Toolbox Talk: Staying Safe in Confined Spaces

A confined space toolbox talk can save lives. Here’s why and what to cover.

In a typical year, more than 100 people die from working in a confined space, so it’s important to remind your crews how to remain safe. A toolbox talk devoted to confined spaces could make the difference between a successfully completed project and a project involving an injury or fatality.

Here are the basics to cover.

What is a confined space?

A confined space has limited or restricted means for entry or exit and is big enough to work in but not meant to be occupied continuously.


  • Manholes
  • Crawl spaces
  • Tunnels
  • Pipelines
  • Water mains
  • Storm drains
  • HVAC ducts
  • Shafts

Confined space dangers

If the confined space poses a potential hazard to health or life, it’s a permit-required confined space (PRCS). OSHA requires contractors to have a competent person who determines if a permit is required.

There are many potential dangers in a PRCS, including:

  • Asphyxiation, caused by a lack of oxygen in the space or toxic gases
  • Injury from a fire and/or explosion if there’s a buildup of dust or if flammable liquids are present
  • Shock or electrocution from electrical hazards
  • Injury from being entrapped in mechanical equipment
  • Entrapment if the access point(s) are blocked
  • Drowning from water or another liquid that engulfs the space
  • Heat exhaustion or heat stroke from a high ambient temperature
  • Respiratory problems due to dust buildup

The best way to keep safe is to stay aware the dangers and recognize the symptoms and warning signs of possible problems.

Everybody has a role in safety

OSHA requires the general contractor, subcontractor and owner to keep each other informed about any potential dangers in the confined space. If someone sees or suspects a problem, they must let the other jobsite partners know about it right away.

Authorized entrants must know the hazards they might face and the symptoms that indicate they’ve been exposed to those hazards. They must know how to use any necessary PPE — and make sure they use it.

The entry attendant must stay in communication with the workers in the space, alert them if there’s a problem and call the emergency rescue team if necessary. They may attempt a rescue themselves as long as they don’t go into the space.

The entry supervisor makes sure the PRCS is safe to enter and monitors conditions in the space. They must ensure that the rescue team is available. One person can serve as both the entry supervisor and the entry attendant if they have been trained for both jobs.

Keeping yourself and others safe

A confined space is less dangerous if workers:

  • Have had proper training and know what to watch for
  • Understand the potential risks
  • Test the atmosphere before ventilating
  • Report any changing/potentially dangerous conditions to the entry supervisor and/or the competent person
  • Wear the appropriate PPE
  • Get out immediately if they’re told to

Need help determining which confined space standard you should be following? Read more here.

The OSHA requirements mentioned above are from OSHA Standard 1926 Subpart AA.


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Nothing is more important than safety on the worksite, but compliance doesn’t have to cost you. With expert knowledge and smart solutions, United Rentals can help your site stay safe without sacrificing efficiency.

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