Titanium, the ninth most common element in the Earth’s crust, is a metal commonly found in plants and animals. Titanium naturally interacts with oxygen to form titanium oxides, commonly found in ores, indigenous dusts, sands and soils.
Many people are familiar with titanium dioxide as an active ingredient in sunscreen. Titanium dioxide works as a UV filtering ingredient in sunscreen – it helps protect a person’s skin by blocking the absorption of the sun’s ultraviolet light that can cause sunburn and is also linked to skin cancer.
Pure titanium dioxide is a fine, white powder that provides a bright, white pigment. Titanium dioxide has been used for a century in a range of industrial and consumer products, including paints, coatings, adhesives, paper, plastics and rubber, printing inks, coated fabrics and textiles, as well as ceramics, floor coverings, roofing materials, cosmetics, toothpaste, soap, water treatment agents, pharmaceuticals, food colourants, automotive products, sunscreen and catalysts.
Titanium dioxide is produced in two main forms. The primary form, comprising over 98 percent of total production, is pigment grade titanium dioxide. The pigmentary form makes use of titanium dioxide’s excellent light-scattering properties in applications that require white opacity and brightness. The other form in which titanium dioxide is produced is as an ultrafine (nanomaterial) product. This form is selected when different properties, such as transparency and maximum ultraviolet light absorption, are required, such as in cosmetic sunscreens.
Pigment-grade Titanium Dioxide
Pigment-grade titanium dioxide is used in a range of applications that require high opacity and brightness. In fact, most surfaces and items that are white and pastel, and even dark shades of color, contain titanium dioxide. Pigment-grate titanium dioxide is used in a range of applications, including:
- Paints and Coatings: Titanium dioxide provides opacity and durability, while helping to ensure the longevity of the paint and protection of the painted surface.
- Plastics, Adhesives and Rubber: Titanium dioxide can help minimize the brittleness, fading and cracking that can occur in plastics and other materials as a result of light exposure.
- Cosmetics: Pigment-grade titanium dioxide is use in some cosmetics to aid in hiding blemishes and brightening the skin. Titanium dioxide allows for the use of thinner coatings of make-up material for the same desired effect.
- Paper: Titanium dioxide is used to coat paper, making it whiter, brighter and more opaque.
- Food Contact Materials and Ingredients: The opacity to visible and ultraviolet light offered by titanium dioxide protects food, beverages, supplements and pharmaceuticals from premature degradation, enhancing the longevity of the product. Specific classes of high purity pigment-grade titanium dioxide are also used in drug tablets, capsule coatings and as a decorative aid in some foods.
Ultrafine-grade, or Nanoscale Titanium Dioxide
Ultrafine-grades of titanium dioxide are most commonly used in the following specialty applications:
- Sunscreen: Nanoscale titanium dioxide becomes transparent to visible light while serving as an efficient UV light absorber. Because the particle size is so small, nano-titanium dioxide does not reflect visible light, but does absorb UV light, enabling a transparent barrier that protects the skin from the sun’s harmful rays. According to the Skin Cancer Foundation, using sunscreens containing titanium dioxide can help prevent the occurrence of skin cancer.
- Catalysts: Nanoscale titanium dioxide is used as a support material for catalyst applications. Major uses include in the automotive industry to remove harmful exhaust gas emissions and in power stations to remove nitrous oxides
Titanium dioxide has been used as a bleaching and opacifying agent in porcelain enamels, giving them brightness, hardness, and acid resistance. In modern times it is used in cosmetics, such as in skin care products and sunscreen lotions, with claims that titanium dioxide protects the skin from ultraviolet radiation because of its property to absorb ultraviolet light.
Why is it used in cosmetics and personal care products?
Titanium dioxide is used as a colorant to make cosmetics and personal care products that are applied to the skin (including the eye area), nails, and lips white in color. It helps to increase the opaqueness, and reduce the transparency of product formulas. Titanium dioxide also absorbs, reflects, or scatters light (including ultraviolet radiation from the sun), which can cause products to deteriorate.
Titanium dioxide is an important active ingredient used in some sunscreen products. Sunscreens are regulated by the U.S. Food and Drug Administration (FDA) as over-the-counter (OTC) drugs. As such, they must be shown to be safe and effective and must comply with all other requirements listed in the FDA’s OTC sunscreen monograph. Individual sunscreen active ingredients are reviewed by FDA and only those that are on FDA’s monograph approved list may be used in sunscreen products marketed in the U.S.
Titanium dioxide is generally a white powder that gives products a white color. However, when it is made into a very fine powder, it no longer gives the product a white color. It is this fine material, sometimes called microfine or nanoscale titanium dioxide that is used in many OTC sunscreen products. Use of this ultrafine material enables the sunscreens to be applied as a clear film that consumers prefer over the antiquated, white opaque lotions. The availability of microfine titanium dioxide in sunscreen products helps increase consumer acceptance and usage. Practicing sun safety, including proper sunscreen use, is important in helping to reduce the incidence of skin cancer.
As a pigment, titanium dioxide is an FDA-approved food additive that is used to enhance the white color of certain foods, such as dairy products and candy, and to add brightness to toothpaste and some medications. It is also used as a flavor enhancer in a variety of non-white foods, including dried vegetables, nuts, seeds, soups, and mustard, as well as beer and wine.
Titanium Dioxide is used as an opacifying agent and a colorant. In OTC drug products, it is used as a sunscreen agent.