What is the correct sequence for atmospheric testing?

The correct sequence for atmospheric testing begins with measuring oxygen levels, followed by flammable gases, and finally toxic gases. Starting with oxygen is crucial because ensuring sufficient oxygen concentration is essential for the safety of personnel. If the oxygen level is too low, it poses an immediate and severe risk to life, making it the top priority in any atmospheric testing scenario.

After confirming that the oxygen level is adequate, the next step is to test for flammable gases. This is important for assessing the potential for fire or explosion hazards in the environment. Understanding the presence and concentration of flammable gases helps in evaluating the risks and taking necessary precautions.

Finally, testing for toxic gases is completed. Although toxic gases can pose significant health risks, addressing oxygen levels and flammable gases first helps to create a safer environment for responders before testing for further hazards. By following this sequence, responders can effectively prioritize their efforts to ensure safety during operations in hazardous environments.