BREATHING AIR SYSTEMS FOR CONFINED SPACE RESCUE

BREATHING AIR SYSTEMS FOR CONFINED SPACE RESCUE

BY MICHAEL DUNN

A recent study released by the National Institute for Occupational Safety and Health (NIOSH) indicates that asphyxiation was the cause of death in 45 percent of 670 fatalities that occurred in confined spaces over a recent 10-year period. Forty-one percent of the deaths were due to gas poisonings and 14 percent to drowning.1 If proper respiratory protection equipment had been worn by the victims and rescuers involved in these confined space incidents, many of these fatalities could have been avoided.

An atmosphere that is oxygen-deficient, flammable, or toxic often displays no outward signs of an impending tragedy. Proper selection, knowledge, and use of the appropriate respiratory protection equipment are vital to the rescuer`s safety. Knowledge of the applicable regulations concerning respiratory protection equipment are also valuable to the rescuer. One rule must always hold true when dealing with confined space rescue: The safety of the rescuer must come first.

RESPIRATOR TYPES AND CHARACTERISTICS

Rescuers have used three main types of respirators in confined spaces: self-contained breathing apparatus (SCBA), airline supplied respirator with escape bottle (SAR), and the Type C combination airline/SCBA. Each has advantages and disadvantages in confined space rescue.

Open-circuit self-contained breathing apparatus (SCBA). Available from a number of major manufacturers, all of which offer various features to set them apart from their competitors, the SCBAs all have some things in common. They all have a cylinder that contains breathing air under pressure. The cylinder is held in place on the wearer`s back by a harness and strap arrangement. The air in the cylinder, under positive pressure, passes from the cylinder through a pressure-reducing regulator and then is sent to a face piece for use by the wearer. The wearer breathes the air from the face piece and exhales the used air into the surrounding atmosphere–thus the name “open circuit.“

The Occupational Safety and Health Administration (OSHA) refers to this type of breathing apparatus as “fire department style breathing apparatus.” The cylinder must have a minimum rated capacity of 30 minutes to be approved as an SCBA. The rating is determined by a flow rate from the cylinder of 40 liters of air per minute. Common cylinder pressures are 2,216 psi, 3,000 psi, and 4,500 psi; common tank sizes are 45 and 90 cubic feet. Rated capacities on open-circuit SCBA can vary from 30 to 60 minutes. The units are completely portable and can go any place the wearer can fit into.

Primary advantages of SCBA in confined space rescue:

Portability. The wearer is not limited in travel distance by a hose attached to an outside air source.

Availability. SCBAs are readily available within most industrial facilities and from municipal fire departments–they are part of the standard firefighting protective ensemble.

Primary disadvantages of SCBA in confined space rescue:

Limited duration air supply. Rated cylinder capacity is reduced by the wearer`s physical conditioning, exertion, fatigue, stress, familiarity with the breathing apparatus, and other factors. Air capacity on a 30-minute rated cylinder actually may be 10 minutes or less. Rescuer breathing rates easily can approach 100 liters of air per minute, depending on the above variables.

Bulk of unit. Even low-profile, high-pressure units may be too bulky to allow the wearer to pass through an opening into a confined space while properly wearing the unit on the back.

Weight. Even the lightweight models of 30-minute units weigh 20 to 25 pounds, and the 60-minute units can weigh as much as 30 to 35 pounds.

Low-profile maneuver. Rescuers who remove the SCBA cylinder and harness from their backs to enter, exit, or move through the space run a serious risk of the face piece`s dislodging should the cylinder be dropped accidentally (see sidebar on page TK).

CLOSED-CIRCUIT SCBA

Currently, only a few manufacturers in this country make closed-circuit SCBA. Some models offer a positive pressure to the face piece; others do not. The units are available in minimum rated capacities of from 60 minutes to four hours.

Some devices generate oxygen through a chemical reaction that occurs between the moisture in the wearer`s exhaled breath and an oxygen-generating chemical. The generated oxygen is stored in a breathing bag and then inhaled by the wearer.

