sodium thiocyanate

**Sodium thiocyanate** is an inorganic compound with the formula NaSCN, appearing as a white crystalline powder or colorless deliquescent salt[5][6]. It is highly soluble in water, ethanol, and acetone[6]. Sodium thiocyanate is used primarily as a chemical reagent, raw material, and auxiliary in chemical synthesis, fiber production, agriculture, photography, textile dyeing, rubber processing, and construction[2][6]. It has significant analytical applications, especially for detecting iron (Fe^3+) ions and in the synthesis of pharmaceuticals, such as agents that inhibit thyroid hormone production[5][8]. In medicine, sodium thiocyanate was historically used orally as an antihypertensive agent in the early and mid-20th century, with modest blood pressure lowering effects documented at therapeutic plasma concentrations (1400–2000 μM), but it has been replaced by more effective and safer antihypertensive drugs[7]. Mechanistically, it acts as an antihypertensive through probable inhibition of thyroid hormone uptake/binding and antagonism at the thyroid peroxidase enzyme, reducing thyroid activity and thereby lowering blood pressure[3][7][8]. Sodium thiocyanate is also a component of the lactoperoxidase system, where it serves as a substrate for peroxidase enzymes, generating hypothiocyanite ions (OSCN-) with potent antimicrobial activity against bacterial membranes and metabolic enzymes[7][9]. The compound is generally recognized as safe (GRAS) by the FDA for specific food processing purposes, particularly as part of the lactoperoxidase system to prolong shelf life by inhibiting microbial growth[9][11]. It is used as a setting accelerator in concrete admixtures, as a corrosion inhibitor in metallurgy, and as a solvent and color developer in polymers and photographic applications[2][6]. Sodium thiocyanate may cause irritation, sensitization, and environmental harm if mishandled[4][14].

Other names

sodium sulphocyanideNaSCN