Laboratory construction and management are key systems projects that must be considered by laboratories at home and abroad, involving various safety factors such as: gas path management, waste management, laboratory relocation, laboratory layout, information management, instrument sharing, Security management, etc. Today let us begin to “safely” sort out all the details of the lab.
Laboratory Area Code of Conduct:
1. Do not eat, store food, beverages and other personal living items in the laboratory; do not do anything unrelated to experiments and research.
2. Smoking is prohibited throughout the laboratory area (including indoors, corridors, elevators, etc.).
3. Do not bring outsiders into the laboratory without the permission of the laboratory management department.
4. Familiar with the escape route and emergency response measures in emergency situations, and clearly locate the first aid kit, fire extinguishing equipment, emergency eye wash device and shower.
5. Keep the laboratory door and walkway unblocked, reduce the amount of reagents stored in the laboratory, and strictly prohibit the storage of highly toxic drugs without permission.
6. Wash hands before leaving the laboratory. Do not wear lab coats or gloves to enter public places such as restaurants, libraries, conference rooms, offices, etc.
7. Keep the laboratory clean and tidy. After the experiment, the laboratory utensils, utensils, etc. should be washed, dried, and put into the cabinet in time. There are no large amounts of materials in the indoor and countertops, and the test bench should be cleaned at least once a day.
8. If you encounter any problems during the experimental work, please consult the person in charge of the laboratory or equipment, and do not operate blindly.
9. It is strictly forbidden to leave the experimental site for a long time during the experiment.
10. There must be more than two people in the room during nights and holidays to ensure the safety of the experiment.
Storage and storage of chemicals
1. All chemical containers should be clearly and permanently labeled to indicate the content and its potential hazards.
2. All chemicals should have a list of item safety data.
3. Be familiar with the characteristics and potential hazards of the chemicals used.
4. Special markings should be added to chemicals that are unstable or susceptible to peroxide formation during storage.
5. Chemicals should be stored at a suitable height and no chemicals should be stored in the fume hood.
6. The storage location of the corrosive liquid container should be as low as possible, and the collecting tray should be padded to prevent the safety accident caused by pouring.
7. Store unstable chemicals separately and indicate the date of purchase on the label. Separate storage of chemical reagents that may undergo chemical reactions to prevent toxic fumes, fires, and even explosions.
8. Volatile and toxic substances require special storage conditions and should not be stored in the laboratory without permission.
9. Do not store large quantities of flammable solvents in the laboratory. Unused whole bottles of reagents should be placed away from light and heat.
10. When wearing dangerous chemicals, you must wear overalls, wear protective glasses, and wear full-toe shoes without toes. Long hair must be bundled.
11. Corrosive chemicals, toxic chemicals, organic peroxides, pyrophoric substances and radioactive materials should not be kept together, especially bleach, nitric acid, perchloric acid and hydrogen peroxide.
Use of organic solvents
Flammable organic solvent
Many organic solvents can cause fire or even explosion if not handled properly. The mixture of solvent and air spreads rapidly once it is burned. The firepower can ignite flammable objects in an instant, and it is ignited in places where oxygen is sufficient (such as caused by leaking oxygen cylinders), and the firepower is fiercer, which can burn some non-combustible substances. When a flammable organic solvent vapor is mixed with air and reaches a certain concentration range, an explosion may occur.
When using flammable organic solvents, pay attention to the following:
(1) Place the container of flammable liquid on a lower reagent rack.
(2) Keep the container closed and open the lid of the closed container when the liquid needs to be poured.
(3) Use flammable organic solvents in areas where there is no source of ignition and good ventilation (such as a fume hood), but be careful not to use too much.
(4) When storing flammable solvents, the storage should be reduced as much as possible to avoid danger.
(5) When heating flammable liquid, use oil bath or water bath, and do not heat with open flame.
(6) When using flammable organic solvents, special attention should be paid to the use temperature and experimental conditions. Table 1 shows the ignition point, auto-ignition temperature and combustion concentration range of commonly used organic solvents.
(7) Combustion of a mixture of chemical gas and air can cause an explosion (for example, 3.25 g of acetone gas is equivalent to 10 g of explosive energy), so the combustion experiment requires careful operation.
