What is a critical action during a toxic gas incident?

In the context of a toxic gas incident, assessing the situation by a gas free engineer is a critical action because it allows for a thorough and professional evaluation of the environment and the hazards involved. The gas free engineer possesses specialized knowledge and tools to determine the concentration of toxic gases, identify potential sources of the leak, and understand the specific safety measures needed to mitigate risks. This assessment is essential for ensuring the safety of personnel and determining the appropriate response strategy.

While evacuating the area, notifying emergency services, and sealing the area are indeed important actions that may follow, they are contingent upon the information provided by the gas free engineer's assessment. Without this initial evaluation, any response could potentially lead to increased risk for both responders and bystanders.