Chlorine gas leaks are detected with which indicator?

• A. Ammonia solution (white vapor)
• B. Odor detection
• C. Soap bubbles
• D. UV light

Answer: (A)

Chlorine gas leaks are detected by odor because chlorine has a distinct, sharp, bleach-like smell that serves as an immediate warning to people nearby. This sensory cue can prompt quick evacuation and follow-up checks. But odor detection isn’t perfect—some people may not notice the smell, or exposure can dull the sense of it. That’s why facilities also rely on fixed chlorine detectors and alarms for reliable safety.

The other indicators aren’t appropriate for confirming chlorine leaks. Ammonia solution would not indicate a chlorine leak and can react dangerously with chlorine; soap bubbles aren’t a standard method for detecting chlorine gas leaks; and UV light doesn’t reveal chlorine gas in typical conditions.