products intended for consumers) and concludes that it will be used safely up to a concentration of 25% in the finished product. Its effectiveness is conditioned by the size of the particles. The most effective are 0.1 to 0.5 micrometers (100 to 500 nanometers, these are non-nano), because they absorb UV well.
But it has a major drawback: it whitens the skin as soon as its concentration in the formula exceeds 5%, (for particles whose size is between 200 and 500 nanometers).
This is the reason why the [Nano] forms were invented, in order to avoid this white mask effect on the skin.
It is very often associated with Zinc Oxide (also authorized in ORGANIC cosmetics), because the latter covers the spectrum of UVA rays (long and short) well, and the combination of these 2 mineral screens offer a very good protection index.
Unlike chemical filters, Titanium Dioxide is very well tolerated in the skin, it does not induce photo-allergies, and is also heat stable.
For all these reasons, Titanium Dioxide, and particularly its non-nano form, makes it an ingredient of choice in organic sun protection products. Again, favor the use of sunscreens containing Titanium Dioxide in non-nano form. They offer very good sun protection without the inconvenience of penetrating the skin. Indeed, the non-nano form is not absorbed at the level of the skin and remains on the surface of the epidermis.