Practical Tips | The “Eight Musts” for Working inside Containers and Equipment in Confined Spaces”

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Accidents in confined spaces occur seasonally, with March to October being the period when such accidents are most likely to happen, especially during spring and summer. Therefore, extra caution is required when carrying out activities in confined spaces during this time frame! Given that the chemical manufacturing industry involves flammable, explosive, harmful, and toxic substances, it is necessary to identify potential hazards based on the operating conditions before entering containers and equipment. It is also important to raise awareness of self-protection, conduct safety assessments in advance, develop measures to prevent accidents, and implement these measures in the construction plans. Today, the editor shares eight essential things for working with containers and devices – let’s see if you’re doing all of them! What is referred to here are containers and equipment; in chemical production, various towers, vessels, boxes, cabinets, kettles, tanks, basins, furnaces, pipes, wells, ditches, pools, hoppers, silos, as well as larger mechanical devices that may enter such spaces, along with other poorly ventilated confined areas, are all collectively termed container equipment. Dangers of working inside a container: 1. There is a risk that harmful and toxic substances from connected containers or pipelines could mix and cause harm, and there is also a possibility that harmful and toxic elements from outside the container could enter it, making it difficult for those working inside to anticipate and avoid such hazards. 2. Poor ventilation within the container makes it difficult for toxic and other harmful substances to disperse. Moreover, during operation, harmful and toxic residues may gradually be released, increasing the amount of toxic or flammable substances while simultaneously reducing oxygen levels, thereby raising the risk. 3. Poor lighting can lead to accidental operations. 4. The space inside the container is limited, increasing the risk of mechanical injuries and object strike accidents. 5. When performing maintenance in tall containers, the large height difference between components increases the risk of falls ； The combustible components inside the device (such as grids, scaffolding, packaging materials, etc.) are highly flammable and can cause fires quickly. 6. It is difficult to carry out rescue in case of an accident inside the container. 7. The temperature inside the container is high, the operator’s body temperature is elevated, the workload is heavy, respiration and blood circulation speed up, resulting in an increased intake of toxins. It has been determined that the amount of air a human breathes is related to the level of physical activity; the amount of air needed when at rest is eight times greater than that required while running. High temperatures accelerate the evaporation of residues inside the container, increasing the amount of toxins that reach the human body and making it easier to suffer from poisoning. 8. High humidity inside the container. The residual liquid already present in the container, along with sweat from the workers, increases the humidity inside the container; an increase in humidity accordingly raises the level of risk. The reason is that it increases the solubility of the toxin in the human body, thereby increasing its absorption. Some chemicals, such as cyanide, produce highly toxic hydrogen cyanide gas when exposed to moisture ； Some substances with low toxicity can become more toxic when exposed to moisture. Higher humidity reduces human resistance, increasing the risk of electric shock. Because in a dry environment, the human body’s resistance can reach 1000–1500 ohms, while in a humid environment it can drop to 600–800 ohms. Therefore, the voltage of portable lights should generally not exceed 36 volts; in humid environments as well as inside metal containers such as towers and tanks, it should not exceed 12 volts. The “Eight Musts” for working inside containers and equipment: Given the numerous dangers associated with working inside containers, which greatly increase the likelihood of accidents, it is essential to follow the “Eight Musts” when entering such containers or equipment. These include obtaining the necessary permits, and having those applications approved; this process allows for the development of appropriate safety measures and the clarification of responsibilities among personnel, ensuring that these measures are actually implemented. Handling permits and conducting thorough approvals carefully is the first and very important step in strengthening safety measures for working inside containers and equipment. It helps to avoid chaos resulting from reckless operations and reduces the risk of accidents; even in cases of emergency repairs, approval procedures are necessary. In emergency accident rescue situations, the on-duty safety officer must consider implementing appropriate safety measures for entering the container. Safety isolation is necessary; it is a critical measure for working inside containers and equipment. It has two meanings: one is to define the scope covered by this task. Second, it effectively prevents toxic and harmful substances from devices and pipelines outside the system from interfering with or causing damage to this system. Therefore, safety isolation must be taken seriously, and the methods must be reliable. The power supply must be cut off, and safety lighting must be used. For the cleaning and maintenance of any power-driven equipment, the power source must be disconnected first. Entering containers or equipment results in a confined working space; if there are moving parts, working among these internal components without turning off the power supply can very easily lead to personal injury accidents. Replacement of air is necessary; people must enter containers and equipment to work there. Whether for preventing fires, explosions, or poisoning, such replacement is essential, and entry is only permitted after sampling and analysis show satisfactory results. Safety analysis must be conducted within the specified time frame; it is a necessary step before entering a container for work, and it serves as an important means to verify whether the conditions for safe operation inside the container are met. Working inside a container without conducting analysis, or without analyzing it as required or within the specified time frame, is highly arbitrary and dangerous; it has proven to be an unsound approach. Relying on unscientific methods such as simply sniffing is unreliable and should be abolished. It is necessary to wear the prescribed protective equipment. This equipment represents the last line of defense that must be employed when safety measures related to processes, equipment, and the environment are in place, as it cannot guarantee 100% protection for workers from harm. As a precaution, appropriate protective equipment or tools must be worn for all general labor tasks. It is particularly important to wear protective equipment in containers and equipment where the working space is limited, the conditions are complex, there are many risk factors, and things change frequently. This is because objects inside the container can cause accidents such as impact injuries, mechanical harm, falls from heights, chemical burns, and poisoning. Someone must provide external supervision, and those who enter the containers or equipment to carry out work must remain at their posts. This involves many risk factors, complex and changing conditions, a high likelihood of accidents, difficulties in entering and exiting the equipment, poor communication between the inside and outside, difficulty in detecting accidents when they occur, and challenges in providing rescue. Assign a dedicated person to monitor the operations inside the device from outside, so as to promptly detect unsafe conditions and provide immediate assistance. Appointing a supervisor is an important organizational measure to prevent accidents during operations in containers and equipment and to carry out emergency rescue. Emergency rescue backup measures must be prepared. These measures refer to the material and organizational preparations needed to carry out emergency rescue in the event of an accident during operations inside containers or equipment. Now, when workers inside a container are in danger, supervisors and those around them will actively participate in the rescue efforts. However, due to the lack of proper backup measures for such rescues, actions are taken blindly, leading to chaos at the accident site. Rescue workers may enter the container in violation of safety rules, which can result in tragic outcomes such as one person being poisoned and multiple others dying. Emergency backup measures for working inside containers and equipment are often overlooked; there have been too many lessons learned in this regard… Therefore, supervisors and project leaders must pay close attention to this issue. While assigning someone to oversee the work, it is also necessary to implement appropriate rescue methods and measures so that in the event of an accident, help can be provided promptly to minimize losses.