This type of unit is most commonly used in shipboard firefighting and sometimes is referred to as “oxygen breathing apparatus (OBA),” or “rebreathers.” All air exhaled by the wearer is recirculated within the unit, thus the term “closed circuit.”

Another type of closed-circuit breathing apparatus used by industry and the fire service uses a small cylinder of compressed oxygen to enrich the wearer`s exhaled air. A chemical that absorbs carbon dioxide is used to maintain an acceptable air/oxygen breathing concentration. All air exhaled by the wearer is recirculated within the unit.

Primary advantages of closed-circuit SCBA in confined space rescue:

Portability. The wearer is not limited in travel distance by a hose attached to an outside air source.

Profile. A closed-circuit SCBA may have a lower profile than that available with open-circuit SCBA.

Air capacity. Because the wearer`s exhaled air is recirculated within the system, the rated duration times are minimums. Actual times can be much longer.

Primary disadvantages of closed-circuit SCBA in confined space rescue:

Bulk of unit. Even the lower profile offered by these units may be too bulky to allow the wearer to pass through an opening into a confined space while properly wearing the unit on the back.

If the unit is of the oxygen-generating type, the wearer can`t tell how much of the chemical is left to generate the needed oxygen–a vital safety concern that, along with other considerations, eliminates this as a viable alternative for most confined space rescue operations.

AIRLINE-SUPPLIED RESPIRATOR (SAR)

Many companies manufacture airline-supplied respirators (SARs). An SAR for use in confined spaces should have the following attributes:

It should be complete with its own wearing harness.

It should have an emergency escape bottle. The bottles range in size from a five-minute capacity, the standard size for most manufacturers, to a 20-minute capacity.

It should be supplied directly from a stored, compressed air source. Some arrangements have the SAR supplied from a compressor with no stored-air backup supply, which could lead to fatal results if the compressor loses power (see sidebar on page TK).

Primary advantages of supplied air respirators in confined space rescue:

Air sources. SARs have two sources of air for the rescuer–airline supply and emergency escape bottle–instead of the single source offered by an SCBA. Should the primary airline supply fail, the rescuer can activate the emergency escape bottle for another air source and exit the space.

Portability. Many of the new designs use self-contained breathing apparatus bottles as a stored air source and can be set up virtually anywhere, including inside the confined space itself.

Compactness. SARs have a very low profile when compared with SCBA or Type C combination SCBA/SAR, enabling the rescuer to enter the confined space without removing the unit.

Primary disadvantages of supplied air respirators in confined space rescue:

Travel distance. Airline-supplied respirators are limited to a maximum of 300 feet of air hose from the regulator to the rescuer.

Entanglement. Airlines add another hazard when working in congested areas because of the possibility of hose entanglement with machinery, piping, agitator blades, other rescuers` air hoses and safety lines, and so forth.

Air capacity. Since airlines provide the rescuer with up to 300 feet of travel distance, the rescuer could penetrate farther into the space than the amount of “breaking time” available from the escape air bottle to make it back to safety, should the primary air source fail. This is an important safety consideration.

TYPE C COMBINATION AIRLINE/SCBA

A Type C combination airline/SCBA is a fire department-style, 30-minute minimum, self-contained breathing apparatus with a connection that enables the wearer to attach an airline to an outside air source.

Primary advantages of Type C combination air systems in confined space rescue:

Portability. While the wearer is still limited to 300 feet in travel distance by a hose attached to an outside air source, the airline can be disconnected once inside the space to enable the rescuer to exceed the 300-foot limit of the airline as long as the rescuer uses no more than 20 percent of the cylinder`s rated air capacity (for example, six minutes off the airline if wearing a 30-minute bottle). (Mine Safety & Health Administration 30 CFR Subpart H)

Air sources. The rescuer has two sources of air–airline supply and 30-minute minimum air bottle–instead of the single source offered by an SCBA. If the primary airline supply fails, the rescuer can activate the air bottle for another air source for escape.

Primary disadvantages of Type C combination air systems in confined space rescue:

Bulk of unit. Even low-profile, high-pressure units may be too bulky to allow the wearer to pass through an opening into a confined space while properly wearing the unit on the back.

