THIMEROSAL is an antiseptic as well as antifungal agent. It is used in pharmaceutical preparations especially in injectables of multidose type. It acts as a preservative in vaccines and prevents adverse effects. Moreover, it has no impact on vaccineís potency. For example, Diphtheria and tetanus (DT), tetanus and diphtheria (TD), Tetanus toxoid (TT) vaccines contain thiomersal. It is also used in veterinary medicine where it topically acts as antibacterial and antifungal agent.