1.1 Physical and Chemical Properties
(1)Molecular Formula: H2S
(2)Molecular Weight: 34.06
(3)Appearance and Properties: colorless, foul-smelling gas
(4)Relative Density: 1.13 (Air = 1)
(5)Melting Point: -85.5℃
(6)Boiling point: -60.4℃
(7)Solubility: soluble in water, soluble in ethanol
(8)Explosive Limit 4.0-46.0%
1.2 Hazards:
(1)Route of Invasion: inhalation, absorption through skin
(2) Health hazards: hydrogen sulfide is a strong neurotoxicant and has a strong irritating effect on mucous membranes. Short-term inhalation of high concentrations of hydrogen sulfide appear tearing, eye pain, runny, burning sensation in the throat, cough, chest tightness, headache, fatigue, blurred consciousness. Some patients will have myocardial damage. In severe cases, cerebral edema and pulmonary edema may occur. Extremely high concentrations (above 1000mg/m3) can lead to sudden coma within seconds, respiratory and cardiac arrest, and lightning-type death.
1.3 Protective measures:
(1) Engineering controls: tightly sealed, provide adequate exhaust and full exhaust, provide safety showers and eyewash facilities.
(2) Respiratory protection: gas masks must be worn when the concentration in the air exceeds the standard. Positive pressure self-contained breathing apparatus is recommended to be worn when rescuing or evacuating an emergency situation.
(3) Eye protection: wear chemical eye protection.
(4) Protective clothing: wear anti-static clothing.
(5) Hand protection: wear chemical resistant gloves.
(6) Other: Smoking, eating and drinking are prohibited at the work site. After work, bathe and change clothes to maintain good hygiene habits.
1.4 First aid:
(1) Skin contact: remove contaminated clothing, rinse thoroughly with soap and water, and seek medical attention.
(2) Eye contact: immediately turn over the upper and lower eyelids, flush with running water or saline for 15 minutes, seek medical attention.
(3) Inhalation: Get out of the scene to fresh air, keep the airway open, keep warm and rest. Give oxygen when breathing is difficult, and when breathing stops, immediately administer artificial oxygen and seek medical attention.
1.5 Leakage treatment:
Evacuate the leakage contaminated area to the wind, and isolate until the gas dissipates, cut off the source of ignition. Emergency personnel wear positive pressure self-contained breathing apparatus and general protective clothing. Cut off the gas source, spray water to dilute and dissolve, and extract (indoors) or powerfully ventilate (outdoors). If possible, send residual or leaking gases by exhaust fans to a water washing tower or to a fume hood connected to the tower. Or through an aqueous ferric chloride solution, install a check to prevent the solution from flowing back.
Carbon monoxide
2.1 Physical and chemical properties
(1)Molecular formula: CO
(2)Molecular weight: 28.01
(3)Appearance and properties: colorless, odorless gas
(4)Relative density: 0.967 (air=1)
(5)Melting point: - 199.1℃.
(6)Boiling point: -191.4℃
(7)Solubility: low solubility in water, but easily absorbed by ammonia
(8)Explosive limit: 12.5-74.2%
2.2 Hazards
(1)Invasion pathway: inhalation
(2)Health hazards: carbon monoxide enters the human body and will and hemoglobin in the blood, due to CO and hemoglobin binding capacity is much stronger than the binding capacity of oxygen and hemoglobin, and then the number of hemoglobin can be combined with oxygen is reduced dramatically, thus causing hypoxia in the body tissues, resulting in asphyxiation and death of the human body
2.3 Protective Measures
(1) Respiratory Protection: When the concentration in the air exceeds the standard, wear a self-absorbing transition-type Gas mask (half mask). In case of emergency rescue or evacuation, it is recommended to wear air respirator and carbon monoxide filtering self-rescuer.
(2) Eye protection: no special protection is needed in general, and safety eye protection can be worn when exposed to high concentrations.
Body protection: wear anti-static work clothes.
(3)Hand protection: wear general work protective gloves.
