Vent Early, Vent Continuously, and Vent Properly.

During a confined space rescue scenario, performing ventilation can have a huge impact on achieving a positive outcome at the incident. With few exceptions, there is no downside to ventilating in a confined space, but the upsides can be literally life changing.

In the simplest terms, ventilation is the process of circulating air with the goal of removing “bad” air (oxygen-deficient, toxic, explosive, etc.) from a confined space and replacing it with “good” (fresh) air. There are different methods to accomplish this task, but each with the same basic goal. In most cases, ventilation is an attempt only to control or mitigate a hazard rather than eliminate it. If ventilation ceases for any reason, the hazard may rapidly return.

Ventilation serves several important purposes. It improves the environment for the victim by directly removing or diluting the contaminants in the space. By creating a flow of air, ventilation can improve the ambient conditions of the space which can be extremely helpful for a victim’s status. Lastly, and of equal importance, ventilation also improves the operating conditions for the rescuers, which is critical as well.

Vent Early

If a victim is in a bad air environment, the clock is ticking. Of course, the exact contents of the space ultimately determine survivability, but the point is, there is not much time regardless. And getting rescuers into the space and in contact with the victim may easily take 4 to 6 minutes or much longer. Ventilation, on the other hand, can be quickly activated outside of the space and at work removing contaminants almost immediately. It is one of the single best things rescuers can do early in the incident.

The first step in venting early is understanding the space where rescue will be performed. This is where effective preplanning really pays dividends. After understanding the potential hazards, one of the first pieces of information rescuers will need is the dimensions of the space to be ventilated. Since air is measured in cubic feet, multiply the width times the height times the depth of the space (in feet) to arrive at the cubic feet of air volume.

Ventilation is the process of circulating air with the goal of removing “bad” air (oxygen-deficient, toxic, explosive, etc.) from a confined space and replacing it with “good” (fresh) air.

The next piece of critical information is the size of the fans that will be used for ventilation. Fans are measured in—or rated by—the cubic feet per minute (CFM) they will move. Take the total cubic feet of the space and divide it by the fan’s rated CFM, and you can determine how long it will take to exchange the air in the space. The faster the air can be exchanged, then the lower the toxicity levels, the lower the percentage of lower explosive limits (LEL), the higher the oxygen levels, and the more fresh air is circulating around the victim. So, when it comes to fans, bigger—or at least “bigger” CFMs—is definitely better.

Another important part of the preplanning process is to identify the ventilation openings for the intake and its path to discharge. Ideally, both of these points will not be the entrance from which rescuers expect to effect the rescue. But often this is not the case. When assessing these locations, it is important that the intake air be drawn from a non-contaminated source and that the discharge air will not spread contamination to people or equipment. This is also a good time to consider where and how ducting will be executed.

Preplanning should also take into consideration the interior of the space. Is it a wide-open vessel? Or are there obstructions—such as trays or mixing equipment—that can obstruct airflow and create dead air spaces? The configuration of the space can interfere with ventilation and may require extra or larger fans to adequately move air through it.

At the declaration of an emergency, deploying ventilation and performing air monitoring should occur concurrently with size up. Starting ventilation is like applying a cervical collar at the scene of an automobile accident; it is one of those things you know you are going to perform each and every time. And while it is expected that everyone will be appropriately trained, ventilation can be handled by support personnel while the rescue technicians are readying for entry.

This is the time to gather baseline atmospheric data about the space with air monitoring. Because gases can have varying weights (meaning they may float or sink), OSHA requires measuring intervals of every four (4) feet. As highlighted earlier, this underscores the importance of identifying the space’s dimensions and configuration.

It is highly desirable to monitor the space prior to the commencement of ventilation. Knowledge of the baseline monitoring results better arms the rescue team to deal with the space in terms of their own protection, thus possibly affecting equipment choice(s). With continuous monitoring, the value of ventilation can also be unequivocally realized with increasing oxygen levels, decreasing toxicity, and decreasing percentage of LEL. It is this improvement of the space’s atmosphere, with so little comparative effort, where the beauty and value of ventilation lie.

Vent Continuously

Most industrial standard operating guidelines require five (5) complete air exchanges before entering a confined space. But this is under working conditions. During a rescue, there may not be time for that degree of ventilation to take place. This again highlights the vent early aspect of response.

