Confined space entry programs are an essential part of ensuring the safety of your employees. There are significant hazards and risks in confined spaces ranging from hazardous atmospheres like oxygen deficiency and inert gases to physical hazards like rotating and energized equipment. That’s where the "Hierarchy of Controls" comes into play. This is a systematic approach that is widely used among industry and safety professionals to reduce risks and protect workers. Let’s outline the hierarchy, discuss simple examples of each, and explain why implementing it can improve your company’s confined space entry program.

What is the Hierarchy of Controls? 

The hierarchy of controls was first introduced by the National Safety Council in 1950 and was later adopted by OSHA and NIOSH in the 1970’s and 1980’s. This is a five-tiered, systematic approach to managing hazards in the workplace where prioritization is placed on eliminating and controlling hazards over the use of personal protective equipment. The hierarchy is typically depicted as an upside-down triangle with the following tiers:  

• Elimination – Remove the hazard completely  
• Substitution – Replace the hazard with something less dangerous 
• Engineering Controls – Isolate people from exposure to the hazard 
• Administrative Controls – Change the way people work to reduce exposure 
• Personal Protective Equipment (PPE) – Equip workers with protective equipment

Let’s break down each step in a little more detail and discuss how it relates to your confined space entry program.  

Elimination 

This is the most effective measure in the hierarchy as "eliminating exposure" to the hazard removes the risk entirely. One example that’s beginning to be more common in industry is the use of remote operated drones. The use of these devices eliminates the need to make entry into confined spaces to conduct routine inspections. It may not always be feasible or possible, but when it is, it’s a great strategy to reduce exposure for employees.  

"Elimination is the most effective measure in the hierarchy as eliminating exposure to the hazard removes the risk entirely."

Substitution  

When elimination isn’t an option, the next step is to replace the hazard with something safer. For instance, if a tank cleaning job uses a toxic solvent that has significant negative respiratory health consequences, switching to a non-toxic, biodegradable cleaner lowers the risk. While these cleaners may be less effective, the trade-off is the significant reduction in exposure and risk for workers in the confined space.  

Engineering Controls  

If the hazard can’t be removed or replaced, isolation with engineering controls is the next most effective control measure. Take, for example, sewer systems prone to hazardous atmospheres. By installing ventilation systems to deliver fresh air, toxins in the atmosphere can be diluted to an acceptable level for entry while also minimizing inhalation exposures to employees. While engineering controls can require significant financial investments initially, the benefits far outweigh reliance on PPE, and generally lead to long-term cost savings in the future.  

"While engineering controls can require significant financial investments initially, the benefits far outweigh reliance on PPE, and generally lead to long-term cost savings in the future."

Administrative Controls 

In many cases, despite our efforts of elimination, substitution, and implementation of engineering controls, the residual hazard and risk is still too high to be considered acceptable for safe entry into confined spaces. This is where modifying work practices can further reduce exposure. For example, in hot climates, confined space entries during the peak of summer days increase the chance of heat stress. Rescheduling these tasks for night shifts, when temperatures are more manageable, or shortening shifts from 12 to 8 hours, limits environmental risks. Strategic planning and timing of these tasks can make a significant impact on the safety of your entry.  

Personal Protective Equipment  

And finally, as the last line of defense, PPE can be used to protect workers when all other control measures fall short. Consider our example of using ventilation to dilute toxins. In some situations, ventilation may not be enough to reduce exposure to below the permissible or occupational exposure limits. In these cases, workers will have to rely on respiratory equipment to provide sufficient protection from inhalation hazards. While using personal protective equipment is ubiquitous in industry work, it’s important to realize that this is the least effective measure of protecting workers for several reasons.  

• It relies on the user to wear it and use it correctly - if it's even used in the first place!  

• It only protects the single user wearing it. 

• The hazard is still present. 

Two Important Notes 

Something important to stress with the hierarchy is that while this is laid out in a linear “Elimination, if not, then substitution, if not, then…” progression, in practical application, you will likely be using a combination of multiple control measures in tandem to create a safe entry condition.

Another important note is that while our goal should always be to reduce exposures or risk to ALARA (as low as reasonably achievable) or ALARP (as low as reasonably practicable), the fact is that there will almost always be some level of residual risks that we will not be able to fully eliminate due to factors such as cost, time restraints, physical or technological limitations.   

