Confined Space Safety 101: First Steps You Need to Take Before Sending Workers into a Confined Space
Planning for the worst case scenario can prevent a day at work from turning into a tragedy.

With approximately 1.6 million workers entering confined spaces each year, how to keep these workers safe is a topic worth discussing. In fact, OSHA estimates that employers fully complying with safety standards would prevent 53 deaths, 5,000 lost days, and 5,700 other accidents annually.
Unfortunately, a NIOSH review determined that many injuries and fatalities related to confined spaces happened simply because employers and their workers failed to recognize, plan, and control for the hazards related to this type of work.
With proper diligence, you can help your employees stay safe in these challenging conditions. This article will cover the first things you must consider before sending anyone to work in a confined space.
What Are Confined Spaces?
Safety starts with identifying what is (and is not) a confined space. OSHA defines a confined space as one with the following attributes:
- Large enough for an employee to enter fully and perform assigned work
- Not designed for continuous occupancy by the employee
- Has a limited or restricted means of entry or exit
Examples of confined spaces include:
- Condenser pits
- Manholes
- Ventilation ducts
- Excavated holes
- Rail car tankers
- Sumps
- Containment cavities
- Vaults
- Vessels
- Silos
Employers and workers must take note that some confined spaces require permits to enter, and it’s always a good idea to double-check local or state regulations.
Hidden (and Not So Hidden) Confined Space Hazards
The safety risks posed by confined spaces vary depending on the type of space. Accidents take many forms and include:
- Hazardous atmospheres
- Temperature extremes
- Engulfment
- Flooding
- Falling objects
Employees who work in confined spaces at heights (for example, at the top of a grain elevator) must ensure they have adequate fall protection in addition to confined space safety gear (find out How to Keep Agricultural Workers Safe from Common Grain Bin Hazards).
Gas is one of the most common and dangerous hidden hazards of confined space work. Even a small amount can be enough to cause suffocation, combustion, or poisoning. Since some gases can’t be seen or smelled, testing the atmosphere prior to worker entry is critical to ensuring their safety. Make sure your equipment is designed to detect any chemicals that may be present and are able to identify them even at levels well below the defined exposure limits.
While continuous monitoring is ideal, it’s not always possible. The space, however, should still be tested at regular intervals to ensure that conditions remain safe for workers. If workers exit the space and need to re-enter, run another test to confirm that it is safe for entry.
Communication in Confined Spaces
There is a lot of attention placed on equipment function and atmospheric testing in confined spaces – and for good reason. But communication is just as important and must be carefully considered prior to entry. Keeping an open line of communication ensures that workers receive immediate assistance in the event of an emergency.
Adequate planning should account for communication between those within the confined space, those in the confined space and those outside of it, and with emergency services. Ideal communication systems should be:
- Hands-free
- Wireless
- Full-duplex
- Independently powered
- Integrated with hearing protection
While two-way radios are acceptable for some applications, hard-line intercom systems or wearable devices are often the best choices when no direct line of sight can be guaranteed.
Plan for the Worst-Case Scenario
When working in these areas, planning can make the difference between arriving home safely after just another day on the job and a tragedy. Studies show that about 60 percent of all confined space fatalities involve rescuers. Rose-colored glasses have no place in confined space safety, and employers need to map out a rescue plan specific to each space they have workers in.
Rescue procedures must be established prior to worker entry and should be written down. While all personnel should be adequately trained in emergency procedures, untrained workers should never attempt a rescue.
Rescue procedures should be practiced regularly to make sure all rescuers are comfortable with their roles. Those who know exactly what they need to do are often much calmer in stressful or hectic emergency situations than those who are uncertain.
Mitigate Risks with Employee Training
Of course, all the safety procedures in the world won’t protect workers who don’t know how to apply them. This is why employee training is such an important part of confined space safety.
Employers have an OSHA-mandated responsibility to protect workers from all known safety hazards. Part of this involves providing comprehensive and ongoing training on safety in confined spaces. Training topics should include
- Recognizing confined spaces
- Identifying safety hazards in and around confined spaces
- Controlling risk factors
- Effective communication in confined spaces
- Inspecting safety equipment for proper function
- Rescue procedures, specific to the particular confined space
Well-trained workers are likely to identify and control for hazards and get the job done safely – a win for everyone.
Just the Beginning
Every confined space is different and will require a unique plan and approach. Never send employees into a confined space without first fully understanding the risks they'll face and having a concrete plan for keeping them safe from harm. With the basic considerations we presented here, along with some careful planning, you will be well on your way to ensuring the safety of your workers.
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Written by Jessica Barrett

Jessica is a freelance writer and editor from Toronto, Canada. She specializes in creating content for nonprofits and has written for organizations working in human rights, conservation, education, and health care. She loves traveling and food, speaks Spanish, and has two dogs, one of whom she rescued while living in Mexico.
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