Emergency treatment of seven common dangerous chemicals

Dangerous chemicals generally have inflammable and explosive, toxic and harmful characteristics, in the emergency treatment must understand their characteristics, take appropriate measures to deal with correctly and timely. The seven common dangerous chemicals mentioned in this article refer to liquefied petroleum gas, natural gas, cyanide, potassium permanganate, chlorine gas, liquid ammonia and gasoline, and their emergency treatment measures are as follows:

(1) Liquefied petroleum gas

1. Liquefied petroleum gas is a kind of fuel widely used in industrial production and daily life of residents. It is mainly composed of propane, propylene, butane, butene and other hydrocarbon media, but also contains a small amount of H2S, CO, CO2 and other impurities. Appearance and properties: colorless gas or yellowish brown oily liquid, with special odor; Flash point -74℃; Boiling point from -0.5℃ to -42℃; Ignition temperature 426 ~ 537℃; Lower explosive limit [%(V/V)]2.5; Upper explosion limit [%(V/V)]9.65; Relative to air density: 1.5 ~ 2.0; Insoluble in water.

2. Forbidden compound: strong oxidant, halogen.

3. Dangerous characteristics: Class 2.1 flammable gas, extremely flammable; Heat, open flame or spark can cause combustion; Can form explosive mixture with air; Vapor heavier than air, can be spread along the ground, vapor diffusion after ignition source ignition back; The packaging container may explode when heated, and the cracked cylinder is a flight hazard.

4. Health hazards: Without protection, direct inhalation of anesthetic liquefied petroleum gas vapor can cause dizziness, headache, excitement or drowsiness, nausea, vomiting, slow pulse, etc.; In severe cases, sudden collapse, urinary incontinence, loss of consciousness, and even respiratory arrest may occur. Incomplete combustion can lead to carbon monoxide poisoning. Frostbite can be caused by direct contact with liquids or their jets.

5. Environmental hazards: harmful to the environment, can cause pollution to the atmosphere, residual liquid can also cause pollution to soil, water.

6. Public safety: Steam spreads along the ground and tends to accumulate in low-lying areas (such as sewage drains, sewers, etc.). Therefore, stay in the upwind and do not enter low-lying areas; Irrelevant personnel should immediately evacuate the leakage area at least 100 meters; Evacuate irrelevant personnel and establish a warning zone, traffic control should be implemented if necessary.

7. Personal protection: wear positive pressure self-contained breathing apparatus; Wear ESD clothes.

8. Large leakage: Consider isolation of at least 800 meters (800 meters radius exclusion zone centered on the leak source).

Fire: If there is a storage tank, tank car or tank car in the fire site, isolation of 1600 meters (centered on the leak source, with a radius of 1600 meters).

9. Disposal of poisoning

Skin contact: Seek medical treatment for frostbite.

Inhalation: Quickly remove from the scene to a place with fresh air to keep the airway unobstructed. If breathing is difficult, give oxygen; If breathing stops, give artificial respiration immediately and seek medical attention.

10. Leakage disposal

(1) Establish a warning zone. A full martial law will be imposed at least 800 meters away from the leak site according to the terrain and weather. Draw cordons, set up clear signs, and inform personnel in and around the warning area to leave quickly by various means and means, and prohibit all vehicles and unrelated personnel from entering the warning area.

(2) Eliminate all fire. Immediately in the warning area power outage, a ceasefire, the extinction of all possible fire and explosion of tinder. Before entering the danger zone, spray the ground wet with a water gun to prevent sparks from friction and impact. Ensure that the equipment is grounded during operation.

(3) Control the source of leakage. Caulk or turn over container to avoid liquid leakage when safe. If the pipeline is broken, it can be blocked by wood wedge, plugging device or clamp method, and then blocked temporarily by high grade quick-frozen cement covering method.

(4) diversion and pressure relief. If all process pipelines are intact, liquid hydrocarbons can be imported into the emergency tank through the liquid outlet line and blowdown line, or the liquefied petroleum gas boundary level can be raised above the leak site by the water injection lifting method.

(5) Tank cover. From a safe distance, the temperature and concentration of combustible gas are reduced by spraying the tank wall and the leak point with a mounted water gun in the form of a flower and a stationary spray gun.