Entanglement. Airlines do carry the potential for hose entanglement in confined spaces (making airline-management techniques training essential to your program).

Low-profile maneuver. A dropped cylinder could dislodge the rescuer`s face piece.

OSHA/ANSI REGULATIONS AND STANDARDS

OSHA 29 CFR 1910.146, Permit-Required Confined Spaces, does not specifically address the use of respiratory protection equipment for rescue. OSHA uses many related standards (discussed later) when making its rulings on the use of respiratory protection equipment for the rescue of persons from confined spaces.

OSHA currently mandates the use of SCBA or Type C combination airline/ SCBA for confined space rescue operations. OSHA states in correspondence, “The standard (OSHA is referring to 29 CFR 1910.134) would not permit an air-line respirator with escape provision for the standby person (i.e., rescuer). The designation of an SCBA is to allow sufficient air for the person to conduct the rescue; if an air-line respirator with escape provision is used and the air-line fails on beginning the rescue attempt, the rescuer will only have sufficient air in the escape respirator to escape without performing the rescue, thus jeopardizing the life of the person to be rescued.”2

Section (e) (3) (iii) of 29 CFR 1910.134, OSHA`s respiratory protection standard, states: “Persons using airline respirators in atmospheres immediately dangerous to life or health shall be equipped with safety harnesses and safety lines for lifting or removing persons from hazardous atmospheres, or other and equivalent provisions for the rescue of persons from hazardous atmospheres shall be used. A standby man or men with suitable self-contained breathing apparatus shall be at the nearest fresh air base of emergency rescue.” The persons using the airline respirators referred to here would be the persons authorized by the employer to be in the space for routine work purposes, not the rescuers.

Appendix A, Section 5, of 29 CFR 1910.272, Entry into Bins, Silos and Tanks, OSHA`s grain-handling facilities standard, states: “Employers should carefully read 1910.134(e) (3) and assure that their procedures follow these requirements.”

29 CFR 1910.94, Section 1910.94 (d) (11) (v), of OSHA`s ventilation standard, states: “If, in emergencies, such as rescue work, it is necessary to enter a tank which may contain a hazardous atmosphere, suitable respirators, such as self-contained breathing apparatus, shall be used.”

29 CFR 1910.156, Section 1910.156 (f) (1) (ii), OSHA`s fire brigade standard, says: “Approved self-contained breathing apparatus with full facepiece shall be provided to and worn by brigade members while working inside buildings or confined spaces where toxic products of combustion or an oxygen deficiency may exist.”

Section 1910.156 (f) (1) (v) says: “Self-contained breathing apparatus shall have a minimum service life rating of 30 minutes except for escape self-contained breathing apparatus (ESCBA) used only for emergency escape purposes.”

ANSI standard Z117.1-1989, Safety Requirements for Confined Spaces, was used as the model for the development of OSHA`s Permit Required Confined Space standard, 29 CFR 1910.146. OSHA refers to Section 14.2 of the ANSI standard, which mandates that “All rescue personnel must use self-contained breathing apparatus (SCBA) or Combination Type C Air-line/SCBA breathing equipment, when entering the confined space to rescue victims.” The ANSI standard also states: “If it is established that the cause of the emergency is not a hazardous atmosphere, rescue breathing equipment is not required.”

ANSI`s explanatory note to this section states: “In some instances, the entrance to the confined space may be such that an SCBA unit on the rescuer will not fit through the opening of the confined space. This should have been pre-determined in hazard identification and evaluation or drills. In this event, the rescuer may be required to use Combination Type C Airline/SCBA type breathing equipment.”

