What is a Permit Required Confined Space vs. a Non-Permit One?
Introduction:
Confined spaces are a part of most of the workplaces, from oil refineries to construction sites, agriculture, and even chemical plants. These normal-looking spaces harbor hidden dangers that kill around 100 workers in the U.S. every year. Among these fatalities, around 60% occur due to toxic gas leaks and oxygen deficiency. Confined spaces contain deadly and multiple hazards such as low oxygen levels, poor air quality, flammable atmospheres that cause fire and explosions, and other toxic gases. Confined spaces also contain various physical hazards, including falls, engulfment, and entrapment. But not all confined spaces are the same and they differ due to the hazards present in them. Confined spaces are of two different types: permit-required confined spaces and non-permit-required confined spaces. In this blog post, we will explain critical differences between these two, the training required for both types, and why workers should know these differences to protect themselves effectively.
What is a Confined Space?
The confined space is a small, enclosed area with unique challenges and hazards. Those who work regularly inside confined spaces need to know confined spaces' characteristics, effective hazard recognition and hazard control. According to OSHA, 3 criteria define a confined space it should be large enough for an employee to enter and do the designated tasks, have limited means of exit and entry, and not be meant for continuous human occupancy. Examples include vessels, silos, tanks, vaults, pits, storage bins, and tunnels. These spaces often restrict airflow, complicate rescue operations, and may contain hazardous atmospheres such as toxic gases or oxygen deficiency.
These risks are addressed by OSHA's regulation 29 CFR 1910.146. It requires employers to implement recognition, evaluation, control measures, training, permit systems, and rescue procedures.
What is a Permit-Required Confined Space (PRCS)
According to OSHA, a Permit-Required Confined Space (PRCS) is a sub-category of confined space that contains serious hazards and entrants need to have a permit for entering these spaces. PRCS have unique risks that are a danger to the lives of workers, especially when right precautions are not taken rigorously.
Primary Characteristics of PRCS:
If a confined space contains one or more of the following hazards, then it is defined as a PRCS:
- Hazardous Atmosphere: A confined space that has toxic gases, flammable vapors, and insufficient oxygen levels (below 19.5% or above 23.5%), needs permit to access, enter & work in it.
- Engulfment: Confined spaces storing liquids, solids, and other types of materials such as dirt and grain can trap and bury the entrant and cause them to suffocate, crush, and drown.
- Entrapment: A confined space having inwardly converging walls or downward sloping floors and other such structures that can entrap workers and cause them to asphyxiate.
- Other Serious Hazards: Permit-Required Confined Spaces (PRCS) not only contain atmospheric hazards but also harbor health and physical hazards. Mechanical hazards within confined spaces include rotating and moving parts of machinery that can entangle or strike workers. Other hazards include electrical risks such as electrocution from energized circuits and exposed wires. health-related hazards within confined spaces include extreme temperatures, and high noise levels.
What are OSHA's Requirements for PRCS?
Before entering into PRCS, employer must evaluate the confined space and assign it as a permit-required or non-permit-required confined space. The determination of the type of confined space is made by the employer who is a competent person himself. A competent person must be trained as a Competent Person for Confined Space Training so that they can recognize hazards within confined spaces and determine its type.
After the designation of space as permit-required, next step is to issue an entry permit before starting work. The entry supervisor prepares and authorizes entry permit. The entry permit must clearly mention location of confined space, entry purpose, authorized duration, and hazards present within confined space, acceptable entry conditions, and protection required, such as PPE, ventilation, and air quality monitoring equipment.
The employees who enter confined spaces should be trained depending on their roles:
- Authorized Entrants: These are workers who enter within confined space and should be trained to recognize the hazards, test and monitor atmosphere, use proper PPE, and stick to emergency exit procedures.
- Attendants: They are stationed outside confined space and should be trained to monitor the atmospheric conditions within and outside confined spaces, pick up signs of distress and emergency, and prevent unauthorized entry.
- Entry Supervisors: These are assigned to keep the overall safety during entry within confined space. The entry supervisors must be trained to verify suitable entry conditions within the confined spaces. They should know all the entry procedures and keep safety equipment accessible for those entering the confined space and ensure the availability of rescue services outside PRCS.
OSHA mandates the ongoing atmospheric monitoring of confined spaces when entering and working. Regardless of the type of confined space, rescue services and equipment must be readily available outside a confined space to tackle emergencies in lower-risk environments as well.
Even in NPRCS, OSHA still mandates employees to be trained to differentiate between the confined spaces. They should know safe entry procedures within confined spaces and response procedures in case of any emergency.
The Common Examples of Permit-Required Confined Spaces:
Below are some examples of permit-required confined spaces:
- Utility tunnels and underground vaults.
