The Hazards Associated with The Use of Chlorinate Lime

　　Risks Associated with the Use of Chlorinated Lime

　　For those who may not be aware, chlorinated lime is a chemical substance extensively used in the fields of public health and environmental sanitation. Its uses include the purification of drinking water, swimming pool water, and wastewater; the sanitization of contaminated apparatus and soil; and as a whitening agent in various industries such as textiles, leather, pulp, and paper. In recent times, it has also been employed as a powerful oxidizing agent for neutralizing certain hazardous substances. Chlorinated lime is somewhat analogous to the lime commonly used for stabilization and pH control in drinking water systems across the United States. This substance, synthesized by subjecting chlorine gas to slaked lime [Ca(OH)2], results in a compound with the formula CaOCl2, recognized for its bleaching properties and frequently referred to as bleaching powder. Although it is popularly called chloride of lime, this is a misnomer, as it is actually a crystalline mixture of calcium hypochlorite [Ca(OCl)2], calcium chloride [Ca(Cl)2], and calcium hydroxide [Ca(OH)2:H2O], containing 30-35% active chlorine. It is often confused with calcium hydrochloride, which is marketed under the brand name HTH (high-test hypochlorite).

　　What are the risks associated with chlorinated lime? While it is stable and safer to handle than liquid chlorine, with a lower risk of air pollution, chlorinated lime can react with acids, even the weak carbonic acid in the atmosphere, to liberate chlorine. As a potent oxidizing agent, it can vigorously react with substances such as oil and grease. Its hygroscopic nature and solubility in water make it capable of causing skin burns, necessitating storage away from moisture. Typically, chlorinated lime is prepared in solution with specific concentrations for different applications. Its use in powder form in poorly ventilated areas, where the release of chlorine gas is a risk, is not recommended. A safer option for creating high pH solutions for disinfection is hydrated or slaked lime, as opposed to chlorinated lime. Read Next: Swimming and Chlorine: Protecting Your Skin, Hair, and Health