The Occupational Safety and Health Administration (OSHA) has specific requirements for confined space entry to ensure worker safety. These requirements are outlined in the OSHA standard 29 CFR 1910.146, which applies to permit-required confined spaces in general industry. Key requirements include:

1. Identification and Evaluation: Employers must identify and evaluate all confined spaces to determine if they are permit-required confined spaces.

2. Permit System: A written permit system must be implemented for entry into permit-required confined spaces. This includes specifying the measures taken to isolate the space, control hazards, and protect entrants.

3. Training: Employees must be trained to understand the hazards of confined spaces and the procedures for safe entry and exit. This training should be provided to all employees who may enter confined spaces, as well as those who may assist in rescue operations.

4. Atmospheric Testing: Before entry, the atmosphere within the confined space must be tested for oxygen content, flammable gases and vapors, and potential toxic air contaminants.

5. Monitoring: Continuous monitoring of the atmosphere is required if there is a potential for atmospheric hazards to develop during entry.

6. Rescue and Emergency Services: Employers must have a plan for rescue and emergency services, which may include on-site rescue teams or arrangements with local emergency services.

7. Communication: Effective communication must be maintained between the entrants and the attendant outside the confined space.

8. Signage and Barricades: Confined spaces should be clearly marked with signs and barricades to prevent unauthorized entry.

These requirements are designed to protect workers from the hazards associated with confined spaces, such as toxic atmospheres, engulfment, and entrapment. Employers should ensure compliance with these standards and regularly review their confined space entry procedures to maintain safety.