Stannous fluoride is a chemical compound with the molecular formula SnF2. It is a white crystalline powder that is slightly soluble in water and has a wide range of applications, particularly in dental care products. Stannous fluoride is commonly used as an active ingredient in toothpaste and mouthwash to help prevent dental cavities and reduce tooth sensitivity. It works by inhibiting the growth of bacteria that produce acids that erode tooth enamel. Stannous fluoride is also used as a reducing agent in organic synthesis and as a catalyst in various chemical reactions. Stannous fluoride is considered relatively safe for human use when used as directed, although it can cause skin and eye irritation upon contact in its concentrated form.