What is the primary safety concern when using chlorine gas as opposed to calcium hypochlorite or sodium hypochlorite? The potential for a _____________ leak.

• A. Liquid
• B. Solid
• C. Powder
• D. Gas

Answer: (D)

Chlorine gas presents its biggest safety risk as a gas leak because it is a toxic, inhalation hazard in air. When chlorine is used as a gas, any leak releases it directly into the surrounding space, where it can rapidly reach dangerous concentrations, spread through rooms and ventilation, and cause respiratory harm or even asphyxiation. Chlorine gas is also dense enough to pool in low areas, increasing the risk in basements or enclosed spaces. In contrast, calcium hypochlorite is a solid and sodium hypochlorite is a liquid; spills of those forms don’t create the same immediate airborne hazard. That’s why the primary safety concern is a gas leak.