The safe use and emergency treatment of common refrigerants

R22: At present, the most widely used is R22, that is, difluorochloromethane. 

R22 is a colorless, odorless, non-toxic, non-corrosive gas, chemically stable, not easy to burn and explode, and its relative density is 1.18 (water = 1 ), relative vapor density of 3.0 (air = 1), R22 is almost insoluble in water, soluble in organic solvents such as ether and chloroform. Freon is safer and more reliable than ammonia when used as a refrigerant, but it destroys the ozone layer and produces greenhouse gas.

R134a is a very low-toxicity, non-fluorine, non-flammable in the air, safety category A1, very safe low-temperature refrigerant.

R407C is a mixture of R32 refrigerant and R125 refrigerant plus R134a refrigerant in a certain proportion. It is an environmentally friendly, low-toxic, non-flammable and safe refrigerant that does not destroy the ozone layer.

Note for use:

Freon accident risk:

1. Freon itself is non-toxic and a kind of suffocating gas. Freon is heavier than air. After leakage, it will stay in a low and poorly ventilated place. When it mixes with air to a certain concentration, it will cause hypoxia in the environment and cause people to be in the environment. Staying in this environment can cause suffocation due to lack of oxygen. Excessive inhalation or long time can inhibit respiratory function and cause coma or even death.

2. Freon can decompose to produce toxic and harmful gases such as phosgene, hydrogen chloride, hydrogen fluoride, etc. when it meets an open flame and under the action of water vapor, which can cause poisoning.

3. The human body directly contacts the liquid freon, which can cause frostbite.

4. If the container or gas cylinder storing Freon encounters high heat, the internal pressure will increase, and there is a danger of cracking and physical explosion.

R407C and R134a:

1. Avoid entering highly concentrated water vapor. Although this type of refrigerant is not easy to burn under normal temperature and pressure conditions, its mixture can burn under high pressure and high concentration air conditions. The storage of refrigerants should be far away from fire sources and high-temperature metal surfaces.

2. R407C and R134a refrigerants have low toxicity, but high-dose inhalation of R407C will cause anesthesia, and very high concentrations will cause abnormal heart rhythms and cause sudden death. The high refrigerant concentration of R407C and R134a in the atmosphere will cause suffocation due to lack of oxygen.

3. Contact with refrigerants on eyes, hands and skin will cause frostbite.

4. The mixed gas with air shall not be used for pressure and leak detection tests.

5. Do not overheat the liquid reservoir containing refrigerant. Thermal decomposition will produce strong toxicity

And (R407C strongly corrosive) (R134a irritating) steam. If it overheats, the reservoir will explode.

6. Do not hit or abuse the refrigerant bottle.

7. The refrigerant bottle must be placed vertically.

8. Use a suitable wrench to open and close the refrigerant bottle valve.

Emergency measures for leakage:

R22:

1. When a Freon leak occurs in the refrigeration system, the operator should quickly stop the unit, cut off the power supply, confirm the leak point (use a refrigerant leak detector if necessary), close the front and rear valves of the leak point as much as possible, and cut off the connection with the system valve.

2. Open doors and windows for ventilation, quickly evacuate people in the leakage area to the upwind, and isolate them, strictly restrict access.

3. Notify the department head and maintenance personnel.

4. The person in charge of the department organizes personnel to arrive at the scene to deal with the accident, and timely conduct reasonable exhaust of the leakage area to accelerate the spread.

5. On-site rescue personnel shall not blindly enter the leakage site, and must enter the high-concentration area of the leakage to cut off the source of the leakage and plug the leak. The rescue personnel shall wear self-contained positive pressure air breathing apparatus.

6. When welding leaking pipelines and other facilities, the Freon must be completely discharged, and the leaking container must be properly handled, and used after repair and inspection.

7. When the leakage of Freon in the area has not been processed, open flame operation is prohibited in the area.

8. When dealing with leaks, pay attention to prevent maintenance personnel from being frostbited by the leaked refrigerant.

9. If someone inhales Freon, they should be quickly removed from the scene to a place with fresh air, keep the respiratory tract unobstructed, call the emergency number, if breathing is difficult, give oxygen, if breathing stops, immediately perform artificial respiration.

10. Once skin contact with Freon causes frostbite, immediately rinse with plenty of water for at least 15 minutes and seek medical attention.

11. Once eyes come into contact with Freon liquid, immediately rinse with plenty of water for at least 15 minutes and seek medical attention.

R407C and R134a:

A. Inhalation

Low-concentration inhalation has a stimulating effect on mucous membranes, and high-concentration R407C atmosphere will cause anesthesia, including loss of consciousness. Extremely high inhalation will cause abnormal heart rate and sudden death.

Acute poisoning: mild cases manifest as skin and mucous membrane irritation, rhinitis, laryngitis, and tracheitis; there may be corneal and skin burns. In severe cases, laryngeal edema, glottic stricture, airway mucosal cells shedding, airway obstruction and suffocation, toxic pulmonary edema and liver damage may occur.

If inhaled accidentally, the injured should be kept away from the high concentration area and allowed to recover in a warm place. Give oxygen if necessary. If breathing stops or becomes weak, give artificial respiration and seek medical attention.

B. Skin contact

Skin contact with splashed liquid may cause frostbite. If frostbite occurs: soak the affected part in warm water kept at 38～42℃ for rewarming. Don't rub it. Do not use hot water or radiant heat. Change contaminated clothing. Use a clean, dry dressing and seek medical attention.

Warning: After frostbite, clothing may stick to the skin.

C. Eyes

The splashed liquid may cause frostbite, cloudiness of the crystals, perforation of the cornea, and even blindness. If you accidentally get into your eyes, you should immediately rinse with eyewash or clean water, and do not close your eyes for at least 15 minutes. Seek medical attention immediately.

D. Ingestion

This situation is unlikely-but if it happens, it will cause frostbite. Do not force vomiting. If the injured person is still conscious, he should wash his mouth with clean water and make him drink 200-300ml of water. And seek medical attention immediately.

E. Further medical treatment and medical support. 

For R407C, since cardiotonics can cause heart disease, adrenaline and similar sympathetic drugs should be avoided.

When the refrigerant leaks, a large amount of smoke emerges from the leak, and the surrounding environment has a strong pungent smell; the equipment and pipelines at the leak are cold and severely frozen.

Protective measures, protective equipment and emergency procedures for workers:

The warning zone is delineated according to the gas affected area, and irrelevant personnel are evacuated from the crosswind and upwind direction to the safe zone. For safety, keep away from the leak location. It is recommended that emergency response personnel wear positive pressure self-contained breathing apparatus and general work clothes. Do not touch or cross the spill. Cut off the source of leakage as much as possible. The sprayed water suppresses the vapor or changes the direction of the vapor cloud to prevent the water flow from contacting the leakage. It is forbidden to directly impact the leak or source of leakage with water.

Environmental protection measures:

Cut off the source of leakage as much as possible. If there is good ventilation, a small amount of spillage can evaporate. If the spill volume is large, ventilate the area and cover it with sand or other suitable absorbent material. Prevent liquid from entering drains, sewers, basements or work pits, and prevent gas from spreading through sewers, ventilation systems and enclosed spaces. Because its steam will cause suffocation.

The containment and removal methods of the leaked chemicals and the disposal materials used:

Leaked gas is allowed to be discharged into the atmosphere. Keep the leaking place ventilated

If combustion occurs, use extinguishing media to extinguish the fire. Flush the refrigerant tank to cool it down; or use a fire extinguishing device.