Physical and chemical properties of 1. 1
(1) Molecular formula: H2S
(2) Molecular weight: 34.06
(3) Appearance and properties: colorless and odorous gas.
④ Relative density: 1. 13 (air = 1)
(5) Melting point: -85.5℃
(6) Boiling point: -60.4℃
(7) Solubility: Soluble in water and ethanol.
(8) The explosion limit is 4.0 ~ 46.0%
1.2 Danger:
(1) Invasion route: inhalation and percutaneous absorption.
(2) Health hazard: Hydrogen sulfide is a strong nerve agent, which has a strong stimulating effect on mucosa. Tears, eye pain, runny nose, burning sensation in throat, cough, chest tightness, headache, fatigue, confusion and so on appear after inhaling high concentration of hydrogen sulfide in a short time. Some patients will have myocardial damage. In severe cases, brain edema and pulmonary edema may occur. When the concentration is extremely high (above 1000mg/m3), it can suddenly coma, respiratory and cardiac arrest within a few seconds, leading to lightning strike death.
1.3 protection measures:
(1) engineering control: strictly seal, provide adequate and comprehensive ventilation, and provide safe shower and eye washing equipment.
(2) Respiratory system protection: When the concentration in the air exceeds the standard, a gas mask must be worn. It is recommended to wear positive pressure self-contained breathing apparatus in emergency rescue or evacuation.
(3) Eye protection: Wear chemical eye protection.
(4) Protective clothing: Wear antistatic clothing.
(5) Hand protection: Wear chemical-resistant gloves.
(6) Others: Smoking and eating are prohibited in the workplace. Take a shower and change clothes after work, and maintain good hygiene habits.
1.4 first aid mode:
(1) Skin contact: Take off contaminated clothes, rinse thoroughly with soapy water, and seek medical attention.
(2) Eye contact: Open the upper and lower eyelids immediately, rinse with flowing water or normal saline for 15 minutes, and see a doctor.
(3) Inhalation: leave the site quickly to fresh air, keep the respiratory tract unobstructed, and pay attention to keep warm and rest. Oxygen should be given when breathing is difficult, and artificial oxygen inhalation and drug treatment should be given immediately when breathing stops.
1.5 leakage treatment:
Evacuate the personnel in the leaked contaminated area to the windward, isolate them until the gas is exhausted, and cut off the fire source. Emergency personnel should wear positive pressure self-contained breathing apparatus and general protective clothing. Cut off the air source, spray water for dilution and dissolution, exhaust (indoor) or strong ventilation (outdoor). If possible, send the residual or leaked gas to the water washing tower or fume hood with exhaust fan. Or through ferric chloride aqueous solution, install a check device to prevent the solution from flowing back.
carbon monoxide
2. Physical and chemical properties of1
(1) molecular formula: CO
(2) Molecular weight: 28.05438+0
(3) Appearance and properties: colorless and odorless gas.
(4) Relative density: 0.967 (air = 1)
(5) Melting point:-199. 1℃
(6) Boiling point:-19 1.4℃
(7) Solubility: the solubility in water is low, but it is easily absorbed by ammonia water.
(8) Explosion limit: 12.5 ~ 74.2%
2.2 Harm
(1) Invasion route: inhalation.
(2) Health hazard: Carbon monoxide will combine with hemoglobin in the blood after entering the human body. Because the binding capacity of CO and hemoglobin is much stronger than that of oxygen and hemoglobin, the number of hemoglobin that can bind oxygen decreases sharply, leading to hypoxia and suffocation.
2.3 protective measures
(1) Respiratory system protection: When the concentration in the air exceeds the standard, wear a self-priming transitional gas mask (half mask). In case of emergency rescue or evacuation, it is recommended to wear air respirator and carbon monoxide filter self-rescuer.
(2) Eye protection: generally, special protection is not needed, and eye protection can be worn when exposed to high concentrations.
Physical protection: wear anti-static work clothes.
(3) Hand protection: Wear general operating protective gloves.
(4) Others: Smoking is strictly prohibited at the work site. Implement pre-job and regular experience. Avoid high concentration inhalation. Work in storage tanks, confined spaces or other high concentration areas must be supervised.
2.4 First aid measures
(1) Inhalation: leave the site quickly and go to fresh air; Keep the respiratory tract unobstructed; If breathing is difficult, give oxygen; When breathing and heartbeat stop, artificial respiration and chest compressions should be performed immediately. See a doctor.
