Titanium dioxide (TiO2) is widely used as a pigment in paints, sunscreens, and food coloring. While generally considered safe for these uses, inhalation of titanium dioxide dust in significant quantities can pose health risks, primarily lung inflammation and damage. The International Agency for Research on Cancer (IARC) has classified titanium dioxide as a possible human carcinogen (Group 2B) when inhaled in powder form. However, this classification is based on animal studies, and there is limited evidence of its carcinogenic effects in humans through inhalation. In consumer products, the particles are typically bound within matrices or in forms not easily inhaled, reducing the potential for harm. Regulatory bodies like the U.S. Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA) have deemed titanium dioxide safe for use in foods and cosmetics, subject to concentration limits. Nonetheless, given its potential risks, occupational exposure during manufacturing processes is subject to regulation and control measures to minimize inhalation.

Titanium is not made, but rather, extracted and refined from minerals found in the Earth's crust. Its primary source is the mineral ilmenite (FeTiO3), along with rutile (TiO2) and a few others. Titanium is obtained through a series of complex processes. The Kroll process is the most common method, which involves creating titanium tetrachloride (TiCl4) by chlorinating titanium oxide ore with carbon and chlorine. Then, the TiCl4 is reduced by magnesium in a high-temperature, inert atmosphere, producing metallic titanium and magnesium chloride. This metallic titanium is then melted and cast into ingots, bars, and other forms for various uses. Its unique characteristics such as high strength, light weight, and corrosion resistance make it invaluable in aerospace, biomedical devices, and many other applications.

Tensides, commonly known as surfactants, are compounds that reduce surface tension between two liquids, a gas and a liquid, or a liquid and a solid. They play a crucial role in various industries, including detergents, cosmetics, pharmaceuticals, and food processing. Surfactants can act as detergents, wetting agents, emulsifiers, foaming agents, and dispersants, owing to their ability to interact with both hydrophobic (water-repelling) and hydrophilic (water-attracting) substances. Their dual nature allows them to remove dirt and oil, stabilize mixtures like emulsions, and enhance the texture and spreadability of products. When selecting a tenside for a particular application, considerations include biodegradability, toxicity, and the intended use, ensuring environmental and health safety standards are met. Continuous research in green chemistry seeks to develop eco-friendly surfactants that maintain effectiveness while minimizing negative impacts.