tin 4 oxide is a white or off-white crystalline solid or powder. It has a melting point of 1127°C and a density of 6.95 g/cm3. tin 4 oxide can be dissolved in concentrated sulfuric acid or hydrochloric acid. It occurs naturally as the mineral cassiterite and is used in ceramic glazes and colors, as a putty, and as a polishing powder for steel and glass.
Tin oxide is a compound of tin and oxygen. Tin is a post-transition metal with variable valences, so it has an oxidation number of 4. Oxygen, which is a nonmetal with an oxidation number of 2, bonds to the tin atoms to form the chemical compound.
Inhalation of tin dust or fume can cause irritation to the respiratory tract. Symptoms include dry cough, sneezing, and itching of the nose or throat. Inhalation of tin oxide can also cause stannosis, a benign form of pneumoconiosis, which is characterized by mild focal emphysema around the alveoli in the lungs. Several studies have shown that exposure to tin oxide may also cause a small increase in the risk of skin cancer.
Tin is an element that has been used since the Bronze Age to make the alloy bronze. It is also found in pewter, tin cans and in bronze cutlery. Tin (IV) oxide is used as an opacifier and as a constituent of coloured pigments in high quality tableware eg bone china and porcelain products, and also for tin cans. The Specific Release Limit for tin in foods is 250mg/kg.