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Ammonia is a colorless gas with a strong pungent odor. It is soluble in water to form ammonia solution, and can be used as a fertilizer. Ammonia can be liquefied by applying pressure at room temperature to form liquid nitrogen, which facilitates transportation. Ammonia is an important chemical raw material with a wide range of applications, commonly used in petroleum refining, fertilizer production, synthetic fibers, and leather manufacturing. In manufacturing industries such as pharmaceuticals, plastics, and dyes. During the production, transportation, storage, and use of ammonia, damage to pipes, valves, storage tanks, etc. can lead to ammonia leaks that cause poisoning. 【Mechanism of poisoning】 Ammonia, when it comes into contact with water in human tissues, forms ammonia solution, which can dissolve tissue proteins and saponify fats. Ammonia can destroy the activity of various enzymes in the body, affecting tissue metabolism. Ammonia has a strong stimulating effect on the central nervous system. 　　1. Ammonia is highly irritating; inhaling high concentrations of ammonia can stimulate the central nervous system, leading to convulsions, seizures, drowsiness, and coma. Inhaling extremely high concentrations of ammonia can reflexively cause cardiac arrest and respiratory failure. 　　2. Ammonia is a basic substance, and ammonia water has a highly corrosive effect. Alkaline burns are more severe than those caused by acidic substances, as alkalines have greater penetration power; ammonia-induced burns on the skin result in deep wounds that are prone to infection and slow to heal, similar to second-degree burns. 　　3. Ammonia vapor, when inhaled into the respiratory tract, reacts with water to form ammonia water. Ammonia can penetrate through the mucosa and alveolar epithelium to reach the submucosa, pulmonary interstitium, and capillaries, causing: (1) vocal cord spasm, laryngeal edema, and tissue necrosis. The shedding of necrotic tissue can cause asphyxiation. Injured mucosa is prone to secondary infection. 　　(2) Damage, edema, bleeding, spasm, etc. of the tracheal and bronchial mucosa. It affects the ventilation function of the bronchi. 　　(3) Alveolar epithelial cells, pulmonary interstitium, and pulmonary capillary endothelial cells are damaged, leading to increased permeability and interstitial edema in the lungs. Ammonia stimulates sympathetic nerve excitement, causing the lymphatic trunks to spasm, hindering lymphatic return and increasing pulmonary capillary pressure. Ammonia destroys alveolar surfactant. The aforementioned effects ultimately lead to pulmonary edema. 　　(4) Factors such as mucosal edema, increased inflammatory secretions, pulmonary edema, reduced alveolar surfactant, and narrowing of the tracheal and bronchial lumens severely impair the lung’s ventilation and gas exchange functions, leading to systemic hypoxia. 【Clinical manifestations】 Upon contact with ammonia, a strong pungent odor is detected, along with tearing and stinging in the eyes. If concentrated ammonia solution gets into the eyes, it can damage the cornea and cause corneal ulcers; in severe cases, it may lead to corneal perforation, lens opacity, iris inflammation, and even blindness. 　　Inhaling ammonia can cause sore throat, pain in the larynx, and hoarseness. High inhalation concentrations of ammonia can cause laryngeal spasm and vocal cord edema, leading to asphyxiation. 　　Ammonia entering the trachea and bronchi can cause coughing, expectoration, and blood in the sputum. In severe cases, there may be hemoptysis and pulmonary edema, difficulty breathing, and the production of white or bloody frothy sputum; large and medium-sized rales can be heard throughout both lungs. 　　Inhaling high concentrations of ammonia can induce consciousness disorders such as convulsions, seizures, drowsiness, and coma. In some patients, inhaling extremely high concentrations of ammonia can lead to cessation of breathing and heartbeat. 　　In cases of secondary lung infection, patients experience high fever, bloody yellow sputum, difficulty breathing, and cyanosis. Damage to the digestive tract can cause abdominal pain, vomiting, etc., and later on, jaundice and liver function impairment (toxic hepatitis) may occur. 