What Is It?

Titanium dioxide is a naturally-occurring mineral found in the earth’s crust. Because of its white color, opacity, and ability to refract light, the ingredient is often used as a pigment, brightener, and opacifier in consumer products, meaning that it helps make a formulation more opaque. Most notably, it is used as an inorganic, mineral UV filter in sunscreens for its ability to absorb UV radiation, in lieu of toxic chemical UV filters (e.g., oxybenzone, avobenzone, octinoxate, etc.). Titanium dioxide exists in three crystalline forms – anatase, rutile, and brookite – though anatase and rutile are the primary forms used industrially and in consumer products.

Why It Matters

Titanium dioxide is increasingly being used as a replacement for chemical UV filters, such as oxybenzone or octinoxate (known for their toxicity to humans and aquatic ecosystems, like coral reefs), in sunscreen. Titanium dioxide is also commonly used as a pigment in color cosmetics and personal care.

Titanium dioxide has been under increased scrutiny since the European Union banned its use in foods citing potential genotoxicity concerns, though it’s still present in many food products in the United States. So why is the average consumer being encouraged to opt for titanium dioxide and zinc oxide sunscreens? Here, we unravel the controversies and confusion behind the safety of titanium dioxide so you can make the right choices for you and your family as a conscientious consumer.

Where It’s Found

Titanium dioxide is used as a UV filter in sunscreens. It is also used as a pigment in makeup, as well as in personal care like toothpaste, soap, skincare, and more. You’ll also find it in food and candy in some countries, where it’s used as a pigment.

Found In

Loose powder cosmetics
Sunscreens
Lotions
Pigmented personal care products

The Health Concern

Titanium dioxide can be both safe and unsafe, depending on its use and form. The safety of titanium dioxide can change depending on a) how we are exposed to it (i.e., by inhalation, skin contact, or ingestion) and b) the size and other physicochemical properties of the titanium dioxide particles. For instance, the crystalline structure of titanium dioxide particles (anatase vs. rutile) can have impacts on its toxicity. Anatase and rutile mixtures are suspected of inducing cytotoxicity (toxicity to cells) or oxidative stress.

1—These complexities are what make titanium dioxide a tricky ingredient to understand, especially for the conscientious consumer deciphering contradictory news headlines. Titanium dioxide particles vary by size and can be classified as nanoparticles (<100 nanometers in diameter) or non-nanoparticles (>100 nanometers in diameter). Generally, nanoparticles can be 1000 times smaller than the width of a human hair. Despite nanoparticles becoming increasingly common across industries, they have not been properly assessed for human or environmental health effects, nor are they adequately regulated. However, because of their infinitesimally small size, nanoparticles may be more chemically reactive and therefore more bioavailable.

2—The dramatic difference in size can also cause nanoparticles of a substance to behave differently than larger particles of the same substance; these characteristics may lead to potential damage in the human body or ecosystem.

3—For this reason, nanoparticles and non-nanoparticles of titanium dioxide are best considered distinct ingredients and assessed separately. Next, the way in which you’re exposed to titanium dioxide can impact its effects:

• Inhalation of Titanium Dioxide — The International Agency for Research on Cancer (IARC) classifies inhalable titanium dioxide as a group 2B carcinogen, or “possibly carcinogenic to humans”.4 Titanium dioxide can be inhaled from products containing powdered titanium dioxide, like loose powders, pressed powders, eyeshadows, and blushes, or from aerosolized sunscreens or dry shampoos. Titanium dioxide is also an occupational chemical of concern, as workers might inhale titanium dioxide when manufacturing products.5
• Ingestion of Titanium Dioxide — Oral exposure to titanium dioxide particles is potentially linked to DNA strand breaks, chromosomal damage, and oxidatively generated DNA lesions. Both nanoparticles and microparticles of titanium dioxide (anatase and rutile) exhibit the ability to induce oxidation of DNA. The crystalline form (anatase or rutile), size, and extent to which titanium dioxide nanoparticles may group together are hypothesized to impact genotoxic potential. However, the extent of genotoxicity with reference to these and other physicochemical properties of titanium dioxide particles is not clear.

How to Avoid It

If shopping for sunscreen or color cosmetics, opt for sunscreens containing non-nanoparticle titanium dioxide.

Avoid any products containing nano-scale titanium dioxide.

Avoid aerosolized or loose powder products containing titanium dioxide of any particle size that might be ingested or inhaled.

Apply these simple tips when considering products containing titanium dioxide:

Avoid titanium dioxide in powdered makeup – including loose and pressed powders, eyeshadows, and blush – as well as makeup you may ingest like lipstick or lip balm.

Opt for sunscreen lotions and creams instead of aerosol sunscreens.

Choose sunscreens labeled as “non-nano” or “non-nanomaterial.” If the label doesn’t specify whether the titanium dioxide is nanoparticle size, skip it altogether and choose another option, or contact the company for clarification.

Avoid foods and candy containing titanium dioxide of any particle size.