(4) Other: Smoking is strictly prohibited at the work site. Practice pre-employment and regular experience. Avoid high concentrations of inhalation. Supervision is required when entering tanks, confined spaces, or other high-concentration areas of operation.
2.4 First Aid Measures
(1)Inhalation: quickly get out of the scene to the fresh air; keep the airway open; if breathing is difficult, give oxygen; in case of respiratory and cardiac arrest, immediately carry out artificial respiration and chest cardiac compression. Seek medical attention.
(2) Fire extinguishing method: cut off the gas source. If the gas source cannot be cut off immediately, do not allow the burning gas to be extinguished. Spray water to cool the container and move the container from the fire to an open area if possible.
2.5 Emergency treatment of leakage
Rapidly evacuate people in the leakage contaminated area to the upwind place, and immediately isolate 150m, strictly restrict access. Cut off the fire source. It is recommended that emergency personnel wear self-contained positive-pressure respirators and fire protective clothing. Cut off the source of leakage as far as possible. Reasonable ventilation to accelerate diffusion. Spray water to dilute and dissolve. Construct a dike or dig a pit to contain the large amount of wastewater generated. If possible, send the leaking gas to an open area with an exhaust fan or install a suitable nozzle to burn it off. It can also be piped to a furnace or alcove for burning. Leakage container to be properly handled, repair, inspection and then use.
Ammonia
3.1 Physical and chemical properties:
(1)Molecular formula: NH3
(2)Molecular weight: 17.031
(3)Appearance and properties: colorless, irritating malodorous odor
(4)Relative density: 0.6 (air=1)
(5)Melting point: - 77.7℃
(6)Boiling point:-33.5℃
(7)Solubility:very soluble in water
(8)Explosion limit:15-28%
3.2 Hazards
(1)Invasion route:inhalation, absorption through the skin
(2)Ammonia is inhaled into the lungs and then easily enter into the bloodstream through the alveoli, and a large amount of ammonia gas can be inhaled for a short time. Inhalation of large quantities of ammonia can appear tearing, sore throat, hoarse voice, cough, sputum with blood, chest tightness, dyspnea, can be accompanied by dizziness, headache, nausea, vomiting, fatigue, etc., the serious cases can occur pulmonary edema, adult respiratory distress syndrome, at the same time, may occur in respiratory tract irritation symptoms. Ammonia is also an alkaline substance that is corrosive and irritating to all skin tissues it comes in contact with. It can absorb the water in the skin tissue, denature the tissue protein, and saponify the tissue fat and destroy the cell membrane structure. In addition to the corrosive effect when the concentration is too high, it can also cause cardiac arrest and respiratory arrest through the reflex action of the trigeminal nerve endings
(3) Poisoning performance
①Mild inhalation of ammonia poisoning manifestations of rhinitis, pharyngitis, sore throat, hoarseness of pronunciation. Ammonia into the trachea, bronchial will cause coughing, sputum, sputum with blood. In severe cases, hemoptysis and pulmonary edema, dyspnea, white or bloody frothy sputum, and both lungs are covered with large and medium blister sounds. Patients have burning throat, cough, sputum or hemoptysis, chest tightness and retrosternal pain.
②Acute inhalation of ammonia poisoning occurs by accidents such as pipeline rupture, valve burst and so on. Acute ammonia poisoning is mainly characterized by respiratory mucosal irritation and burns. The symptoms vary according to the concentration of ammonia, inhalation time and personal sensibility.
③ Acute mild poisoning: dry throat, sore throat, hoarseness, cough, cough, chest tightness and mild headache, dizziness, fatigue, bronchitis and peribronchitis.
4 Acute moderate poisoning: aggravation of the above symptoms, dyspnea, sometimes with blood in the sputum, mild cyanosis, conjunctival congestion is obvious, laryngeal edema, dry and wet rales in the lungs.
