• The decisions an employer must make regarding confined spaces in the workplace may be helpfully visualized using the flowchart provided in 29 CFR 1910.146, Appendix A.

Before work begins, an employer must identify all confined spaces in the workplace and determine for each space whether it is a permit-required confined space.

If a workplace contains permit spaces, the employer must

• Alert employees to the locations and dangers of these spaces using warning signs or equally effective means,
• Determine who will be authorized to enter and work in permit spaces, and
• Prevent all unauthorized entry into these spaces.

If a host employer will authorize contractors to enter permit spaces, then the host employer and controlling contractor must share specific information before entry begins.

If the employer decides that employees:

• Will not be authorized to enter permit spaces, then the employer must implement the measures necessary to prevent all employee entry into permit spaces.
• Will be authorized to enter permit spaces, then that employer must write and implement a comprehensive program for protecting employees from the hazards of permit spaces and regulating employee entry into these spaces. The employer must still prevent all unauthorized entry into the permit space.

When a permit space is about to be entered:

• If the space meets the conditions for alternate entry procedures, the employer may authorize employees to enter using the alternate entry procedures instead of the procedures laid out in the employer’s permit space program.
• If the space does not meet the conditions for alternate entry procedures, but the employer can verify that the space meets the acceptable entry conditions detailed on the employer’s permit program, then employees may begin entry according to the terms of the permit program.