What is the best method for detecting chlorine leaks?

The best method for detecting chlorine leaks involves using ammonia. When ammonia is introduced to chlorine gas, it forms a white cloud of ammonium chloride, which is an indication of the presence of chlorine. This is a reliable and immediate visual cue for workers to identify a chlorine leak in the area, allowing for prompt corrective actions to be taken to ensure safety.

Other methods listed may not be as effective; for instance, while litmus paper can change color in the presence of acids or bases, it is not specific to chlorine detection. Orthotoluidine, primarily used in water quality testing for chlorine levels, is not a direct leak detection method. Copperas, or ferrous sulfate, does not serve as an indicator for chlorine and is not an appropriate choice for leak detection. Hence, the use of ammonia provides a direct and observable response to the presence of chlorine gas, making it the best method for detecting chlorine leaks.