(8) During use, beware of the following common sources of ignition: open flames (Bunsen burners, welding torches, oil lamps, fireplaces, ignition seedlings, matches), Mars (power switches, friction), heat sources (electric heating plates, filaments, electric heating sets, Oven, radiator, movable heater, cigarette), electrostatic charge.
2. Toxic organic solvents
The toxicity of organic solvents is caused by local anesthesia stimulation or malfunction of the entire body when the solvent is in contact with the human body or absorbed by the human body. All volatile organic solvents, their vapors are always toxic when exposed to human body for a long time, high concentration, such as: primary alcohols (except methanol), ethers, aldehydes, ketones, partial esters, benzyl alcohol solvents Easy to damage the nervous system; methyl carboxylates, formates can cause lung poisoning; benzene and its derivatives, glycols and other blood poisoning; halogenated hydrocarbons can cause liver and metabolic poisoning; tetrachloroethane And ethylene glycol can cause severe kidney poisoning. Therefore, you should pay attention to the following matters when using:
(1) Try not to directly contact the skin with organic solvents, so be sure to do personal protection. For details, see: Three Laboratories' personal protection knowledge.
(2) Pay attention to keep the experimental site ventilated.
(3) If toxic organic solvents overflow during use, remove all sources of ignition according to the amount of spillage, remind the laboratory personnel to spray with fire extinguishers, then use absorbent to clean, bag, seal, and treat as waste solvent. .
Use of electricity
1. It is strictly forbidden to pull the wires in the laboratory.
2. Before using the socket, you need to know the rated voltage and power. Do not use the electrical socket for overload.
3. It is forbidden to connect the power strips in series on the power strip. Do not use multiple appliances at the same time for the same time on the same patch panel.
4. Large instrument equipment requires a separate socket.
5. Do not use temporary wiring boards for a long time.
6. Save electricity. Air conditioners, lighting fixtures, computers and other electrical appliances should be turned off before leaving the laboratory before work and on holidays. Even if these appliances do not need to be turned on during the working day, they should be turned off at any time.
Use of water
Laboratory water is divided into three categories: tap water, pure water and ultrapure water. Pay attention to the following matters when using:
1. Save water and take water according to demand.
2. Select the appropriate water according to the quality requirements of the water required for the experiment. Wash glassware should first use tap water, and finally rinse with pure water; chromatographic, mass spectrometry and biological experiments (including buffer configuration, hydroponics, microbial culture preparation, chromatography and mass spectrometry flow equivalent) should use ultrapure water.
3. Do not store ultrapure water or pure water. If it is not used for a long time, open the water intake switch and let the ultrapure water or pure water flow out for about several minutes before re-enabling.
4. Close the faucet with Bishop.
Use of liquid nitrogen
Liquid nitrogen is often used as a refrigerant. Refrigerant can cause frostbite. A small amount of refrigerant can cause blindness when it comes into contact with the eyes. The rapid evaporation of gas generated by liquid nitrogen may cause oxygen deficiency in the site. Care should be taken when using and handling liquid nitrogen:
1. Wear insulated protective gloves.
2. Wear a long-sleeved lab coat with a knee length.
3. Wear shoes with ankles and no feet, wear protective glasses, and wear a protective mask if necessary.
4. Keep the ambient air flowing.
Use of lotion
The washing liquid is divided into an acidic washing liquid (sodium sulfate or potassium dichromate sulfuric acid solution), an alkaline washing liquid (sodium hydroxide-ethanol solution), and a neutral washing liquid (common detergent).
1. The acidic washing solution is placed in a glass jar, and the alkaline washing solution can be placed in a plastic bucket.
2. When using alkaline washing solution, the grinding device of the glass instrument should be disassembled and then placed in the washing liquid tank to prevent the grinding mouth from being corroded by the alkaline liquid to cause adhesion. The glass instrument should be pre-washed with acetone and water before placing the lye.
Use of instruments, facilities and appliances
Proper use of all kinds of glassware is very important to reduce personal injury. Damaged glassware is not allowed in the laboratory. For glassware that cannot be repaired, it should be disposed of in accordance with waste. The chemicals remaining in the glassware should be removed before repairing the glassware.
