The Danger of Confined Spaces

Confined spaces are rife in many industries; while they’re not designed for humans to specifically work within, sometimes it’s unavoidable. So what should you be looking out for in a confined space?

What Defines a Confined Space?

Contrary to what the name suggests, confined spaces don’t have to be small. They can be above or below ground, and are usually classified as confined when they meet these criteria:

• Not primarily designed for humans to work in.
• Restricted entry and exit points that are difficult to access.
• Has a hazardous atmosphere, either low oxygen or the presence of toxic gas.
• Contains substances or material such as a liquid that could trap or engulf personnel.

Where are Confined Spaces Found?

Some confined spaces are easy to identify, but others are less so; even a poorly-ventilated room can turn into a confined space if the right conditions arise. Nonetheless, there are some industries that are well-known for confined space work.

• Agriculture: Silos.
• Chemical and petrochemical: tank, pipeline, cold box, clean box.
• Construction: sewer, chimney, elevator shaft, septic tank.
• Civil Engineering: Tunnel.
• Renewables: Turbine blades foundations, rotor and hub.
• Aerospace: Many parts of an aeroplane, including wings.

What Dangers are Present?

Dangers can be constantly present in a confined space, or they can change as conditions shift within the space.

• High or low concentrations of atmospheric oxygen.
• Toxic gases, fumes or vapour.
• Presence of free-flowing solids or liquids.
• Fire or explosions from high concentrations of flammable gas, fume or vapour.
• Residues that could release toxic gas, fumes or vapour when disturbed.
• High temperature conditions.

It’s not just possible conditions that could arise in a confined space. Physical factors can also build up to create an extremely dangerous environment:

• Poor lighting and visibility.
• Electrical risks.
• Falling objects.
• Moving parts of equipment or machinery.
• Biological or bacterial risks.
• Heightened platforms, presenting a fall risk.

When Is a Confined Space Too Dangerous?

Many situations within a confined space are fluid, and can evolve in a fraction of a second to become life threatening. Ask yourself these questions to determine whether you should allow personnel to enter a confined space.

What are the General Conditions of the Confined Space?

While this may sound pretty self-explanatory, it’s important for you to determine all major and minor risks associated with the confined space. Consider atmospheric hazards, as well as physical characteristics of the space, such as falling from a height.

What are the Possible Work-Related Risks?

Consider what sort of tasks your personnel will be carrying out within the confined space, and whether this could lead to additional hazards. Cleaning liquids could react with material in the space and change the atmosphere, or ignition sources such as a welder could cause an explosion.

What’s Happening Outside?

Usually, a confined space is not a totally isolated unit. Contamination from nearby plants, water/steam from nearby processes or even a power cut affecting internal ventilation could all pose significant risks to personnel within a confined space.

What Changeable Risks are There?

Changeable risks are, by definition, difficult to predict. Fluctuating gas concentrations or heavy rain causing floods will require dynamic risk assessments, to ensure that work is only carried out within an acceptable range of risk. Once risk moves outside the acceptable range, work must stop and another formal assessment must be carried out to determine when it is safe to return to the space.

What is Needed in Case of an Emergency?

According to recent statistics, the majority of fatalities occur among rescuers, so it is crucial to factor these people into your safety protocols. Determine the equipment and safety measures that are required, as well as the time needed to successfully rescue personnel from the confined space. Ensuring the rescuers safety is critical to a successful rescue, so all safety measures should be taken, even if this results in a longer rescue time.

How to Prevent Confined Space Incidents

Confined spaces are inherently dangerous, so it’s vital that measures are taken to reduce any risk where possible:

• Training: Ensure that any worker entering a confined space is fully trained and sufficiently prepared for work within the confined space.
• Ventilation: Prior to any personnel entering the confined space, ensure that suitable ventilation is in place where possible. Depending on the space, increasing the number of openings may be adequate, or you may need to employ mechanical ventilation.
• Preparation: Before any worker enters the space, create a comprehensive emergency plan; including details on entry and exits for rescuers. It is essential to avoid entering a space unprepared and risk exposure to the same hazards, no matter how much you may want to help personnel in distress.
• Gas Detection & Communication: Gas detection is one of the most important parts of PPE for personnel in confined spaces. Wireless portable gas detectors can automatically alert workers within the space to imminent dangers, whilst simultaneously alerting safety managers outside of the space in real-time so they can raise the alarm. This automatic communication adds an extra layer of safety to personnel working within the space and reduces the risk to rescuers at the same time.

Working in confined spaces is essential to many industries, but conditions within them can become unavoidably dangerous at a moment’s notice. Ensure that you and your team are fully prepared and trained before entering the space, and remember to check your PPE and gas detection equipment regularly.