Five Tips to Improve Safety in Confined Spaces

When workers in confined spaces need your help, you can’t act on impulse.

• By Ryan Thompson
• May 01, 2022

A lot can happen in four minutes, especially when those four minutes are spent in a confined space.

Confined spaces are prone to oxygen displacement, and just four minutes without oxygen can cause brain damage or even death. It should be no surprise, then, that confined spaces are the leading cause of multiple fatalities in the workplace. That’s why it’s so important to take extra precautions to ensure entrants and hole watches are trained on how to safely work in and around confined spaces. 

You’ve heard the story dozens of times: a worker enters a confined space, often for routine maintenance or repair, and is overcome by an atmospheric hazard. When the entrant doesn’t respond to the hole watch, their supervisor and peers get worried, so one of them enters the confined space to check on the original entrant only to be overcome by the same gas hazard. Unfortunately, this scenario is too common—The National Institute for Occupational Safety and Health (NIOSH) reports that 60 percent of confined space deaths are among these “would-be” rescuers who enter a confined space without understanding the hazards within, only to fall victim to the same hazard. 

When someone around you is in danger, your instinct is to help. In some cases, this behavior is helpful, like when you catch a toddler before he falls and hits his head. Unfortunately, there are plenty of times when this behavior can make a dangerous situation even more dire. For example, even though you have good intentions, slamming on your car’s brakes or swerving to avoid hitting a squirrel or other small animal in the road could cause a dangerous multi-car pileup. 

While you always want to act swiftly, it must be balanced to ensure that the actions you take to help others won’t cause further harm to yourself or other people around you.

What you do and how you decide to do it can make the difference between a regular day on the job and tragedy—especially when working around confined spaces. 

When workers in confined spaces need your help, you can’t act on impulse—you need to be prepared with a plan in place long before the first worker enters a confined space.

When creating a confined space entry plan, there are five best practices to keep in mind to help everyone make it home safely. 

Step 1: Have a Plan 

Make sure you understand the confined space regulations in your region, then document the steps everyone needs to take before, during and after a confined space entry. 

At minimum, your plan should include details on what equipment should be used to detect atmospheric hazards, when the atmosphere should be tested, and the order in which hazards should be assessed. 

For example, many regions require that workers use a direct-reading gas detector to assess oxygen levels, flammable gases and vapors, and toxic air contaminants. 

After documenting your confined space safety plan, make sure all employees can access it quickly and easily. But you can’t stop there. You must also train your workers on this plan. Eighty five percent of fatalities in confined spaces were among people who hadn't been trained; therefore, it’s crucial that your team is trained and understands how to safely test the atmosphere within a confined space. 

Step 2: Know Your Hazards 

Knowing the gas hazards that could be present in a confined space is critical for reducing risk. Once you know what gas hazards are likely to be present, you can create a thorough plan for detecting those hazards—including which gas monitors workers must use.

You should identify potential hazards before every confined space entry because every space is different. 

To improve safety in and around confined spaces, it’s important to monitor all of these potential hazards. Multi-gas monitors, whether personal monitors or area monitors, are ideal for this purpose. 

Step 3: Bump Test, Zero and Calibrate 

Once you know your hazards, you can select tools to identify them. An essential tool you need when entering a confined space is a gas detector with the right sensors for your application. But once you select the right sensors, you still need to confirm that your monitor is working properly. 

You need to bump test (also known as a functional test), zero and calibrate those sensors—skipping even one of these steps puts you at risk of entering a confined space without a gas detector that can alert you to deadly hazards. Bump tests show you whether the sensors can identify gas and whether the alarms and on-screen alerts are working, while calibration shows you whether the gas detector is accurately reading gas concentrations. Zeroing the gas detector in clean, fresh air ensures that you’ve set an accurate baseline for readings. 

Step 4: Use a Sampling Pump 

While this may seem fundamental, it's so important: the gas detector you are using for pre-entry sampling must be equipped with a sampling pump to draw air from the confined space to the gas detector. 

When workers face the pressure of getting a job done quickly, it's easy to cut corners. One common mistake we see is workers putting the gas detector on a rope and dropping it in the confined space, then pulling it out. This will not always detect gas hazards. Instead, it may damage your gas monitor which can harm critical functions and lead to costly repairs. 

You can easily avoid this with a sampling pump. It's also recommended that you follow the 2x2 rule, which is to check levels for two minutes plus two seconds for every foot of tubing. For example, if you are using 20 feet of tubing, you would test for two minutes and 40 seconds to make sure the gas detector has had ample time to read the atmosphere. 

Repeat this process at the top, middle and bottom of the space because different gases settle at different heights, depending on their weight relative to air. 

Step 5: Continuously Monitor Throughout the Entry 

It's not enough to check for gas hazards in the confined space then throw your monitor back in the truck. Conditions in confined spaces can change rapidly and dramatically, exposing workers to new hazards. Continuously monitoring the confined space is one of the best things you can do to prevent accidents. 

Direct-reading monitors are often required because they not only tell workers whether the atmosphere in a confined space is safe, but also how safe. Is the oxygen concentration just barely above 19.5 percent or is there enough margin for the entrant to continue working safely?

But how will others know if a confined space entrant is at risk? You can improve safety even further by using connected monitors, which wirelessly share gas readings and alarms so the attendant always knows exactly what’s happening within the confined space. If conditions trend toward danger, workers will have the notice they need to exit the confined space safely. 

If a monitor indicates dangerous levels of toxic gases, combustible gases or oxygen deficiency (or enrichment), workers must evacuate the confined space, ventilate and retest the atmosphere before re-entering. 

It's estimated that each week, two workers who enter a confined space won't make it home. Are you doing everything in your power to make sure that doesn't happen to your people? 

This article originally appeared in the May 2022 issue of Occupational Health & Safety.