Confined space entry requires adherence to safety procedures, a company's permit-space program, and the use of protective equipment provided by the employer. Regulations governing entry into confined spaces are specified by OSHA in 29 CFR 1910.146. [3]

A confined space is defined as a space large enough for an employee to enter, with restricted entry or exit, and not designed for continuous occupancy. A permit-required confined space has hazards related to atmospheric conditions, engulfment, or other serious recognized hazards. [3]

Key safety procedures include:

• Hazard assessment
• Ventilation
• Entry permits
• Rescue procedures
• Atmospheric testing

A confined space hazard assessment and control program should be written for work in each confined space and include:

• Roles and responsibilities of each person
• How to identify confined spaces
• Identification and assessment of potential hazards
• Atmospheric testing and monitoring procedures
• A plan to eliminate or control all identified hazards
• Written work procedures
• Training program for all workers entering confined spaces
• An entry permit system for each entry into a confined space
• Development of an emergency plan
• An emergency response system
• Reporting and investigating incidents
• Record and documentation control
• Program review

[4] Before entering a permit space, all mechanical equipment must be locked out/tagged out and blocked against motion, and all lines containing hazardous materials should be shut off. [3]

Test the air before entry and periodically while work is in progress. Entry permits must be used for entry into a confined space that presents or has the potential to present hazards related to atmospheric conditions or any recognized serious hazard. [3]

## Hazard Assessments

Identify potential hazards which may include:

• Atmospheric hazards such as lack of oxygen, combustible gases or vapors, combustible dusts and toxic gases/vapors
• Non-atmospheric hazards such as noise, chemical contact, electrical hazards, mechanical exposure, temperature extremes, engulfment and entrapment

[6] Dangerous vapors and gases can accumulate in confined spaces, and fires, explosions, and physical hazards can injure or kill an unprotected worker. [3]

The primary hazard associated with confined spaces is oxygen deficiency, which may be reduced by displacement or consumption. [3]

Fire and explosion are serious dangers because fumes and vapors will ignite more quickly in the trapped air. [3]

Toxic air contaminants can irritate the respiratory or nervous system, cut off the oxygen supply, or get into the lungs and asphyxiate you. [3]

## Ventilation Requirements

Ventilation should maintain an oxygen level between 19.5 percent and 23.5 percent and keep toxic gases and vapors within accepted levels prescribed by OSHA. [1]

Mechanical ventilation systems, where applicable, shall be set at 100% outside air. Where possible, open additional manholes to increase air circulation. Use portable blowers to augment natural circulation if needed. After a suitable ventilating period, repeat the testing. Entry may not begin until the testing has demonstrated that the hazardous atmosphere has been eliminated. [2]

## Emergency rescue plans

At least one person should remain outside to summon help or offer assistance and should maintain constant communication with those inside the space. [1]

If a situation arises that requires emergency entry, the attendant should not enter until additional help arrives. [1]

A rope tied around a worker's waist is not an acceptable rescue method. A full body harness and lifeline is a better approach because it can be attached to a block and tackle which a single rescuer/attendant can operate. [1]

Call the fire department services for rescue. Where immediate hazards to injured personnel are present, workers at the site shall implement emergency procedures to fit the situation. [2]

Before employees enter a permit space, you must develop and implement procedures to remove entrants in the event of an emergency or when they are unable to self-rescue. Where feasible, use non-entry rescue retrieval systems unless it will increase the overall risk to the entrant. [5]