Fire is one of the several hazards that are present in a confined space. The hazards found in a confined space are likewise present in any other workplace but can be even more hazardous. Among the hazards in a confined space are the following:
- Poor air quality;
- Chemical exposures due to skin contact or ingestion as well as inhalation of 'bad' air;
- Fire Hazard;
- Process-related hazards such as residual chemicals, release of contents of a supply line;
- Safety hazards such as moving parts of equipment, structural hazards, entanglement, slips, falls;
- Temperature extremes including atmospheric and surface;
- Shifting or collapse of bulk material;
- Barrier failure resulting in a flood or release of free-flowing solid;
- Uncontrolled energy including electrical shock;
- Visibility; and
- Biological hazard.
The rest of this article contains details about confined space rescue. Relevant and important information on the topic is particularly useful for all concerend.
Confined-space rescues are deceptively dangerous. Seemingly straight-forward operations tempt our natural instinct to jump in and save someone, but confined spaces present critical physical and atmospheric hazards that may not be immediately apparent. Statistics prove this point: Every time someone dies in a confined-space accident, two would-be rescuers die as well. Bystanders and professionals alike often fail to recognize that the physical or atmospheric hazards that have overcome the initial victim pose dangers to them as well. These deaths are unnecessary and preventable; the key is proper education and training.
Before committing personnel to confined-space operations, address the following questions frankly: Is your organization ready for the next confined-space rescue or recovery? Does your organization know how to identify a confined space? Does your organization know how to identify the inherent dangers that emergency responders face when dealing with confined spaces? Does your organization have the proper equipment and training to overcome hazards during confined-space entry?
According to OSHA, a confined space is large enough and configured so that a person can enter and perform assigned work, but has limited or restricted means for entry or exit and is not designed for continuous human occupancy. Confined spaces include tanks, vessels, silos, storage bins, hoppers, vaults and pits.
The limited access, cramped environment and associated risks of confined-space operations put unique demands on response personnel. A confined-space rescue team needs to be highly trained and properly equipped before it responds to and attempts any confined-space rescue. Confined-space rescuers need to be trained to NFPA standards, specifically 1670, Operations and Training for Technical Search and Rescue Incidents, chapters 6 (Rope Rescue), and 7 (Confined-Space Rescue); and 1006, Rescue Technician Professional Qualifications, Chapter 9 (Confined-Space Rescue). NFPA 1670 defines three levels of training for both rope rescue and confined-space rescue: awareness, operations and technician. Not all team members require the most advanced training to participate in confined-space rescue, and your training plans for your personnel will require you to identify which of your personnel need which skills and knowledge.
All of your emergency responders don't need the most advanced training either, but they do all need basic awareness and operations training. During a confined-space rescue you will need many people who can fill different roles. Having everyone trained to operations or technician level will give the incident commander more flexibility and capabilities during rescue operations and will help to ensure the safest and most efficient response. One thing to remember is that the more complex the rescue, the more technicians you will need to complete. A simple rescue from a confined space requiring vertical access to the victim demands a team of six to 10 emergency responders; NFPA 1670 says a rescue team will be made up of a minimum of six individuals who are able to work at the technician level and a minimum of four individuals able to operate at operations level.
Confined-space rescue team members need regular and consistent rope rescue training. The rescuers need to be proficient in assembling and operating simple and compound mechanical advantage, lowering, belay and anchor systems.
A simple mechanical advantage is one of the following systems: 4:1 block and tackle, 3:1 block and tackle, 3:1 horizontal Z-rig and 3:1 vertical Z-rig. Understanding simple systems enables rescuers to employ complex systems, which are made up of two or more simple systems used in conjunction to increase pulling capacity. An example of a compound system is a 4:1 horizontal piggy-back, which is used to attach to another system.
Lowering systems consist of some type of friction device like a brake bar or eight plate that is used to lower a person or litter to the ground. Deciding whether to use a brake bar or eight plate depends on the weight that will be lowered or the number of people who will be lowered. An eight plate is used for a single-person load that doesn't exceed 300 pounds, while brake bars have been designed for either one- or two-person loads up to 600 pounds. Brake bars were designed to provide more friction, which provides more control during lowering activities. The greater control you have during lowering operations, the safer your victims and rescuers will be.
Any time you're using a lowering system you also will need to have a belay system in place to capture the load if the primary lowering system fails. When you're building your belay system, you'll need to determine how much weight you plan to belay off. A belay system normally consists of either a munter hitch or a 540-rescue belay; a munter hitch is designed to handle less than 300 pounds and is considered a one-person load, while the 540-rescue belay is designed for less than 600 pounds and two person loads. The 540-rescue belay is a device that provides a higher degree of safety than the munter hitch. Anchor systems need to be attached to objects that can hold the loads and forces generated by belay, lowering and haul systems. An anchor point is the backbone of the whole rescue, and finding one that can provide plenty of support will enhance the rescue operation while increasing the cushion of safety. When selecting an anchor point, rescuers need to know the difference between questionable and bomb-proof anchor points. Questionable anchor points need to be avoided if possible; if you must use them, they need to be supported by a load-distributing anchor system when there are no bomb-proof anchor points available. A bomb-proof anchor is just what it implies — an anchor that will hold up during an explosion. Many things can be considered bomb-proof anchors, such as steel beams, buildings or large objects made of concrete.