By venting continuously, you are constantly improving the interior conditions. Ventilation operates under the premise of increasing returns—the longer it is performed, the better the conditions inside of the space. And the conditions will continue to improve so long as ventilation is provided. This is why it is vitally important to never interrupt ventilation once it has begun.

If electric ventilation fans are used, try to ensure they are on an uninterruptible power supply if possible. If generators are being used to supply power, ensure there is ample fuel.

In concert with the continuous ventilation, there should be continuous air monitoring. It is important to continue to identify any areas where readings are not improving. If the ventilation has been set up and sized properly, the air monitoring results should reveal a steadily improving atmosphere (as long as hazards are not actively being introduced into the space). In some instances, remedying problem ventilation areas may be something as simple as adjusting the ducting.

Vent Properly

Ventilation supplies the aforementioned stellar results only if it is done properly. And there can be no question that performing ventilation properly is a matter of both science and mathematics. It is a quantifiable problem.

But in the real world with a relentlessly ticking clock, once the basic dimensions are known, there is also a degree of “voodoo magic” that comes into play with being able to read the space and quickly determine the ventilation inlets, outlets, and configurations inside that may impede airflow. That “magic” comes with training and experience. While most rescuers want to spend their training time performing the glamour skills—such as rigging and patient packaging—it is important to remember that in a bad air situation, it will be ventilation that can have the greatest immediate effects.  In training, teams need to quit only verbalizing that ventilation is set up and actually perform this lifesaving skill.

Setting up ventilation is a great task both for new team members or for those in technician training. The rescue leader or ventilation officer of course decides the ventilation plan, but actually setting up the equipment can be delegated to new or support personnel. It is a crucial task that needs to be completed and provides immediate and tangible results while positively affecting the outcome of the incident.

In the rescue world, ventilation is similar to rope—you need the right size and the right amount.

How to perform ventilation properly can be a course in and of itself and is a topic that carries with it some debate. The debate usually centers around positive pressure ventilation versus negative pressure ventilation. But when applied correctly, both are proven performers in ventilation. It is the proper use of the equipment on hand that actually matters when it comes to performing effective ventilation.

So, while neatly avoiding the ventilation debate or getting too far into the weeds with a how-to course on ventilation, we will address some of the more salient points with ventilation that should be considered. These are the kind of things that, if not done or done wrong, can impede your ventilation efforts and/or create an unsafe environment.

In the rescue world, ventilation is similar to rope—you need the right size and the right amount. Bigger, more powerful ventilation fans move more air, help eliminate dead air spaces, and exchange the air in the space quicker. If larger fans are not available, it is often possible to use multiple fans to increase airflow. Ducting fits into this “rope” category as well—it is paramount to effective ventilation, so it pays to have plenty of it. Fan manufacturers provide guidance on how far ducting can be extended to or from their fans and how it affects the capacity or the amount of air moved.

The next important thing is to be familiar with the equipment. Seeing equipment for the first time at an emergency is unacceptable. This stresses the importance of training with your gear and developing competency with it in advance of an incident. It is also most definitely advisable to follow the equipment manufacturer's instructions with regard to use and cleaning. 

Just as important as the fans is a solid air monitoring plan. The rescuers should be aware of the potential atmospheric hazards and have obtained the appropriate monitoring equipment. The air monitoring should continuously measure the entire space with results constantly provided to the vent team; this allows for adjustments if a particular part of the space is not seeing the expected improvements in air quality.

It is also critical to consider the intake air source and the discharge path for exhaust or discharge air. Since fresh air will be sent to the victim, it is imperative that its source be free of contaminants. In the same regard, the hazardous atmosphere from inside the space is also being vented somewhere. This location should be free of personnel and equipment or any other environmental concerns.

If your team is employing positive pressure ventilation, there will almost always be some degree of (and often all of) the exhaust occurring at the rescue opening or portal. This means that the outside team is probably being exposed to the space’s atmosphere. Therefore, air monitoring should be conducted in their vicinity continuously while ventilation is in progress. These crew members may very well need to wear PPE to protect them from the hazard. Neglecting topside air monitoring is a frequently overlooked step that can have dangerous consequences.

Ventilation is a foundation skill that often does not receive the attention it deserves. Short of supplying breathing air directly to the victim, there is no more effective step than ventilation for improving air quality inside of a confined space and ultimately the survivability of the victim. We encourage all rescue teams to include ventilation as a standard part of their rescue training regimen. And when at the actual emergency… vent early, vent continuously, and vent properly.

