The Occupational Safety and Health Administration (OSHA) has specific requirements for confined space entry, particularly for permit-required confined spaces, as outlined in 29 CFR 1910.146. Here are the key requirements:

1. Permit-Required Confined Space Program: Employers must develop and implement a written permit space program that complies with OSHA standards. This program should include measures to prevent unauthorized entry, identify and evaluate hazards, and specify acceptable entry conditions [1].

2. Entry Permit: Before entry is authorized, an entry permit must be prepared, documenting the completion of necessary safety measures. The permit should include details such as the space to be entered, purpose, duration, authorized entrants, hazards, and emergency procedures [2].

3. Atmospheric Testing: The internal atmosphere must be tested for oxygen content, flammable gases and vapors, and potential toxic air contaminants before entry. Continuous monitoring is required to ensure that acceptable entry conditions are maintained [3].

4. Training: Employers must provide training to ensure that employees understand the hazards and procedures associated with confined space entry. This training should be provided before employees are assigned duties, whenever there is a change in operations, or when there are deviations from procedures [4].

5. Duties of Personnel: Specific duties are assigned to authorized entrants, attendants, and entry supervisors to ensure safety. For example, attendants must monitor entrants and summon rescue services if needed, while entry supervisors must verify that all safety measures are in place before allowing entry [5] [6].

6. Rescue and Emergency Services: Employers must have procedures for summoning rescue services and providing necessary emergency services. Rescue teams must be trained and equipped to perform rescues safely [7].

7. Communication and Equipment: Proper communication procedures and equipment, such as personal protective equipment and testing devices, must be provided to ensure safety during entry operations [2].

These requirements are designed to protect employees from the hazards associated with confined space entry and ensure safe operations. Employers must comply with these standards to maintain a safe working environment.