Confined Spaces: Permit Required vs. Non-Permit Required

An employer is required to perform certain tasks to comply with the appropriate standard.

By Alexandra Walsh

Imagine climbing into a small, enclosed space at work, unsure whether the air you’re breathing is toxic or a hidden danger is waiting. Many workers face this reality and knowing the difference between permit-required and non-permit confined spaces can be a matter of life or death.

OSHA’s Confined Space Definition

Under §1910.146(b), OSHA defines a confined space as a space that:

• Is large enough and configured so that an employee can bodily enter and perform assigned work
• Has limited or restricted means of entry or exit and
• Is not designed for continuous employee occupancy.

OSHA further divides its definition of confined spaces into those that require an entry permit and those that don’t.

Confined Space Statistics

Confined spaces pose significant risks, with OSHA reporting that nearly 100 fatalities happen every year in the United States due to confined space incidents. These deaths often result from hazardous atmospheres, including toxic gases or oxygen-deficient environments, accounting for about 60% of such fatalities.

Alarmingly, over half of these fatalities involve rescuers who are untrained or unprepared for the dangers of confined spaces. Industries like well drilling, construction, and utilities are particularly vulnerable because confined spaces such as wells, tanks, and manholes are common. These statistics underscore the critical need for proper training, assessing hazards, and complying with safety regulations to prevent tragic
outcomes.

Permit-Required Confined Space vs. a Non-Permit Space

Essentially, the difference between a permit-required confined space and a non-permit space depends on whether there are hazards inside.

There are a few circumstances that make a confined space one that requires a permit. An entry permit is required when the confined space has one or more of the following characteristics:

• Contains (or has the potential to contain) a hazardous atmosphere
• Contains a material that has the potential for engulfment of an entrant; that is, becoming surrounded, swallowed up, or overwhelmed by a hazardous condition
• Has an internal configuration such that an entrant could be trapped or asphyxiated by inwardly converging walls or by a floor which slopes downward and tapers to a
  smaller cross-section
• Contains any other recognized serious safety or health hazard.

A non-permit confined space is defined as a confined space that does not contain (or, for atmospheric hazards, does not have the potential to contain) any hazard capable of causing death or serious physical harm.

OSHA Confined Space Requirements

There are actually three OSHA confined space standards: General Industry (§1910.146) defined at the beginning of this column; Construction (§1926 Subpart AA); and Shipyard (§1915 Subpart B).

The confined space regulations in each industry are similar, with General Industry establishing the broad requirements and the Construction and Shipyard standards getting specific on unique circumstances encountered in those environments.

When a workplace or worksite contains a confined space, an employer is required to perform certain tasks to comply with the appropriate standard.

It’s worth noting that the confined space standard differentiates between the duties of host employers (who own the building or property), the controlling employer (who arranges for the workers to be brought in), and the entry employer (who comes on-site and performs the work).

Evaluate Confined Space for Hazards

Employers must evaluate any confined space for hazards, including (but not limited to) the atmospheric, engulfment, or configuration hazards specified in the definition.

Atmospheric hazards cover any conditions that expose employees to the risk of death, incapacitation, impairment, injury, or acute illness. These can include:

• Flammable gas, vapor, or mist more than 10% of its lower flammable limit
• Airborne combustible dust at a concentration that meets or exceeds its lower flammable limit
• Oxygen concentration below 19.5% or above 23.5%
• Hazardous substances with an established permissible exposure limit
• Any other atmospheric condition that is immediately dangerous to life or health.

Engulfment hazards are liquids or finely divided “flowable solids” (like grain or dirt) that can cause death or injury by aspiration, strangulation, constriction, or crushing.

If, at some point, the confined space’s use or configuration changes, then the employer is required to reevaluate the space’s hazards and classification.

If the employer finds hazards in the space that merit an entry requirement, then they are required to get a permit before anyone enters that space.

Inform Employees of the Risk

OSHA requires employers to warn potentially exposed employees about the existence and location of the permit-required confined space, as well as the dangers it poses.

This requirement can be met with signs “or by any other equally effective means,” for example, a physical barricade.

Implement Safety Controls

Permit-required confined spaces have hazards that have not been eliminated, but that doesn’t mean employers shouldn’t control those hazards. In fact, it’s required.

The exact requirements depend on the specific hazards, the work being performed, the industry standard being followed, and more. A few examples of possible safety controls include:

• Taking effective measures to prevent entry
• Developing and implementing a written permit space program
• Erecting a temporary barrier when entrance covers are removed to prevent accidental entry or falling objects
• Performing pre-entry atmospheric testing
• Using forced air ventilation to eliminate atmospheric hazards
• Providing PPE, ingress/egress equipment, and other necessary equipment
• Arranging for an outside attendant to monitor and assist the entry worker
  • Developing a rescue plan.

Train Entering Workers

The confined space requirements include worker training as the confined space standard is complicated, and compliance can be a matter of life and death.

Employers must provide training to each affected employee before they begin their duties, any time there’s a change in permit space operations that affects hazard exposure, and whenever they suspect inadequate knowledge on employees’ part.

Although the standard doesn’t establish a required frequency, many employers choose to require regular refresher training to help employees stay knowledgeable about the rules.

Change in Confined Space Classification

A permit-required confined space can be reclassified as a non-permit space if you eliminate the potential hazards. This means you’ve:

• Tested, inspected, and confirmed a lack of actual or potential atmospheric hazards
• Eliminated other potential hazards entering into the space
• Documented the basis for determining a lack of hazards with a signed statement
• Made the statement available to all employees entering the space.

For confined space classification, atmospheric hazards cannot be considered “eliminated” through forced air ventilation.

Once a confined space is reclassified, it can remain non-permit for as long as non-atmospheric hazards remain eliminated.

Reassessment Schedule

Confined spaces should be reassessed:

• Periodically: At regular intervals based on workplace policies and OSHA requirements
• After any changes: When there are modifications to the workspace, processes, or conditions that could introduce new hazards
• Following incidents: If an accident, near-miss, or hazardous event occurs
• Before each entry: For permit-required spaces, atmospheric testing and hazard evaluations should be performed before allowing workers to enter.

A consistent reassessment schedule ensures ongoing compliance and helps maintain worker safety.

Alexandra Walsh is the vice president of Association Vision, a Washington, D.C.–area communications company. She has extensive experience in management positions with a range of organizations.