Lactoperoxidase-catalysed reactions yield short-lived intermediary oxidation products of SCN, providing antibacterial activity.
The major intermediary oxidation product is hypothiocyanite OSCN, which is produced in an amount of about 1 mole per mole of hydrogen peroxide. At the pH optimum of 5.3, the OSCN is in equilibrium with HOSCN. The uncharged HOSCN is considered to be the greater bactericidal of the two forms. At pH 7, it was evaluated that HOSCN represents 2% compare to OSCN 98%.
The action of OSCN against bacteria is reported to be caused by sulfhydryl (SH) oxidation.
The oxidation of -SH groups in the bacterial cytoplasmic membrane results in loss of the ability to transport glucose and also in leaking of potassium ions, amino acids and peptide.
OSCN has also been identified as an antimicrobial agent in milk, saliva, tears, and mucus.
OSCN is considered as a safe product as it is not mutagenic.