- Storage tanks and vessels containing hazardous substances.
- Grain bins and silos.
- Septic tanks and pits with an oxygen-deficient atmosphere and toxic gases within them.
- Vats and boilers in which a toxic and flammable atmosphere might develop.
What is a Non-Permit Required Confined Space?
Definition and Characteristics of Non-PRCS
A Non-PRCS is a confined space that is large enough so that workers can enter and perform their duties but has no hazardous atmosphere and any other serious safety concerns in it that can cause harm to employees or lead to fatality. Non-permit confined spaces have fewer risks for the workers as compared to permit-required confined spaces. But still, it has challenges such as a limited work area and cramped space that need vigilance during work and entry.
Why non-PRCS don’t Require a Permit?
Non-permit required confined spaces do not have any hazards present and are safe to work in, therefore, they do not require permits. If a permit-required confined space rectifies all hazards within it, then it should be reclassified by employers as a non-permit-required confined space. All the steps taken to make a space non-PRCS must be documented in detail, such as energy source isolation, removal of hazardous materials, and others. Regardless of the absence of hazards, inside non-PRCS, one must take cautionary steps and follow safety protocols to eliminate unforeseen risks.
What are Examples of Non-Permit-Required Required Confined Spaces?
- Common examples of NPRCS are Tunnels and utility vaults, except for the hazardous atmospheres.
- Cleaned and ventilated tanks and storage bins with a lack of hazardous materials.
- Crawl spaces under buildings with good air quality and absence of hazards.
- Pits and elevator shafts with the absence of toxic gases and risks of engulfment.
- Maintenance pits and ducts with controlled or absent hazards.
How to Differentiate between PRCS and Non-PRCS?
The main differences between PRCS and Non-PRCS are due to presence and absence of hazards inside the space. The given below table breaks down the differences between two spaces.
| Feature / Criteria | Permit-Required Confined Space (PRCS) | Non-Permit Confined Space (NPRCS) |
|---|---|---|
| Authorization | Only authorized entrants may enter; requires supervisor oversight. | Anyone trained in awareness-level confined space procedures may enter. |
| Training Required | Full PRCS training for workers and supervisors; includes hazard recognition, emergency procedures, and PPE use. | Confined Space Awareness Training; basic understanding of confined spaces, entry hazards, and general safety. |
| Atmospheric Testing | Always required before and during entry; continuous monitoring if conditions may change. | Not routinely required; only if hazards are suspected or introduced. |
| Entry Permit | Required for each entry; documents hazards, controls, and personnel. | Not required; entry may be made without a permit. |
| PPE Requirements | Specific PPE based on hazard assessment is required: respirators, gloves, protective suits, harnesses, lifelines, etc. | Minimal PPE based on general safety is required; usually hard hats, gloves, eye protection. |
| Attendant Required | Yes. Attendants should be stationed outside to monitor entrants and summon rescue if needed. | Not required but recommended for awareness in some workplaces. |
| Emergency / Rescue Plan | Mandatory. Trained personnel and rescue equipment should be on standby. | Not mandatory. Follow standard workplace emergency procedures. |
| Hazard Assessment | In-Depth Hazard Assessment is required for every entry. | Only Basic Hazard Assessment is required. |
| Lockout / Tagout / Energy Control | Required if mechanical or electrical hazards exist. | Only if hazards are introduced; generally minimal. |
Why Employees and Employers Must Understand Permit vs. Non-Permit Confined Spaces?
Those who work inside confined spaces must know differences between these two spaces in order to carry out the necessary steps such as suitable training, atmospheric monitoring, entry procedures, and emergency readiness.
Misclassification of a permit-required space as non-permit-required confined space can lead to entry without required safety protocols, and devastating results, including suffocation, poisoning, and fatal accidents. In contrast, incorrectly classifying the NPRCS as a PRCS can lead employees to take unnecessary precautionary measures and cause further operational burdens for the workers.
By understanding and identifying a confined space correctly, employers and safety managers can execute correct control measures to tackle the particular risks and stay compliant with OSHA's standards, and most importantly, keep workers safe and alive.
The Bottom Line:
Any working professional dealing with confined spaces should know the differences between PRCS and NPRCS. Misunderstanding and misclassifying a confined space can lead to severe and even fatal results. Regardless of the type of confined space you work in, you need to have the basic training, i.e, OSHA Confined Spaces Awareness Training. Those who work within the PRCS then need the OSHA Permit-Required Confined Space Entry Training as well, along with the basic Confined Space Awareness training. So why wait? Explore and enroll in our courses today and get certified. Because staying informed and prepared is a necessity.
