Titanium dioxide is a natural mineral oxide of titanium with the chemical formula TiO2. It’s commonly used as a pigment in a wide range of products, from paint and ceramics to beauty products. It’s even used in food, particularly cake decorations, where it’s recognised by the E-number E171. But does this substance actually have any health benefits?
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The Health Benefits of Titanium Dioxide
Concerns about the potential health risks caused by titanium dioxide have been spoken about for a while now. While it’s mostly considered safe, its propensity to enter the body as nanoparticles when inhaled has led to many people calling for a ban on this product’s use in things like food and cosmetics.
It’s true that at high concentrations, titanium dioxide has the potential to irritate the eyes, nose, and throat. However, this substance has been deemed safe to use by the FDA (the US’s Food & Drug Administration) for a few reasons:
- When used topically, TiO2 isn’t readily absorbed by the skin and can be easily washed off
- When used as a pigment, such as in soap, TiO2 is very stable and inert
- When used at safe concentrations, TiO2 nanoparticles don’t permeate the skin
- TiO2 nanoparticles are also unable to reach viable cells or enter the bloodstream
There are strict guidelines in place to ensure that titanium dioxide never exceeds a safe limit. For example, in sunscreens, the Scientific Committee on Consumer Safety (SCCS) confirmed that titanium dioxide nanoparticles can be used safely at 25% concentration.
Similarly, the FDA limits the use of titanium dioxide in food to 1%. So, while TiO2 can pose health risks, we’d only experience these if chronically exposed to high concentrations of it.
In fact, what many people don’t realise is that there are actually a few health benefits of titanium dioxide. These benefits include:
- Protection against UV rays
Titanium dioxide is one of the whitest naturally-occurring substances, and it also has a very high opacity. This is because its particles have a relatively high refractive index. Refractive index is the ratio between the speed of light in a vacuum and its speed in the medium it passes through. A higher refractive index means that light is significantly slowed down, and this is what makes titanium dioxide ideal for use in sunscreens.
This compound can significantly bend and scatter light rays, including ultraviolet rays, making it very effective at blocking harmful radiation from the sun. UV, in particular, can potentially damage the DNA of the skin cells, which can lead to cancer. As a sunscreen ingredient, titanium dioxide can help to prevent the development of skin cancer, as well as milder risks such as sunburn.
- Protection against degradation
The high refractive index of TiO2, alongside its relatively inert nature, makes it very useful in protecting food products, beverages, supplements, and medicines against premature degradation. Exposure to UV rays in sunlight can easily degrade the molecular structures of these products by breaking down their molecular bonds.
Fortunately, since it’s commonly used as a pigment in product containers, such as drug tablets and capsule coatings, titanium dioxide can help to significantly extend the shelf life of products like these because of its ability to scatter UV rays. This is the main reason why many drug tablets and capsules are white in colour: it’s not only a design choice, it’s also a practical one.
- Antiviral and antimicrobial properties
The antibacterial and antiviral properties of titanium dioxide have been well-documented since around 1985, with various peer-reviewed researches having described the potential use of this substance for disinfecting purposes. This is because it has antifungal and antibacterial properties against a range of different types of bacteria.
The antimicrobial properties of TiO2 are directly proportional to its particle size. It works by suppressing the photo-activation and dark repair of the genetic materials of microbes.
Is Titanium Dioxide Safe in Sunscreen?
One of the major applications of titanium dioxide is its use as an ingredient in sunscreen. As we mentioned earlier, it works by effectively blocking the UV rays from sunlight. However, some European health regulators have raised concerns about the potential carcinogenic threat of this substance.
Primarily, the red flag was raised by the International Agency for Research on Cancer, or IARC. Based on meta analysis and preliminary investigations, it was discovered that, when rats inhaled TiO2 nanoparticles, they experienced increased tumours. However, it’s important to note that more extensive studies involving workers who were exposed to the substance, did not indicate a correlation between TiO2 exposure and an increased risk of cancer.
It should also be pointed out that inhalation of TiO2 nanoparticles is the main reason for increased tumour incidence in lab rats. As titanium dioxide particles in sunscreen are not freely suspended in air, there’s very little chance that they can be inhaled as nanoparticles. As we touched on earlier, when applied topically to the skin, either as sunscreen or soap, titanium dioxide isn’t readily absorbed by the skin and is entirely safe to use.
What Are the Benefits of Titanium Dioxide in Sunscreen?
As an ingredient in sunscreen, titanium dioxide and other metal oxides are more effective at blocking ultraviolet rays than organic ingredients.
UV light from the sun has wavelengths ranging from 280 nm to 400 nm. Shorter wavelengths like these are classified as UV-B, meaning they’re more energetic and have a higher potential to cause damage to the skin. While longer wavelengths aren’t very energetic, they’re still energetic enough to break molecular bonds, such as DNA molecular bonds in skin cells. UV rays with longer wavelengths are classified as UV-A.
The rated sun protection factor (SPF) of most sunscreen products, no matter how high the number, can only block UV-B that causes sunburn: they cannot block UV-A types of radiation. Being less energetic, UV-A radiation can pass through sunscreen and even through glass with protective tint. This is the type of UV radiation that causes skin aging.
If you want proper UV protection, both the short wavelengths and long wavelengths of UV must be blocked. Organic ingredients in sunscreen, such as octyl methoxycinnamate, can only block UV-B waves. This is where metal oxide ingredients like titanium dioxide are most effective: they can block both types of radiation. What’s even better is that TiO2 won’t degrade or break down after prolonged exposure to the UV rays, unlike other organic ingredients.
Does Titanium Dioxide Have Skin Care Benefits?
The primary benefit of titanium dioxide for the skin is its protection against UV rays and potential skin cancer. But another benefit this substance has on the skin is its antimicrobial properties, meaning that lotions and cosmetic products that contain TiO2 can provide some levels of protection against skin infections.
Is Titanium Dioxide Used in Tablet Coating?
Pharmaceutical companies need to package medicines and nutritional supplements into small but tough containers. Just as medicine glass bottles are usually brown in colour in order to block sunlight, so are plastic medicine containers white in order to safeguard against UV rays.
To protect medicines and make them ready for consumption, pharmaceutical companies enclose medicines in capsules and tablets with titanium dioxide coatings – hence the white colour. The medicine is protected from premature degradation due to UV exposure. The coatings also prevent oxidation as the products will be protected from the oxygen in the air.
What Are The Benefits of Using Titanium Dioxide in Soap?
Many cosmetic and hygienic products like toothpastes, lipsticks, lotions, and soaps contain titanium oxide. Here, the compound serves as an opacifier that improves both the aesthetics and the shelf life of the products. The use of TiO2 in soap helps to significantly improve its colour, while also adding to soap’s germicidal properties.
