Sulphite is not usually present in surface waters. If sulphite is discharged in effluents or from domestic wastewaters, it readily oxidizes to sulphate. Sodium sulphite, the most common form of sulphite is an excellent reducing agent and is commonly used as an oxygen scavenger to control corrosion. Sulphite concentrations in boiler and process waters must be monitored regularly to protect the systems. Our sulphite test kit works when sulphite in salt form has been added to waters. It is a titration method, easy to use and easy to read.