Class II preservatives like KMS and benzoic acid are added to

Class II preservatives like KMS and benzoic acid are added to inhibit microbial growth.
Class II preservatives are obtained by chemical derivation of compounds.
KMS is Potassium Metabisulphite. It is a white crystalline powder with a pungent odour. It is mainly used as an antioxidant or chemical sterilant.
Benzoic acid (BA) is a commonly used antimicrobial preservative in food and beverages, especially in carbonated beverages, as it presents its strongest antibacterial activity at pH 2.5 - 4.0. BA has inhibitory effects on the proliferation of bacteria and yeasts, a major cause of food spoilage.