(6) Control the vapor cloud. If possible, the boiler car or steam belt can be directed at the leak point and pumped to disperse the combustible gas; Cover the leaking liquid phase with medium expansion foam or dry powder to reduce the evaporation of liquefied gas; Divert the vapor cloud with spray water (or forced ventilation) so that it disperses in a safe place.

(7) On-site monitoring. Combustible gas detector shall be used at any time to monitor and detect the gas concentration in the warning area, and personnel shall be ready to evacuate at any time.

(8) Precautions: do not use water to directly impact the leakage or leakage source; Prevent leakage to the sewer, ventilation system and sealed space diffusion; The containment zone can be isolated until the LPG concentration reaches below 25% of the lower explosive limit.

11. Combustion and explosive disposal

(1) Selection of fire extinguishing agent

Small fire: dry powder, carbon dioxide extinguisher;

Fire: Water curtain, mist - like water.

(2) Close the valve and cut off the material to prevent leakage.

Close the valve and cut off the air: If the valve is not burned out, wear fire-proof clothing, with pipe pliers, under the cover of the water gun, approach the device, close the valve and cut off the air source.

Diversion pressure relief: if the process pipeline is intact, liquid hydrocarbon can be imported into the emergency tank through the liquid outlet pipeline and blowdown pipeline, reducing the storage of the tank.

Water injection floating: If the leakage occurs at the bottom or lower part of the tank, the existing or temporarily installed pipeline is used to inject water into the tank. By using the difference in specific gravity between water and liquefied petroleum gas, the liquefied petroleum gas is floated above the crack, so that the water flows out from the crack, and then the leakage is stopped. In order to prevent the discharge of liquefied gas from the top safety valve, it can be taken to pour liquid first, then water injection repair or water injection while guiding liquid.

(3) Active cooling, stable combustion, prevent explosion. Organize enough forces to control the fire within a certain range, use shooting water to cool the fire and adjacent tank walls, and protect adjacent buildings from the threat of fire, so as to prevent the fire from spreading. Without cutting off the leakage source, it is strictly prohibited to extinguish the flame that has been burning steadily.

Dry powder suppression method: after the temperature drops, dry powder is sprayed into the stable burning flame to cover the flame and terminate the combustion, so as to extinguish the fire.

2. Natural gas

Refer to liquefied petroleum gas disposal.

(3) cyanide

Cyanide is a compound containing the cyanide root (-CN). Its variety, such as hydrocyanic acid, sodium cyanide, potassium cyanide, zinc cyanide, acetonitrile, acrylonitrile, etc., can be used for refining gold and silver, metal quenching treatment, electroplating, but also can be used to produce dyes, plastics, fumigants or insecticides. Most cyanide is highly toxic or highly toxic, oral sodium cyanide 50 ~ 100mg can cause sudden death.

1. Route of exposure

Cyanide can enter the body through respiratory tract, skin and eye contact, ingestion, etc. All inhalable cyanide can be absorbed through the lungs. Cyanide through the skin, mucous membranes, conjunctiva after absorption, will cause irritation, and appear toxic symptoms. Most cyanide is absorbed immediately through the gastrointestinal tract.

2. Emergency treatment

(1) Individual protection of rescue workers

If cyanide is suspected at the rescue site, rescue workers should wear a one-piece adhesive cloth anti-poison jacket and rubber oil-resistant gloves. Respirators can be used for respiratory protection. In case of possible contact with cyanide vapor, a self-priming filter gas mask (full face mask) should be worn. During on-site rescue, rescue workers should prevent the contaminated skin or clothes of the victims from contaminating them again.

(2) Patient rescue

Move the infected out of the contaminated area immediately. Check whether the victim has stopped breathing, if not, give artificial respiration; If there is no pulse, perform CPR immediately. If necessary, the victim should be provided with pure oxygen and specific antidotes. Resuscitation should be performed to ensure that the victim's airway is not blocked. Endotracheal intubation may be performed if the victim has respiratory distress. When the condition of the victim does not permit intubation, cricothyroid chondrotomy may be performed if conditions permit.

(3) decontamination of patients

Decontamination should be performed by all persons exposed to cyanide:

(1) Take off contaminated clothing as soon as possible and put it in a double-layer plastic bag. At the same time, wash your skin and hair with plenty of water for at least 5 minutes. Pay attention to eye protection during the washing process.

