20 dangers in confined spaces and how drones mitigate them
The 20 biggest dangers when working in confined spaces
When it comes to working in confined spaces, safety and risk minimisation are paramount. These areas are often difficult to access, poorly ventilated and harbour unforeseeable dangers. A thorough risk assessment is essential before people enter these environments. In the following 20 points, we highlight the main hazards that can occur when working in confined spaces. This includes the possibility of minimising many of these risks through the use of drone technology such as the Flyability Elios 3 to be reduced.
1. lack of oxygen
The oxygen content in normal breathing air is around 20.9 %. If the oxygen content in confined spaces falls below 19.5 %, there is a risk of breathlessness, dizziness and ultimately suffocation. Oxygen deficiency can be caused by the displacement of oxygen by gases such as nitrogen or carbon dioxide. Oxygen consumption by people or machines in enclosed spaces without adequate ventilation can also lead to life-threatening situations. It is particularly dangerous if the oxygen level falls below 16 %, as this can lead to unconsciousness.
2. excess oxygen
An excessively high oxygen content - above the natural value of 20.9 % - can significantly increase the risk of ignition. Even a small spark is enough to cause a fire or explosion, as oxygen promotes the flammability of materials. Such an excess can be caused by leaks in oxygen cylinders or faulty welding equipment. Special care must therefore be taken when handling oxygen in confined spaces.
3. hazardous gases
Toxic gases that are difficult or impossible to detect can accumulate in confined spaces. Particularly dangerous gases are
- Hydrogen sulphide (H₂S): A highly toxic gas that smells like rotten eggs in low concentrations, but can be odourless and lethal at higher concentrations. It often occurs during the decomposition of organic substances.
- Carbon monoxide (CO): A colourless and odourless gas produced by incomplete combustion. Carbon monoxide prevents the transport of oxygen in the blood and leads to rapid asphyxiation.
- Methane (CH₄): An explosive gas that is often released in sewage treatment plants or during the decomposition of organic material. Although it is non-toxic, it is extremely flammable.
- Carbon dioxide (CO₂): Can displace oxygen in large quantities and lead to asphyxiation.
4. risk of explosion
Explosive gases and their mixtures with air are dangerous if their concentration is within a certain range, which is defined as Explosive area or Ignition range is labelled. This area is characterised by the Lower explosion limit (LEL) and the Upper explosion limit (OEG) defined. Here are some important gases, their explosion limits and the conditions under which they become explosive:
- Methane (CH₄)
Below explosion limit (LEL): 4.4 vol.-% Methane in air
Upper explosion limit (OEG): 16.5 vol.-% Methane in air
Conditions: Methane is explosive at room temperature and normal pressure in a concentration range from 4.4 % to 16.5 %. It often occurs during the decomposition of organic materials or in mines. An ignition source (e.g. spark or flame) can trigger an explosion at these concentrations. - Hydrogen (H₂)
UEG: 4 Vol.-% Hydrogen in air
OEG: 77 Vol.-% Hydrogen in air
Conditions: Hydrogen has a very wide ignition limit and is explosive in an extremely wide range. Even a small amount of hydrogen in the air (from 4 %) can explode if an ignition source is present. Hydrogen is often used in industrial processes and in the refining of crude oil. It is one of the most dangerous gases due to its easy flammability and wide explosion limit. - Propane (C₃H₈)
UEG: 2.1 vol.-% Propane in air
OEG: 9.5 vol.-% Propane in air
Conditions: Propane is often used as a fuel for heating systems and camping cookers. It forms explosive mixtures at a concentration of 2.1 % to 9.5 % in air. Propane is heavier than air and can collect in low-lying areas, making it particularly dangerous in confined spaces. - Butane (C₄H₁₀)
UEG: 1.8 vol.-% Butane in air
OEG: 8.4 vol.-% Butane in air
Conditions: Butane is often used in gas cylinders and is particularly dangerous in confined spaces as it is heavier than air and collects on the floor. Even low concentrations of 1.8 % to 8.4 % can cause an explosion in combination with an ignition source. - Carbon monoxide (CO)