In a letter written to OSHA asking for clarification of the 1910.134(e) (iii) standard, OSHA replied that if a fire department-style, 30-minute minimum SCBA will not allow the rescuer to fit through an opening into a confined space, then the rescuer will use a Type C combination airline/ SCBA. OSHA further states that the rescuer should remove the airline/SCBA from his back, pass the unit through the opening of the confined space, and then redon the unit after entering the space. OSHA says the airline can be disconnected at this point.3

Removing the breathing apparatus to pass it through a tight opening and then redonning the unit is a skill that typically hasn`t been developed or practiced enough by industrial and municipal rescue teams. Rescuers who haven`t become proficient at this technique will be more prone to accidentally dropping the unit, which could have disastrous results. Yet, even experienced personnel, under the tight and stressful conditions of confined spaces, could drop–and have dropped–their units, in some cases with tragic results. For this reason, some members of the rescue community oppose the use of SCBA in confined space rescue. Some fire departments with heavy rescue companies/capabilities have established stringent policies against such practice. Others have modified their techniques to minimize the chance of face piece dislodgment even if the cylinder is dropped.

The perfect respirator for confined space rescue would have the following attributes:

unlimited air supply,

very low weight and bulk,

be self-contained and have no airline to drag behind the wearer,

a breathing attachment for the victim (remember the unlimited air supply part), and

provision for excellent visibility and communications while wearing the face piece.

The reality in confined space rescue respiratory protection is much different. Currently, there is not one, all-around, all-purpose respirator that meets all of the needs for confined space entry and rescue.

In many instances, a supplied air respirator with an acceptable escape provision (15- to 20-minute air supply minimum) is the safest for confined space entry and rescue. In other cases, where there is room to maneuver inside the confined space, a fire department-type, open-circuit SCBA with a 30- to 60-minute air supply or a closed-circuit SCBA with a 60- to 240-minute air supply is an acceptable choice.

Consider the following scenario: A victim is injured inside a confined space with an unknown atmosphere. The confined space rescue team`s size-up reveals that, because of the internal configuration of the space, the airline-type SAR is the safest for conducting the rescue. The rescue team makes a safe entry and rescue using airline-type SARs. The victim recovers with no serious ill effects, and no one on the rescue team is injured. The local OSHA inspector investigates the circumstances and cites the rescue team for the use of airline-type SARs for rescue purposes, resulting in a large fine.

Is this a remote possibility or today`s reality? Unfortunately, this may very well be the reality.

To limit a confined space rescue team to a fire department-style, 30-minute minimum duration SCBA is like limiting a carpenter to using just a hammer to build a new house. Rescue personnel must be given the latitude of selecting and using the most appropriate respirator for the job at hand–i.e., safe entry into confined spaces to rescue injured victims. Nevertheless, your rescue program should be managed such that every attempt is made to comply as closely as possible with the intent and letter of the law. n

References

1. “Worker Deaths in Confined Spaces: A Summary of Surveillance Findings and Investigative Case Reports,” NIOSH Publications, Dissemination, DSDTT, Cincinnati, Ohio.

2. Correspondence: TS STD 1-0 1910.134/1910. 146, U.S. Department of Labor Occupational Safety & Health Administration, Philadelphia, Pa.

3. Correspondence: 60SHA (TS), U.S. Department of Labor Occupational Safety & Health Administration, Dallas, Texas.

(Top) SAR with a 10-minute escape bottle and Type C combination SCBA/SAR with a 30-minute bottle. (Bottom left, right) Closed-circuit SCBA, also called “oxygen breathing apparatus” or “rebreathers,” in 45- and 60-minute versions. (Photos courtesy of author.)

The size of an SCBA often may prohibit access to or egress from a confined space without removing the unit from the back and passing it through the space. This carries an obvious danger, is the subject of some controversy among fire departments, and has elicited contradiction within OSHA itself. Note: These photos were not taken to illustrate proper/complete protective clothing for confined space rescue.

The reduced profile of the SAR with a 10-minute escape bottle allows the rescuer to access the manway. An important safety concern: Don`t penetrate farther on supplied air than your air bottle can take you back!

MODIFYING PROCEDURES FOR SCBA SAFETY… “IN THE HOLE”

BY JOHN NORMAN

The decision about what type of mask–SCBA, SAR, or Type C airline/SCBA–to utilize when performing a confined space rescue depends on many variables: the types of masks available, the size of the opening to the space, the distance inside the space to the rescue site, and conditions/obstacles within the space.