② If skin or eyes come into contact with cyanide, wash immediately with plenty of water or normal saline for more than 5 minutes. If they wear contact lenses and they are easy to remove, they should be removed immediately. In case of difficulty, ask for professional help.

③ If it is oral poisoning, gastric tube should be inserted and activated carbon should be taken as soon as possible. Gastric lavage and vomit must be isolated and stored separately.

3. Dangerous characteristics: non-combustible. A highly toxic cyanide gas produced by high heat or in contact with acids. It reacts violently with nitrate, nitrite and chlorate and has the risk of explosion. Acid or exposed to the air can absorb water and carbon dioxide decomposition of highly toxic hydrogen cyanide gas. The aqueous solution is alkaline corrosive liquid.

4. Fire extinguishing method: This product is not flammable. In case of fire, the commodities should be rescued as far as possible to prevent package damage and environmental pollution. Fire fighters should wear gas masks and full fire fighting suits and fight fires upwind. Extinguishing agent: dry powder, sand. Carbon dioxide and acid and alkali extinguishing agents are prohibited.

5. Emergency treatment: isolate the contaminated area and restrict access. It is recommended that emergency personnel wear dustproof masks (full covers) and protective suits. Do not contact spills directly. Small leakage: Collect in a dry, clean, covered container with a clean shovel. It can also be rinsed with hypochlorite solution, which is diluted and placed in the wastewater system. Lots of leaks: Cover with plastic sheeting and canvas. It is then collected for recycling or transported to a waste disposal site for disposal.

(4) potassium permanganate

(Inorganic oxide reference disposal)

Potassium permanganate, common name: manganese oxide, soluble in water, lye, slightly soluble in methanol, acetone, sulfuric acid. Used in organic synthesis, oil industry, oxidation, medicine, disinfection and so on.

1. Contraindications: strong reducing agents, active metal powder, sulfur, aluminum, zinc, copper and its alloys, flammable or combustible materials.

2. Health hazard: inhalation can cause respiratory tract damage. Splash in the eyes, stimulate the conjunctiva, serious burns. Irritate the skin. Strong solutions or crystals are corrosive to the skin. Oral administration corroded the mouth and digestive tract, causing burning sensation in the mouth, upper abdominal pain, nausea, vomiting, oropharyngeal swelling, etc. In patients with high oral dose, the oral mucosa is brown and black, swelling and erosion, severe abdominal pain, vomiting, bloody stool, shock, and finally death from circulatory failure.

3. Dangerous characteristics: This product is inflammable, corrosive and irritating, which can cause burns to human body. Strong oxidant. Explosion occurs when it encounters sulfuric acid, ammonium salt or hydrogen peroxide. Encounter glycerin, ethanol can cause spontaneous combustion. Contact or mix with organic matter, reducing agent, inflammable matter such as sulfur, phosphorus and so on May cause combustion and explosion risk.

4. First aid measures

Skin contact: Immediately remove contaminated clothing and rinse with plenty of running water for at least 15 minutes.

Eye contact: Immediately lift eyelids and rinse thoroughly with plenty of running water or saline for at least 15 minutes.

Inhalation: Quickly remove from the scene to fresh air. Keep your airway clear. Give oxygen if breathing is difficult. If breathing stops, give artificial respiration immediately.

To ingest: Gargle with water and drink milk or egg whites.

5. Fire extinguishing method: water, mist water and sand are used to extinguish the fire.

6. Emergency treatment: isolate the contaminated area and restrict access. It is recommended that emergency personnel wear dustproof masks (full covers) and protective suits. Do not contact spills directly. Small spills: Mix with sand, dry lime, or soda ash. Collect in a dry, clean, covered container with a clean shovel. Large leakage: collect and recycle or transport to waste disposal site.