Applying the Hierarchy to your Confined Space Program  

Now that we have a better understanding of what the hierarchy of controls is and some practical examples of each type of control, let’s look at steps we can take to implement it into your confined space entry program.  

• Start by identifying and evaluating all confined spaces on your worksite and conducing a comprehensive assessment of the existing and potential hazards and risks associated with entry into each space. This includes identifying baseline physical, chemical, atmospheric, and environmental hazards without any existing control measures in place.  

• Next, rank each of the identified spaces from greatest to least risk. There are multiple ways that this can be accomplished, but using a 5 x 5 Risk Matrix and assigning a quantified risk score is a simple and effective method.  
  

• Finally, prioritize the confined spaces with the greatest risk score first, working your way down the list towards those spaces that pose less risk to workers. Systematically apply the hierarchy of controls to each hazard in each space until all risks are at an acceptable level.   

"By systematically evaluating and addressing hazards, you ensure that each confined space entry is conducted as safely as possible."

Incorporating the Hierarchy of Controls into your confined space entry program is a great way to minimize the risks that your employees face. By systematically evaluating and addressing hazards, you ensure that each confined space entry is conducted as safely as possible. While some control measures may come with higher initial costs, the long-term benefits far outweigh these investments, both in terms of effectiveness and cost savings. By applying this approach to your confined space program, you can better manage hazards and create safer working environments for your team. 

Interested in learning more about confined space entry programs and the hierarchy of controls? Check out our Entrant Attendant Supervisor Course.

Here’s a common question that we get here at Roco – Is a trench a confined space?   

The short answer, under normal circumstance, is “no”. In fact, this is one of those instances where OSHA is pretty clear about it. OSHA’s 1926 Subpart AA addresses Confined Spaces in Construction, specifically, 1926.1201 – Scope states “This standard does not apply to construction work regulated by Subpart P (Excavations)." 

Unfortunately, the answer isn’t that cut and dry. So, let’s “dig” into this a little more and “unearth” some of the nuance in this “space." (Completely unapologetic about puns)  

Similarities in Excavations and Confined Spaces 

While excavations are typically not categorized as confined spaces, the numerous similarities between them make this an easy point of confusion. Below are some of the key areas where excavations and confined spaces overlap. 

Both confined spaces and excavations often present restricted entry and exit points. This limitation can make it more difficult for workers to get in and out quickly, which is especially critical in the event of an emergency. Access to confined spaces may be through small openings, while trenches can have steep or unstable walls that limit easy exit. 

Both types of spaces must be large enough for a worker to enter and carry out their job. In the case of excavations, workers often need to physically enter the trench to perform tasks such as installation, repairs, or inspections, just like they would in a confined space. 

Neither excavations nor confined spaces are designed for workers to occupy them continuously. These spaces are temporary work zones, and prolonged exposure can increase the risk of exposure to dangerous conditions such as poor atmospheric conditions.  

In both confined spaces and excavations, atmospheric testing is essential to ensure that conditions are safe for workers. Tests for oxygen levels, toxic gases, or other hazardous substances are common practices in confined spaces, and these same tests can be necessary in excavations under certain circumstances, especially if hazardous atmospheres are reasonably expected to be present. 

"In both confined spaces and excavations, atmospheric testing is essential to ensure that conditions are safe for workers."

Both types of spaces require specific rescue procedures in place to safely extract workers if they become injured or trapped. Rescue plans must be prepared, with the proper equipment and trained personnel ready to respond in case of an emergency. These plans are necessary because both confined spaces and excavations can pose a life-threatening situations if an emergency arises. 

Excavations and confined spaces are both associated with a high risk of fatalities and serious injuries. While the risks may vary depending on the nature of the work and the environment, both contain similar (and different) hazards that are a serious cause for safety and health concerns.

If you noticed, the first 3 similarities outlined in this article are the defining characteristics of a confined space in 1910.146 – Permit Required Confined Spaces. Because of these similarities, many construction companies and facilities opt to treat excavations like confined spaces when it comes to safety measures, sometimes requiring confined space entry permits and specific safety protocols before entering these areas. 

