After oral ingestion, the absorption of titanium dioxide particles is low, however they can accumulate in the body, Maged Younes, chair of the European Food Safety Authority's expert Panel on Food Additives and Flavourings, said in a May 2021 statement.

In 2017, French researchers from the Institut National de la Recherche Agronomique (INRAE) were among the first to examine the effects of E171 nanoparticles on the body. They fed rats a dose of 10mg of E171 per kilogram of body weight per day, which was similar to human exposure in food. The research, which was published in Scientific Reports, showed that E171 was able to traverse the intestinal barrier, pass into the bloodstream, and reach other areas of the body in rats. Researchers also found a link between immune system disorders and the absorption of titanium dioxide nanoparticles. 

Thermogravimetric analysis (TGA) was conducted in a sample of vitaminB2@P25TiO₂NPs using a TA-THA Q5000 equipment. Temperature ramp rate: 10 °C/min, maximum temperature: 1000 °C, under air. Part of the same sample was mounted on conductive copper tape grids and observed through a Carl Zeiss Sigma scanning electron microscope (SEM) with an EDS probe, at the “Laboratorio de Microscopía y Análisis por Rayos X” (LAMARX) of National University of Córdoba (Argentina).

Ultimately, most experts advise moderation, as titanium dioxide is typically found in processed foods that come with their own health risks.

“Unlike some other chemicals used in food, titanium dioxide has no nutritive, preservative, or food safety function—its use is purely cosmetic,” said CSPI principal scientist for additives and supplements, Thomas Galligan. “The prospect of titanium dioxide nanoparticles damaging DNA is concerning enough for us to recommend consumers avoid foods that have it.” 

Pendant longtemps on a reproché au lithopone sa mauvaise tenue à l'extérieur, due à la dégradation photolytique du sulfure de zinc et/ou à la présence de traces de chlore, provoquant un noircissement du revêtement. Même si la recherche a permis d'éradiquer en grande partie ce problème, on réserve son emploi dans les peintures intérieures pour les raisons suivantes :

Pigment grade titanium dioxide is produced at a much larger particle size than nano grade. It is used as a colourant to whiten and brighten product formulations. Nano grade titanium dioxide is manufactured into very fine (nano) particles and is transparent and colourless. It is commonly used in sunscreens to provide effective protection from potentially harmful UV rays.

Stability and darkening:

There are numerous manufacturers of titanium dioxide; the largest include Delaware-based Chemours (a spin-off of DuPont Chemical), Texas-based Kronos, and China-based Lomon Billions Group, all of which manufacture pigments for use in products like paints, coatings, and plastics. UK-based Venator is a major supplier of titanium dioxide used in food and cosmetics, along with paints, paper, plastic, and more. As a pigment, it is called Pigment White 6 (PW6), titanium white, or CI 77891. As a food additive, it is known as E171.

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.

Lithopone: an alternative to titanium dioxide

Lithopone B311 Datasheet

Stability and darkening[edit]

It is suitable as an alternative to titanium dioxide when higher acid resistance is required, such as in adhesive joints and sealants.