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Six Questions That Help Define Confined Space Safety

Nov 04, 2019

More than two million workers operate in confined spaces every year. Each of these spacesConfined space warning sign on sidewalk has unique hazards and risks that the employee needs to address. From hazardous atmospheric conditions to biological hazards and potential combustible materials, safety professionals have much to consider before workers enter confined spaces.

Answering a few key questions can help you ensure that workers stay safe in confined spaces and that your organization has proper procedures in place for emergency rescue.

1. What Is a Confined Space?

To effectively address the hazards workers face in confined spaces, you must become familiar with the terminology. This starts with an understanding of what a confined space is and how such an environment differs from other conditions that workers may encounter.

OSHA defines a confined space as a space that:

  1. Is large enough and so configured that an employee can bodily enter and perform assigned work
  2. Has limited means for exit and entry (e.g., tanks, vessels, silos, storage bins, hoppers, vaults and pits)
  3. Is not designed for continuous employee occupancy.

Terry Ketchum of the ANSI/ASSP Z117 Committee on Safety Requirements for Entering Confined Spaces says it’s best to treat every space as a confined space if you are uncertain of the conditions workers will encounter once they enter. 

2. What Are the Hazards?

A confined space may contain any number of hazards, from biological and mechanical to physical, chemical or atmospheric. The space may be oxygen-deficient or oxygen-enriched. It may contain bacteria capable of producing flammable or toxic gases, as well as physical hazards such as electrical or radiological risks, structural issues or the potential for engulfment, where a worker is surrounded and effectively captured by a liquid or flowable solid substance.

As a starting point, Ketchum recommends referencing any previous assessments or permits for a confined space for guidance on the types of hazards present. It’s also beneficial to consult other safety professionals and meet with agencies such as utility companies for assistance in dealing with any power, water or gas considerations within a confined space.  

3. How Do I Mitigate Hazards?

To address whatever hazards may exist in a confined space, a qualified person should conduct an initial survey of the operations to be performed. Z117 defines a qualified person as “a person who by reason of training, education and experience is knowledgeable in the operation to be performed and is competent to judge the hazards involved and specify controls and/or protective measures.”

The initial survey should document the number of employees working in the space; the likelihood, magnitude and potential consequences of each hazard; and potential changes in conditions or activities. With this information, you can then develop strategies for mitigating each hazard using the hierarchy of controls.

4. Do I Need a Permit?

Confined spaces are divided into two categories, permit-required and non-permit-required. What separates these two categories are the conditions in the space. A permit-required confined space has one or more of the following characteristics:

  1. Contains or has the potential to contain a hazardous atmosphere
  2. Contains a material that has the potential to engulf an entrant
  3. Has an internal configuration such that an entrant could be trapped or asphyxiated by inwardly converging walls or by a floor that slopes downward and tapers to a small section
  4. Contains any other recognized serious safety or health hazard.

“The intent of the permit system is to provide a systemic review for hazards, communicate that information to all involved and provide an approval process for confined space entry,” says Ketchum. “It is imperative that any confined space be treated as a permit-required confined space until the space has been determined to be free of hazards.”

For entry into non-permit-required spaces, an employer must develop and implement safe work procedures. This should include assessing the conditions and precautions needed for safe entry, as well as identifying what constitutes a change in conditions, which would require a reevaluation of the confined space.

5. What PPE Do My Workers Need? 

The answer to this question depends to some extent on the hazards identified in the confined space. In general terms, much of the PPE will be similar to what a worker would wear in any working environment, such as hard hats, gloves, eye and face protection, and foot protection. Auxiliary PPE could include flame-resistant clothing, chemical gloves or fall protection harnesses, depending on the specific hazards identified within a particular confined space.

6. What If Something Goes Wrong? 

Unfortunately, things can go awry in a confined space and workers may need to be evacuated or rescued. An employer must have a plan in place to respond to identified or potential emergencies, including the timely evacuation, rescue or retrieval of confined space entrants.

“Things sometimes go wrong, even when you think you have addressed everything,” says Ketchum. “Plan ahead, be prepared for ‘what if’ situations and practice the response actions.”

Furthermore, Ketchum emphasizes that a facility should not depend on local emergency response for confined space rescue as local authorities may not have the capabilities and resources necessary to perform a rescue operation. Therefore, your emergency response plan should include training and equipping on-site rescue teams so they are ready to respond in emergency situations.

Planning for these scenarios and practicing them in advance of an emergency will also help  ensure that both workers and the response team will respond appropriately to prevent any serious injuries or fatalities.

“To effectively manage situations like this, you need to practice,” says Ketchum. “We need to be vigilant and constantly assess our confined spaces, particularly permit-required spaces to quickly respond to changes in the work environment.” 

Listen to our podcast with Terry Ketchum of the Z117 committee for further insights on how to keep workers safe in confined spaces.

Related Links

ANSI/ASSP Z117.1, Safety Requirements for Entering Confined Spaces

Confined Spaces: Common Misconceptions & Errors in Complying with OSHA’s Standard

Confined Space Incident Reconstruction: The Future Depends on Understanding the Past

Cargo Trunk Tanks: An Often-Unrecognized Confined Space Hazard

Anatomy of a Confined Space Fire

 

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