Before entering a space, what must be tested in the internal atmosphere?

The correct answer focuses on the critical safety measures necessary before entering a space with potentially hazardous conditions. Testing the internal atmosphere for oxygen levels and flammable gases is essential to ensure that the environment is safe for personnel to enter.

Oxygen concentrations are vital because an atmosphere that is deficient in oxygen can lead to asphyxiation, while an excess can create conditions for combustion. Additionally, the presence of flammable gases poses a significant risk of fire or explosion. Therefore, ensuring adequate oxygen levels and checking for any combustible substances is a fundamental part of the safety procedures outlined in occupational health and safety regulations.

Testing for temperature levels, sound levels, or work surface integrity can be important in various contexts, but they do not directly address the immediate hazards posed by the atmospheric composition within a confined space. Consequently, checking the atmosphere for oxygen and flammable gases is the primary concern to safeguard the health and safety of individuals who may be entering such environments.