OSA Magazine Logo

The Ins and Outs of Confined Space Rescue

Published: 10th Sep 2011 in OSA Magazine

If a man was drowning in a rough sea, would you jump in to save him? Might it cross your mind that you could drown as well? In more than 60% of reported confined space fatalities, the would-be rescuer also loses their life. The following are true stories of worker fatalities as reported to NIOSH (National Institute of Occupational Safety & Health).

Case one

A 54-year-old worker died inside a floating cover of a sewage digester while attempting to restart a propane heater that was being used to warm the outside of the sewage digester cover prior to painting it. Workers had wired the safety valve open so that the flow of propane would be constant, even if the flame went out. The heater was located near an opening in the cover of the digester. When the worker attempted to restart the heater, an explosion occurred that vented through the opening. The worker crawled away from the heater into an area that was oxygen deficient and died. A co-worker attempted a rescue and also died.

Case two

A 20-year-old construction worker died while attempting to refuel a gasoline engine powered pump used to remove wastewater from a 66 inch diameter sewer line that was under construction. The pump was approximately 3,000 feet from where the worker had entered the line. The worker was overcome by carbon monoxide. A co-worker, who had also entered the sewer line, escaped. A 28-year-old state inspector entered from another point along the sewer line and died in a rescue attempt. Both deaths were due to carbon monoxide intoxication. In addition to the fatalities, 30 firefighters and eight construction workers were treated for carbon monoxide exposure.

Case three

Two workers (26 and 27 years old) were overcome by gas vapours and drowned after rescuing a third worker from a fracturing tank at a natural gas well. The tank contained a mixture of mud, water, and natural gas. The first worker had been attempting to move a hose from the tank to another tank. The hose was secured by a chain and when the worker moved the hose, the chain fell into the tank. The worker entered the tank to retrieve the chain and was overcome.

Case four

A 22-year-old worker died inside a toluene storage tank that was 10 feet in diameter and 20 feet high, while attempting to clean the tank. The worker entered the tank through the 16 inch diameter top opening using a 1⁄2 inch rope for descent. Although a self- contained breathing apparatus was present, the worker was not wearing it when he entered the tank. The worker was overcome and collapsed onto the floor of the tank. In an attempt to rescue the worker, fire department personnel began cutting an opening into the side of the tank. The tank exploded, killing a 32-year-old firefighter and injuring 15 others.

What is a confined space?

Confined spaces represent potentially serious safety and health risks for rescue personnel. During most confined space situations, response time and access are limited; therefore, there are many hazards to prepare for. Untrained personnel could spend hours trying to ineffectively remove a victim – time that the victim may not have. If the victim has stopped breathing, rescue personnel have only four to six minutes before brain damage begins from the lack of sufficient oxygen.

Many workplaces contain spaces that are considered ‘confined’ because their configurations hinder the activities of employees who must enter, work in, and exit them. A confined space has limited or restricted means for entry or exit ,and it is not designed for continuous employee occupancy. Confined spaces include, but are not limited to underground vaults, tanks, storage bins, manholes, pits, silos, process vessels and pipelines.

The United States Occupational Health and Safety Administration (OSHA) uses the term “permit-required confined space” to describe a confined space that has one or more of the following characteristics: contains or has the potential to contain a hazardous atmosphere; contains a material that has the potential to engulf an entrant; has walls that converge inward or floors that slope downward and taper into a smaller area which could trap or asphyxiate an entrant; or contains any other recognised safety or health hazard, such as unguarded machinery, exposed live wires, or heat stress (OSHA).

Managing confined spaces

It is important for managers and safety personnel to have thorough knowledge of the confined spaces located on your site. All confined spaces should be located and identified.

Include detail such as configuration, size, number of entries, specific hazards involved and the number of workers that could potentially be affected if an emergency situation occurred. Note any anomalies such as an elevated or hard to reach entry point or other hazards that surround the location, which may require specific personal protective equipment just to gain access to the confined space.

A map of your site should include where all confined spaces are located and the best routes for emergency personnel to reach each one. Once enough information is gathered, important decisions can be made concerning creating a rescue plan, the number of rescue personnel needed, the type and amount of rescue and personal protective equipment needed, and the different types of training that will be required.

A thorough rescue plan includes:
• A barricade area for crowd control
• Additional ventilation options
• Control of other hazards (cave-ins or traffic, for example)
• Protective clothing and equipment
• Appropriate lighting equipment (explosion-proof)
• Methods of communication
• A standby rescue team
• Victim removal procedures and devices
• Available emergency vehicles
• Medically trained personnel
• Identified duties of each person on staff

Minimal training requirements for permit-required confined space rescue personnel include: proper use of rescue and personal protective equipment, knowledge of designated responsibilities and procedures for assigned rescue duties, basic first aid and cardiopulmonary resuscitation skills – with at least one member holding current certification – and practice by means of simulated rescues at least once every 12 months removing dummies, mannequins or people from actual or representative permit-required confined spaces.