【Conventional treatment】 1. Quickly leave the area where poisoning occurred and breathe fresh air or oxygen. Respiratory stimulants may be used as appropriate when breathing is shallow and slow. CPR should be performed immediately for those with stopped breathing and heartbeat. One should not give up easily. In cases of laryngospasm or vocal cord edema, tracheal intubation or tracheotomy should be performed promptly. 　　2. Remove clothing and thoroughly wash the skin that has come into contact with ammonia with clean water or 1%–3% boric acid solution. Rinse the eyes with 1%–3% boric acid solution, then apply antibiotic and cortisone eye drops. 　　3. Intravenous infusion of 10% glucose solution, calcium gluconate, adrenocortical hormones, and antibiotics to prevent infection and laryngeal edema. 　　4. Nebulization of flumethasone and antibiotic solutions. 　　5. Comatose patients are given an intravenous injection of 250 ml of 20% mannitol, once every 6–8 hours, to reduce intracranial pressure. 【Hyperbaric oxygen therapy】 1. Therapeutic principle: There has been debate regarding whether patients with ammonia poisoning can undergo hyperbaric oxygen therapy. Some people are concerned that during pressurization, respiratory secretions or debris may be forced into the bronchi and alveoli, blocking the airways and exacerbating infections; therefore, they believe that hyperbaric oxygen therapy is not suitable for ammonia poisoning. The author believes that when a patient is in a critical state of severe hypoxia, pulmonary edema, cerebral edema, or shock, failing to correct the hypoxia and control pulmonary edema, cerebral edema, and shock promptly can quickly put the patient’s life at risk. At this point, only hyperbaric oxygen therapy can rapidly correct hypoxia, control pulmonary edema and cerebral edema, break the vicious cycle, and create conditions for the body to recover while providing sufficient time. Principles of hyperbaric oxygen therapy: (1) Rapid correction of tissue hypoxia: Damage to the bronchi and alveoli caused by ammonia poisoning, as well as pulmonary edema, impairs the lung’s ventilation and gas exchange functions. The arterial oxygen partial pressure (PaO2) can drop below 8.0 kPa (60 mmHg); in severe cases, it may even fall to 4 kPa (30 mmHg), resulting in severe hypoxia in the body. In this case, when oxygen is administered via a nasal cannula at normal pressure, the arterial oxygen partial pressure does not exceed 8.0–9.3 kPa (60–70 mmHg), whereas breathing pure oxygen in a high-pressure environment can easily raise the arterial oxygen partial pressure to above 13.3–26.6 kPa (100–200 mmHg). This allows for the rapid correction of hypoxia in the tissues. Improve tissue aerobic oxidation, increase energy supply, and correct tissue acidosis. 　　(2) Under high pressure, the volume of bubbles in the respiratory tract decreases or they burst, reducing the amount of foam in the respiratory tract and thus maintaining its patency. 　　(3) Hyperbaric oxygen can reduce intracranial pressure and prevent or treat cerebral edema. 　　(4) High blood pressure can prevent and treat pulmonary edema. 　　(5) Hyperbaric oxygen can control shock. 　　(6) Hyperbaric oxygen can rapidly alleviate hypoxia in various organs and accelerate their repair, such as the heart, liver, kidneys, brain, etc. 　　2. Treatment methods and precautions: Since ammonia poisoning is generally a severe and life-threatening condition, with significant damage to the respiratory mucosa and deep wounds, secretions and debris pose a risk of blocking the airways. Therefore: (1) The treatment pressure should not be too high; 0.2 MPa is appropriate. The pressure increase time is appropriately extended to 40–50 minutes to avoid sharp pressure changes that could cause the respiratory tract to be blocked by debris. The decompression time should also be extended by 40–50 minutes accordingly. The stabilization time remains unchanged, and the oxygen inhalation time cannot be extended arbitrarily. 　　(2) Hyperbaric oxygen therapy should be conducted under the supervision of medical staff in the same chamber, and equipment for tracheal intubation and tracheotomy should be available ； Prepare a suction device and a large syringe. Regular treatment should not be interrupted inside the cabin. 　　(3) If hypoxia is not adequately corrected and pulmonary edema or cerebral edema remains uncontrolled after the first hyperbaric oxygen therapy session, another session can be administered after several hours.

