Which of the following is NOT a method of controlling gas layers?

Gas layers can lead to dangerous situations in confined spaces or environments where gas accumulations occur. Therefore, controlling these gas layers is crucial for safety. The correct answer indicates that using gas masks is not a direct control method for gas layers themselves, but rather a protective gear used to safeguard individuals when exposed to harmful gases.

The installation of hurdles is a method typically used to physically manage the flow of gases and prevent them from reaching dangerous concentrations. Regular training sessions equip personnel with the knowledge and skills to identify and respond to gas layer risks effectively, significantly aiding in prevention and control efforts. Deployment of sails can refer to techniques that manipulate airflow and disperse gas layers, enhancing ventilation and reducing gas concentration.

In contrast, while gas masks protect individuals from inhaling harmful gases, they do not control the layers of gas itself; therefore, they serve more as a personal safety device rather than a method for controlling gas concentrations within an environment.