UEG: 12.5 vol.-% Carbon monoxide in air
OEG: 74 Vol.-% Carbon monoxide in air
Conditions: Carbon monoxide is produced during incomplete combustion of carbon-containing substances (such as wood, petrol, coal). It is particularly dangerous because it is odourless and can accumulate unnoticed. Carbon monoxide is explosive in a concentration range from 12.5 % to 74 %. - Ethan (C₂H₆)
UEG: 3.0 vol.-% Ethane in air
OEG: 12.4 vol.-% Ethane in air
Conditions: Ethane is often used as a raw material in the chemical industry. It forms explosive mixtures at a concentration of 3 % to 12.4 % when mixed with air and ignited. - Acetylene (C₂H₂)
UEG: 2.5 vol.-% Acetylene in air
OEG: 100 vol.-% Acetylene in air
Conditions: Acetylene is explosive over an extremely wide range, which makes it very dangerous. It can explode even at low concentrations of 2.5 %. Acetylene is often used for welding and must be stored carefully due to its high instability. - Ammonia (NH₃)
UEG: 15 vol.-% Ammonia in air
OEG: 28 Vol.-% Ammonia in air
Conditions: Ammonia is used in the chemical industry and as a fertiliser. In a concentration range of 15 % to 28 % in the air, it can become explosive. It is also toxic and irritating to the respiratory tract.
Conditions for an explosion:
- Ignition source: An explosion can only occur if an ignition source is present. This can be a spark, an open flame, a hot object or even a static discharge.
- Explosive concentration: The gas must be present in a certain concentration that lies between the LEL and the LEL. If the concentration is too low (below the LEL), the mixture is too lean, and if the concentration is too high (above the LEL), it is too rich to explode.
- Temperature: The higher the temperature, the more likely it is that a gas will ignite. Some gases can self-ignite at high temperatures even without an ignition source, a process known as spontaneous combustion.
- Print: High pressure increases the likelihood of an explosion, as the concentration of the gas in the air can rise more quickly. Gases can accumulate more easily in dangerous concentrations in confined spaces.
- Ventilation: In poorly ventilated confined spaces, gases can accumulate unnoticed as they are not diluted or channelled away. The lack of sufficient air exchange increases the risk of an explosive atmosphere.
Examples of potentially explosive situations:
- Tank cleaning: Gases such as methane or hydrocarbons can accumulate in disused tanks or silos. When working in these areas, sparks from tools or machines can trigger an explosion.
- Sewage treatment plants: Methane and hydrogen sulphide are often produced during the decomposition of organic material. There is a risk of explosion in poorly ventilated areas such as septic tanks.
- Storage of chemicals: Ammonia or butane in storage tanks that are not properly ventilated can accumulate and become explosive, especially if there is no continuous monitoring.
5. risk of suffocation due to bulk material
Bulk materials such as grain, sand or chemicals can cause damage when working in Silos slip or slide down and bury people. As soon as a person is buried under the debris, there is an acute risk of suffocation as the weight of the material makes it impossible to move quickly or free them.
6. mechanical hazards
In confined spaces, there are often moving machines or systems that can cause serious injuries if they are started up incorrectly or unexpectedly. For example, rotating mixers, conveyor belts or ventilation systems can pose a hazard if they are accidentally activated while people are in the vicinity.
7. danger from falling
Many confined spaces, such as silos or shafts, require working at great heights or depths. Inadequate protection against falls - for example due to a lack of ladders, fall protection or safety posts - can lead to serious accidents. Even minor carelessness can be fatal if no protection system is installed.
8. electrical hazards
Confined spaces are often damp or conductive, which significantly increases the risk of electric shocks. Insufficiently insulated cables or improperly operated electrical appliances can cause fatal electrical accidents. Residual current circuit breakers (RCDs) are also particularly dangerous as they can fail in the event of defects.