Laboratory personnel should pay attention to the following when using various glassware:
(1) Wear protective gloves when installing the glass tube on the rubber stopper or rubber hose. First, smooth the ends of the glass tube with fire and apply water or grease to the joint as a lubricant. Do not attempt to pull on the glassware that is bonded together to avoid hurting your hands.
(2) The outer layer of the dewar should be covered with a layer of tape or other protective layer to prevent splashing of the glass shards when broken. The glass distillation column should also have a similar protective layer. When using glassware for extreme pressure (above atmospheric or subatmospheric) operation, it should be done after the protective baffle.
(3) The broken glass should be placed in a special trash can. The broken glass is rinsed with water before it is placed in the trash can.
(4) When performing vacuum distillation, appropriate protective measures (such as plexiglass baffles) should be used to prevent the glassware from exploding or rupturing and causing personal injury.
(5) Ordinary glassware is not suitable for pressure reaction, even at lower pressures, it is prohibited to use ordinary glassware for pressure reaction.
(6) Do not place heated glassware on a cold surface to prevent the glass from breaking due to sudden changes in temperature.
2. Rotary evaporator
The rotary evaporator is a commonly used instrument in the laboratory. Pay attention to the following items when using it:
(1) The pressure applied to the rotary evaporator is generally 10 to 30 mmHg.
(2) Each connecting part of the rotary evaporator is fixed with a special clip.
(3) The solvent capacity in the rotary evaporator flask should not exceed half.
(4) The rotary evaporator must be rotated at an appropriate speed.
3. Vacuum pump
Vacuum pumps are equipment for filtration, distillation and vacuum drying. There are three types of vacuum pumps commonly used: air pumps, oil pumps, and circulating water pumps. The pump and oil pump can be vacuumed to 20 ~ 100mmHg, and the high vacuum oil pump can be vacuumed to 0.001 ~ 5mmHg. Pay attention to the following when using:
(1) A cold trap must be connected before the oil pump.
(2) The water in the circulating water pump must be replaced frequently to prevent the residual solvent from being detonated by the motor spark.
(3) Before using it, first cool the distillate, then slowly deflate, then close the balance after reaching equilibrium.
(4) The oil pump must change oil frequently.
(5) The rubber hose on the exhaust port of the oil pump should be connected to the fume hood.
4. Fume hood
The role of the fume hood is to protect laboratory personnel from toxic and harmful gases, but not all toxic gases. Pay attention to the following when using:
(1) Chemicals and laboratory equipment cannot be placed at the exit.
(2) Ventilation cannot be turned off during the experiment.
Thermometers generally include alcohol thermometers, mercury thermometers, quartz thermometers, and thermocouples. Low temperature alcohol thermometer measuring range -80 °C ~ +50 °C; alcohol thermometer measuring range 0 °C ~ +80 °C; mercury thermometer measuring range 0 °C ~ +360 °C; high temperature quartz thermometer measuring range 0 °C ~ +500 °C, thermocouple Not commonly used in the laboratory. Laboratory personnel should use a suitable thermometer. The thermometer should not be used as a stir bar to avoid breakage or breakage, resulting in other hazards. After the mercury thermometer is broken, most of the mercury is sucked out by a pipette, placed in a specific closed container and marked, and disposed of by the chemical reagent company, and then the remaining mercury is covered with sulfur, and cleaned after several days.
6. Gas cylinder
The material in the cylinder is often under high pressure. When the cylinder is dumped, exposed to heat, or in an irregular operation, it may cause an explosion. In addition to explosive and easy to spray, cylinder gas is flammable, toxic and corrosive. Therefore, the use of cylinders should pay attention to:
(1) Characteristics of normal safety gas cylinders:
1 The surface of the cylinder should have a clear label indicating the gas name.
2 cylinders are color-coded.
3 All gas cylinders must be equipped with a pressure relief valve.
(2) Storage of gas cylinders:
1 Compressed gas is a first-class dangerous goods, to minimize the number of cylinders stored in the laboratory, and it is strictly forbidden to store hydrogen in the laboratory.
2 gas cylinders should be placed upright against the wall and prevent dumping measures; exposure to sunlight, away from heat, corrosive materials and potential impact should be avoided; cylinders should not be placed in corridors and foyers to prevent obstruction and other accidents during emergency evacuation. occur.
