Cyanogen chloride is a toxic chemical compound with the formula NCCl. This linear, triatomic pseudo-halogen is an easily condensed colorless gas. More commonly encountered in the laboratory is the related compound cyanogen bromide, a room-temperature solid that is widely used in biochemical analysis and preparation. This paper presents a description for Cyanogen chloride formation and creations, its effects on animals and human bodies, and finally methods to control its percentages in drinking water under the acceptable levels. The method of controlling its concentration in water is summarized by using suitable chemical additives and noting the time for settlement and then removed from the samples. A comparison between 4 additives in removing Cyanogen chloride is performed for the same sample of water. It is found that as the concentration of NCCl increases the pOH of the sample increases while pH decreases. Also, for the four additives NH4+, CN-1, Cl2 and SO2 for the water samples, it was found that SO2 is the most efficient chemical additive in removing CNCl since it needs the lowest time of removing CNCl.