Beyond training with ropes, rescue personnel need to have equipment and skills for conducting atmosphere testing. Monitoring oxygen levels, lower explosive limits, and CO and H2
S levels is essential both before personnel enter a confined space and during the course of operations. Oxygen levels from 19.5% to 23.5% are considered safe; if oxygen levels are below 19.5% the atmosphere is considered to be oxygen-deficient. An oxygen-deficient atmosphere can lead to asphyxiation, unconsciousness and death; rescue crews can't enter without some type of supplied oxygen system. If the oxygen levels are above 23.5%, on the other hand, the atmosphere is considered to be oxygen-enriched, which means an increased flammability hazard. No rescue crews can enter any confined space with a reading above 10% of the LEL. This type of environment increases the possibility of an explosion, and there's nothing team member can do to protect themselves from it while inside the confined space. Proper ventilation techniques will reduce and control the LEL and CO levels, giving rescuers a safer environment to enter the confined space to perform a rescue operation.
When entering a confined space, it's important for personnel to monitor the atmosphere continuously because conditions can and will change. Some gases will be lighter than air, while others are heavier. These heavier gases can settle in the area of operations and increase the dangers to rescuers and victims. Monitoring needs to be conducted in all directions and every couple of feet to detect any changes in the environment. There are many different types of equipment that can be used to assist in monitoring the environment, such as multi-gas atmospheric monitors, combustible gas monitors and oxygen concentration monitors. Personnel should be proficient in the use of all of them.
After completing the initial training, the next step is to confirm that the confined-space rescue team has all the proper equipment. Rescue equipment is very expensive, and team leaders will have to decide what equipment needs to be purchased. Much of the equipment that's used for confined-space rescue can be used for other types of rescue operations, and costs can be reduced by considering ways for rescue teams to have access to each other's equipment; this savings, in turn, makes it possible to buy other new equipment.
Confined-space rescuers will need special equipment to help remove victims from a confined space. Stokes, Skeds and Miller backboards are great to support the spine when removing the victims; in addition, all rescuers that enter any confined space are required to have a Class III harness. Class III harnesses are full-body harnesses that have several attachments to allow vertical and horizontal rescues.
Communications is one of the most important elements of any type of emergency, but for confined-space rescues it's vital. Hardline communications devices have been developed that can improve operations by allowing communications in situations where conventional radio systems don't work.
Another great technology that has been developed for confined-space rescues is the low-profile air system, which provides rescuers with air while giving them more maneuverability in tight areas. The low-profile air system also can add a degree of safety by allowing rescuers to enter smaller access points without having to remove their air packs.
After the initial training is completed and equipment has been allocated, it's time to form a preplan for organizing and coordinating confined-space rescues.
Team leaders can develop a preplan without considering the exact type of rescue that will be performed. Having a preplan or checklist available at the beginning of a confined-space rescue operation would make it safer to follow steps before rescue teams are allowed to enter a confined space to attempt a rescue. NFPA 1006 can assist team leaders in developing a preplan or checklist to confined-space rescues.
Here are a few things to think about when developing preplans and checklists:
- The number of victims and their location.
- Whether victims are entrapped or engulfed.
- The type of confined space with access points.
- Lock-out/tag-out procedures.
- Atmosphere reading procedures.
- Atmosphere ventilation procedures.
- Crew assignments.
- Accountability procedures.
- Rapid invention team procedures.
- Decontamination procedures.
After entries have been preplanned and procedures developed, the incident commanders will need to weigh risks versus benefits before committing rescuers to a confined-space rescue operation. The benefits must outweigh the risk before entering a confined space, but the risk must also be removed or diminished to provide adequate safety for emergency responders during the rescue. When entering a confined space, rescue teams must be 100% correct all the time; one mistake can cause serious injury or death. We can't afford to compromise the safety of any rescuer for any reason.
Most hazards can be eliminated or reduced to make a safe entry, but it takes time. Identifying the incident as either a rescue or recovery situation will determine how much time can be spent mitigating hazards. Time is critical during a rescue because a person without oxygen will begin to develop permanent brain damage after six minutes. During a recovery, time is not as important, and the incident commander needs to wait until all hazards have been removed before committing rescuers.
Confined spaces are extremely dangerous to everyone who enters them for many reasons. No matter how someone has become a victim in a confined space, it's up to every organization that has a confined-space rescue team to be properly equipped and trained. The organization also has a responsibility to maintain rescue crews' knowledge levels and develop preplans and checklists. When developing confined-space rescue teams, NFPA 1670 and 1006 are great resources in helping identify all the areas of training that need to be developed, along with information about preplanning.
Only after rescue members have been given the proper training, proper equipment and preplans is the team is ready to perform confined-space rescues.