If an atmospheric reading indicates elevated hazards, what action is required?

• A. Continue entry but with more PPE.
• B. Extend the entry time.
• C. Evacuate and reevaluate before re-entry.
• D. Ignore and monitor.

Answer: (C)

When atmospheric readings show elevated hazards, the priority is to stop entry and remove personnel until the atmosphere can be made safe. PPE and extending the entry time do not eliminate the risk from toxic gases, oxygen deficiency, flammable atmospheres, or heat stress; PPE reduces exposure but cannot guarantee safe conditions if the air itself is unsafe. Evacuating allows you to prevent exposure, verify detector readings, and plan proper mitigation—such as ventilation, purge, or removal of the hazard—before attempting re-entry. After evacuation, re-evaluate with calibrated detectors, confirm oxygen levels are within acceptable range, and check for any changes in the environment. Only when readings confirm a safe, stable atmosphere should a re-entry permit be resumed and work begin again. Ignoring the warning or simply monitoring without action risks serious harm.