Confined spaces can be hazardous due to limited entry/exit, potential atmospheric hazards, and other dangers. Safety procedures are essential to protect workers. A confined space is defined as a space that:

• Is large enough for a worker to enter.
• Has limited or restricted means for entry or exit.
• Is not designed for continuous occupancy. [9]

A comprehensive confined space program should include:

• Description of roles and responsibilities
• Identification and assessment of potential hazards
• Atmospheric testing and monitoring procedures
• Hazard elimination or control plans
• Written work procedures
• Training programs
• Entry permit system

[3] A hazard assessment must be performed before workers enter a confined space. This assessment includes testing the atmosphere to determine the presence of toxic gases, flammable or explosive gases, and oxygen levels. [4] [4]

Air quality should be tested throughout the confined space before entry, and continuous monitoring should be considered where atmospheric conditions may change. Testing should verify that oxygen content is within safe limits and that hazardous atmospheres are not present. [6] [6]

Natural ventilation is unreliable; therefore, mechanical ventilation is typically necessary to maintain air quality. A warning system should be in place to notify workers of ventilation equipment failure. [2] [2]

A detailed emergency plan should be part of the confined space hazard assessment and control program. Rescue personnel qualified in confined space rescue procedures should be immediately available. The plan should include procedures for summoning rescue and emergency services and preventing unauthorized personnel from attempting a rescue. [5] [5] [7]

An entry permit system is an administrative tool used to document the completion of a hazard and risk assessment for each confined space entry. The permit should include the scope of work, possible hazards, atmospheric testing details, hazard control measures, communication means, and the emergency plan. [1] [8]

The attendant should:

• Understand the hazards inside the confined space.
• Monitor the confined space and surrounding area.
• Maintain constant two-way communication with workers inside.
• Order immediate evacuation if a hazard is detected.
• Call for emergency assistance immediately if an emergency develops.
• Be immediately available to provide non-entry emergency assistance. [5]