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Burns (also known as scalds) refer generally to damage to human tissue caused by heat; common types include burns from flames and scalds caused by hot liquids. Certain non-thermal factors such as electricity, chemicals, and radiation can also cause damage to human tissues similar to burns. The treatment and healing process of burn wounds are complex and take a long time. After wound healing, sequelae such as scar contracture and functional impairment may remain.

The main types of injuries caused by mechanical accidents are as follows: 1. Injuries resulting from the rotational movement of mechanical equipment parts and components. For example, in machinery and equipment, components such as gears, idler wheels, pulleys, chucks, shafts, lead screws, screw rods, and shaft joints all undergo rotational motion. The main forms of injury caused by rotational motion to people are entanglement and object impact injuries. 　　 　　2. Injuries caused by the linear movement of parts and components of mechanical equipment. For example, the pressure-applying components of hammers, punch presses, and sheet-cutting machines, the headstock of shaper machines, the bed surface of gantry milling machines, as well as the main and trolley parts of bridge cranes and their lifting mechanisms, all move in a straight line. Injuries caused by components used for linear transportation mainly include crush injuries, blows, and crushes. 　　 　　3. Injuries caused by cutting tools. For example, the cutting tools used on lathes such as turning tools, those on milling machines like milling cutters, the drills used on drilling machines, the grinding wheels on grinders, and the saw blades on saws are all tools used for processing parts. The main injuries caused by cutting tools when machining parts are burns, punctures, and cuts. 　　 　　4. Injuries caused by the parts being processed. Mechanical equipment can cause injury to people during the processing of parts. Such injury accidents mainly include: ① The workpiece being not secured properly and being flung out, thus injuring people; for example, if the chuck on a lathe does not hold the workpiece firmly, it will be flung out during rotation and injure someone. ②The parts being processed may cause injuries from being lifted and handled. 　　 　　5. Injuries caused by the electrical system. The mechanical equipment used in factories is powered mostly by electricity; therefore, each piece of equipment has its own electrical system. It mainly includes electric motors, distribution boxes, switches, buttons, local lighting fixtures, as well as neutral (ground) and power supply wires. The main harm caused by electrical systems to humans is electric shock. 　　 　　6. Injuries caused by hand tools. 　　 　　7. Other injuries. In addition to causing the various injuries mentioned above, mechanical equipment can also lead to other types of injuries. For example, some mechanical devices generate intense light and high temperatures during use, while others release chemical energy, radiation, as well as harmful dust and toxic substances, all of which can cause damage to the human body.

This post was last edited by Chemical Gas Purification on 2010-11-20 08:42: 1. Ensure that all components on the pressure vessel are properly installed and ready for use before use； 2. Ensure that the pressure vessel is horizontally supported and securely fixed at the spacing (S) recommended by the manufacturer ； 3. Ensure that the fixation of the pressure vessel and its piping connections have sufficient flexibility and cushioning capacity to accommodate the radial and axial expansion of the pressure vessel under pressure ； 4. Ensure that the system equipment provides overpressure protection (greater than 105% of the design pressure) for the pressure vessel ； 5. Ensure regular inspection of end plates and piping connections; replace any components that are corroded or damaged promptly ； 6. Ensure that all rubber seals and the inner surfaces of the pressure vessel have been properly coated with lubricant before use ； 7. It is not allowed to attempt to remove any components from pressure vessels under pressure ； 8. No rigid fixation or connection of pressure vessels is permitted ； 9. It is not allowed to operate a pressure vessel without a thrust ring installed downstream of it ； 10. Pressure vessels must not be used beyond their specified operating conditions ； 11. Pressure vessels must not experience any leaks during use, nor must the end plate components remain in a wet state. 12. Operation at excessive temperature or pressure is strictly prohibited ； 13. Regularly check that the safety accessories are complete, sensitive, and reliable ； Abnormal phenomena were detected, such as ； Work pressure, medium temperature, and wall temperature exceed the allowable values and cannot be reduced ； The compressed components develop safety-threatening defects such as cracks, bulging, deformation, and leakage ； 14. In the event of a failure in the safety accessories, a break in the piping, or damage to the fasteners, emergency measures must be taken, the issue must be addressed promptly, and it must be reported to the relevant authorities. 15. Pressure vessel operators must receive training as required and obtain a certification by passing an exam before they can operate independently.