Quaternary ammonium compounds membrane-active agents

Biocides probably have multiple target sites on viral particles and the overall damage caused results in loss of viral infectivity (Table 5.1). When compared to bacterial cells, however, viruses present only a few structural targets to biocides the envelope (when present), the glycoproteins, the capsid and the nucleic acid. The activity of biocides against the viral envelope has not been well documented but it can be expected that membrane-active agents such as phenolics and the cationic biocides (e.g. chlorhexidine and quaternary ammonium compounds — Q ACs) will act against the viral envelope, which is a typical unit membrane. The capsid is... 

Both spheroplasts and protoplasts are equally sensitive to lysis by membrane-active agents such as quaternary ammonium compounds (QACs), phenols and chlorhexidine. This demonstrates that the difference in sensitivities of whole cells to these agents is not due to a difference in sensitivity of the target cytoplasmic membrane but in the different permeability properties of the overlying wall or envelope structures. 

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