3 flammable gas cylinders and combustion-supporting gas cylinders shall not be mixed; flammable and flammable pressure cylinders shall not be less than 10 meters away from open flame; flammable gas and toxic gas cylinders shall be placed outdoors and placed in a standardized and safe manner. In the iron cabinet.
(3) Use of gas cylinders:
1 Clean the water and dust at the outlet of the cylinder valve before opening the pressure reducing valve. After the cylinder is used, the cylinder main valve is closed and the excess pressure in the pressure reducing valve is released. The helmet must be put on (except for the helmet in the original design) to prevent the valve from being damaged. Care must be taken when removing the helmet to avoid inadvertent opening of the cylinder main valve.
2 Do not use the cylinder completely (especially acetylene, hydrogen, oxygen cylinders), and must maintain a certain positive pressure.
3 Gas cylinders must be used in well ventilated areas where the pressure reducing valve and outlet valve are intact, and local ventilation should be added when toxic gases are involved.
4 Wear protective goggles, face shields, gloves and work aprons when using cylinders containing toxic or corrosive gases. It is strictly forbidden to strike and collide with the pressure cylinder.
5 Oxygen cylinder pressure reducing valves, valves and pipelines are prohibited from oiling or grease.
6 cylinder transfer should use the cylinder cart and keep it upright, at the same time, close the pressure reducing valve.
Centrifugation is a very effective route for solid-liquid separation, especially when separating small solid particle suspensions. Pay attention to the following points when using:
(1) When using a centrifuge, the centrifuge tube must be symmetrically balanced, otherwise water should be used as a balance to keep the centrifuge balanced.
(2) Cover the centrifuge before starting the centrifuge, start at a lower speed, and then adjust to the desired centrifugal speed.
(3) When the centrifugation operation is completed, the lid must be opened after the centrifuge has stopped running. Never open the lid or touch the rotating part of the centrifuge before the centrifuge is completely stopped.
(4) Glass centrifuge tubes require higher quality. Hot or organic solvents should not be placed in the plastic centrifuge tubes to avoid deformation of the tubes during centrifugation.
(5) The centrifuged solution is generally controlled at about half of the volume of the centrifuge tube, and it is not possible to put too much liquid in order to avoid the liquid from escaping during centrifugation.
When using the syringe, it is necessary to prevent the needle from being stabbed and the syringe broken and hurting the hand. The needle and the syringe should be tightened to prevent leakage. Used syringes must be washed in time. Useless syringes should be destroyed and disposed of again to prevent misuse by others.
9. Refrigerator and freezer
The refrigerator in the laboratory has no explosion-proof device and is not suitable for storing flammable, explosive and volatile solvents.
(1) It is strictly forbidden to store personal food in the refrigerator and freezer.
(2) All low boiling point reagents stored in refrigerators and freezers should have a standardized label.
(3) All containers placed in the refrigerator and freezer shall be sealed, the refrigerator cleaned regularly and unnecessary samples and reagents removed.
Major safety accidents in the laboratory
Forgetting to turn off the power, causing the equipment or electrical appliances to be energized for too long, the temperature is too high, causing fire; improper operation or improper use, the fire source is exposed to flammable substances, causing fire; the power supply line is aging, overload operation, resulting in the line Fever, causing fire; throwing cigarette butts, touching flammable substances, causing fire, etc.
The occurrence of such accidents is universal and can occur in any laboratory.
2. Explosion accident
Violation of the operating procedures, igniting flammable materials, which in turn leads to explosion; equipment aging, faults or defects, causing leakage of flammable and explosive materials, causing explosions in case of sparks.
Most of these accidents occur in laboratories with inflammable and explosive materials and pressure vessels.
3. Biosafety accidents
Omissions and accidents in the management of microbiology laboratories can not only cause infections in laboratory workers, but also cause environmental pollution and infection in large areas. The waste generated by biological laboratories is even more dangerous than chemical laboratories. Infectious bacteria, viruses, chemical pollutants and radioactive substances can pose great harm to human health and environmental pollution.
4. Poisoning accident
Violation of the operating procedures, bringing food into the toxic laboratory, causing poisoning; equipment and equipment
Chemical, there are faults or defects, resulting in leakage of toxic substances or toxic gases, resulting in poisoning; poor management, resulting in the loss of toxic substances, causing environmental pollution; wastewater discharge pipelines are blocked or modified, resulting in toxic waste water It flows out when it is processed, causing environmental pollution.
