Displaying 4 results of Tetracaine Impurities Tetracaine is a local anesthetic medication used to numb the skin or mucous membranes. However, it is important to note that tetracaine can contain impurities that may be harmful to human health. These impurities can include residual solvents, heavy metals, and other toxic substances. Therefore, it is critical to ensure that tetracaine products are properly tested and quality controlled to minimize the risk of impurities.