Some consumer advocacy groups and health agencies — particularly, those at the Environmental Working Group — have been pushing federal officers at the Food and Drug Administration (FDA) to reconsider their existing rules on the additive, which is commonly found in processed snacks and sweets.

As early as sixty years ago, zinc sulphide was first thought of as a pigment for coloring India rubber and a patent for the process of its manufacture was issued in England. But it was not until twenty years later that zinc sulphide and its manufacture was seriously considered as a pigment for paint, and in 1874 a patent was issued for a process of manufacturing a white pigment, composed of zinc sulphide and barium sulphate, known as Charlton white, also as Orr's white enamel. This was followed in 1876 by a patent issued to a manufacturer named Griffith and the product, which was similar in character to Charlton white, was known as Griffith's patent zinc white. In 1879 another patent for a more novel process was obtained by Griffith & Cawley, the product made under this process proving the best of the series placed upon the market up to that date. After that time many new processes were patented, all, however, tending to the same object, that of producing a white pigment, composed of zinc sulphide and barium carbonate, the results, however, in many cases ending with failure.

Titanium dioxide is added to some food packaging to preserve the shelf life of a product.

The author thanks Marco Leona, Scientist-in-Charge of the Department of Scientific Research at the Metropolitan Museum of Art for conducting fluorescence spectrometry on Wheel of Fortune and a valuable discussion of the research, as well as Silvia Centeno, Research Scientist at the Metropolitan Museum of Art, who performed Raman analysis on the watercolors and also contributed her insight. The phenomenon of the phosphorescing lithopone was originally discovered during the author's fellowship in the Sherman Fairchild Center for the Conservation of Works on Paper, funded by the Andrew W. Mellon Foundation. The author thanks all her colleagues for their ideas and support during the research of this paper, and special thanks to Rachel Mustalish for her assistance in editing this work.

It is expected that the implementation of rutile titanium dioxide market manufacturers will be stable this week, the new single quotation of the production link will be firm, the supply of low-cost goods will be reduced, and the reference range of the overall market transaction will rise slightly. It is expected that the market transaction reference is 15200-16200 yuan/ton, and the weekly average price may refer to 15600 yuan/ton. In addition, considering the difference of orders received by different manufacturers, some manufacturers may still have 300-500 yuan/ton of negotiation room. On the demand side, most buyers still have inventory to use, so the current new batch transaction intention is not strong; On the supply side, some producers are expected to increase the load next week, so the industry time output may be slightly increased. On the whole, it is expected that the overall trading range will rise slightly next week, but most producers will adjust the real single negotiation range according to their own orders, and the new single stable price of mainstream producers.

Lithopone was discovered in the 1870s by DuPont. It was manufactured by Krebs Pigments and Chemical Company and other companies. The material came in different seals, which varied in the content of zinc sulfide. Gold seal and Bronze seals contain 40-50% zinc sulfide, offering more hiding power and strength. Although its popularity peaked around 1920, approximately 223,352 tons were produced in 1990. It is mainly used in paints, putty, and in plastics.

Risk managers at the European Commission and in EU Member States have been informed of EFSA’s conclusions and will consider appropriate action to take to ensure consumers’ protection.

Porcelain White, 32 per cent sulphide, 68 per cent barium sulphate.

However, it’s also important to note that such adverse effects depend heavily on the form of the titanium dioxide. It can come down to characteristics like “particle shape, purity, surface charge, solubility, agglomeration rate, photo-activation, etc.”

2. What foods contain titanium dioxide?

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.