OSHA's requirements for confined space entry are detailed in the standard 29 CFR 1910.146, which outlines the necessary practices and procedures to protect employees from the hazards associated with entering permit-required confined spaces. Key requirements include:

1. Permit-Required Confined Space Program: Employers must develop and implement a written program for permit-required confined spaces, which includes measures to prevent unauthorized entry, identify and evaluate hazards, and establish safe entry procedures [1].

2. Entry Permit System: Before entering a confined space, a valid entry permit must be issued. This permit should list the names of authorized entrants, the purpose of entry, the hazards involved, and the measures taken to ensure safety [2].

3. Hazard Assessment and Monitoring: Employers must evaluate the workplace to determine if any spaces are permit-required confined spaces and inform employees of the hazards. Continuous monitoring of the atmosphere within the space is required to ensure safety [3].

4. Training: Employees must be trained to understand the hazards of confined spaces and the procedures for safe entry and work. This includes training on the use of personal protective equipment and emergency procedures [2].

5. Rescue and Emergency Services: Employers must provide rescue and emergency services, including the necessary equipment and trained personnel, to ensure a prompt and safe rescue if needed [2].

6. Communication and Coordination: Effective communication systems must be established to maintain contact between entrants and attendants. Coordination is also required when contractors are involved in confined space operations [4].

These requirements are designed to ensure that confined space entry is conducted safely, minimizing the risk of accidents and ensuring that employees are protected from potential hazards.