27 Apr The True Danger Of Confined Spaces
The True Danger of Confined Spaces
The danger of confined spaces should never be underestimated. Confined spaces can contain hazardous atmospheres, engulfment hazards, electrical hazards, fire and explosion hazards, and other conditions capable of causing serious injury or death with little or no warning.
Many confined-space hazards cannot be detected by sight or smell. A space that appears safe may contain an oxygen-deficient or toxic atmosphere or may become hazardous after work begins.
Guide for Discussion
Why Confined Spaces Are Dangerous
Confined-space incidents have resulted from hazards including:
- Oxygen-deficient or oxygen-enriched atmospheres.
- Toxic gases, vapors, fumes, or other airborne contaminants.
- Flammable or explosive atmospheres.
- Fires and explosions, including those occurring near the point of entry.
- Electrical shock.
- Engulfment or entrapment in unstable materials.
- Falling objects.
- Mechanical or process hazards.
- Configuration hazards that can trap or asphyxiate an entrant.
These hazards may exist before entry or may be introduced or intensified by welding, cutting, painting, cleaning, chemical use, or other work performed inside the space.
Know Before You Enter
Never enter a confined space until it has been evaluated and you are authorized to enter.
Before entry:
- Determine whether the space is a confined space and whether it is a permit-required confined space.
- Identify actual and potential hazards associated with the space.
- Follow the applicable confined-space entry procedure and permit.
- Isolate the space from hazardous energy, materials, and processes as required.
- Test the atmosphere with properly calibrated direct-reading instruments.
- Provide ventilation or other controls when necessary.
- Ensure required PPE and entry equipment are available.
- Establish communication between entrants and the attendant.
- Confirm that appropriate rescue procedures and resources are in place before entry begins.
Atmospheric Testing
Atmospheric testing is critical because dangerous conditions may be invisible and odorless.
Before entry, test the atmosphere in the following order:
- Oxygen content.
- Flammable gases and vapors.
- Potential toxic air contaminants.
An atmosphere containing less than 19.5% oxygen is oxygen-deficient, while an atmosphere containing more than 23.5% oxygen is oxygen-enriched.
Testing and monitoring must continue as necessary to ensure acceptable entry conditions are maintained throughout the work.
Permits and Entry Procedures
When a permit-required confined space is involved, the entry permit must identify the hazards, acceptable entry conditions, required controls, atmospheric testing results, entrants, attendants, entry supervisor, communication procedures, PPE, rescue provisions, and other information required for safe entry.
Never ignore, bypass, or modify permit requirements simply to save time.
If conditions change or a prohibited condition develops, entrants must exit the space immediately.
Hot Work Creates Additional Hazards
Welding, cutting, brazing, grinding, and other hot work can introduce additional hazards into a confined space, including:
- Fire and explosion.
- Welding fumes and gases.
- Oxygen depletion or enrichment.
- Heat stress.
- Ignition of previously unidentified combustible materials.
Required hot-work permits, ventilation, atmospheric monitoring, fire-prevention measures, and other controls must be established before the work begins.
Confined Spaces Are Not Just Tanks
Confined spaces may include tanks, vessels, silos, pits, manholes, vaults, sewers, pipelines, and other spaces that meet the definition of a confined space.
Do not assume that a space is safe simply because workers have entered it before. Each space and each entry must be evaluated based on the conditions present at that time.
Never Attempt an Unplanned Rescue
Many confined-space fatalities involve people attempting to rescue an incapacitated worker without proper training or equipment.
- Never enter a confined space to perform a rescue unless trained, equipped, and authorized to do so.
- Use non-entry rescue whenever feasible.
- Entrants must use retrieval equipment when required.
- Rescue services must be identified and capable of responding appropriately to the hazards of the space.
An unprotected rescuer can quickly become another victim.
Remember
The danger of confined spaces often comes from hazards you cannot see, smell, or recognize without proper evaluation and testing. Never enter based on assumptions. Identify the hazards, test the atmosphere, follow the entry permit and procedures, maintain required monitoring and communication, and ensure rescue provisions are ready before anyone enters.