What criteria trigger a transition from Observation/Assessment to Entry?

• A. Hazards must be unstable but mitigated by PPE.
• B. An approved permit is optional if staff is trained.
• C. Stable or manageable hazards, confirmed air readings within PPE capabilities, and an approved permit with adequate staffing.
• D. Entry is allowed whenever there is time pressure.

Answer: (C)

The key idea is that you only move from observing and assessing the space to actually entering it when risk is controlled and formal authorization is in place. That means hazards must be stable or properly manageable, the atmosphere must be measured and confirmed safe for the specific PPE and respiratory protection you’ll use, and there must be an approved entry permit backed by adequate staffing or standby personnel.

If hazards are still volatile or not fully controlled, entry isn’t appropriate because conditions could worsen once someone is inside. If atmospheric readings show oxygen levels or contaminant concentrations outside what the selected PPE and monitoring can handle, entry would be unsafe. And without a formal permit that documents hazards, controls, and required staffing, there’s no validated plan for safe entry and rescue if something goes wrong.

Time pressure shouldn’t drive the decision to enter; safety criteria and formal authorization do.