THE OBSCURE HISTORY OF A UBIQUITOUS PIGMENT: PHOSPHORESCENT LITHOPONE AND ITS APPEARANCE ON DRAWINGS BY JOHN LA FARGE

“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.” 

“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.” 

North America

Uses

Lithopone is manufactured by a process (Fig. 1) in which barium sulfide solution is prepared by reducing barite ore (BaSO ₄) with carbon and leaching the resulting mass.

The US and Canada, however, approve the use of titanium dioxide as a food additive. Canada's recent review of titanium dioxide reconfirmed its safety and pointed out that many of the toxicity studies the EU reviewed were not relevant to the safety of titanium dioxide as a food ingredient, and that the ban is based on an abundance of caution and uncertainty.

Furthermore, lithopone is a versatile pigment that can be easily mixed with other coloring agents to create custom shades and finishes. This flexibility allows leather suppliers to meet the diverse needs of their customers and produce a wide range of leather products in different colors and styles. Whether it's a classic black leather jacket or a trendy pastel-colored purse, lithopone can be tailored to suit any design requirements.

Prof. Matthew Wright, chair of EFSA’s working group on E171, noted: “Although the evidence for general toxic effects was not conclusive, on the basis of the new data and strengthened methods we could not rule out a concern for genotoxicity and consequently we could not establish a safe level for daily intake of the food additive.”

Lithopone B301, Lithopone B311 powder is also widely applied in paints and enamels

Magnesium occurs in seawater and in ores such as dolomite (CaCO ₃ MgCO ₃), magnesite (MgCO ₃), and carnallite (MgCl ₂ KCl 6H ₂O).

Testing samples were made mixing 100 uL of TiO₂NPs suspensions (0.2 mg/mL and 0.02 mg/mL) and vitamins@P25TiO₂NPs (0.2 mg/mL and 0.02 mg/mL) with 100 μL ATCC 29,213 methicillin-sensitive Staphylococcus aureus (MSSA) (10⁷ in PBS, pH 7). Controls were made replacing nanoparticles with the same volume of PBS. The concentrations of nanoparticle suspensions were chosen based on the FDA approved maximal and the minimal amount usually found in sunscreens, which are 20% and 2% (this is equivalent to 0.2 mg/mL and 0.02 mg/mL for nanoparticles suspensions). The cream concentration, on the other hand, was an intermediate value of 10%.