Understanding and Mitigating Confined Space Hazards

There are some unique hazards when it comes to working in confined spaces. This is basically an enclosed area that has limited access and poor ventilation. Some examples of confined work spaces are silos, tanks, tunnels and sewers.

A significant hazard

When it comes to confined spaces is the presence of toxic vapours and gas. The oxygen levels can also be low which can lead to respiratory distress or asphyxiation. When oxygen levels drop below 19.5%, cognitive function can be impaired. This will lead to you losing consciousness and in severe cases, death. Some of the toxic gases that can be found in a confined space Perth are hydrogen sulphide, methane, carbon monoxide and ammonia. Even if these are at low concentrations, they can pose health risks. There can also be flammable vapours or gas which can lead to fire hazards or explosions when there is limited ventilation. When workers are in a confined space, there is a risk of being trapped by materials like sand, liquids, grain etc. Engulfment is when a worker is surrounded by a substance and doesn’t have the ability to escape. When you are trapped by equipment, machinery or structural features of the confined space, this is called entrapment.

There are certain physical hazards

In confined spaces as well such as protruding objects, sharp edges, moving machinery or uneven surfaces. These can lead to puncture wounds, lacerations and crush injuries. Some of the biological hazards that may be present are bacteria, mould and other pathogens. These can pose some health risks to the workers such as skin irritations, respiratory problems etc. Before entering a confined space, you need to carry out a comprehensive risk assessment so that potential hazards can be identified with the level of risk. The characteristics of the confined space have to be assessed such as the shape, size and accessibility. The hazards in the confined spaces should be identified such as biological hazards, physical hazards, entrapment or engulfment hazards. The likelihood of potential hazards and the severity should be assessed using hazard identification checklists and other risk assessment tools. The mitigation methods for these hazards will be discussed in confined space training.

The air quality inside

The confined space should be continuously monitored using atmospheric monitoring equipment such as gas detectors. This allows workers to detect the low oxygen levels and presence of hazardous gases. Adequate ventilation should be provided ensuring that fresh air is continuously brought into the place all the while removing contaminants and hazardous gases from the area. There are fixed or portable ventilation systems that can be used for this. The workers should wear personal protective equipment such as eye protection, fall protection, respiratory protection, hearing protection etc. There should also be strict control procedures for entering the confined space such as permit-to-work systems, permits for confined space entry, pre-entry checks etc. so that access to the area is managed for authorised personnel only. There should be emergency response plans developed and implemented to address potential emergencies. The workers should be provided with training in rescue techniques.

Hester Griffith
the authorHester Griffith