⑤ Acute severe poisoning: severe cough, hemoptysis large amount of pink foamy sputum, shortness of breath, palpitation, dyspnea, laryngeal edema further aggravated, obvious cyanosis, or the emergence of acute respiratory distress syndrome, heavier pneumothorax and mediastinal emphysema and so on.
6 severe inhalation poisoning: laryngeal edema, vocal stenosis, and respiratory mucosal detachment can occur, can cause tracheal obstruction, causing asphyxia. Inhalation of high concentrations of ammonia can directly affect the pulmonary capillary permeability and cause pulmonary edema, can induce convulsions, convulsions, drowsiness, coma and other disorders of consciousness. Individual patients inhaling extremely concentrated ammonia can occur respiratory arrest.
(4)Skin and eye contact hazards
①Low concentration of ammonia on the eyes and moist skin can quickly produce irritation. Moist skin or eye contact with high concentrations of ammonia can cause serious chemical burns. Acute mild poisoning: tearing, photophobia, blurred vision, conjunctival congestion.
②Skin contact can cause severe pain and burns, and can occur coffee-like coloring. The corroded area is gelatinous and soft, and deep tissue destruction can occur.
③ High concentration of vapor is a strong irritant to the eyes, can cause pain and burns, leading to significant inflammation and may occur edema, epithelial tissue destruction, corneal clouding and iris inflammation. Mild cases generally resolve, while severe cases may persist for long periods of time with complications such as persistent edema, scarring, permanent clouding, bulging of the eye, cataracts, adhesions to the eyelids and eyeballs, and blindness. Multiple or sustained exposures to ammonia can lead to conjunctivitis.
3.3 First Aid
(1) Ingestion: Immediately rinse the mouth of a person who has accidentally ingested it, take diluted vinegar or lemon juice by mouth, and seek medical attention.
(2)EYE CONTACT: Immediately lift the eyelids and flush with running water or saline for at least 15 minutes. Or rinse with 3% boric acid solution. Seek immediate medical attention.
(3) Skin contact: first rinse with water or 2% vinegar solution, immediately flush with water for at least 15 minutes. If there are burns, seek medical attention. If localized redness, swelling and blistering of the skin occurs, rinse with 2% vinegar solution.
(4) Inhalation: Get out of the scene quickly to fresh air. Keep the airway open. When breathing is difficult, give oxygen. When breathing stops, immediately carry out artificial respiration. Seek medical attention. If the nasal mucosa is strongly stimulated, 1% ephedrine solution can be dropped, and in severe cases, chymotrypsin should be inhaled.
(5) When a person is found to be poisoned by ammonia inhalation, he should be allowed to leave the scene quickly and take off the clothes and pants contaminated by ammonia, and go to the hospital as soon as possible to avoid accidents.
3.4 Leakage Disposal
Ammonia's effect on human physiology Ammonia is colorless with a strong irritating odor, and has a large toxicity to the human body. Chronic ammonia poisoning can cause chronic bronchitis, emphysema and other respiratory diseases, acute ammonia poisoning is reflected in more than a cough, breathlessness and so on.
(1) A small amount of leakage.
Retreat all persons in the area. Prevent inhalation of vapors and contact with liquid or gas. Disposal personnel should use respirators. Prohibit entry into confined spaces where ammonia may pool and enhance ventilation. Plug leaks only when safety is assured. Leaking containers should be moved to a safe place and valves should be opened to relieve pressure only when it is safe to do so. Leaks may be collected and adsorbed with inert absorbent materials such as sand, soil, vermiculite, etc. Collected leaks should be placed in closed containers labeled accordingly for waste disposal.
(2) Massive leaks.
Evacuate all unprotected persons from the premises and move upwind. Leakage disposal personnel should wear a fully enclosed heavy-duty chemical resistant clothing, wear a good air respirator, and dilute the leaking area with a stream of spray water after taking good personal protective measures. Through the dilution of the water gun, so that the scene of the ammonia gas gradually dispersed, the use of non-sparking tools to seal the leak.
