Our Odor Control Tablets help to balance the pH of your machine sump. They are not a perfume. They prevent the foul smells that are given off by bacteria as they decay. Used as directed, they work with all coolants we are aware of currently, and are perfectly safe to you and the environment. If foul smells are a routine concern, make sure your concentrations are correct and consistent, tramp oils are removed, and there is proper aeration to each sump, especially when they are not in use.