Differences  

Excavations and confined spaces are different in nature. A confined space is a structure that meets three specific criteria: it must be large enough to enter, have limited means of access and egress, and not be designed for continuous occupancy. Examples include tanks, silos, vessels, and many other types of enclosures. In contrast, excavations are man-made cuts, cavities, trenches, or depressions in an earth surface, formed by earth removal and typically don’t meet the definition of a confined space, even though they may present similar risks. 

Regulatory standards also vary between these two types of work. Confined spaces are governed by OSHA’s 1910.146 and 1926 Subpart AA which addresses hazards and entry procedures, while excavations fall under 1926 Subpart P, which addresses safety concerns like cave-ins and structural integrity.  

When an Excavation is a Confined Space 

Although excavations are generally not confined spaces, certain conditions may cause an excavation to be considered a confined space under specific circumstances. For example, if the excavation is deep enough to encase a structure like a large tank or pipe that meets the qualifications of a confined space, then the area within the excavation would need to meet the confined space entry criteria for the structure itself. In such cases, the space within the excavation (the confined space) would be regulated by the standards for confined space entry, even though the excavation itself remains governed by excavation safety standards. This means that workers might still need to follow confined space entry protocols, including testing the air quality and using specialized equipment and procedures for entry and rescue, while also adhering to excavation safety standards to prevent the risk of cave-ins or other earth-related hazards. 

"...if the excavation is deep enough to encase a structure like a large tank or pipe that meets the qualifications of a confined space, then the area within the excavation would need to meet the confined space entry criteria for the structure itself." 

Conclusion 

So, is a trench/excavation a confined space? Usually, not. OSHA clearly states such in the construction confined spaces standard. However, with all the overlap outlined above, it’s no wonder companies get “buried” in the confusion. At the end of the day, the most important thing is to realize that both confined spaces and excavations have many similar hazards and lead to numerous injuries and fatalities in the workplace each year. Regardless of your workplace’s policies and procedures, ensure that measures are in place to protect workers from the hazards inherent to their specific job scope and have a rescue plan in place for the unfortunate event that the unexpected happens.  

Chris McGlynn, M.S., CSP is a Certified Safety Professional and Nationally Registered Paramedic who serves as the Director of Safety and VPP Coordinator for Roco Rescue. He is a Director-at-Large on the VPPPA Region VI Board of Directors and Secretary of the American Society of Safety Professionals Region IV Board of Directors. Chris also represents ASSP on the ANSI Z117 Confined Space and Z390 Hydrogen Sulfide Training Standard Development Committees and is an active OSHA Special Government Employee within the Voluntary Protection Program. He is currently working towards a Ph.D. in Occupational Safety & Health through West Virginia University's Statler College of Engineering.  

When it comes to emergency response, the difference between a successful rescue and a tragedy often comes down to preparation and the resilience of your systems under stress. Whether it’s a confined space incident, a high angle rescue, or a hazardous materials incident having the right strategies in place is critical. Here are five key ways to make your industrial rescue team more effective. 

Have a Plan 

Every worksite has its own unique hazards, and your rescue plan needs to reflect that. Identify potential threats, map out response procedures, and make sure everyone knows their role. Regularly review and update your plan as equipment, personnel, and environments change. If your team isn’t ready before an emergency, they won’t be ready when it happens. The worst time to figure out if your plan will work is during an emergency 

"The worst time to figure out if your plan will work is during an emergency"

Continuous Training 

There’s no substitute for hands-on training. A rescue team that only talks about emergencies won’t perform well when the real thing hits. High pressure situations demand specialized skills—rope access, patient packaging, confined space extraction, hazmat response, and more. Training should be realistic, scenario-driven, and conducted under the same pressures your team will face in an actual rescue. If your training doesn’t push limits, you’re setting up for failure. 

"There’s no substitute for hands-on training"

Full Speed Drills 

A good plan and solid training mean nothing if they’re not reinforced through repetition. Regular drills are critical to sharpening skills and exposing weak points before they become life-threatening failures. Walk-throughs are useful, but full-scale simulations with time pressure, environmental stressors, and live casualties (even if they’re just well-coached role players) will tell you exactly where you stand. If it doesn’t work in a drill, it won’t work in the field. 

Multiple Forms of Communication

Industrial rescues are dynamic, chaotic, and unforgiving. In the heat of an operation, communication can be the difference between success and disaster. Establish clear, consistent communication protocols before an emergency occurs. Practice using radios, hand signals, and direct verbal commands so that when the pressure is on, there’s no hesitation or confusion. If your team can’t communicate effectively under stress, it’s only a matter of time before that failure costs lives. 