To the local government and "119" and the local environmental protection department, public security traffic police department alarm, alarm content should include the accident unit; the time of the accident, the location, the name of the chemical and the amount of leakage, the degree of danger; there are no casualties, as well as the name of the alarm, telephone.
Prohibit contact with or crossing the leaking liquid ammonia, prevent leaks from entering gutters and drains, and enhance ventilation. Smoking and open flames are prohibited on the premises. To plug or turn over leaking containers to prevent liquid ammonia from escaping, if it is safe to do so. To aerosolize water to suppress vapors or redirect the flow of vapor clouds, but direct impact of water on leaking liquid ammonia or the source of the leak is prohibited. Prevent leaks from entering bodies of water, sewers, basements, or confined spaces. Prohibit entry into confined spaces where ammonia may pool. After cleaning, decontaminate all protective clothing and equipment before storage and reuse.
Nitrogen gas
4.1 Physical and chemical properties:
(1) Molecular formula: N2
(2) Relative molecular weight: 28.01
(3) Relative density: 0.97 (air=1)
(4) Appearance and properties: colorless, odorless gas
(5) Melting point: -209.8°C
(6)Boiling point: -195.6°C
(7)Solubility: slightly soluble in water, ethanol.
4.2 Hazards
The excessive content of nitrogen in the air decreases the partial pressure of oxygen in the inhalation gas, causing hypoxia and asphyxiation. Inhalation of nitrogen concentration is not too high, the patient initially feel chest tightness, shortness of breath, weakness; followed by restlessness, extreme excitement, running, shouting, trance, unsteady gait, known as "nitrogen Moetzin", can enter a coma or comatose state. Inhalation of high concentrations, the patient can quickly coma, due to respiratory and cardiac arrest and death. Divers deep for when, can occur nitrogen anesthesia; if from the high-pressure environment too quickly into the atmospheric environment, the body will form nitrogen bubbles, compression of the nerves, blood vessels, or caused by the emblem of vascular obstruction, the occurrence of "decompression sickness".
4.3 First-aid measures
Inhalation: Quickly get out of the scene to fresh air. Keep the airway open. If breathing is difficult, give oxygen. If breathing stops, give artificial respiration immediately. Seek medical attention.
Oxygen
Toxicological data
1. Acute toxicity: human inhalation TCLo: 100pph/14H;
2. Reproduction data:
Woman inhalation TCLo 26-39 weeks after conception: 12pph/10M Abnormalities of the reproductive and cardiovascular systems;
Rat female conception. Inhaled TDLo: 10pph/12H 22 days after conception;
Inhaled TDLo: 10pph/9H 22 days after conception;
Inhaled TDLo: 10pph/24H 8 days after conception;
Inhaled TDLo: 10pph/24H 8 days after conception;
Inhaled TDLo: 10pph/24H 8 days after conception;
3.3. Mutagenicity:
Human lymphocytes: 40pph/4D cytogenetic effect;
Rodent- hamster ovary: 20pph/3D (Continuous) cytogenetic effect;
Rodent- hamster lung: 80pph cytogenetic effect;
Inhalation of TCLo at 8 days after conception in mice: 10pph/24H skin and subcutaneous tissue and reproductive abnormalities;
3. Rodent- hamster ovary sister chromatid: 20pph replication affected;
Rodent- hamster lung: 95pph/24H causes cellular mutations.
4. Subacute and chronic toxicity: at atmospheric pressure, living in 80% oxygen for 4d, rats began to die one after another, rabbits have all the optic cells destroyed; in pure oxygen, rabbits have all the optic cells destroyed in 48h, dogs have deaths in 60h, monkeys have respiratory difficulties in 3d, and they die in 6~9d.