9. lack of rescue options
In emergencies, rescue teams may have difficulty getting into confined spaces or getting an injured person out. Bottlenecks, blocked entrances or hard-to-reach areas slow down rescue operations considerably, which can be life-threatening in critical situations.
10. chemical reactions
Various chemicals that are processed or stored in confined spaces can trigger dangerous reactions when they come into contact with each other. For example, acids and bases can have strong exothermic reactions when combined, releasing toxic vapours or causing fires. It is particularly dangerous if these reactions take place in poorly ventilated rooms.
11. temperature hazards
Confined spaces can be exposed to extreme temperatures. Hot surfaces or chemical reactions can cause burns, while cold media can cause frostbite. There is also a risk of heat or cold accumulating in the confined space and not being dissipated due to a lack of ventilation.
12. biological hazards
Biological hazards often occur in damp or poorly ventilated confined spaces. Bacteria such as Legionella can accumulate in water or damp environments and cause serious infections if inhaled. Moulds and other microorganisms are also a danger and can cause respiratory diseases.
13. narrowed access openings
Confined spaces can be exposed to extreme temperatures. Hot surfaces or chemical reactions can cause burns, while cold media can cause frostbite. There is also a risk of heat or cold accumulating in the confined space and not being dissipated due to a lack of ventilation.
14. insufficient lighting
Many confined spaces lack sufficient light, which makes working dangerous. Sources of danger are not recognised and missteps or collisions can lead to serious injuries. Poor visibility can also lead to important work steps being overlooked.
15 Mental stress
The confinement and isolation in confined spaces can lead to considerable stress. Claustrophobia, anxiety and panic attacks are common reactions to working in confined spaces. This mental stress can lead to mistakes and careless behaviour, which in turn increases the risk of accidents.
16. insufficient lighting
In confined spaces, there is a risk of tools or components falling from above. It is particularly dangerous when working on several levels or when materials are improperly secured. Even small objects can cause serious injuries if they fall from a great height.
17. noise and vibration exposure
Confined spaces amplify noise and vibrations, which can lead to hearing damage and fatigue. Noise levels that persist over long periods of time impair concentration and well-being, which increases the likelihood of errors.
18. dust generation
Dust that accumulates in confined spaces can not only lead to breathing problems, but can also form explosive air mixtures. Particularly dangerous are combustible dusts, which can cause serious explosions when they accumulate and ignite.
19. danger of slipping and tripping
Slippery surfaces, standing water or tools lying around increase the risk of slipping or tripping in confined spaces. Due to the confined space, a fall can have more serious consequences as the person cannot catch themselves or avoid falling.
20. inadequate monitoring of the atmosphere
In confined spaces, it is essential to continuously monitor the concentration of oxygen and potentially hazardous gases. Without suitable measuring devices, the atmosphere can change suddenly, leading to acute health hazards before they are even noticed. Incomplete monitoring often leads to unforeseen accidents.
Conclusion
Working in confined spaces involves significant risks that can quickly become life-threatening without the right precautions. Such operations often require workers to make complex and costly preparations, including wearing extensive personal protective equipment (PPE) such as respirators, protective suits and safety harnesses. In addition, working in confined spaces requires careful planning and extensive safety measures, which are both time-consuming and resource-intensive.
The Flyability Elios 3 drone offers a revolutionary way to avoid many of these risks. It enables safe and efficient inspections without the need for people to enter these dangerous spaces. This eliminates many of the costly and time-consuming preparations, and staff are not exposed to direct danger. The use of drone technology can not only increase safety, but also significantly improve the efficiency of inspection processes, resulting in considerable time and cost savings for companies. This innovative solution can both minimise risks to employees and reduce the need for PPE and complex safety precautions.
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Frequently asked questions
Important sensors include gas sensors, thermal imaging cameras, HD cameras with lighting, LiDAR scanners and collision sensors to comprehensively analyse the conditions in the room.
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