(2) Fire extinguishing method: cut off the gas source. If the gas source cannot be cut off immediately, it is not allowed to extinguish the burning gas. Spray water to cool the container, and if possible, move the container from the fire to an open place.
2.5 Emergency treatment of leakage
Evacuate the personnel in the leaked contaminated area to upwind quickly, and immediately isolate 150m, and strictly restrict access. Cut off the fire. It is recommended that emergency personnel wear self-contained positive pressure breathing apparatus and fire protection clothing. Cut off the leakage source as much as possible. Reasonable ventilation and accelerated diffusion. Spray water is diluted and dissolved. Build a dike or dig a pit to contain a large amount of wastewater. If possible, use an exhaust fan to send the leaked gas to an open place, or install a suitable nozzle for combustion. It can also be introduced into the furnace by pipeline and burned in the concave surface. Leaked containers should be properly treated, repaired and inspected before use.
ammonia
3. Physical and chemical properties of1:
(1) Molecular formula: NH3
(2) Molecular weight: 17.438+0
(3) Appearance and properties: colorless, with pungent odor.
(4) Relative density: 0.6 (air = 1)
(5) Melting point: -77.7℃
(6) Boiling point: -33.5℃
(7) Solubility: extremely soluble in water.
(8) Explosion limit: 15 ~ 28%
3.2 Harm
(1) Invasion route: inhalation and percutaneous absorption.
(2) Ammonia can easily enter the blood through alveoli after being inhaled into the lungs. After inhaling a large amount of ammonia in a short time, tears, sore throat, hoarseness, cough, bloodshot sputum, chest tightness, dyspnea, dizziness, headache, nausea, vomiting, fatigue, etc. It could happen. In severe cases, pulmonary edema, adult respiratory distress syndrome and respiratory irritation may occur. Ammonia is also an alkaline substance, which has corrosive and irritating effects on skin tissue in contact. It can absorb moisture in skin tissue, denature tissue protein, saponify tissue fat and destroy cell membrane structure. When the concentration is too high, in addition to corrosion, it can also cause cardiac arrest and respiratory arrest through the reflection of trigeminal nerve endings.
(3) Poisoning manifestations
① Mild ammonia inhalation poisoning is characterized by rhinitis, pharyngitis, sore throat and hoarseness. Ammonia entering trachea and bronchus can cause cough, expectoration and blood in sputum. In severe cases, hemoptysis with pulmonary edema, dyspnea, white or bloody foam sputum, and large and medium-sized blisters on both lungs may occur. The patient has burning throat, cough, expectoration or hemoptysis, chest tightness and retrosternal pain.
② Acute ammonia inhalation poisoning is mostly caused by accidents such as pipeline rupture and valve burst. Acute ammonia poisoning is mainly manifested as irritation and burns of respiratory mucosa. Its symptoms vary with ammonia concentration, inhalation time and personal sensitivity.
③ Acute mild poisoning: dry throat, sore throat, hoarseness, cough, expectoration, chest tightness and mild headache, dizziness, fatigue, bronchitis and bronchiolitis.
④ Acute and moderate poisoning: the above-mentioned symptoms are aggravated, with dyspnea, sometimes bloodshot sputum, mild cyanosis, obvious conjunctival congestion, laryngeal edema, and dry and wet snoring in the lungs.
⑤ Acute severe poisoning: severe cough, a lot of pink foam-like sputum, shortness of breath, palpitation, dyspnea, further aggravation of laryngeal edema, obvious cyanosis, or acute respiratory distress syndrome, severe pneumothorax and mediastinal emphysema.
⑥ Severe inhalation poisoning: Laryngeal edema, glottic stenosis and respiratory mucosa shedding may occur, which may cause tracheal obstruction and suffocation. Inhalation of high concentration ammonia can directly affect the permeability of pulmonary capillaries, cause pulmonary edema, and induce convulsions, convulsions, drowsiness, coma and other conscious disorders. Individual patients who inhale extremely concentrated ammonia will have respiratory and cardiac arrest.
(4) Harmful manifestations of skin and eye contact.
① Low concentration ammonia can quickly stimulate eyes and moisturize skin. Wet skin or eyes exposed to high concentrations of ammonia can cause serious chemical burns. Acute mild poisoning: tears, photophobia, blurred vision and conjunctival congestion.
② Skin contact can cause severe pain and burns, and coffee-like coloring can occur. The corroded part is gelatinous and soft, which can cause deep tissue damage.