5. Other toxic effects: TCLo: 100% (100%) (human inhalation, 14h); TCLo: 80% (rat inhalation).
Excessive oxygen inhalation negative effects:
As early as the mid-19th century, British scientists Paul Burt first found that if the animals breathe pure oxygen will cause poisoning, and human beings are the same. If a person is greater than 0.05MPa (half an atmosphere) of pure oxygen in the environment, all the cells have a toxic effect, inhalation time is too long, it may occur "oxygen poisoning". The capillary barrier of the lungs is destroyed, leading to pulmonary edema, pulmonary bruising and hemorrhage, seriously affecting the respiratory function, which in turn causes damage to the organs due to lack of oxygen. In a pure oxygen environment of 0.1MPa (1 atmosphere), a person can only survive for 24 hours before pneumonia occurs, which eventually leads to respiratory failure and death by asphyxiation. People in 0.2MPa (2 atmospheres) high-pressure pure oxygen environment, can stay up to hours ~ 2 hours, more than will cause brain poisoning, life rhythm disorders, mental disorganization, memory loss. If you add 0.3MPa (3 atmospheres) or even higher oxygen, people will have brain cell degeneration and necrosis within a few minutes, convulsions and coma, resulting in death.
In addition, excessive oxygen intake also promotes life aging. Oxygen into the human body and cell oxidizing enzyme reaction, can generate hydrogen peroxide, and then into lipofuscin. This lipofuscin is to accelerate cellular aging of harmful substances, it accumulates in the myocardium, so that cardiomyocyte aging, cardiac function decline; accumulates in the wall of blood vessels, resulting in aging and hardening of blood vessels; accumulates in the liver, weakening the liver function; accumulates in the brain, resulting in intellectual decline, memory loss, people become demented; accumulates in the skin, the formation of age spots.
Effects of Oxygen Deficiency and Oxygen Enrichment on the Human Body
Poisoning or Leakage Handling
First Aid Measures
Inhalation: Get out of the scene quickly to fresh air. Keep the airway open. If breathing stops, immediately perform artificial respiration. Seek medical attention.
Fire extinguishing methods: use water to keep the container cool to prevent heat explosion and sharply fuel the fire. Rapidly cut off the gas source, water spray to protect the cut off the gas source of personnel, and then according to the cause of the fire to choose the appropriate extinguishing agent to extinguish the fire.
On-site treatment
Rapidly evacuate the leaking contaminated area to the upwind place, and isolation, strict restrictions on access. Cut off the source of fire. It is recommended that emergency personnel wear self-contained positive pressure respirators and general work clothes. Avoid contact with combustible or flammable materials. Cut off the source of leakage as far as possible. Reasonable ventilation to accelerate diffusion. The leaking container should be properly handled, repaired and inspected before reuse.
Operation Disposal and Storage
Precautions for operation: Confined operation. Confined operation, provide good natural ventilation conditions. Operators must be specially trained and strictly comply with the operating procedures. Keep away from fire and heat source, smoking is strictly prohibited in the workplace. Keep away from flammable and combustible materials. Prevent gas leakage into the workplace air. Avoid contact with active metal powder. Load and unload gently when handling to prevent the cylinder and accessories from breaking. Equipped with appropriate varieties and quantities of fire-fighting equipment and leakage emergency treatment equipment.
Storage precautions: store in a cool, ventilated warehouse. Keep away from fire and heat source. Storage temperature should not exceed 30 ℃. Should be stored separately from flammable materials, active metal powder, etc., do not mix storage. The storage area should be equipped with leakage emergency treatment equipment.
Individual protection
Engineering control: airtight operation. Provide good natural ventilation.
Body protection: Wear general operating overalls.
Hand protection: Wear general work protective gloves.
Other protection: Avoid inhalation of high concentrations.
Storage and transportation method
Packaging method: steel cylinder.
Transportation method: oxygen cylinders must not be stained with grease. The safety cap on the cylinder must be worn when the cylinder is used for transportation. Cylinders are generally placed flat, and should be the mouth of the cylinder in the same direction, not cross; the height shall not exceed the vehicle's protective railing plate, and use triangular wooden pads stuck firmly to prevent rolling. It is strictly prohibited to mix and transport with flammable or combustible materials and active metal powder. In summer, it should be transported in the morning and evening to prevent sunlight exposure. Railroad transportation should be prohibited from slipping.