An emulsifier is an important ingredient for making a stable suspension for liquid-based pestisides. It helps to keep the active ingredients in the mixture evenly dispersed and prevents them from settling. The emulsifier also helps to reduce surface tension to prevent agglomeration of the active ingredients. There are many types of emulsifiers, such as polysorbates, polyglycerols, and lecithins, that can be used depending on the desired properties of the suspension.