Every confined space entry must have an attendant. An attendant is a trained individual stationed outside of the space who monitors the entrants inside and performs all attendant duties. One of the biggest responsibilities of the attendant is to keep their co-workers safe. To do this, the attendant must maintain continuous communication with all entrants within the confined space by voice, radio, phone, or visually. If the space is so configured that none of these methods work, other possibilities for communication include tugging on a rope, tapping, or waving a flashlight.

Attendants need to know and be able to:
• recognise hazards that may be faced during entry
• recognise the effects of hazard exposure in authorised entrants
• keep track of all authorised entrants in the confined space and warn unauthorised persons to stay away
• test the air inside and outside the space continuously to ensure it’s safe for entrants to continue working
• ensure all rescue and communication equipment is in working order

The attendant must be fully aware of the emergency action plan and how to call for help in the event of an emergency. The attendant serves as the first line of communication for emergency personnel, and communicates information such as how many entrants are in the space, what hazards exist, what actions were taken to remediate hazards prior to entry, and what personal protective equipment is being used.Where regulated, this information is included on a permit, which is obtained from a supervisor prior to entering the space.

The attendant must stay at their post unless they are replaced by another trained attendant, and must never enter the confined space, even if the entrants are in trouble.


There are three categories of confined space rescue: self rescue, non-entry rescue and entry rescue.

Because of the speed at which confined space hazards can incapacitate and kill, self-rescue is the preferred plan. The self-rescue plan provides entrants with the best chance of escaping a permit space when hazards are present. Whenever authorised entrants recognise their own symptoms of exposure to a dangerous atmosphere, or when a prohibited condition is detected, entrants are still able to escape from the space unaided and as quickly as possible (CalOSHA, 1998).

Non-entry rescue is the next best approach when self-rescue is not possible, because non-entry rescue can be started right away and prevents additional personnel from being exposed to unidentified and/or uncontrolled confined space hazards. Usually, equipment and other rescue aids are employed to assist in removing endangered entrants. In situations where configurations of the space or other elements prevent the removal of the worker, entry rescue may be the only solution (CalOSHA, 1998).

Entry rescue involves rescuers entering the space to retrieve the entrant and/or provide the victim with emergency assistance such as CPR, first aid, and air via SCBA or a supplied air respirator (SAR), if needed.An entry rescue plan needs to be developed ahead of time in the event of an emergency for which the non-entry rescue plan is not appropriate.

This is a last resort option as having more personnel enter an area that has already incapacitated one or more persons places the rescuer at considerable risk. Entry rescues must be carefully planned and executed to avoid creating more victims in need of rescue. Rescuers need to be aware of their surroundings and must reevaluate their plans immediately if there is any change in the conditions of the confined space. In the event of an entry rescue, standby rescuers are recommended should the initial entry rescuer(s) encounter trouble (CalOSHA, 1998).

Due to the unique nature of confined space rescues, specialised equipment is necessary to perform a safe and successful rescue.This may include:
• Full body harness with retrieval line attached – all authorised entrants and rescuers entering permit-spaces are required to use full body harnesses and retrieval lines, unless it is determined that the retrieval equipment would increase the overall risk of entry, or would not contribute to the rescue operation
• Wristlets – may be used in rescue when it can be shown that they are the safest and most effective means of rescue
• Hand-cranked mechanical winch and tripod
• Ladder
• Explosion-proof lighting
• Stretcher
• Approved head protection (CalOSHA, 1998)

Anticipating atmospheric hazards

Thorough pre-planning and preparation is the key to successfully dealing with the variety of permit-required confined space hazards that may be encountered. Potential hazards can be grouped into two main categories: atmospheric and physical. Most confined space injuries and deaths are caused by invisible atmospheric hazards such as oxygen deficiency, flammable gases and vapours, or toxic gases.

Oxygen deficiency within a confined space occurs when the concentration of oxygen drops below 19.5%. In a matter of minutes your judgment and muscular coordination are affected by the lack of sufficient oxygen. Your sense of hearing, touch, and location may also be affected. Continuous exposure will cause you to lose consciousness, and death may occur in minutes depending on the oxygen content of the air.

Flammable gases and vapours can cause deadly fires and explosions in confined spaces. For this to happen, three elements must be present: fuel, oxygen, and a source of heat (ignition source). These are the three elements of the fire triangle. Sources of heat include: open flames, sparks from cutting operations, use of unapproved electrical equipment, release of static electricity, friction and smoking. Toxic gases represent risks ranging from irritation to asphyxiation. Initial symptoms might include: eye and respiratory irritation, headaches, dizziness, nausea and fatigue.