While these concerns may be new to some users, the City of New York (NY) Fire Department (FDNY) has recognized them and has been prepared to deal with them for many years. For at least the past 28 years, FDNY has had written procedures documenting actions to be taken when entering tanks, manholes, and other vessels. When first written, these procedures called for the rescuer to enter with the SCBA face piece in place on the face, with the backplate/cylinder assembly suspended above the member on a rope until the rescuer reached the bottom of the tank, where he would then don the assembly conventionally. This could be performed with either 30- or 60-minute cylinders, giving 15 or 30 minutes of work time. This procedure was successful in several situations, permitting effective rescue to be completed. A key element in rescuer safety in this instance is to limit the distance/time the rescuer travels from the exit point to ensure escape before exhausting the air supply. Yet, there still was potential danger to rescuers.

More complex rescues in FDNY are handled by the department`s rescue companies utilizing Type C airline/SCBA. In 1984, FDNY conducted an extensive evaluation of the department`s confined space capabilities and decided to stay with an upgraded version of its Type C airline/SCBA, instead of an SAR with escape bottle, due to the extremely limited duration of such bottles and the extremely difficult conditions encountered in past incidents. It was felt that the use of a 30-minute bottle was vital to ensure rescuer safety in many of the situations that could be encountered. Overcoming the size of the 30-minute bottle is not a major concern to FDNY, since every firefighter has been trained in two maneuvers designed to permit them to function with the standard mask under constrictive field conditions: the reduced profile maneuver and the quick- release emergency escape procedure.

The reduced profile maneuver entails removing the SCBA`s right shoulder strap and twisting the SCBA to the left on the wearer`s waist in line with the wearer`s profile. This procedure often is performed as a matter of routine to permit passing between the building wall and the stairway leading to the balcony above when operating on a building`s fire escape.

The emergency escape maneuver is just what it sounds like. It is performed if a firefighter finds his SCBA has become seriously entangled on obstructions within the fire area and must be untangled to permit him to escape. In this case, the firefighter removes the SCBA`s right shoulder strap and fully extends the left shoulder strap. After firmly grasping the left shoulder strap in the left hand, the member releases the waist belt buckle and turns to the left to face the mask and untangle it using the right hand. In completing the department`s Mask Confidence course, each member must perform both of these maneuvers. In addition, the member also must remove the SCBA completely and then pass the SCBA ahead of him as he “escapes” under an obstruction. He then must redon the SCBA while maintaining the blacked-out SCBA face piece in place on the face at all times.

Following the Little Creek Naval Base confined space incident in 1988, the department again analyzed its own operations in confined spaces. In that incident, a Naval Base fire officer attempting a rescue of a worker in a ship`s tank attempted to pass his SCBA ahead of himself into a compartment. The officer lost his grip on the SCBA, which pulled his face piece from his face as it fell. Tragically, he was overcome before he could redon the face piece. Today, FDNY members are taught that if it is necessary to remove the SCBA or airline/SCBA from the back to enter a space, the harness must be physically attached to the harness or lifeline in such a manner that loss of control of the harness cannot pull the face piece from the face. Doing this will permit entry through virtually any size opening a member can fit through while ensuring the safety of the rescuer. n

(Right) A member wearing his airline/SCBA attached to his full body harness assists a “victim” through a vertical manway.

(Below) A firefighter passes a Type C airline/SCBA ahead of himself into a narrow horizontal passage. (Photos by John Norman.)

BREATHING APPARATUS “IN THE HOLE”… AN OPINION

BY MICHAEL G. BROWN

The issue of which type of breathing apparatus is “appropriate” for confined space rescue operations has been a hot topic among technical rescue teams for many years. Unfortunately, the myriad details and regulations imposed on us by OSHA, NIOSH, ANSI, etc. make the issue even more cloudy.

I had the misfortune of helping to remove a friend, Captain Bobby Hoeflein, from the bowels of the USS Ponce on Tuesday, September 27, 1988. He was killed in a herculean, but ill-fated, attempt to remove an unconscious civilian contract worker from deep within the cofferdam spaces of the 880-foot-long Ponce. The worker had entered the space with an SAR without a stored air backup supply. Bobby could not pass through the portals with the SCBA and removed the cylinder/harness from his back. The SCBA slipped from his hands, pulled the mask from his face, and forced him to consume two or three breaths of intensified gasoline vapors as his last conscious act.