Additional Resources

• Confined Space Types – Are All Your Bases Covered?
• Confined Space Rescue Types Chart & Compliance Guide (pictured here)
  
  

The alarming rise in trench-related fatalities has spurred US Department of Labor to announce enhanced nationwide enforcement.

In 2022’s first six months, 22 workers have fallen victim to the deadly hazards present in trenching and excavation work – surpassing 15 in all of 2021 – and prompting the U.S. Department of Labor’s Occupational Safety and Health Administration to launch enhanced enforcement initiatives to protect workers from known industry hazards.

To stress the dangers of disregarding federal workplace safety requirements for trenching and excavation work, OSHA enforcement staff will consider every available tool at the agency’s disposal. These actions will place additional emphasis on how agency officials evaluate penalties for trenching and excavation related incidents, including criminal referrals for federal or state prosecution to hold employers and others accountable when their actions or inactions kill workers or put their lives at risk.

Read the full press release: https://content.govdelivery.com/accounts/USDOL/bulletins/3213baa

Additional Resources

If you’re concerned that your rescue service may not be adequately prepared, give us a call or check out these resources for more information on how to keep you and your personnel safe around trenches.

• Trench Safety & Rescue Article: Read More
• Trench Training: Competent Person | Trench Rescue Technician
• OSHA’s Trenching and Excavation Webpage

We’re often asked, “Can I use a crane as part of my rescue plan?” 

If you’re referring to using a crane as part of moving personnel or victims, the answer is “No, except in very rare and unique circumstances.” The justification for using a crane to move personnel, even for the purposes of rescue, is extremely limited. Therefore, it is very important to understand the “do’s and don’ts” for using a heavy piece of equipment in a rescue operation.

On the practical side, the use of a crane as a “stationary, temporary high-point anchor” can be a tremendous asset to rescuers. It may also be part of a rescue plan for a confined space –  a top entry fan plenum, for example. The use of a stationary high-point pulley can allow rescue systems to be operated from the ground. It can also provide the headroom to clear rescuers and packaged patients from the space or an elevated edge.

Because of the dangers involved in moving personnel with heavy equipment, OSHA strictly limits its use.

The security of the system's attachment to the crane and the ability to “lock-out” any potential movement are a critical part of the planning process. If powered industrial equipment is to be used as a high-point, it must be treated like any other energized equipment with regard to safety. Personnel would need to follow proper Lock-out/Tag-out procedures [Control of Hazardous Energy 1910.147]. Any equipment used in the rescue operation would need to be properly locked out – (i.e., keys removed, power switch disabled, etc.). You would also need to check the manufacturer’s limitations for use to ensure you are not going beyond the approved use of the equipment.

Because of the dangers involved in moving personnel with heavy equipment, OSHA strictly limits its use. In order to utilize a crane, properly rated “personnel platforms or baskets” must be used. Personnel platforms that are suspended from the load line and used in construction are covered by 1926.1431. There is no specific provision in the General Industry standards, so the applicable standard is 1910.180(h)(3)(v). This provision specifically prohibits hoisting, lowering, swinging, or traveling while anyone is on the load or hook.

OSHA prohibits the hoisting of personnel by crane or derrick except when no safe alternative is possible. The use of a crane for rescue does not provide an exception to these requirements unless very specific criteria are met.

An OSHA Letter of Interpretation (LOI 1993-02-17) states, “OSHA has determined, however, that when the use ofa conventional means of access to an elevated worksite would be impossible or more hazardous, a violation of 1910.180(h)(3)(v) will be treated as de minimis if the employer has complied with the provisions set forth in 1926.550(g)(3) through (g)(8).”

Note: De minimis violations are violations of standards which have no direct or immediate relationship to safety or health. Whenever de minimis conditions are found during an inspection, they are documented in the same way as any other violation, but are not included on the citation.

Therefore, the hoisting of personnel is not permitted unless conventional means of transporting employees  is not feasible. Or, unless conventional means present even greater hazards (regardless if the operation is for planned work activities or for rescue). Where conventional means would not be considered safe, personnel hoisting operations meeting the terms of this standard would be authorized. OSHA stresses that employee safety, not practicality or convenience, must be the basis for the employer's choice of this method.

However, it is also important to note that OSHA specifically requires rescue capabilities in certain instances, such as when entering permit-required confined spaces [PRCS 1910.146]; or when an employer authorizes personnel to use personal fall arrest systems [PFAS 1910.140(c)(21) and 1926.502(d)(20)]. In other cases, the general duty to protect an employee from workplace hazards would require rescue capabilities. 

