OSHA 10-Hour Construction ReviewFocus Four HazardsMedium
A worker is performing maintenance inside a large, enclosed storage tank that previously contained chemicals. Atmospheric testing has been conducted, but the tank's configuration makes natural ventilation poor. Which of the following is an essential control measure to ensure continuous breathable air for the worker inside this confined space?
- AImplementing continuous forced-air ventilation.
- BProviding the worker with a dust mask for protection.
- CRelying on the worker to exit if they feel unwell.
- DEnsuring the worker has a two-way radio for communication.
Show answer & explanationAnswer & explanation
Correct answer: A. Implementing continuous forced-air ventilation.
Confined spaces with poor natural ventilation require continuous forced-air ventilation to ensure a safe, breathable atmosphere and prevent the accumulation of hazardous gases or oxygen deficiency. This is a critical engineering control for maintaining atmospheric safety.
Why the other options are wrong
- B. A dust mask does not protect against atmospheric hazards like oxygen deficiency or toxic gases.
- C. Relying on a worker's subjective feeling is a reactive measure and highly unsafe in a hazardous atmosphere.
- D. Communication is important but does not address the atmospheric hazard itself.
Confined Space Ventilation
Forced-air ventilation is a critical control measure used in confined spaces to maintain a breathable atmosphere, especially where natural ventilation is inadequate or hazardous atmospheres may develop.
- Removes hazardous gases and introduces fresh air.
- Prevents oxygen deficiency or enrichment.
- Must be continuous and directed to the work area.
Memory trick: Test the air, then ventilate with care!