At some point, most atmospheric monitors will display a “negative” or minus reading for a flammable gas or toxic contaminant. First of all, it is not actually possible for an atmosphere to contain a “negative amount” of a substance. These negative readings usually result from improper use of the monitor.

Most monitors will “Field Zero” or “Fresh Air Calibrate” its sensors when powered on. Because of this, it is very important to power on the unit in a clean, fresh air environment away from confined spaces, running equipment or other possible contaminants. Otherwise, the monitor may falsely calibrate based on the contaminant that is present.For example, a monitor that is powered on in an atmosphere that contains 10 ppm of a contaminant and then moved to fresh air may display a reading of minus 10 ppm. Even more troublesome, if that same monitor is then brought to a confined space that actually contains 25 ppm of the contaminant, it may display a reading of only 15 ppm. As you can see, this could easily lead to the improper selection of PPE for the entrant and result in a confined space emergency.

As always, it is very important to consult with the manufacturer of your particular atmospheric monitor in order to determine how to use it properly. Don’t take any chances with this critical part of preparing for confined space entry or rescue operations.

To our knowledge, there is no regulatory requirement. However, we’ve heard this before and have used it as well when stressing the importance of proper PPE for rescuers, particularly when IDLH atmospheres may be involved. Here’s our thinking… if the entrant’s PPE did not provide adequate protection and he or she is now requiring rescue assistance, then using their “same level of protection” isn’t going to protect you either!

What triggers the use of a greater level of protection? This comes from the rescuer’s assessment of the hazards – including the use of an independent atmospheric monitor from that used by the entrant(s). That’s why it’s so important for the rescue team to provide their own atmospheric monitoring equipment. It also illustrates why written rescue preplans are so important – you need to preplan what equipment and techniques will be required well in advance of an emergency. It’s critical; the PPE selected must be adequate to protect the rescuers.

When preparing rescue preplans, you must also take into consideration any unusual hazards or circumstances that may arise from any work being done inside or near the space. For example, special cleaning solvents might be used or other hazards may be introduced into the space by the workers. Referencing and understanding the MSDS as well as “listening to what your monitor is telling you” are key factors in PPE determination.

OSHA does mention, however, if the atmospheric condition is unknown, then it should be considered IDLH and the use of positive pressure SCBA/SAR must be used. This will protect you from low O2 levels and other inhalation dangers; however, you must also consider LEL/LFL levels. Other factors include non-atmospheric conditions as well. For example, have you considered “skin absorption” hazards and what precautions must be taken?

So, the bottom line, the decision to go with breathing air for rescuers can be determined from your hazard assessment; or, in some cases, by company policy; and even required by OSHA when there’s an unknown atmosphere involved. Remember, it’s much better to be safe than sorry!

A blog reader, who is a member of a municipal rescue team assigned to an airport, expressed concern about fulfilling “timely response” obligations for permit-required confined space entries within his district. Here are some suggestions from our Tech Panel…

First of all, the departments and agencies involved must carefully consider the obligations in providing rescue response for permit-required confined spaces.

Obviously, we cannot advise on departmental policy concerning response and notification, this must be determined by management officials. However, for you as an emergency responder, we cannot stress enough the importance of preplanning and conducting a hazard analysis for all confined spaces within your response area. The information gained by the analysis will help you determine what level of “timely response” may be required for a particular type of entry.

OSHA does not set a specific response time because there are too many variables involved – plus, they don’t want to set requirements that might cause a rescue team to “rush” into entering a space to attempt a rescue. OSHA does reference how long a person might survive an IDLH atmosphere (such as an oxygen deficient atmosphere) before becoming incapacitated (4 to 6 minutes). However, even this is up to interpretation depending on the level of oxygen present. For example, an 18% O2 level vs. a 6% O2 level, both are O2 deficient but have very different response requirements for successful rescue.

Another important consideration is when an entrant is entering an IDLH environment. In this case, having a team standing by the portal, fully equipped and ready to go may be the only way to meet a timely response for that situation. OSHA’s 1910.134, Respiratory Protection, “requires that employers provide a standby person or persons capable of immediate action to rescue employee(s) wearing respiratory protection while in work areas defined as IDLH atmospheres.”

Most entries, however, are not IDLH. This means that other forms of “external” rescue (vs. internal rescue) may be appropriate. Many times, in the rush of the moment, rescuers forget about external retrieval. Guessing that many of the spaces around the airport are manholes or vaults, these can most often be handled by the confined space attendant with an external retrieval system. This would include a mechanical winch attached to a tripod with a cable attached to the entrant’s high-point dorsal connection. Of course, this decision would be based on a prior hazard analysis.

NOTE: It’s important to note that ALL entrants are required to have “an immediate means of retrieval.” Reference OSHA 1910.146 [note to paragraph (k)(1)(i)] concerning timely response: “What will be considered timely will vary according to the specific hazards involved in each entry…”

As a final note, if hazard analysis and rescue preplans have not been conducted on your potential sites as required by OSHA, we encourage you to do so. Taking the time to do so will better enable you to determine what would be considered an appropriate “timely response” for a particular type of entry. It will also better prepare you as an emergency responder should the need arise.

We had this question from a reader and wanted to post for all to read.

Would a proper tailboard briefing conducted before a confined space entry be sufficient for identifying hazards that may be encountered by the entrants or the rescue team?

