Safety meeting: Confined spaces

Keep in mind that when it comes to staying safe inside a confined space, one of the biggest challenges we face is the significant number of different hazards that could put us at risk for potentially fatal injuries.

In fact, according to the U.S. Bureau of Labor Statistics (BLS), 114 U.S. employees die every year from injuries related to confined space work.

(What are the primary hazards posed by confined spaces?)

The biggest risk while working inside a confined space is a toxic atmosphere. Oxygen-deficient and hazardous atmospheres account for 56% of fatalities inside confined spaces, according to the BLS.

That’s why you should never go into a confined space if the atmosphere contains less than 19.5% oxygen – unless you’re wearing a self-contained breathing apparatus. Also remember that an atmosphere that has too much oxygen content – higher than 21% – can also be dangerous, because it’ll cause flammable materials, such as clothing and hair, to burn violently.

The atmosphere inside a confined space can also become hazardous due to the materials being stored inside the space, e.g., decaying organic matter that could produce deadly hydrogen sulfide. And the work being done inside the space – welding, cutting, brazing, sanding, or degreasing – could also produce a toxic atmosphere.

To avoid the risks posed by hazardous atmospheres, always test the quality of the air before entering a confined space, keeping in mind that you should sample the entire space because some gases and vapors are heavier than air and will settle at the bottom of the space, while some substances are lighter than air and will settle at the top of the danger zone.

You can also improve the quality of the atmosphere by using blowers, fans, or local area ventilation to ventilate the space and remove harmful gases.

Other significant risks during confined space work are physical hazards such as falling objects and structural collapses, which cause about 20% of confined space fatalities. Never enter a confined space until you’re sure all structures, such as trench walls, are properly secured.

And don’t forget about engulfment, which occurs when workers are trapped by soil, water, grain, or some other substance. It accounts for about 11% of confined space deaths.

You can reduce the chances of engulfment by never entering a confined space without first putting on safety equipment. Also make sure an attendant is stationed outside the space and that all equipment has been locked out before you go into the danger zone.

Thanks for your attention. And remember, let’s stay safe out there!

(From the July 20, 2026, issue of Safety Alert for Supervisors. To start your no-obligation trial subscription to the publication right now, please click here.)