How can a chlorine leak typically be detected?

Detecting a chlorine leak is typically accomplished by its strong, distinct smell. Chlorine has a sharp, pungent odor that is easily recognizable and acts as a warning signal for its presence in the air. This characteristic makes olfactory detection one of the most immediate and effective methods for identifying leaks, especially in an industrial setting where chlorine is used for water treatment.

Other methods may involve instruments or monitors designed to measure chlorine levels, but the sense of smell can often alert workers to a problem quickly. The other options provided do not serve as reliable or safe methods for detecting a chlorine leak. For instance, using a lighted candle could pose severe safety hazards, as chlorine is a toxic gas that can react dangerously. Similarly, both a dry rag and an oil-soaked rag would not effectively indicate a chlorine leak. Thus, the presence of its characteristic odor remains the simplest and most direct way to identify a chlorine leak.