Displaying 2 results of Tetrahydrozoline Impurities Tetrahydrozoline is a medication used to reduce redness in the eyes. However, like any other medication, it may contain impurities that could be harmful to health. Tetrahydrozoline impurities include residual solvents, heavy metals, and other organic impurities that may cause adverse reactions in some individuals. Therefore, it is essential to ensure that tetrahydrozoline and its products are free from these impurities before use.