Such accidents occur mostly in chemical and chemical laboratories with chemicals and highly toxic substances and laboratories with toxic gas emissions.
5. Equipment damage accident
Cause: A sudden power failure caused by a line fault or a lightning strike causes the heated medium to fail to restore the original state to cause damage to the equipment; the high-speed moving equipment collides or squeezes due to inadvertent operation, resulting in equipment damage. Most of these accidents occur in laboratories that are heated by electricity.
6. Electromechanical injury accident
Improper operation or lack of protection, causing crushing, snagging and collisions; infringement of operating procedures or failure of equipment and equipment, faults and defects, resulting in electric shock and arc sparks; improper use of high temperature gas, liquid to human hurt.
Such accidents occur mostly in mechanical laboratories with high-speed rotation or impact motion, or in electrical laboratories with live working and in laboratories with high temperatures.
7. Equipment or technology stolen accident
The flow of laboratory personnel is large, equipment and technology management is difficult, and the safety awareness of laboratory personnel is weak, so that criminals can take advantage of it.
Such accidents are frequent incidents of laboratory safety, which not only cause property damage, but also affect the normal operation of the laboratory, and may even cause leakage of core technologies.
1. Eliminate human hidden dangers
The main part of the experimental work is people. The unsafe factors of human beings are the main cause of laboratory safety accidents. Therefore, only by starting with "people" and improving the safety awareness and literacy of experimental personnel through various means can we minimize the potential safety hazards.
※Hong Kong's universities attach great importance to laboratory safety. For example, graduate students are required to undergo mandatory safety training and examinations arranged by the University Safety and Environmental Affairs Office before using controlled materials or instruments. Undergraduate students of science and engineering should also be forced to conduct safety training. There are both major and online courses, as well as general safety training courses such as fire prevention and escape. Tsinghua University has developed an online learning and examination system for laboratory safety courses, using modern network information technology and rich network information resources to carry out laboratory safety education.
2. Build a secure environment
A good security environment is an important factor in ensuring the security of the laboratory. To build a secure environment, you should start with hardware and software.
The laboratory (floor) should be equipped with complete safety facilities, such as fire equipment, alarm devices, emergency sprinklers, eye wash, first aid kits, and waste collection devices. It is necessary to check the safety passage frequently to ensure the smooth passage of the safety passage and ensure that the experimental electricity and water are safe and qualified.
Clear the safety personnel of each laboratory, and clearly mark the potential hazards of each laboratory, clearly inform the safety precautions and usage rules of various instruments and equipment, and clearly mark the hazards and emergency treatment measures of the chemicals. Regular safety inspections, safety learning and safety knowledge experiment technology and management competitions, strict incentives and penalties should be established to create a safe atmosphere.
3. Improve the system and improve safety awareness
Establishing a sound and clear laboratory management system and strictly implementing it is an important guarantee for the sustainable development of laboratory safety work, and also a necessary condition for the operation of the safety access system.
※The universities in Hong Kong generally have a school-level safety and environmental protection committee. The executive vice-president is responsible for formulating the school's safety policy, safety rules, safety guidelines, improving various rules and regulations, safety and environmental protection facilities, and setting up safety and environment. The Office of Management manages the day-to-day management so that safety management can be carried out efficiently.
Chemical laboratory safety management system
Strengthen defense, check frequently, and plug holes.
Non-workers are not allowed to enter the instrument room, and doors and windows are closed immediately when no one is indoors.
The instrument room is not a guest, no accommodation, without the consent of the leader, declined to visit.
No personal valuables may be stored in the office. In the event of a theft, protect the scene and report to the leadership and security departments in a timely manner.
2. Fireproof, explosion-proof
The equipment room is equipped with fire protection equipment: fire extinguishers, sand boxes, etc. It is strictly forbidden to heat the inside of the instrument room.
The flammable and explosive chemicals should be properly kept separately. The storage should be done according to the performance of the drugs, and safety should be paid attention to.
When doing chemical experiments, it must be carried out in strict accordance with the operating procedures, and beware of accidents such as fire and explosion.