Explain, with examples, at least three distinct physical hazards that can be found in a confined space, detailing how each could lead to injury, and what controls could be used to mitigate the hazards.

Physical hazards in confined spaces are a significant concern and can lead to severe injuries or fatalities if not properly identified and controlled. These hazards often stem from the physical characteristics of the space itself or from the work being performed within it. Here are three distinct physical hazards with examples, injury pathways, and mitigation strategies:

First, engulfment is a severe physical hazard where a worker can be trapped and suffocated by a free-flowing solid or liquid material within the confined space. For example, a grain silo or a tank containing sand, flour, or liquid can cause engulfment. If a worker is inside such a silo or tank, and if the material is disturbed, it can move quickly, burying the worker and preventing them from breathing or escaping. For example, if a worker steps into a bin of grain that was thought to be empty but in fact was full of grain, the worker may not be able to pull themselves out and could end up being buried. Another example might be a worker who was cleaning a tank, when a large batch of liquid suddenly enters the tank. The worker would quickly become overwhelmed and might not be able to escape. Engulfment is especially dangerous because it can happen very quickly, and the victim may not have time to react or escape the hazard. To mitigate engulfment risks, several measures can be taken. One of the most important steps is to lockout/tagout the feed system of any solid or liquid material that is being stored in the confined space. Another step is to never enter the confined space alone. A harness and retrieval line is important for the worker in case of emergencies, and also as a method to pull the worker out of the space. An attendant must be present outside the confined space at all times to watch over the worker. The worker must be properly trained for working in this type of confined space and all safety procedures must be followed.

Second, entanglement and entrapment are physical hazards involving being caught or trapped by equipment, structures, or materials within the confined space. This type of hazard could be a rotating shaft in a machine, or any cables or hoses. An example is a large mixing tank where the agitator could start, or a worker could get a hand or foot caught in its moving parts. Another example is a sewer system, where pipes and connections could create narrow spots where workers can become trapped. If a worker gets an arm caught in a mixer, the rotating blades could cause serious lacerations, fractures or crush injuries, and entanglement could cause the worker to lose consciousness or cause death by blood loss. If a worker gets trapped in a narrow space in a sewer, they could become exhausted, lose consciousness or even drown if water levels suddenly rise. These hazards are often difficult to foresee, and are very dangerous if safety precautions are not taken. To mitigate these hazards, it is essential to completely lockout and tagout any equipment that has moving parts, or that can present a risk of entanglement. All equipment that can move or rotate must be locked out. The space should be thoroughly evaluated before entry, and any potential entrapment locations must be identified. Workers should wear tight fitting clothing to avoid entanglement and should never wear loose clothing or jewellery. The use of a safety harness is vital for retrieval and may prevent injuries and death. Proper lighting is crucial, as a well-lit space may allow workers to avoid dangerous areas and entanglement or entrapment hazards.

Third, slips, trips, and falls are also significant physical hazards in confined spaces. These hazards can be due to uneven surfaces, slippery floors, inadequate lighting, or clutter within the space. For example, if a worker is working in a confined space, and has to use a ladder that has been poorly maintained, or if the floor is uneven or covered with oil or grease, the worker is at high risk of falling. Another example is a water tank that has sludge on the floor, which makes footing difficult and could easily lead to slips and falls. If a worker slips and falls, injuries such as sprains, fractures, concussions, and lacerations can happen. In cases where the fall is into dangerous or unyielding equipment, it can lead to death. Slips, trips and falls can happen suddenly, which makes them especially dangerous. To mitigate slips, trips, and fall hazards, the area must be well lit and maintained with clear and even surfaces. Any liquids that may cause a fall should be cleaned before entry. If the floor is uneven, it should be marked with brightly coloured tape, and proper footwear with good traction should be worn. Guardrails or barriers should be placed where there is a danger of falling off of edges, and ladders should be inspected before use, to ensure they are safe and can be used properly.

In summary, physical hazards in confined spaces present significant risks and require thorough planning and control. Proper training, the implementation of comprehensive control measures, and adherence to safety procedures are crucial for preventing injuries and fatalities. Continuous assessment, hazard identification, and proactive mitigation strategies must always be considered to ensure the safety of workers in these challenging environments.