(5) chlorine gas

1. Chlorine gas is a serious drug. It is yellow-green non-flammable gas at room temperature and has irritability. After pressure liquefaction or freezing liquefaction, it is yellow-green oily liquid. Chlorine gas soluble in carbon disulfide and carbon tetrachloride and other organic solvents, slightly soluble in water. When dissolved in water, hypochlorous acid (HCLO) and hydrochloric acid are formed. The unstable hypochlorous acid is rapidly decomposed into reactive oxygen species. Therefore, water will strengthen the oxidation and corrosion of chlorine. Chlorine gas can react with lye, such as sodium hydroxide and potassium hydroxide solutions, to form chlorides and hypochlorites. Chlorine gas reacts with carbon monoxide at high temperatures to form phosgene, which is more toxic. Chlorine gas can form explosive mixtures with combustible gases. Liquid chlorine reacts explosively with many organic compounds such as hydrocarbons, alcohols, ethers, hydrogen and so on. As a strong oxidant, chlorine is a basic organic chemical raw material, widely used in textile, paper, medicine, pesticides, metallurgy, tap water fungicide and bleach.

2. First aid measures

(1) Skin contact should be treated as acid burn. Remove contaminated clothing immediately and rinse with plenty of running water. Chloracne can be applied to the affected area with dexamethasone ointment.

(2) When the eye is in contact, lift the eyelid, rinse thoroughly with running water or normal saline, and drop eye drops.

(3) If inhaled, immediately remove from the site to a place with fresh air. If breathing is cardiac arrest, artificial respiration and external chest compressions should be performed immediately.

3. Leakage disposal

Quickly evacuate the contaminated area to the upper wind, and immediately isolate, according to the field test results and possible hazards, determine the scope of the isolation area, strictly restrict access. In general, the initial isolation radius is 150m for small leaks and 450m for large leaks. Emergency personnel should wear positive pressure self-contained air breathing apparatus and wear protective clothing. Cut off the source of leakage as much as possible. All combustible and flammable materials should be removed or eliminated at the site of leakage, and oil stains should be strictly prohibited on tools used to prevent explosion accidents. Prevent leakage of liquid chlorine into the sewer. Reasonable ventilation to accelerate diffusion. The spray lye absorbs chlorine gas that has evaporated into the air, preventing it from spreading widely and poisoning people outside the quarantine zone. Do not spray water on leaking liquid chlorine cylinders. Large quantities of waste water produced by the construction of embankments or by the digging of pits. If possible, use copper pipes to direct the leaking chlorine gas to the lye pool to completely eliminate the potential harm caused by chlorine gas. The leaking liquid chlorine cylinder can be put into the lye tank, which should be large enough to contain generally 1.5 times the theoretical consumption of alkali. Real-time detection of chlorine content in the air, when chlorine content exceeds the standard, can be absorbed by spray lye.

(6) liquid ammonia

Liquid ammonia, also known as anhydrous ammonia, is a colorless liquid. In order to facilitate transportation and storage, gaseous ammonia is usually pressurized or cooled to obtain liquid ammonia. Ammonia dissolves easily in water and forms an alkaline solution of ammonium hydroxide. It is corrosive and volatile. Gas ammonia relative density (air =1) : 0.59, liquid ammonia relative density (water =1) : 0.7067(25℃), spontaneous combustion point: 651.11℃, boiling point (℃) : -33.4

1. First aid measures

(1) Remove pollution

If the patient has only been exposed to ammonia and has no symptoms of skin or eye irritation, decontamination is not necessary. If contact is liquid ammonia and clothing is contaminated, remove clothing and put it in a double plastic bag.

In case of eye contact or eye irritation, rinse with plenty of water or normal saline for more than 20 minutes. If blepharospasm occurs during irrigation, 1 ~ 2 drops of 0.4% obucaine should be slowly dropped and continue to rinse fully. Contact lenses should be removed if they are easily removed and do not damage the eyes. The skin and hair should be washed with plenty of water for at least 15 minutes. Take care to protect your eyes when rinsing your skin and hair. The patient should be immediately evacuated from the contaminated area and resuscitated by three steps (airway, breathing, circulation) :

Airway: Ensure that the airway is not blocked by tongue or foreign body.

Breathing: Check whether the patient is breathing. If not, provide ventilation with a pocket mask.

Circulation: Check for pulse and perform CPR if there is no pulse.

If skin contact with ammonia can cause chemical burns, it can be treated as thermal burns: appropriate fluids, analgesics, maintenance of body temperature, and cover the injured surface with disinfectant pads or clean sheets. Be aware of frostbite if skin comes into contact with high-pressure liquid ammonia.

