What are the hazards in a confined space?
All hazards found in a regular workspace can also be found in a confined space. However, they can be even more hazardous in a confined space than in a regular worksite.
Hazards in confined spaces can include:
•Poor air quality: There may be an insufficient amount of oxygen for the worker to breathe. The atmosphere might contain a poisonous substance that could make the worker ill or even cause the worker to lose consciousness. Natural ventilation alone will often not be sufficient to maintain breathable quality air.
•Chemical exposures due to skin contact or ingestion as well as inhalation of ‘bad’ air.
•Fire Hazard: There may be an explosive/flammable atmosphere due to flammable liquids and gases and combustible dusts which if ignited would lead to fire or explosion.
•Process-related hazards such as residual chemicals, release of contents of a supply line.
•Noise.
•Safety hazards such as moving parts of equipment, structural hazards, entanglement, slips, falls.
•Radiation.
•Temperature extremes including atmospheric and surface.
•Shifting or collapse of bulk material.
•Barrier failure resulting in a flood or release of free-flowing solid.
•Uncontrolled energy including electrical shock.
•Visibility.
•Biological hazards.
Many factors need to be evaluated when looking for hazards in a confined space. There is smaller margin for error. An error in identifying or evaluating potential hazards can have more serious consequences. In some cases, the conditions in a confined space are always extremely hazardous. In other cases, conditions are life threatening under an unusual combination of circumstances. This variability and unpredictability is why the hazard assessment is extremely important and must be taken very seriously each and every time one is done.
•Rescue of the victim is more difficult. The interior configuration of the confined space often does not allow easy movement of people or equipment within it.
•Natural ventilation alone will often not be sufficient to maintain breathable quality air. The interior configuration of the confined space does not allow easy movement of air within it.
•Conditions can change very quickly.
The important thing to remember is that each time a worker plans to enter any work space, the worker should determine if that work space is considered a confined space. Be sure the confined space hazard assessment and control program has been followed. Please see the OSH Answers document Confined Space – Program for more information.