"If your team can’t communicate effectively under stress, it’s only a matter of time before that failure costs lives."

Gear 

Your equipment is only as effective as the person using it. Regular maintenance and inspection ensure gear is operational when needed, but familiarity with its use is just as crucial. Every rescuer should know their tools so well that grabbing the right piece of gear becomes instinctive. Whether it’s an air monitor, a rope system, a mechanical advantage setup, or a patient immobilization device, your team must be able to deploy equipment efficiently and troubleshoot it under pressure. In a rescue, every second matters. 

Industrial rescue is about preparation, execution, and constant improvement. The teams that get the job done are They're the ones that plan, know their gear, drill, communicate, and  train relentlessly. If you want to be effective, these are five areas to focus on with your program. At the end of the day, when the call comes in, you won’t have time to get ready. You’ll either be ready, or you won’t. 

Under the Streets of New York: Another Day in the Life of Roco CSRT

• Chief Bob Kauer, Chief Kenny Greene, Chief Bill Stio
• CSRT job with contractor to place crack gauges on the walls of storm drain conduit
• Entry required to be made at low tide due to the outlet of conduit is into the east river
• Workers and rescuer to be lowered approximately 25’ into 3’ deep water
• Entrants required to wear waterproof exposure suits
• Conduit concrete and brick lined approximately 15’ in diameter
• Wade through 3’ deep water along tunnel extending 300’ to place the gauges
• Unique challenge of working in standing water, cold weather, changing tide
• Ongoing project to place additional gauges and periodic monitoring of the gauges

Recently the NY CSRT crew was contracted by ConEdison for a unique project to assist one of its construction contractors. The project is the construction of a new electrical substation for ConEdison along the bank of NY’s East River. During the project NYC DEP was concerned with the integrity of the storm drain conduits and tunnels beneath the streets surrounding the project. This required the inspection of these location and the installation of crack gauges to monitor the interior of the tunnels. The presenting hazard for this entry was the proximity of the river and the tidal rise of the river water to make the entry. Additionally, the time of year was also a factor being winter and the temperature of the air and water in the tunnels. This required an additional piece of equipment that we would not normally use for CSRT. The entrants and rescuer needed to wear ice rescue suits in order to make the entry possible along with the usual safety measures that we would follow.

In the Early morning of January 18th NY’s CSRT Manager Bob Kauer along with CSRT Chief’s Kenny Greene and Bill Stio prepared to make the entry for the inspections and installation of crack gauges. The crew planned for the entry at one hour before low tide on the river. This was necessary due to the fact that the water level in the tunnel was approximately 3’ deep at low tide. The work period was calculated and determined to give us approximately one to one-half hour of entry time before the water level was too deep to safely work. Equipment was assembled and entrants donned their protective suits and prepared for entry. With the manhole cover removed and atmosphere cleared for entry the job began, with a CSRT member lowered in the space before the contractors. Once the water level was confirmed the contractors were lowered the 25’ into the space to start their inspections. They made their way upstream of the entry point conducting a visual inspection while the rescuer maintained visual and audible communication with them. The work continued downstream of the entry point first with visual inspection and then once identified the installation of the crack gauges.

Once the tide passed slack and started to rise the entrants took note that both the water level was quickly rising and the temperature was falling. They were able to complete the inspection and installation of the equipment along with the necessary measurements. The decision was made that the water level was rapidly rising to safely remain inside the tunnel. All entrants made the 300’ trek back to the entry point to be hauled back to the surface by the topside crew. All entrants were removed from the space and entry point closed after an hour and a half assignment.

Things to consider knowing that all confined space entries are not similar nor routine. Some specialized equipment not normally utilized may be necessary for the entry. Such as in this case the necessity of ice rescue exposure suits that offer cold water protection as well as buoyancy. The need to employ floating water rescue rope as safety lines as the usual kernmantle rescue rope will not float on water. This was a successful entry for the assistance and protection of the personnel we work alongside on a day to day basis.