2. Leakage disposal

(1) Small amount of leakage

Evacuate all personnel in the area. Prevent inhalation of vapors and contact with liquids or gases. Disposal personnel should use respirators. Do not enter the confined space where ammonia gas may collect, and enhance ventilation. It can only be stopped if it is safe to do so. The leaking container should be moved to safety and the valve should only be opened to relieve pressure if it is safe to do so. Sand, vermiculite and other inert absorbing materials can be used to collect and absorb the leakage. Collected leaks should be placed in airtight containers with appropriate labels for disposal.

(2) A large amount of leakage

Evacuate all unprotected personnel in the area and move upwind. Spill disposal personnel should wear full body protective clothing and breathing equipment. Eliminate nearby fire sources. Do not touch or cross the leaking liquid ammonia, prevent leakage into the sewer and drainage channels, improve ventilation. Smoking and open flame are prohibited in the premises. To ensure safety, plug or turn over the leaking container to avoid leakage of liquid ammonia. Spray water to suppress the vapor or change the direction of the vapor cloud, but do not use water to directly impact the leaking liquid ammonia or leak source. Prevent spills from entering water bodies, sewers, basements or enclosed Spaces. Do not enter confined Spaces where ammonia may collect. After washing, remove all protective clothing and equipment before storage and reuse.

3. Disposal of combustion and explosion

(1) combustion and explosion characteristics

Ammonia is a flammable gas at room temperature, but it is difficult to ignite. The explosion limit is 16% ~ 25%, and the most flammable concentration is 17%. At maximum explosion pressure, the concentration is 22.5%.

(2) Fire treatment measures

In the process of storage and transportation, in case of fire, the following measures should be taken:

(1) Isolate, evacuate and transfer people in distress to a safe area, establish a warning zone of about 500 meters, and implement traffic control on the main road leading to the accident site. Except for fire fighting and emergency treatment personnel, other personnel are forbidden to enter the warning area, and evacuate irrelevant personnel quickly.

② Before entering the fire site, fire personnel should wear chemical protective clothing and positive pressure breathing apparatus. Ammonia gas easily penetrates clothing and dissolves easily in water. Fire fighters should pay attention to the protection of parts of the human body with a large amount of sweat, such as reproductive organs, armpits, anus and other parts.

③ Dry powder or CO2 extinguisher should be used in small fires, and water curtain, mist water or conventional foam should be used in large fires.

(4) Storage tank fire, as far as possible to extinguish the fire or use remote control water gun or water cannon.

Do not directly spray water on the leakage port or safety valve to prevent freezing.

⑥ Safety valve sound or discoloration should be evacuated as soon as possible, do not stay at both ends of the tank.

(7) Gasoline

Gasoline, the main components of C4 ~ C12 fatty hydrocarbons and naphthene, colorless or light yellow volatile liquid, with special odor. Insoluble in water, easily soluble in benzene, carbon disulfide, alcohol, fat. Mainly used as fuel for gasoline engine, used in rubber, shoe, printing, leather, pigment and other industries, can also be used as mechanical parts cleaning agent. Relative vapor density (air =1) : 3.5, liquid relative density (water =1) : 0.70 ~ 0.79, melting point <-60℃, boiling point (℃) : 40 ~ 200, flash point: -50℃, ignition temperature: 415 ~ 530℃, explosion upper limit %(V/V) : 6.0 ~ 1.3.

1. Forbidden compound: strong oxidant.

2. Health hazard: mild eye irritation. Acute intoxication: Anesthetic effect on the central nervous system. Mild poisoning symptoms include dizziness, headache, nausea, vomiting, unsteady gait, ataxia. Toxic encephalopathy by inhalation at high concentrations. Very high concentrations of inhalation cause sudden loss of consciousness and reflex apnea. Inhalation pneumonia can be caused by fluid inhalation into the respiratory tract. Splashing into the eyes can cause corneal ulceration, perforation, and even blindness. Acute contact dermatitis caused by skin contact, even burns. Swallowing causes acute gastroenteritis, and severe cases have symptoms similar to acute inhalation poisoning, and can cause liver and kidney damage. Chronic poisoning: neurasthenic syndrome, vegetative nerve dysfunction, peripheral neuropathy. Severe poisoning presents with toxic encephalopathy, with symptoms similar to schizophrenia.