③ High-concentration steam has a strong irritation to eyes, causing pain and burns, leading to obvious inflammation, including edema, epithelial tissue destruction, corneal opacity and iris inflammation. Mild cases will generally be relieved, and severe cases can last for a long time, and there will be complications such as persistent edema, scar, permanent turbidity, exophthalmos, cataract, eyelid and eyeball adhesion, blindness and so on. Repeated or continuous exposure to ammonia can lead to conjunctivitis.
3.3 First aid methods
(1) By mistake: If taken by mistake, rinse your mouth immediately, take diluted vinegar or lemon juice orally, and seek medical advice.
(2) Eye contact: Lift the eyelid immediately and rinse it with flowing clear water or normal saline for at least 15 minutes. Or rinse with 3% boric acid solution. See a doctor at once.
(3) Skin contact: rinse with clean water or 2% vinegar solution first, and then rinse with water immediately for at least 15 minutes. If you have burns, please see a doctor. If the skin is swollen and blistered locally, it can be washed with 2% vinegar.
(4) Inhalation: leave the site quickly and go to a place with fresh air. Keep the respiratory tract unobstructed. Oxygen is given when breathing is difficult. When breathing stops, give artificial respiration immediately. See a doctor. If the nasal mucosa is strongly stimulated, 1% ephedrine solution can be dripped, and chymotrypsin can be inhaled in severe cases.
(5) When someone is found to be poisoned by inhaling ammonia, he should be allowed to leave the scene quickly, take off his clothes and trousers contaminated by ammonia and go to the hospital as soon as possible to avoid accidents.
3.4 Leakage treatment
Effects of ammonia on human physiology Ammonia is colorless, has a strong pungent smell and is highly toxic to human body. Chronic ammonia poisoning can cause respiratory diseases such as chronic tracheitis and emphysema, while acute ammonia poisoning is characterized by coughing and holding your breath.
(1) A small amount of leakage.
Evacuate all personnel in the area. Prevent inhalation of steam and contact with liquid or gas. Disposal personnel should use breathing apparatus. It is forbidden to enter the closed space where ammonia may gather, and the ventilation should be strengthened. Only when safety is ensured can plugging be carried out. The leaking container should be moved to a safe place, and the valve can only be opened to relieve pressure when safety is ensured. Leakage can be collected and absorbed by inert absorbent materials such as sand and vermiculite. The collected leakage should be placed in a sealed container and labeled accordingly for disposal.
(2) a large number of leaks.
Evacuate all unprotected personnel there and move to the upwind direction. Leakage disposal personnel should wear fully enclosed heavy chemical protective clothing and air respirator, and after taking personal protective measures, dilute the leakage area with spray water. Through the dilution of the water gun, the ammonia gas in the field is gradually dispersed, and the leakage point is blocked with a spark-free tool.
Give an alarm to the local government and "1 19" as well as the local environmental protection department and the public security traffic police department, and the alarm content shall include the accident unit; The time and place of the accident, the name of the chemicals, the amount of leakage and the degree of danger; Whether there are any casualties and the name and telephone number of the alarm person.
It is forbidden to touch or cross the leaked liquid ammonia, prevent leakage from entering sewers and drains, and strengthen ventilation. Smoking and open flames are prohibited in the premises. Under the condition of ensuring safety, the leaking container should be blocked or turned over to avoid the leakage of liquid ammonia. Spray water to suppress steam or change the direction of steam cloud, but it is forbidden to directly impact the leaked liquid ammonia or leakage source with water. Prevent leakage from entering water bodies, sewers, basements or confined spaces. It is forbidden to enter a confined space where ammonia gas may accumulate. After cleaning, all protective clothing and equipment should be cleaned before storage and reuse.
nitrogen (N)
4. Physical and chemical properties of1:
(1) Molecular formula: N2
(2) Relative molecular weight: 28.438+0
(3) Relative density: 0.97 (air = 1)
(4) Appearance and properties: colorless and odorless gas.
(5) Melting point: -209.8℃
(6) Boiling point:-195.6℃
(7) Solubility: slightly soluble in water and ethanol.
4.2 Harm
The high nitrogen content in the air reduces the oxygen partial pressure of inhaled air, leading to hypoxia and suffocation. When the inhaled nitrogen concentration is not too high, the patient initially feels chest tightness, shortness of breath and weakness; Then there are fidgety, extremely excited, running around, shouting, being in a trance, and unsteady gait. This situation is called "nitrogen poisoning" and can enter a lethargic or coma state. Inhalation of high concentrations can lead to rapid coma and death due to respiratory and cardiac arrest. When divers are deeply replaced, the anesthetic effect of nitrogen can occur; If you switch from high pressure environment to normal pressure environment too quickly, nitrogen bubbles will form in the body, which will compress nerves and blood vessels or block the emblem blood vessels, resulting in "decompression sickness".
