What type of respirator should be used in the event of a chlorine leak from a gas cylinder?

In the event of a chlorine leak from a gas cylinder, the appropriate type of respirator to use is a self-contained breathing apparatus (SCBA). This decision is based on the hazardous nature of chlorine gas, which is highly toxic and can cause severe respiratory damage or other health effects upon exposure.

An SCBA provides a safe supply of breathable air from a tank carried on the user's back, creating a completely sealed environment that protects against inhaling harmful substances present in the air. This is particularly important in situations where the air may be contaminated with chlorine gas at high concentrations. The SCBA also allows for mobility and extended use in environments where there is no safe, breathable atmosphere.

Utilizing a gas mask with a canister may not offer sufficient protection in the case of a chlorine leak since the canister's absorption capacity has limits, and chlorine can overwhelm and become ineffective against the gas in high concentrations. Additionally, filtering facepiece respirators and half mask respirators are not suitable as they do not provide the level of protection needed against toxic gases like chlorine, where a controlled supply of uncontaminated breathing air is crucial.