Before entering a permitted confined space, what must be tested?

• A. The temperature of the space
• B. Oxygen content and flammable gases
• C. The humidity level
• D. The structural integrity of the space

Answer: (B)

Before entering a permitted confined space, it is crucial to test the oxygen content and the presence of flammable gases. This is because confined spaces can pose serious hazards, including the risk of asphyxiation due to low oxygen levels or potential explosions from flammable gases.

Testing the oxygen content is essential to ensure there is sufficient oxygen (typically 19.5% to 23.5%) for safe breathing. Lower levels can be life-threatening, while levels above 23.5% can increase the risk of fire or explosion. Additionally, measuring flammable gases is vital, as the presence of these gases can indicate a hazardous environment that could lead to combustion if ignition sources are present.

Other assessments, such as checking the temperature, humidity, and structural integrity, while important for overall safety, do not directly address the immediate respiratory hazards associated with entering a confined space. Therefore, testing for oxygen and flammable gases is the primary concern to ensure worker safety in these environments.