We had been teaching supplied air breathing apparatus [SABA, also known as in-line breathing apparatus or supplied air respirators (SARs)] as the tool of choice for confined space entry for six years by then. Unfortunately, Bobby had not yet had a chance to attend any confined space rescue courses. Even if he had, I`m not sure his department would have purchased SABAs for him to use at that time. You see, we are a traditional business, and we have traditional breathing apparatus and traditional training. Unfortunately for Bobby and others, confined space rescues are not traditional calls.

When we look to our regulatory agencies for answers, we get every possible answer for confined space rescue work: SCBAs vs. SABAs–yes, no, and maybe, depending on the day.

I have researched and experimented with every configuration of breathing apparatus for confined space entry: SABAs; SCBA; SCUBA; liquid air; enriched air; rebreathers; 2,216 psi; 4,500 psi; every manufacturer`s product and in every conceivable configuration. There is no perfect breathing apparatus for the extreme hazards of confined space rescue.

Naturally, Type C combination airline/SCBA breathing systems are superior for their redundancy, but their profile difficulties are the same as those of the individual SCBA–and if the size of the space or opening demands removing the unit from your back, you`ve gained nothing. Therefore, though they all have their pros and cons, in my opinion, the advantages of using SABA during confined space entry and rescue far exceed the advantages offered by any other means.

Unfortunately, many departments have been led to believe that their structural firefighting SCBAs are the cure-all for any hazardous atmosphere. OSHA does not help matters any by issuing a number of conflicting “opinions” on 29 CFR 1910.146-compliant equipment. In one breath, an OSHA administrator in Washington thinks SABAs may be too dangerous to use in confined spaces, as “the airlines could get pinched in a door.” In another, “The employee may find the respirators [SCBA] provided cannot fit through the entry/exit. Maryland employers and firefighters have had this unfortunate experience, resulting in fatalities” (29 CFR 1910.146 preamble, p. 4528).

SCBAs are made for firefighting operations, witness NFPA 1981, Open-Circuit Self Contained Breathing Apparatus for Fire Fighters (1992). Unless the confined space you are entering is on fire, you are entering as a rescuer. The traditional mentality can dangerously lead us to overlook that one tiny detail: Firefighting and rescue operations, although sometimes performed simultaneously, are as different as night and day. At some point, emergency services managers (fire and rescue chiefs) have to come to grips with this fact: Complicated special rescue operations require special training, equipment, and people. The problem becomes exacerbated when departments choose to leave SCBA as the only available tool of choice (by not purchasing and training with SABA), thereby forcing valiant rescuers to attempt bizarre juggling acts with their primary piece of safety equipment.

In short, pressing rescuers into lengthy and complicated confined space entries is hazardous enough, but expecting them to take an SCBA off their backs and gingerly pass it through opening after opening only compounds the hazards.

SABAs can give you unlimited air (what a concept) and a much greater feeling of confidence. Total body profile is greatly reduced without having to remove the device. Yes, you have to learn to manipulate the airlines; but as firefighters, we already have experience in managing (hose) lines.

SCBAs have a very limited amount of air. Ask any big guy that is really huffing how much time he can get out of a 30-minute air cylinder. No SCBA manufacturer will warranty an apparatus during its use “off the back.” And the bottom line becomes, Gravity can snatch that apparatus out of your hands in a heartbeat. I wish Bobby were alive to tell you. n

MICHAEL DUNN is president of Emergency Training Associates, a fire/rescue training consulting company. He was a state industrial firefighting and rescue instructor for 15 years and has been actively involved in the fire service for 28 years. He has an associate`s degree in fire protection technology from Oklahoma State University and is a member of several national and international committees that are developing standards and textbooks for rescue and emergency response, including those of the International Fire Service Training Association, the American Society for Testing and Materials, and the International Association of Dive Rescue Specialists.