Consequently, being “unprepared for rescue” would not be considered a legitimate basis to claim that moving a victim by crane was the only feasible or safe means of rescue.

This is where the employer must complete written rescue plans for permit spaces and for workers-at-height using personal fall arrest systems – or they must ensure that the designated rescue service has done so. When developing rescue plans, it may be determined that there are no other feasible means to provide rescue without increasing the risk to the rescuer(s) and victim(s) other than using a crane to move the human load. These situations would be very rare and would require very thorough documentation. Such documentation may include written descriptions and photos of the area as part of the justification for using a crane in rescue operations.

Bottom line… simply relying on using a crane to move rescuers and victims without completing a rescue plan and very clear justification would not be in compliance with OSHA regulations. It must be demonstrated that the use of a crane was the only feasible means to complete the rescue while not increasing the risk as compared to other means. Even then, there is the potential for an OSHA compliance officer to determine that there were indeed other feasible and safer means.

WARNING: Taking it a step further, if some movement of the crane  is required, extreme caution must be taken! Advanced rigging techniques may be required to prevent movement of the crane from putting undue stress on the rescue system and its components. Rescuers must also evaluate if the movement would unintentionally “take-in” or “add” slack to the rescue system, which could place the patient in harm’s way. The movement of a crane can take place on multiple planes – left-right, boom up-down, boom in-out and cable up-down. If movement of the equipment must take place, rescuers must evaluate how it might affect the operation of the rescue system.

Of course, one of the most important considerations in using any type of mechanical device is its strength and ability (or inability) to “feel the load.” If the load becomes  entangled while movement is underway, serious injury to the victim or an overpowering of system components can happen almost instantly. No matter how much experience a crane operator has, there is no way he can “feel” if the load becomes entangled. And, most likely, he will not be able to stop before injury or damage occurs. Think of it this way, just as rescuers limit the number of haul team members so they can feel the load, that ability is completely lost when energized devices are used to do the work.

For rescuers, a crane is just another tool in the toolbox – one that can serve as a temporary, stationary high-point making the rescue operation an easier task. However, using a crane that will require some movement while the rescue load is suspended should be a last resort! There are simply too many potential downfalls in using cranes. This also applies to fire department aerial ladders. Rescuers must consider the manufacturer’s recommendations for use. What does the manufacturer say about hoisting human loads? And, what about the attachment of human loads to different parts of the crane or aerial?

However, there may be cases in which a crane is the only option. For example, if outside municipal responders have not had the opportunity to complete a rescue plan ahead of time, they will have to do a “real-time” size-up once on scene. Due to difficult access, victim condition, and/or available equipment and personnel resources, it may be determined that using a crane to move rescuers and victims is the best course of action. 

Think of it this way, just as rescuers limit the number of haul team members so they can feel the load, that ability is completely lost when energized devices are used to do the work.

Using a crane as part of a rescue plan must have rock-solid, written justification as a demonstration that it is the safest and most feasible means to provide rescue capability. Planning before the emergency will go a long way in providing options that may provide fewer risks to all involved.

So, to answer the question, “Can I include the use of a crane as part of my written rescue plan?” 

Well, yes and no. Yes, as a high-point anchor. And, no, the use of any powered load movement will most likely be an OSHA violation without rock-solid justification. The question is, will it be considered a de minimis violation if used during a rescue? Most likely it will depend on the specifics of the incident. However, you can be sure that OSHA will be looking for justification as to why using a crane in motion was considered to be the least hazardous choice.

NOTE: Revised 5/2022. Originally published 10/2014.

Additional Resources

• Rescue PrePlans
• OSHA Lock-out/Tag-out Fact Sheet 
• Evaluating Your Rescue Service

We’re often asked, “How many team members should be on a standby rescue team?”

While there is no definitive answer, we wanted to share some practical guidelines that we use here at Roco. We will offer some key points for consideration as well as address relevant standards and regulations. The safety procedures and internal policies for your organization must also be given priority consideration.

In assessing the number of personnel needed, we normally start with the various “types of confined spaces” that are applicable to the site. Other factors include elevation of the space; internal obstructions; and the potential for hazardous atmospheres. In addition, access into and out of the space; size and shape of opening; internal configuration; communications; hazard types and sources; and required PPE. Consideration must also be given to the types of injuries that may occur, which will dictate patient care and movement limitations inside the space.

