Which readings are required before entering a confined space?

• A. Oxygen level, Flammability, and Toxic gases
• B. Oxygen level
• C. Flammability
• D. Toxic gases only

Answer: (A)

Before entering a confined space, you must verify the atmosphere by measuring three things: the oxygen content, the presence of flammable gases, and toxic gases. Oxygen level is checked to ensure it’s safe to breathe and not so low that someone could faint or so high that it increases fire risk. Flammability is assessed to confirm there isn’t a combustible mixture that could ignite if an ignition source is present. Toxic gases are screened to protect workers from poisoning by substances like carbon monoxide or hydrogen sulfide. Using a multi‑gas detector that covers these three readings provides a complete picture of the space’s safety. If any reading is outside safe limits, entry should not proceed until conditions are corrected and re-tested.