You discover a confined space with an oxygen reading of 18.5%, LEL at 5%, and no toxic gases detected. What action should be taken?
Correct Answer
A) Entry prohibited - oxygen deficient
The oxygen level of 18.5% is below the safe minimum of 19.5% required for confined space entry. This atmosphere is oxygen deficient and entry is prohibited until the oxygen level is restored to safe levels.
Why This Is the Correct Answer
OSHA 29 CFR 1926.95 requires a minimum oxygen concentration of 19.5% for safe confined space entry. At 18.5%, the atmosphere is classified as oxygen deficient, creating immediate danger to life and health. Entry is strictly prohibited regardless of other atmospheric conditions until oxygen levels are restored to at least 19.5%. This is a hard safety threshold that cannot be compromised with alternative protective equipment.
Why the Other Options Are Wrong
Option C: Entry with supplied air only
Although supplied air could theoretically protect the worker, OSHA regulations prohibit entry into oxygen-deficient atmospheres regardless of respiratory protection used
Option D: Ventilate and retest before entry
While ventilation might eventually solve the problem, entry is prohibited until testing confirms oxygen levels reach the minimum 19.5% threshold
Memory Technique
Think '19.5 to Stay Alive' - below 19.5% oxygen means no entry allowed
Reference Hint
OSHA 29 CFR 1926.95 - Personal Protective Equipment, Confined Space Entry Standards
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