 As an example, to rescue an entrant from a 24-inch round horizontal portal that is 3-feet off the ground would require fewer personnel than one that is 80-feet off the ground, or if it has an IDLH environment. This is a much different story! Careful consideration must be given to the various factors involved so that rescuers can be adequately prepared to take the appropriate action when needed.

From a regulations standpoint

OSHA’s Permit-Required Confined Space Regulation (29 CFR 1910.146) is our primary reference for this topic. However, this regulation is “performance-based” – and does not provide a specific number of personnel required for stand-by operations. It simply requires that the team or service gets the job done in a safe and timely manner.

Section (d)(9) of the regulation states the requirement to “Develop and implement procedures for summoning rescue and emergency services, for rescuing entrants from permit spaces, for providing necessary emergency services to rescued employees…”. However, the number of team members is left up to the employer or agency.

Section (k) provides more details regarding rescue and emergency services but again does not include a specific number of team members required. It’s all based on the rescue service’s ability to perform rescue from the types of confined spaces to which they may respond. OSHA’s Confined Spaces in Construction (1926 Subpart AA) standard echoes 1910.146 with a few additional requirements, but again offers no specific numbers on rescuers needed for standby operations.

Next, the Respiratory Standard (1910.134), section (g)(3)(i) states that “One employee or, when needed, more than one employee is located outside the IDLH atmosphere;” and Section (g)(3)(iii) adds that…“The employee(s) located outside the IDLH atmosphere are trained and equipped to provide effective emergency rescue” – however, once again, we are given no set number of personnel.

NFPA 1670, Standard on Operations and Training for Technical Search and Rescue Incidents, (2017 Ed) Chapter 7.3.2.1, states that “The role of a confined space rescue service is intended to include entry into the space to perform a rescue and, as a minimum, shall be staffed to provide sufficient members with the following exclusive functions:

1. Rescue entrant/entry team of sufficient size and capability to perform the rescue…
2. Backup rescue entrants of a sufficient number to provide immediate assistance…
3. Rescue attendant…
4. Rescue team leader (supervisor)…”

Still, no definitive number of personnel, but at least it offers some guidance on the positions that should be taken into consideration. If you dig a little deeper into the Appendix of 1670, you can find in A.7.3.2.1, “In general, confined space rescue teams are composed of no less than six members to perform all the required functions listed. However, the size and capability of a team required to perform a specific rescue will depend on many factors, including the condition of the patient, the size and shape of the space, size of the access opening, and the hazards present...”.

How Roco’s stand-by rescue services would typically handle

So, how many team members does it take? We’ll give you an idea of how we address this with Roco’s stand-by rescue services. Our typical Confined Space Rescue Team consists of three personnel including a Crew Chief and two Rescue Technicians. Keep in mind, however, these individuals are experienced, professional emergency responders, who perform stand-by rescue operations and/or train on a regular basis.

Our teams also have the benefit of preplanning the rescue and setting up equipment in advance. Considerable effort goes into rescue planning by Roco teams prior to an entry. Preplanning precautions include:  

1. Analyze, identify and eliminate hazards in and around the confined space.
2. Ensure appropriate administrative and work practice controls are being used and followed.
3. Hazard-specific PPE is provided and correctly used by all personnel involved.
4. Communication methods are defined, verified and implemented (written and verbal).

Also, with our standby teams, the Crew Chief is responsible for filling two roles during an actual emergency… (1) the rescue team leader and (2) either the rescue attendant or the backup rescuer. One Rescue Technician fills the role the Crew Chief didn’t, and the other Rescue Technician becomes the rescue entrant.

This has proven to be an effective and efficient team when providing standby rescue services. Again, we have the benefit of being onsite while the entries are occurring and the opportunity to preplan the rescue. In addition, the job circumstances and scope of work are carefully evaluated prior to committing to a specific number of personnel.

As an example, we typically require a four-person team for jobs involving inert entries and other types of IDLH environments, unusual space configurations (i.e., long distances, entanglement hazards or complex obstructions), or any other high hazard condition. In certain instances, even a two-person team may be appropriate. This would include when there is no potential for atmospheric hazards; large and easily assessable openings; no secondary lowering operations; strictly horizontal movement, etc.