Common toxic gases that can accumulate in confined spaces are carbon monoxide, hydrogen sulfide, sulfur dioxide and ammonia, to name a few. These gases may be generated outside the space or they may form inside from residues, biological activities, or be produced from the work that is being performed.

Because it is impossible to always see or smell atmospheric hazards, monitoring devices must be used in all permit- required confined spaces to detect oxygen content, flammable gases and vapours, and potential toxic air contaminants. Monitoring must be conducted continuously to ensure that conditions do not change during confined space activity.

Gases and vapours can be lighter or heavier than air, and therefore will accumulate at different levels within the confined space. The entire confined space must be tested without the use of ventilation systems, and at various depths. When the space is vertical, remote probes can be used. Also, test outside of the confined space to make sure the surround air is also safe.

Air monitoring should be conducted by trained, authorised personnel prior to entry into a confined space. They should have a thorough understanding of the operation of the equipment and how to read the equipment. It is extremely important to use your air monitoring equipment correctly – you are making life and death decisions. It should also be properly maintained. A sound maintenance programme will ensure that your gas monitors will accurately measure the presence of atmospheric hazards and immediately alert the user to a dangerous condition (Suski, 2005).

Other hazards

Just as dangerous as atmospheric hazards, physical hazards can also cause serious injuries and even death. Physical hazards in confined spaces include: mechanical – moving parts which have not been properly isolated from energy sources; engulfment due to lose materials such as grains, sawdust, or sand; falls caused by slippery or uneven surfaces; poor visibility from inadequate lighting; burns from corrosive chemicals or welding and sudden changes in the weather.

With all these potential obstacles to overcome during rescue situations, pre-planning and training are a must. All rescue situations are different. Using knowledge gathered about each confined space located on your site, ask yourself ‘what if’ questions to be as prepared as possible. Being proactive will allow ‘what if’ scenarios to be solved safely before emergencies occur, when emotions and time are not life threatening factors.
• What if the man way is too small for rescue personnel to enter wearing SCBAs?
• What if the space doesn’t have a standard opening?
• Would a litter basket or body board fit through the manway?
• What if the rescuers need to cut a larger opening?
• What if there is no room to put up a tripod?
• What if there is an explosion?
• What if the rescuers need fall protection to enter the space?

Time and safety are two very important issues during confined space rescue situations. Take the time to establish safe and effective rescue procedures and become familiar with the different confined spaces at your facility, and their hazards. Routinely practice different rescue techniques before you actually need to use them. Confined space rescue situations require immediate action. Do not allow your actions to lead to failure – help yourself and your workers by being prepared for success.

Works cited

CalOSHA. (1998). Is it Safe to Enter a Confined Space? Confined Space Guide. Sacramento: California Department of Education.

OSHA. (n.d.). Safety & Health Topics: Confined Spaces. Retrieved August 2011, from OSHA: http://www.osha.gov/SLTC/confinedspace

Suski,T. (2005, June 1). Common Mistakes in Confined Space Monitoring. EHS Today.

Published: 10th Sep 2011 in OSA Magazine


Sara Wesche

Sara Wesche has been with Summit Training Source for more than nine years. Her creative skill and expert writing abilities led her to the Marketing Specialist position, and ultimately to managing the marketing department in 2003. Sara’s focus has been developing Summit’s World Wide Web presence, to generate sales leads through multiple medias, and to create marketing support materials that solidify Summit’s position as the complete EH&S training solution provider. Sara graduated from Michigan State University with a Bachelor of Arts in Communication. Sara can be reached at SaraW@safetyontheweb.com or at SafetyTraining1 on Twitter.

Summit Training Source has been an environmental, health and safety training innovator for more than 29 years. In excess of 40,000 clients worldwide trust the health and safety of their employees and work sites to Summit’s expert training capabilities. With at least 600 environmental, health, and safety training titles in multiple formats, including Online, DVD, Streaming Video, Summit Elements, and Online OSHA accepted 10 & 30 Hour, Summit provides proven content that delivers the business results expected in today’s competitive global environment.

Summit programmes create an awareness and respect of workplace hazards and reduce incidents, accidents, and their associated costs. Summit was the first training provider to offer interactive CD-ROM training, leading the way into the interactive technology age. Summit’s online platform, Summit Trainingweb®, offers customers global consistency, 24/7 availability, and is based on adult learning theories to create a more comprehensive and engaging programme. Summit’s Online OSHA 10 & 30 Hour training for Construction and General Industry has been authorised by OSHA.

Summit’s programmes are effective, offering a return on investment to customers. Our continued mission is to provide the highest quality training programmes available, meeting industry needs and complying with all regulatory guidelines, enhancing the future productivity, growth, and bottom line results for all our customers.

For free previews of any Summit programme or access to Summit Trainingweb® online courses, call 800-842-0466 or visit http://www.safetyontheweb.com


Sara Wesche





Contact Us Events List Terms and Conditions Privacy Policy Sitemap Maintenance