4.3 First aid measures
Inhalation: leave the scene quickly and go to a place with fresh air. Keep the respiratory tract unobstructed. If you have difficulty breathing, give oxygen. If breathing stops, give artificial respiration immediately. See a doctor.
oxygen
Toxicological data
1. acute toxicity: human inhales tclo:100pph/14h;
2. Copy data:
When women inhale TCLO: 12 PPH/ 1m after pregnancy, the reproductive system and cardiovascular system are abnormal;
22 days after conception, rats inhaled TDLO: 10 PPH/ 12 hours, and the reproductive and respiratory systems were abnormal.
Inhalation of TDLO: 10 PPH/9h on the 22nd day after conception in rats has inhibitory effects on reproduction, respiratory system and neonatal growth.
Mice inhaled TCLO: 10 PPH/24h on the 8th day after conception, and the skin and subcutaneous tissue and reproduction were abnormal.
3. Mutagenicity:
Human lymphocytes: 40pph/4D has influence on cell heredity;
Rodent-hamster ovary: 20pph/3D (continuous) has an effect on cell inheritance;
Rodent-hamster lung: 80pph has an effect on cell inheritance;
Sister chromosome of rodent-hamster ovary: 20pph replication is affected;
Rodent-hamster lung: 95pph/24H leads to cell mutation.
4. Subacute and chronic toxicity: After living in 80% oxygen for 4 days at normal pressure, rats began to die one after another, and all the optic nerve cells of rabbits were destroyed; In pure oxygen, the rabbit's visual cells were completely destroyed in 48h, the dog died in 60h, and the monkey had difficulty breathing in 3d and died in 6-9d.
5. Other toxic effects: TCLO: 100% (100%) (human inhalation,14h); Tclo: 80% (inhaled by rats).
Negative effects of excessive inhalation of oxygen:
As early as the middle of19th century, British scientist Paul Burt first discovered that if animals breathe pure oxygen, it will cause poisoning, and so will humans. If people are exposed to pure oxygen with a concentration exceeding 0.05MPa (half atmospheric pressure), it is toxic to all cells. If the inhalation time is too long, "oxygen poisoning" may occur. The capillary barrier of the lung is destroyed, which leads to pulmonary edema, pulmonary congestion and bleeding, which seriously affects the respiratory function, and then leads to organ hypoxia and damage. In the pure oxygen environment of 0. 1MPa( 1 atmospheric pressure), people can only survive for 24 hours, and pneumonia will occur, which will eventually lead to respiratory failure and suffocation. People staying in the high-pressure pure oxygen environment of 0.2MPa(2 atmospheres) for several hours to at most 2 hours will cause brain poisoning, disordered life rhythm, mental disorder and memory loss. If 0.3MPa(3 atmospheres) or even higher oxygen is added, people will experience brain cell degeneration and necrosis, convulsion and coma within a few minutes, leading to death.
In addition, excessive oxygen inhalation will also promote life aging. Oxygen entering the human body reacts with oxidase in cells to generate hydrogen peroxide, which in turn becomes lipofuscin. This lipofuscin is a harmful substance that accelerates cell aging, accumulates in myocardium, ages myocardial cells and reduces heart function. Accumulation on the wall of blood vessels leads to aging and hardening of blood vessels; Accumulate in the liver and weaken liver function; Accumulate in the brain, causing mental decline and memory decline, and people become dementia; Accumulate on the skin and form senile plaques.
Effects of hypoxia and oxygen enrichment on human body
Treatment of poisoning or leakage
Emergency treatment
Inhalation: leave the scene quickly and go to a place with fresh air. Keep the respiratory tract unobstructed. If breathing stops, give artificial respiration immediately. See a doctor.
Fire extinguishing method: keep the container cool with water to prevent the container from being heated and exploding, and quickly fuel the fire. Cut off the gas source quickly, spray water to protect the personnel who cut off the gas source, and then choose the appropriate fire extinguishing agent according to the cause of the fire.
