Technical Rescue: First Due to a Confined-Space Rescue

Contributor Mike Daley offer insighte to the recognition and identification of confined spaces. He talks about monitoring of the atmosphere, ventilation, lockout/tagout and other important components these incidents.


Two municipal utility workers arrive at a lift station in their community to check a potential leak in a pipe. The two enter the lift station, approximately two stories below grade, and check a flange connection on the pipe. The flange fails during the repair and toxic fumes are released into the space.

One worker is overcome immediately; another worker rushes to climb the ladder to safety only to become overcome approximately halfway up the escape ladder. The local fire department arrives in time to remove both workers from the bottom of the space. One worker is pronounced dead on the scene and the other succumbs to his injuries days later.

 

Stay out of trouble

While the fire department is due credit for jumping into action in an attempt to save the two workers, the department finds itself in trouble for entering the confined space without the proper training, necessary equipment or operational policies in place. Heavy fines and sanctions were put in place against the department, resulting in significant changes regarding the department’s response to these types of incidents.

The scenario described above was an actual confined-space event that could happen anywhere, at any time, in any community. Local fire and EMS providers can find themselves responsible for responding to incidents of this nature in their own response areas. The question is: How will you handle this incident when the time comes?

 

Recognition and identification

The Occupational Safety and Health Administration (OSHA) define both “non-permit” and “permit-required” confined spaces as enclosed spaces that:

1. Are large enough and configured so that an employee can enter and perform assigned work.

2. Have limited or restricted points of entry and egress.

3. Have not been designed for continuous occupancy.

What makes a confined space “permit required” is that the space has or has the potential to have:

1. A hazardous atmosphere.

2. An engulfment hazard.

3. An internal configuration that could trap or asphyxiate an entrant, such as converging walls or tapering floors and cross sections.

4. Any other recognized serious safety or health risk.

The scenario described at the beginning of this article lists a municipal lift station as a confined space. However, you need not look far in your response areas to find dangerous confined spaces. If your response area includes water towers, silos, industrial settings, sewers and storm drains, manholes and lift stations, then you have the potential to respond to an incident of this magnitude.

 

Common hazards

The atmospheric dangers lurking in confined spaces can be placed in four major categories: oxygen deficiency; toxicity; flammable and explosive materials; and airborne particulates. Oxygen deficiency is the most common cause for injury and death in a confined space. In normal air, the oxygen concentration is approximately 20.9%. Responders use a range of 19.5% to 23.5% as an acceptable scale for oxygen content. However, there are many reasons why there would be a variation from the normal concentration, such as rusting, organic and bacterial releases and chemical reactions in a confined space. Any change in air concentration should be investigated and identified when possible.

The toxicity of a material in a confined space carries a wide variety of safety and health concerns, depending on the material. The primary focus of the responder should be to protect against any route of entry into the body; most commonly through inhalation. It is the quickest route to all of the body’s organs, as the material is exchanged in the lungs and travels through the blood to all areas of the body.

We are taught in our entry-level firefighting course that four things are necessary to support combustion: fuel, heat, oxygen and the chemical chain reaction that brings it all together. Suppression techniques can vary to interrupt this process by removing the fuel, disrupting the chain reaction and isolating the heat source. In the confined-space scenario, it is imperative to identify any flammable and explosive conditions that exist in the space. Once identified, rescuers can define the materials’ flammable range, consisting of the lower explosive limit (LEL) and the upper explosive limit (LEL), and determine how to make the space safe to enter.

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