Downtown Albuquerque, New Mexico, is undergoing a facelift. Revitalization of older buildings is seen everywhere. In late 2024, First Responders waded into the middle of this revitalization to intervene in the emotional breakdown of a man. While that itself is not uncommon in Albuquerque or any other large city, the fact that it was 100 feet off the ground on a less-than-stable scaffolding made it a challenging and unique response for Albuquerque Fire Rescue (AFR).

Most first responders are intimately familiar with the law enforcement acronym “EDP.” Whether you live in a small town or a large urban center, EDP or Emotionally Disturbed Persons have become an all-too-common response for many of these agencies. Mental illness, substance abuse and other factors makes for challenging calls for responders as well as for the person struggling with these conditions.

"Whether you live in a small town or a large urban center, EDP or Emotionally Disturbed Persons have become an all-too-common response for many of these agencies."

Albuquerque Fire Rescue (AFR) is a well-trained and progressive fire department. Their Technical Rescue Program has a national reputation of being forward-thinking and very well trained. On this night, their training would prove invaluable in the field.

Near dusk, bystanders reported a man climbing a tall scaffold erected by a construction company to re-stucco a building. Albuquerque Police immediately requested AFR to assist with a Ladder Truck to make access. AFR Ladder 1 and Engine 1 went enroute and immediately requested assistance from the Technical Rescue Team. Squad 2, ALS Rescue 4, Engine 4, Battalion Chief #1 and the on-shift EMS supervisor (Unit 78), responded to assist.

Squad 2 is AFR’s technical rescue rig. This night it was commanded by Captain Dominic Velasquez, who is also a Roco Rescue Chief Instructor. Squad 2 arrived to find Battalion Chief 1 (Emily Kane) and Ladder 1 had already flown their stick and the pipeman (firefighter) who had climbed the ladder had located a man lying unconscious 100 feet up on the scaffold.

Captain Velasquez received direction from Battalion 1 to make access and assess the patient. Velasquez met with the team, informed the two Squad Firefighters that they would be going up and instructed them to grab the gear. The squad driver, the crew from Engine 4, which is led by Lieutenant Kevin Kenney, and two firefighter medics from Rescue 4, remained on the ground and waited for further instructions.

Captain Velasquez and two firefighters ascended to the patient’s location. They found a mid-40’s male, unconscious with an empty bottle of hard liquor lying next to him. They began patient care, and the man woke up – however, he was not happy. The man became combative on the small deck, which was comprised of three 2” x 10” planks with approximately 18” between the scaffold and the building. The danger to both responders and the combative man was heightened considerably.

"Responders repeatedly attempted to verbally deescalate the man but eventually were forced to physically restrain him to protect themselves and to keep the victim from falling."

Responders repeatedly attempted to verbally deescalate the man but eventually were forced to physically restrain him to protect themselves and to keep the victim from falling. The situation was relayed to command, and it was determined that chemical restraint was needed. A technician/Firefighter/Paramedic from Rescue 4 (Lt. Kyle Stevenson) ascended the scaffold with the authorization to administer a sedative. Once the medication was onboard, responders were able to take a deep breath and finalize a plan to lower the man from the scaffolding.

AFR Tech Rescue member and Lieutenant Kevin Kenney (also a Roco Instructor) ran the bottom plan of the rescue, while Captain Velasquez worked the plan up top. A pre-rigged stokes basket was hoisted to the scaffolding deck. Personnel rigged a traditional mainline using a Petzl Maestro and anchored a Petzl ASAP to provide a belay system. There were powerlines obstructing the preferred travel path for a horizontal Stokes basket, so Captain Velasquez made the call to package the patient vertically and performed a low-point vertical lower from the end of the scaffolding.

Rigging two load-sharing anchors to take advantage of the strongest rigging points on the small scaffold deck, the victim was loaded over the edge and carefully transitioned behind the power lines to responders on the ground. The patient was quickly loaded onto a gurney – and in less than 90 minutes after the call was received, the victim was on his way to the hospital.

"Roco congratulates Albuquerque Fire Rescue on a successful rescue response in a very challenging situation."

Roco congratulates Albuquerque Fire Rescue on a successful rescue response in a very challenging situation. We are proud of our partnership with the AFR and commend them for their dedication to maintaining an excellent technical rescue response team. Roco will be presenting the department with the Roco Rescue “Real Rescue” Award in addition to $150 in “Bayou Bucks,” which can be used for Roco training or equipment. Congrats, AFR!