Field treatment
Quickly evacuate people in the leaked and polluted area to the windward, isolate them, and strictly restrict access. Cut off the fire. It is recommended that emergency personnel wear self-contained positive pressure breathing apparatus and ordinary work clothes. Avoid contact with flammable or combustible materials. Cut off the leakage source as much as possible. Reasonable ventilation and accelerated diffusion. Leaked containers should be properly treated, repaired and inspected before use.
Operation, disposal and storage
Precautions for operation: closed operation. Closed operation to provide good natural ventilation. Operators must be specially trained and strictly abide by the operating procedures. Stay away from kindling and heat sources, and smoking is strictly prohibited in the workplace. Keep away from flammable and combustible materials. Prevent the gas in the workplace from leaking into the air. Avoid contact with active metal powder. Lightly load and unload when handling, so as to prevent the cylinders and accessories from being damaged. Equipped with corresponding varieties and quantities of fire fighting equipment and leakage emergency treatment equipment.
Precautions for storage: Store in a cool and ventilated warehouse. Stay away from fire and heat sources. The reservoir temperature should not exceed 30℃. Should be stored separately from flammable (combustible) materials and active metal powder, and should not be mixed. The storage area should be equipped with emergency treatment equipment for leakage.
Personal protection
Engineering control: closed operation. Provide good natural ventilation conditions.
Physical protection: wear general work clothes.
Hand protection: wear gloves for general operation.
Other protection: avoid high concentration inhalation.
Storage and transportation methods
Packing: steel cylinder.
Transportation method: Oxygen cylinders must not be contaminated with grease. When transporting cylinders, you must wear the safety helmet on the cylinders. Cylinders are generally flat, and the bottle mouths should be in the same direction and cannot cross; The height shall not exceed the vehicle guardrail, and it shall be fastened with triangular wooden mats to prevent rolling. It is strictly prohibited to transport with flammable or combustible substances and active metal powder. It should be transported in the morning and evening in summer to prevent sun exposure. When transporting by rail, it is forbidden to slip.
Detection standard of various gases in confined space operation;
1. The oxygen content in the air of the workplace with limited space should be 19.5%-2 1%. If the oxygen content in the air is lower than 19.5%, ventilation measures should be taken.
2. Concentration of combustible gas in confined space: less than 0.4% for hydrogen and less than 0.2% for diesel.
3. The dust concentration in the limited space is less than 20g/m3.
4. The maximum allowable concentration of hydrogen sulfide in a limited space is 10mg/m3.
5. The time-weighted average allowable concentration of carbon monoxide is 20mg/m3, and the allowable concentration of short-term contact is 30mg/m3.
6. The time-weighted average allowable concentration of carbon dioxide is 9000mg/m3, and the allowable concentration for short-term contact is 18000mg/m3.
7. The time-weighted average allowable concentration of ammonia is 20mg/m3, and the short-term contact allowable concentration is 30mg/m3.
8. The maximum allowable concentration of chlorine is 1mg/ m3.
9. The maximum allowable concentration of hydrogen cyanide (calculated as CN) is 1mg/ m3.
10, and the maximum allowable concentration of cyanide (calculated as CN) is 1 mg/m3.
1 1, the time-weighted average allowable concentration of bromine is 0.6mg/m3, and the allowable concentration of short-term contact is 2mg/m3.
12, and the maximum allowable concentration of hydrogen bromide is 10mg/m3.
13, the time-weighted average allowable concentration of liquefied petroleum gas is 1000mg/m3, and the allowable concentration of short-term contact is 1500mg/m3.
14, time-weighted average allowable concentration of nitric oxide 15mg/m3.
15, the time-weighted average allowable concentration of ether is 300mg/m3, and the allowable concentration of short-term contact is 500mg/m3.
16, and the maximum allowable concentration of acetaldehyde is 45mg/m3.
17, the time-weighted average allowable concentration of benzene is 6mg/m3, and the short-time contact allowable concentration is 10mg/m3.
18, the time-weighted average allowable concentration of nitrogen dioxide is 5mg/ m3, and the allowable concentration of short-term contact is 10mg/m3.
19, the time-weighted average allowable concentration of sulfur dioxide is 5mg/ m3, and the short-term contact allowable concentration is 10mg/m3.
20. The time-weighted average allowable concentration of toluene is 50mg/m3, and the short-term contact allowable concentration is 100mg/m3.
2 1, the time-weighted average allowable concentration of methanol is 25mg/m3, and the short-time contact allowable concentration is 50mg/m3.
22. The maximum allowable concentration of formaldehyde is 0.5mg/m3.