What is titanium dioxide? 
 Titanium dioxide (TiO2) is a white solid inorganic substance that is thermally stable, non-flammable, poorly soluble, and not classified as hazardous according to the United Nations’ (UN) Globally Harmonized System of Classification and Labeling of Chemicals (GHS). 
 
 TiO2, the oxide of the metal titanium, occurs naturally in several kinds of rock and mineral sands. Titanium is the ninth most common element in the earth’s crust. TiO2 is typically thought of as being chemically inert. 
 
What products contain TiO2? 
 Titanium dioxide has been used for many years (ca. 90 years) in a vast range of industrial and consumer goods including paints, coatings, adhesives, paper and paperboard, plastics and rubber, printing inks, coated fabrics and textiles, catalyst systems, ceramics, floor coverings, roofing materials, cosmetics and pharmaceuticals, water treatment agents, food colorants and in automotive products, etc … 
 
What are the differences between TiO2 as a pigment and as a nanomaterial 
(ultrafine)? 
 Pigment grade TiO2 is manufactured to optimise the scattering of visible light and consequently white opacity. This requires a primary particle size of approximately half the wavelength of the light to be scattered, that is half of 400 - 700nm for visible light. 

Pigment grade TiO2 is manufactured in order to maximise the number of primary particles in this size range (approx. 200 – 350 nm). However as in all production processes of particulate materials, there will be a distribution of primary particle sizes around the average value and it is likely that a small fraction of the primary particles are < 100 nm, and therefore covered by the nanoparticle ISO definition (ISO/TC 229 Nomenclature system for nanoparticles). In practice, all these particles tend to agglomerate into the micron (µm) size range. 
 
 TiO2 nanomaterials (ultrafine) are transparent and more effective as UV 
absorbers or photocatalysts. The transparency and UV absorbance allow for effective use as a protective ingredient for sunscreens. 
 
 Due to the smaller size of primary particles and higher surface area, TiO2 as a nanomaterial allows the manufacture of various catalysts of enhanced activity. 
 
 TiO2 as a nanomaterial is engineered to have primary particles less than 100 nm 
in order to optimize such properties. 
 
 TiO2 as a nanomaterial is not used as a colorant as it is functionally different from 
pigment size particles and will not impart color or opacity to a product. 
 
 Primary particles are strongly bound or fused together by chemical bonds to form aggregates. These aggregates further agglomerate via van der Waals attractive forces to form particles in the micron (µm) size range. 

What are the benefits derived from TiO2? 
 As a pigment, TiO2 has excellent light-scattering properties and is used in a variety of applications that require white opacity and brightness. 
 
 It absorbs UV light. When TiO2 pigment is incorporated in a polymer, it minimizes degradation of the system (embrittlement, fading and cracking). Surface treating of the TiO2 can further improve this property. 
 
 When used in paint or coating system, this effect ensures the longevity of the paint and the continued protection of the substrate. 
 
 The use of light colored paints for interior applications provides an impression of 
openness and “space”. In addition, the high "luminosity" that comes from light 
colored paints reduces the energy needed to light the interior of buildings when 
compared to darker colors. 
 
 In exterior applications the coolness conferred by TiO2 colored surfaces leads to 
considerable energy savings in warm and tropical area by light reflectance thus 
reducing the need for air-conditioning.