Titanium dioxide (TiO₂) is a multifunctional semiconductor that exists in three crystalline forms: anatase, rutile, and brookite. Owing to an appropriate combination of physical and chemical properties, environmental compatibility, and low production cost, polycrystalline TiO₂ has found a large variety of applications and is considered to be a promising material for future technologies. One of the most distinctive physical properties of this material is its high photocatalytic activity (Nam et al., 2019); however, more recently it has attracted growing interest because of its resistive switching abilities (Yang et al., 2008).

Resumo–Este artigo discute a descoberta de litopônio fosforescente em desenhos de aquarela do artista americano John La Farge datados de entre 1890 e 1905 e a história do litopônio na indústria de pigmento no final do século XIX e início do século XX. Apesar de ter muitas qualidades desejáveis para o uso em aquarela branca ou tintas a óleo, o desenvolvimento do litopônio como um pigmento de artistas foi prejudicado por sua tendência a se escurecer na luz solar. Sua disponibilidade para e uso por parte de artistas ainda não está clara, uma vez que os catálogos comerciais dos vendedores de tintas geralmente não eram explícitos na descrição de pigmentos brancos como algo que contém litopônio. Além disso, o litopônio pode ser confundido com o branco de chumbo durante o exame visual e sua fosforescência de curta duração pode ser facilmente perdida pelo observador desinformado. O litopônio fosforescente foi documentado em apenas um outro trabalho até hoje: uma aquarela de Van Gogh. Além da história da manufatura do litopônio, o artigo detalha o mecanismo para a sua fosforescência e sua identificação auxiliada pela espectroscopia de Raman e espectrofluorimetria.

The updated evaluation revises the outcome of EFSA’s previous assessment published in 2016, which highlighted the need for more research to fill data gaps.  

In terms of sustainability, the use of rutile titanium dioxide in coatings aligns with the global push towards eco-friendliness. The product is non-toxic and, when combined with solvent-free formulations, can contribute to reduced volatile organic compound (VOC) emissions, making it a safer option for both the environment and those applying the coatings.

Titanium Dioxide: E171 no longer considered safe when used as a food additive by European Food Safety Authority, May 6, 2021

Rebecca Capua

The safety of the food additive E 171 was re-evaluated by the EFSA ANS Panel in 2016 in the frame of Regulation (EU) No 257/2010, as part of the re-evaluation programme for food additives authorised in the EU before 20 January 2009.  

Titanium dioxide as used in sunscreens is commonly modified with other ingredients to ensure efficacy and stability. Examples of what are known as surface modifier ingredients used for titanium dioxide include stearic acid, isostearic acid, polyhydroxystearic acid, and dimethicone/methicone copolymer.

≤0.3

This cytotoxic effect was also reported before; i.e. Natarajan et al. conducted an experiment that found a strong oxidative stress, morphological changes in mitochondria and substantial loss in the fusion of primary hepatocytes exposed to P25TiO₂NPs [52].

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.