Tin oxide is a water-insoluble, inorganic metal compound that is used in cosmetic products primarily as an opacifier, viscosity regulator and filler. Due to its opacifying properties, it gives formulations a more opaque appearance. It is used in low concentrations in both wash-off and leave-on products(1-2).

Titanium dioxide is a white micropigment used as an opacifier, powder base, UV filter in sunscreens and colorant (C.I. 77891)(1).

Tocopherol (vitamin E) is a powerful antioxidant that reduces oxidative stress caused by UV radiation and other environmental influences. In the skin, it protects cell structures such as lipids, proteins, and DNA from free radicals, thereby helping to prevent light-induced skin aging (photoaging).(1-3)

Tocopheryl acetate is a derivative of vitamin E (α-tocopherol) and is one of the most commonly used antioxidants in cosmetic products. It helps protect the skin from free radicals. Compared to free tocopherol, tocopheryl acetate is significantly more stable against oxygen, light, and heat, making it particularly suitable for light-sensitive formulations such as sunscreens. Studies show that tocopheryl acetate in suitable formulations can alleviate UV-induced skin reactions such as redness and swelling. Due to its good stability, it is used in many skin care products to support the skin barrier and protect against light-induced skin aging. (1-3)

Tremella Fuciformis Sporocarp Extract or Silver Ear, better known as Snow Mushroom (Tremella fuciformis), is a species of mushroom and belongs to the Tremelaceae family. They contain polysaccharides consisting of mannose, xylose and glucuronic acid.(1) These polysaccharides form a film on the surface of the skin, which increases the water-binding capacity and maintains the water content in the skin.1 Tremella Fuciformis Sporocarp Extract also has a strong antioxidant effect and thus protects against free radicals.(2-3)

Tribehenin has a wax-like consistency, which means that it can make cosmetic products creamy to waxy. It is recommended for use in cosmetic products and has been classified as safe in a safety assessment for cosmetic ingredients(1).

Triethyl citrate or citric acid ester is a solvent and diluent and is considered to be non-sensitizing to the skin. It is even approved for use in foodstuffs(1).

The efficacy of a preparation containing triethyl citrate and ethyl linoleate on acne vulgaris was also investigated in a study. Triethyl citrate is hydrolyzed by C. acnes (triggering acne in certain circumstances) to the diethyl ester and monoethyl ester of citric acid and to citric acid itself. As a result, the microenvironment of the pores becomes acidic, which leads to reduced growth of C. acnes, inhibition of bacterial lipases and modulation of the keratolytic effect(2).

Trihydroxystearin is the triester of glycerin and hydroxystearic acid. It is used as a skin conditioning agent, solvent and viscosity regulator in cosmetic formulations in concentrations of up to 5%(1-2).