chat icon


Permit-Required Confined Space

Permit-Required Confined Space

Permit-required confined spaces (PRCSs) are everywhere. They are found in virtually every industry. Generally speaking, confined spaces can range from anything between grain silos to sewers. However, being able to accurately define a permit-required confined space goes far beyond its denotation; meaning you can’t truly understand what a confined space is without looking carefully at what’s potentially inside. Whether or not a confined space requires a permit relies on careful evaluation of what that space contains.

What is a Permit-Required Confined Space?

A permit-required confined space is a confined space which meets additional criteria that result in a permit requirement. OSHA defines the space as a confined space that meets one or more of the following characteristics.

 A Permit-Required Confined Space:

  • Contains or has the potential to contain a hazardous atmosphere.
  • Contains a material that has the potential for engulfing an entrant.
  • Has an internal configuration where an entrant could be trapped or asphyxiated.
  • Has inwardly converging walls or a floor that slopes downward and tapers to a smaller cross-section.
  • Contains any other recognized serious safety or health hazard. 

A hazardous atmosphere is one that can be especially dangerous. These atmospheres often contain hazardous gases that are undetectable by sight or smell and require the use of special equipment to measure.

Before entering a confined space, trained employees should test to determine the conditions within the space. Before you can work in a confined space, your employer must organize a team that consists of an entrant, attendant, and entry supervisor. Additionally, you must test the entire space must before allowing any employees to enter or perform work. Upon entry, you must adjust all necessary personal protective equipment, such as respirators.

Once trained and authorized employees have entered the permitted confined space with the aid of the entry team members, additional testing should be conducted regularly to verify conditions within the space. Employees must test regularly because conditions within a confined space can change suddenly. Additionally, a rescue team must be assembled and on standby should any accidents take place that require a rescue.

There are many factors that come into play when dealing with permit-required confined spaces. Check out our confined space training at for more information.

Supervisors and Permits


The manager, crew chief, or even the employer, can be the entry supervisor. An entry supervisor identifies confined spaces, authorizes the entrant, and oversees entry operations. They also cancel confined space permits when the job is over or when new hazards arise. If the entry supervisor has proper training and is equipped, they can also act as an authorized entrant or attendant. 

After the employee finishes a task or when new circumstances arise, the supervisor must repeal entry permissions. If the employer has to repeal the permit due to new circumstances, the reason for the repeal must reflect the new circumstances. They must use these circumstances as a sufficient reason to update the permit space program. 

The entry supervisor needs to determine that an employee has tested the space for hazardous conditions before the employee can enter. They must know about any hazards that may be present in the confined space. The supervisor must also ensure that an employee has applied all safety controls listed on the permit before they sign the permit to allow the operation. 


An entry permit outlines the hazards within a confined space and either authorizes or limits entry accordingly. It is a written or printed document provided by the employer, and it must be signed by the entry supervisor. 

After the entry supervisor signs the permit, the supervisor must post the permit at all entrances to the confined space and make it available to the entrants before entry. The entry permit is only valid as long as the job is taking place. The supervisor must note any new conditions and use any canceled permits when revising the confined space program.

The employer should keep confined space permits on file for at least 12 months after they expire. The law requires that the employer is to retain all expired entry permits for a minimum of one year. Each year, they should review all of their past permits. This helps employers determine whether their employees are taking adequate safety precautions so they can make any necessary changes to the confined space program.

What Is OSHA’s Definition of a Permit-Required Confined Space?

A restricted space is a location that is large and set up so that an employee can enter and carry out an assigned task, and has fewer or more limited entry or exit points. For instance, silos, storage bins, vessels, tanks, vaults, and pits are examples of areas that may have fewer entry points.

The employer must notify employees if a workplace has permit areas. Employees at risk in these areas must know of their presence, whereabouts, and the dangers they present.

Non-Permit Required Confined Space

Equipment closets, crawl spaces, machine cupboards, vented vaults, and drop ceilings are examples of non-permit confined spaces.

