Titanium dioxide nanoparticles have also been found in human placentae and in infant meconium, indicating its ability to be transferred from mother to fetus.
Barium sulphate is typically described as a white, odorless powder. This white coloration is due to its crystalline structure and the arrangement of Ba^2+ and SO₄^2− ions within the compound. The brightness and consistency of this white powder are crucial for its use in various applications. For instance, in the pharmaceutical industry, barium sulphate is used as a radiopaque agent in X-ray imaging of the gastrointestinal tract. In this context, its purity and the absence of color impurities are vital for ensuring accurate imaging results.
In a review published in 2022 in the journal Archives of Toxicology, researchers found that the ingestion of E171 is a “a definite health risk for consumers and their progeny.” After reviewing dozens of in vivo, ex vivo and in vitro studies on the toxicity of E171, the researchers wrote that two facts must be noted: “First, reprotoxicity studies show that animals of both sexes are impacted by the toxicity of these nanoparticles, underlining the importance of conducting in vivo studies using both male and female animals. Second, human exposure begins in utero via maternal-fetal transfer and continues after birth by breastfeeding. Children are then chronically re-exposed due to their food preferences. To be relevant to the human in vivo situation, experimental studies should therefore consider nanoparticle exposure with respect to the age or life period of the studied population.”
Titanium dioxide is typically micronized and coated for use in cosmetics products. The micronizing makes this somewhat heavy-feeling ingredient easier to spread on skin, plus a bit more cosmetically elegant. Micronized titanium dioxide is much more stable and can provide better sun protection than non-micronized titanium dioxide.