In closing, we must emphasize that employers are required to ensure that adequate rescue capabilities are readily available. OSHA 1910.146 is a performance-based standard that requires a safe and timely rescue response for confined space incidents. This is one reason it is so important to evaluate the rescue service you are depending upon to provide emergency services (i.e., is the team trained and equipped to provide confined space and elevated rescue appropriate to your needs?). Appendix F of 1910.146 provides a valuable tool for conducting rescue performance evaluations. It is critically important to know in advance that your rescue service is prepared, capable and ready to perform an emergency rescue. 

Additional Resources

• Confined Space Types – Are All Your Bases Covered?
• Confined Space Rescue Types Chart & Compliance Guide (pictured here)
  
  

Blog originally posted in March 2011.

You’ll spot them everywhere – from a local utility company working in your neighborhood to your workplace at an industrial or manufacturing facility during construction. It’s way too common to see an open trench unattended and unprotected. And, as we know, it’s only a matter of time until it collapses.

More and more of our customers are asking questions to address safety-related concerns. For example, who’s signing off on the trench project? Is the person you have signing off that a trench is constructed properly and safe for entry trained to know what to look for? Do they have the authority to act (competent person), or are they assuming that the contractor is “doing the right thing”? It is all too common that supervisors are signing off on trench permits without having any trench safety training or experience. Therefore, they cannot be considered competent persons.

Of course, this is troubling. It’s troubling due to the hazards involved and the personnel who will be entering the trench. A trench collapse happens in seconds, making an escape very unlikely once the soil starts moving. Due to the weight of the soil and the speed of the collapse, most do not survive.

Trench safety starts with the Competent Person. If none are available, who is watching out for the safety of the entrants? Not just anybody will do. According to 1926.650(b), the Competent Person is “one who is capable of identifying existing and predictable hazards in the surroundings, or working conditions which are unsanitary, hazardous, or dangerous to employees, and who has authorization to take prompt corrective measures to eliminate them.” Who on your site is responsible for this? Do they have the authority to correct hazards immediately?

Hopefully, we’ve convinced you of the importance of a trained and experienced Competent Person. Now, what about rescue in case the worst does happen? You’ve got an extremely hazardous situation – is your rescue service prepared for this? Your emergency response team may be trained for most emergencies, but what about this one?

Trench is one of the most dangerous rescue disciplines. It requires special knowledge, such as soil classification, hazard analysis and mitigation, understanding tabulated data, and the proper installation of shoring and shielding systems, just to name a few. It also requires specialized equipment that many response organizations simply don’t possess. This seems to be true for most municipal and industrial teams. With specialized training and equipment required for safe operations, it’s a commitment that most rescue teams just can’t make.

With trench rescue, timeliness is everything. Although it is often a slow and tedious process, proper training and equipment can be the difference between a rescue and a body recovery. Don’t ignore this hazard that may be located on your street or worksite. Take a careful look around, we think you’ll be surprised with the number of trenches and excavations that are occurring on a daily basis.

Did You Know?

After researching many of the questions we have received concerning trench operations, we came across this OSHA Letter of Interpretation that was reviewed most recently on November 8, 2018.
Note: It is always important to review all standards and regulations in their entirety.

Here are some excerpts:

1. Can workers enter a trench with water accumulation if the workers are protected from cave-in by shoring, shields or sloping, and the water level is controlled?

Paragraph .651(h) of 29 CFR 1926 allows workers to work in a trench with water accumulation, provided adequate precautions have been taken to protect employees against the hazards posed by water accumulation. The precautions necessary to comply with the standard vary with each situation, and the precautions you listed, such as additional shoring and control of the water level may not, in all cases, provide the required employee protection. 

2. The Stairways and Ladders Standard requires that a stairway or ladder shall be provided at points of access where there is a break in elevation of 19 inches or more. The Excavation Standard requires a ladder or other means of access and egress when the trench is 4 feet or more. Which of these requirements is applicable to trenching operations?

Be advised that since the specific excavation standard also addresses means of access and egress, the more general requirement in the stairways and ladders subpart is not applicable. A ladder, stairway, ramp or other safe means of access is required only when the trench is four feet or more in depth. Paragraph 651(c)(2) also states…as to require no more than 25 feet (7.62 m) of lateral travel for employees.

3. Must rescue equipment be available at every trenching jobsite that is located near or passes by a gas station, refinery, gas line, sewer main, etc.? Can a contractor rely on the local rescue squad since they are probably better equipped to handle a rescue?