It’s true that a tailboard briefing should be an integral part of the larger overall preplanning for a confined space entry. However, well in advance of the entry, a detailed “hazard analysis” of the space should be performed.

A hazard analysis is used to identify the types of hazards, lock-out/tag-out needs, PPE required for entry, method of entry and important rescue considerations. In fact, OSHA requires these written assessments to be completed prior to an entry being made and the confined space permit acts as a secondary written assessment performed at the time of the entry. Here are some OSHA references concerning this topic…

1910.146(c)(5)(ii)(H)
The employer shall verify that the space is safe for entry and that the pre-entry measures required by paragraph (c)(5)(ii) of this section have been taken, through a written certification that contains the date, the location of the space, and the signature of the person providing the certification. The certification shall be made before entry and shall be made available to each employee entering the space or to that employee’s authorized representative.

1910.146(d)(2)
Identify and evaluate the hazards of permit spaces before employees enter them;

1910.146(d)(3)
Develop and implement the means, procedures, and practices necessary for safe permit space entry operations;

The tailboard briefing should be used to confirm or reinforce the information already gathered in the hazard analysis. Because it deals with an individual space at the time of entry, the tailboard briefing is also a very useful tool in finding out if conditions have changed since the hazard analysis was completed.

So, the bottom line… having a detailed hazard analysis for each space that includes a detailed rescue preplan allows a rescue team to review and prepare for potential problems well in advance. Reviewing this information at a tailboard briefing just prior to the entry helps to remind everyone of the possible hazards, the proper precautions, and the potential solutions should an emergency occur.

There’s no doubt about it, confined space entry is risky business. A first consideration should always be to try and eliminate the known and potential hazards – or, even better, “engineer out” the need for entry when possible. If it’s not possible (or feasible), and entry must be made, then as part of OSHA’s Permit-Required Confined Space standard (1910.146), the employer must take action to protect its workers. This regulation requires employers to develop and implement procedures for summoning rescue and emergency services, for rescuing entrants from permit spaces, and for preventing unauthorized personnel from attempting a rescue.
Planning for rescue of the entrant should always be approached in a logical hierarchy. The first choice for rescue should always be “self-rescue.

However, there are too many lads named “Murphy” lurking about to be able to rely on this as the only means of rescue. That leads to the next option, which is “retrieval rescue.” This means that retrieval (or rescue) of the entrant(s) can be made without anyone else having to enter the space.

NOTE: It’s important to note that the hierarchy of rescue needs to be followed even when an “entry rescue team” is located on site. For example, when an entry is made into a simple vertical vault, a retrieval system must be used even if a trained rescue team is standing by – again, preventing rescuers from having to enter the space unless necessary.

To facilitate non-entry rescue, retrieval systems or methods shall be used whenever an authorized entrant enters a permit space, unless the retrieval equipment would increase the overall risk of entry or would not contribute to the rescue of the entrant. The retrieval system shall include a chest or full body harness, with a retrieval line attached at the center of the entrant’s back near shoulder level, above the entrant’s head, or in such a way to present a small enough profile for successful removal of the entrant. In certain instances wristlets may be used. The retrieval line shall be attached to a fixed point outside the space or to a mechanical device. For vertical entries more than 5 feet in depth, a mechanical device such as a retrieval winch or mechanical advantage rope system shall be available.

Relying on non-entry retrieval rescue requires a thorough and honest assessment of the retrieval system’s ability to function as intended should the need arise. Are there any entanglement issues within the space that would cause the retrieval line to fail? If the entrant must travel around any 90 degree corners or between levels, will the retrieval line work? Any and all potential causes of retrieval system failure would require the need to plan for entry rescue.

One of the advantages of non-entry retrieval rescue is that oftentimes it can be performed by the attendant. Modern retrieval equipment may utilize powerful gear reductions or rope mechanical advantages and are usually quite easy for the attendant to learn to operate. It is encouraged and quite common for the attendant to be trained and capable of performing non-entry rescue. The attendant is prohibited, however, from entering the space to perform rescue unless properly trained and equipped for ”entry rescue,” which is the last option in the hierarchy of rescue.

NOTE: Even if the attendant is trained and equipped for entry rescue, he or she must be relieved by another authorized attendant before abandoning their attendant duties.

Entry rescue requires the rescuer(s) to enter the confined space, thus possibly exposing them to the same hazards as the victim. That’s why it is critical for rescuers to be trained and equipped with the proper PPE to protect themselves from the hazards involved. In fact, OSHA states that if you don’t have the proper PPE or training, DO NOT ATTEMPT THE RESCUE!

This warning is driven by the great number of “would be” rescuers dying in confined spaces while attempting to save a life. Safe, successful entry rescue requires sufficient training in the proper techniques, a proficiency in the use of the appropriate PPE and rescue equipment, and the ability to recognize and identify the hazards and potential hazards in confined spaces.

Again, it’s important to keep in mind that there are many permit required confined spaces where non-entry retrieval is a viable option – and it should be used whenever possible. Vertical utility vaults with no entanglement hazards, horizontal entries with no corners or elevation changes are just a few. The proper course is to always perform a thorough assessment of the space to determine which type of rescue will be needed and to make sure the appropriate rescue response is in place should the entrants need assistance.