3. Environmental hazards: It may be harmful to the environment. Special attention should be paid to the water body.

4. Dangerous characteristics: extremely flammable. Its vapor and air can form an explosive mixture, in the case of open fire, high heat easily combustion explosion. Can react strongly with oxidant. Its vapor is heavier than air, can spread to a considerable distance at a lower place, when the fire source will ignite back, release harmful carbon monoxide, carbon dioxide combustion products.

5. Protective measures: production process, full ventilation. Wear antistatic clothes. Wear rubber oil-resistant gloves. Smoking is strictly prohibited on site. Avoid prolonged and repeated exposure. In case of high concentration contact, wear chemical protective glasses or wear self-priming filter half mask gas mask.

6. First Aid measures:

Skin contact: Immediately remove contaminated clothing and rinse skin thoroughly with soapy water and clean water. Seek medical attention.

Eye contact: Immediately lift eyelids and rinse thoroughly with plenty of running water or saline for at least 15 minutes. Seek medical attention.

Inhalation: Quickly remove from the scene to fresh air. Keep your airway clear. Give oxygen if breathing is difficult. If breathing stops, give artificial respiration immediately. Seek medical attention.

To ingest: to give milk or vegetable oil for gastric lavage and enema. Seek medical attention.

7. Fire extinguishing method: Spray water to cool the container and move the container from the fire site to an open area if possible. Extinguishing agent: foam, dry powder, carbon dioxide. It is useless to extinguish the fire with water.

8. Leakage treatment: quickly evacuate the contaminated area personnel to the safety zone, and quarantine, strictly restrict access. Cut off the fire. It is recommended that emergency personnel wear self-contained positive pressure breathing apparatus and antistatic clothes. Cut off the source of leakage as much as possible. Prevent the flow into the sewer, flood drainage ditch and other restricted Spaces. Small amount of leakage: with sand, vermiculite or other inert material absorption. Or incinerate on the spot if it is safe to do so. A large number of leaks: build a embankment or dig a pit to receive. Cover with foam to reduce steam hazard. Transfer to tank car or special collector with explosion-proof pump, recycle or transport to waste disposal site.

9. Waste disposal method: incineration method.

10. Operation precautions: closed operation, full ventilation. Operators must be specially trained and strictly abide by operating procedures. It is recommended that operators wear ESD clothes and rubber oil-resistant gloves. Keep away from fire, heat source, no smoking in the workplace. Use explosion-proof ventilation systems and equipment. Prevent steam from escaping into the workplace air. Avoid contact with oxidants. The flow rate should be controlled during filling, and there should be a grounding device to prevent electrostatic accumulation. When handling, light loading and unloading should be done to prevent damage to packaging and containers. Equipped with the corresponding variety and quantity of fire equipment and leakage emergency treatment equipment. An empty container may contain harmful residue.

11. Storage precautions: Store in a cool, ventilated warehouse. Keep away from fire and heat. The temperature of the warehouse should not exceed 30℃. Keep the container sealed. Should be stored separately from oxidizer, do not mix storage. Explosion-proof lighting and ventilation facilities are adopted. Do not use mechanical equipment and tools that are prone to spark. The storage area should be equipped with leak emergency treatment equipment and suitable holding materials.

12. Packing method: small opening steel drum; Ampoule bottle outside ordinary wooden case; Threaded glass bottles, iron lid pressed glass bottles, metal barrels (cans) outside ordinary wooden cases.

13. Transportation precautions: steel tank cars are used for shipment during railway transportation, and corresponding varieties and quantities of fire fighting equipment and leakage emergency treatment equipment should be equipped. In summer, it's best to ship in the morning and evening. The trough (tank) car used in transportation should have a grounding chain, and a hole partition can be arranged in the trough to reduce static electricity generated by shock. It is strictly prohibited to mix with oxidizer. During transportation, it should be protected from sun exposure, rain and high temperature. Stay away from flame, heat source and high temperature area during the stopover. Exhaust pipes of vehicles must be equipped with fire retardant devices. Loading and unloading with mechanical equipment and tools that are easy to generate sparks are prohibited. Wooden ships and cement ships are strictly prohibited for bulk transportation.