Antibacterials may be divided into two groups according to their speed of action and residue production: The first group contains those that act rapidly to destroy bacteria, but quickly disappear (by evaporation or breakdown) and leave no active residue behind (referred to as non-residue-producing). Examples of this type are the alcohols, chlorine, peroxides, and aldehydes. The second group consists mostly of newer compounds that leave long-acting residues on the surface to be disinfected and thus have a prolonged action (referred to as residue-producing). Common examples of this group are triclosan, triclocarban, and benzalkonium chloride. See the Table of Antibacterials.