Safety measures and emergency disposal principles

2022-08-05
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Safety measures and emergency disposal principles for hazardous chemicals - nitrobenzene

light yellow transparent oily liquid with bitter almond flavor. Insoluble in water, soluble in ethanol, ether, benzene and other organic solvents. Molecular weight 123.11, melting point 5.7 ℃, boiling point 210.8 ℃, relative density (water =1) 1.20, relative vapor density (air =1) 4.25, saturated vapor pressure 0.02kpa (20 ℃), octanol/water partition coefficient 1.85 ~ 1.88, flash point 87.7 ℃, ignition temperature 482 ℃, explosion limit 1.8% (93 ℃) ~ 40% (volume ratio)

main uses: mainly used as solvent to manufacture aniline, dyes, etc

absorbed through respiratory tract and skin. It mainly causes methemoglobinemia, which can cause hemolysis and liver damage

antidote until the sample is destroyed: intravenous injection of methylene blue

occupational exposure limit: PC-TWA (time weighted average allowable concentration) (mg/m3): 2 (skin)

iarc: suspected human carcinogen

[General requirements]

operators must receive special training, strictly abide by the operating procedures, master the operating skills and have the knowledge of emergency disposal

closed operation to provide adequate local exhaust. Keep away from fire and heat sources. Smoking is strictly prohibited in the workplace. The production, use and storage sites shall be equipped with leakage detection alarms and explosion-proof ventilation systems and equipment. Operators should wear filter gas masks, safety glasses, gas penetrating suits and oil resistant rubber gloves

tanks and other vessels and equipment shall be equipped with liquid level meters and thermometers, and shall be equipped with safety devices with liquid level and temperature remote transmission records and alarm functions

avoid contact with oxidants, reductants and alkalis

safety warning signs shall be set in production and storage areas. Handle with care to prevent damage to the package and container. Fire fighting equipment and leakage emergency treatment equipment of corresponding varieties and quantities shall be provided. If there may be residual harmful substances in the emptied container, it shall be handled in time

[special requirements]

[operation safety]

(1) when opening the nitrobenzene container, make sure that the working area is well ventilated and there is no spark or ignition source; Avoid letting the released steam enter the air of the work area. In the production area, open fire and operations that may produce open fire and sparks are strictly prohibited. If hot work is required during production or maintenance, the approval procedures for hot work must be handled

(2) the workshop producing and storing nitrobenzene shall have reliable fire and explosion prevention measures. In case of fire, dry powder fire extinguisher, carbon dioxide fire extinguisher and sand shall be used

(3) the leakage part of nitrobenzene operating equipment or the part endangering personal safety shall be provided with protective cover and safety barrier to prevent irrelevant personnel from approaching

(4) the cleaning sewage of production equipment and the flushing water of the floor inside the production workshop must be collected into the emergency pool and can only be discharged after passing the treatment

[storage safety]

(1) store in a cool, dry and well ventilated special warehouse

(2) it shall be stored separately from oxidants, acids and edible chemicals, and mixed storage shall not be allowed. The storage area shall be equipped with appropriate materials to contain the leakage. The nitrobenzene storage area shall be provided with cofferdams, with anti-seepage treatment on the ground and inverted tanks or liquid storage tanks

(3) pay attention to lightning protection and anti-static. The storage tanks in the plant (workshop) shall be equipped with lightning protection and anti-static facilities according to the provisions of code for design of lightning protection of buildings (GB 50057)

(4) regularly check the storage tank, tank car, valve and pump of nitrobenzene to prevent leakage

[transportation safety]

all industries are making efforts to integrate environmental protection into enterprises

(1) transport vehicles should have transport signs for dangerous goods and install satellite positioning devices with driving record function. Without the approval of the public security organ, transport vehicles are not allowed to enter the restricted areas for transport vehicles of hazardous chemicals. Do not park in densely populated areas or places with open flames. In summer, it shall be transported in the morning and evening to prevent sunlight exposure

(2) nitrobenzene shall be transported by special tank car. When it is transported by other packaging containers, the containers must be sealed with covers. Transport vehicles shall meet fire safety requirements and be equipped with corresponding fire-fighting equipment. Transport vehicles enter the plant area and maintain a safe speed

(3) it is strictly prohibited to mix with oxidant, reductant, alkali, etc. Transport vehicles shall be equipped with leakage emergency treatment equipment during transportation. During transportation, it shall be protected from sun exposure, rain and high temperature

(4) the pipeline conveying nitrobenzene solution shall not be laid close to the heat source; When the pipeline is laid on the ground, protective measures shall be taken and obvious warning signs shall be set in the sections where there are many activities of people and are easy to be hit by vehicles and foreign objects; When nitrobenzene pipeline is laid overhead, the pipeline shall be laid on the non combustible flat open, push-pull color coated steel plate door and window jg/t 3041 ⑴ 997 support or trestle. Under the laid pipeline, it is not allowed to build buildings irrelevant to the pipeline and stack inflammables; The exterior wall color and mark of nitrobenzene pipeline shall comply with the provisions of basic identification colors, identification symbols and safety signs for industrial pipelines (GB 7231)

[first aid measures]

inhalation: quickly leave the site to a place with fresh air. Keep respiratory tract unobstructed. If breathing is difficult, give oxygen. If breathing stops, give artificial respiration immediately. Seek medical attention

ingestion: drink enough warm water to induce vomiting. Seek medical attention

skin contact: take off contaminated clothes immediately and wash skin thoroughly with soapy water and clear water. Seek medical attention

eye contact: lift the eyelids and wash them with flowing water or normal saline. Seek medical attention

[fire extinguishing method]

firefighters must wear gas masks and full body fire suits to extinguish the fire in the upwind direction. Spray water to cool the container, and move the container from the fire site to an open place as far as possible

extinguishing agent: mist water, insoluble foam, carbon dioxide, sand

[leakage emergency treatment]

the warning area shall be delimited according to the area affected by liquid flow and vapor diffusion, and irrelevant personnel shall evacuate to the safety area from crosswind and upwind. Eliminate all ignition sources. It is recommended that the emergency treatment personnel wear positive pressure self-contained air respirator and anti poison clothing. Do not touch broken containers and spills before wearing appropriate protective clothing. Cut off the source of leakage as far as possible. Prevent leakage from entering water bodies, sewers, basements or confined spaces. Small leakage: absorb or cover with dry sand or other incombustible materials and collect in containers. Massive leakage: build a dike or dig a pit for collection. Absorb a large amount of liquid with lime powder. Transfer to tank car or special collector by pump

as an emergency preventive measure, the leakage isolation distance shall be at least 100m for liquid and 25m for solid. If there is a large amount of leakage, the initial evacuation distance in the downwind direction shall be further increased on the basis of the isolation distance

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