Non-permit confined spaces do not contain hazardous atmospheres or have the potential to cause death or serious harm. Non-permit spaces are not as regulated as permit-required confined spaces. Keep in mind that non-permit confined spaces can become permit-required confined spaces if new hazards arise.

Atmospheric conditions inside confined spaces can change without warning. Employees must test non-permit required spaces before, during, and when exiting the space.

Examples of Confined Space Hazards


Due to the lack of natural airflow, the environment in a confined location may be dangerous. As a result, there may be an atmosphere that is oxygen-deficient, explosive, or poisonous. The oxygen concentration of a confined place is insufficient when it falls below 19.5% of the total atmosphere.

Atmospheric testing is a vital part of working in confined spaces. Many of the injuries and deaths that occur in confined spaces are caused either by poisonous gases or by a lack of oxygen. Atmospheric conditions in confined spaces can change without warning, so it’s important that you test the air throughout the entire job. 

Falling Objects and Engulfment 

There are other dangers when working in a confined space besides airflow. These areas may contain physical risks that could cause employees to fall, become buried or crushed, or even drown. You should be aware of your surroundings when working in a confined space, it is possible for objects to fall or for the enclosed space to collapse. 

Any time an entrance or cover is removed, the opening to the space should be guarded by a railing, temporary cover, or other barrier. This will prevent people and objects from falling into the space.

An engulfment hazard is a situation in which an employee becomes buried or engulfed in loose or flowing material such as grain, sand, water, or manure. In confined spaces, engulfment hazards can be much more deadly because entrants usually have limited visibility and less room to move around. 

Slips and Falls

Common fall risks include physical obstructions to employees, slick surfaces, and low visibility in the confined space. These hazards can be a result of leaks, spills, and fumes.

The entrance into a confined space can either be horizontal or vertical. Both types of entrances may require different entry techniques and precautions. For example, an employee entering a high vertical shaft should wear fall protection equipment to avoid slipping and falling.

Requirements for a Confined Space Program

The employer must create a written permit space program and make it available to employees who are to enter permit places. The employer applies alternative methods for employee access into a permit space under specific criteria.

Before entering confined spaces, you must complete an annual training:

  • Every member of the rescue squad needs to practice removing real people or life-size mannequins. 
  • Each team member needs to have first aid training. 
  • Your team must have one member who has CPR and first aid certification.

Confined space programs detail the employer’s plan for regulating how employees work around confined spaces. Programs also protect employees from permit-required confined space hazards. Employers must review the program annually to ensure the protection of employees. 

The permit-required confined space program must have specific requirements for employers and employees. It must detail how the employer will ensure that all hazards within a space are properly identified. It must also enforce proper ventilation and regular monitoring of oxygen, flammability, toxicity, and explosion hazards. 

What Does the Permit-Required Confined Space Standard Require Employers To Do?

The Permit-Required Confined Spaces standard requires the employer to inspect the workplace to determine which areas require a permit. If at all possible, always allow the constricted space more than one way to enter. Keep the entry locations accessible so that participants can enter and exit securely.

Once an employer has identified a confined space on the worksite, they must have the space tested to determine whether employees will need to obtain an official permit before entering.

A safe, successful confined space entry relies on the coordinated efforts of multiple people. Employers must reevaluate employees after making any major updates to the confined space program. Reevaluation is also required whenever workplace conditions change and increase the physical strain on employees using respirators.

Unauthorized Entry 

The employer must take precautions to prevent unapproved entrance to restricted areas. Employers must take reasonable steps to prevent employees from entering and working in permit places. The employer must create a written permit space program and make it available to employees or their representatives if employees are to enter permit places.

Attendant Procedures

An attendant is an employee who stays outside the restricted area to keep an eye on the entrants. They prevent unlawful access, alert entrants to any dangerous conditions, and call for help if necessary.

When unauthorized individuals approach or enter a permit space while entry is taking place, procedures follow these steps:

  • They must inform unauthorized visitors that they must avoid the permit area. 
  • In the event that unauthorized individuals enter the permitted space, attendants must tell them to leave immediately.
  •  The attendant must also notify authorized entrants and the entry supervisor.