Emergency rescue equipment is required to be readily available where a competent person determines, based on the conditions at each jobsite, that hazardous atmospheric conditions exist or may reasonably be expected to develop during work in an excavation.

In regard to whether a contractor can rely on a local rescue squad instead of providing the rescue equipment, please be advised that many emergency situations associated with the hazards involved with hazardous atmospheres in trenches would normally require an immediate response within a few minutes or even seconds.

A rescue squad would be unable to provide the necessary response and therefore could not be used to comply with 1926.651(g)(2).

4. If a contractor has several of the same make and model trench shields at a jobsite, does he have to have separate manufacturer's tabulated data on hand for each specific shield? We have been told that the shields and the data sheets must have the same serial number in order to be in compliance.

Be advised that only one set of tabulated data is required for each different shield design. If a contractor uses several shields of the identical make and model, only one set of tabulated data would be required for them.

5. Do excavations greater than 20 feet have to be designed by an RPE (Registered Professional Engineer) or can manufacturer's tabulated data be used in lieu of an RPE? For example, a contractor may have boxes rated for depths greater than 20 feet.

Protective systems that are designed using a manufacturer's tabulated data can be used in trenches deeper than 20 feet provided the use is within the limits of the data, including depth limitations and soil type. It should be noted that all tabulated data, by definition (1926.650), must be approved by an RPE.

6. We clearly understand that a ladder has to be secured, but we are not sure how. Contractors have informed us that compliance officers have told them that they cannot secure a ladder to the shoring system or in some cases the trench shield. These same contractors have been told to secure the ladder by driving a stake into the ground and to tie the ladder off to the stake. This alternate method presents three different problems: 1) It is not always possible to drive a stake through concrete or asphalt sidewalks or pavement; 2) This method creates a tripping hazard next to the trench; 3) Some contractors believe that driving a stake could create a stress crack. Please clarify these requirements for us?

Paragraphs 1926.1053(b)(6) and (7) address ladder footing displacement which is not normally a problem in trenches. If a ladder needs to be secured against tipping, it may be secured to a shield or member of a protective structure provided the ladder does not alter the effectiveness of the protective system.

7. Does the competent person have to be standing by the trench at all times during the work shift or can he/she go off site for short periods of time, such as lunch, meeting, or maybe to pick up supplies at the local builder’s supply store? Can the competent person move around the jobsite away from the trench? Often the foreman is the competent person and he may have other responsibilities at the jobsite.

It is not normally necessary for a competent person to be at a jobsite at all times. However, it is the responsibility of a competent person to ensure compliance with applicable regulations and to make those inspections necessary to identify situations that could result in possible cave-ins, indications of failure of protective systems, hazardous atmospheres, or other hazardous conditions, and then to ensure that corrective measures are taken. Consistent with these goals, the competent person may perform other duties.

8. Must an RPE approve all work when digging below a footing, foundation, retaining wall, sidewalk or pavement? We recognize the need for an RPE to design a system to support buildings and structures. However, we don't agree that an RPE is needed to layout a system to support sidewalks, pavement, and in some cases small structures like a small retaining wall. It is often very difficult to find an RPE who is willing to take on small incidental projects.

An RPE approval is not required when the excavation is not "reasonably expected to pose a hazard to employees." In situations where it is reasonably expected to pose a hazard, an RPE approval is not required when a support system, such as underpinning, is provided to ensure the safety of employees and the stability of the structure, or the excavation is in stable rock.

9. At what point and under what conditions would OSHA consider a trench a confined space?

Under normal circumstances, a trench would not be considered a confined space. The excavation standards address the hazards associated with employees entering potentially harmful atmospheres by requiring atmospheric testing and controls where hazardous atmospheres exist or could reasonably be expected to exist.

10. Some compliance officers are telling contractors that they must use a penetrometer or shearvane to estimate the compressive strength of soil and that the thumb test is unacceptable. Keeping in mind that these are field tests. We realize that the thumb test is not accurate, but neither is the penetrometer that many compliance officers swear by. What is OSHA's interpretation for using a thumb test versus an instrument?

Be advised that the thumb penetration test is one of the acceptable methods of estimating soil compressive strength. The compressive strength can be determined by laboratory testing, or estimated in the field using a penetrometer, shearvane, thumb penetration tests, as well as by other methods.

Source: OSHA Letter of Interpretation: Construction standards addressing excavations (reviewed November 8, 2018)

Additional Resources

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