Laboratory safety issues and personal protection

Causes of laboratory biosafety protection problems

Outbreaks of SARS in the spring of 2003 gave laboratory staff a wake-up call. Laboratory biosafety protection has received increasing attention.

China's "General Requirements for Laboratory Biosafety" national standard has been officially released and was formally implemented on October 1, 2004. The standard stipulates the principles of laboratory biosafety management and laboratory construction, and also stipulates aspects of biosafety classification, configuration of laboratory facilities and equipment, personal protection and laboratory safety behavior. This standard addresses the hidden dangers of laboratory safety management and will effectively prevent the recurrence of similar biological safety accidents.

First, laboratory biosafety classification

The National Standard for Laboratory Biosafety, based on the degree of hazards of the biological factors in use and the protective measures taken, classifies biosafety laboratories' biosafety protection levels into four levels, with the lowest level of protection of Class I and the level of protection of Class IV. At the highest level, the establishment and evaluation criteria for laboratories of different levels were determined.

The first-level biosafety laboratory (BSL-1) is a laboratory structural facility, safety operation procedure, and safety equipment applicable to microorganisms known to have no pathogenic effects to healthy adults, such as teaching general microbiology laboratories, etc. Level of protection.

The Secondary Biosafety Laboratory (BSL-2) is a laboratory structural facility, safety operating procedures, and safety equipment suitable for microorganisms that pose a potential hazard to humans or the environment and has Class II protection.

The third-level biosafety laboratory (BSL-3) is a laboratory structural facility, safety operation procedure, and safety equipment applicable to pathogenic microorganisms and their toxins that cause serious and even fatal diseases mainly through the respiratory system. They have Class III protection. Level.

The four-level biosafety laboratory (BSL-4) is equipped with laboratory facilities, safety procedures, and safety equipment that are highly dangerous to the human body. The route of transmission or transmission through the aerosol pathway is unknown. There is no effective vaccine or The pathogenic microorganisms and their toxins of the treatment methods have a level IV protection level.

According to the above definition, at present, the laboratories of disease prevention and control institutions at the municipal and district levels may be required to meet the requirements of the Second Level Biosafety Laboratory (BSL-2) due to exposure to specimens that may contain pathogenic microorganisms. BSL-2 is applicable to humans or The microorganisms with moderate potential hazards in the environment are different from BSL-1 in terms of: (1) whether the experimenter has received training in biosafety protection; (2) whether there are restrictions to enter the biosafety laboratory; (3) Whether or not the use of contaminated sharps is of sufficient importance; (4) Whether certain experimental processes that may produce infectious aerosols or splashes are carried out in biological safety cabinets or other physical restraint devices.

Second, the configuration of laboratory facilities and equipment

Biosafety laboratories have different levels of protection, and the corresponding laboratory facilities and equipment are not all the same.

1. The source of the disease associated with BSL-1 generally does not require special containment devices or equipment such as biological safety cabinets; the surface of the bench should be waterproof, heat resistant, organic solvent resistant, acid and alkali resistant, and resistant to work surfaces. Facilities sterilize other chemicals; should be fitted with flyscreens.

2. BSL-2 is suitable for microorganisms that pose a potential hazard to humans or the environment. The following guidelines should be followed in the configuration and operation of laboratory facilities and equipment:

(1) Use properly maintained biological safety cabinets, preferably secondary biological safety cabinets, or other suitable personal protective equipment, or physical containment devices at all times.

Determine the experimental process that may form infectious aerosols or spills, including centrifugation, grinding, homogenization, violent shaking or mixing, ultrasound rupture, opening of the container with the source of infection (the pressure inside the container may not be consistent with atmospheric pressure), Nostrils were inoculated and infected tissues were collected from the animals or embryonic eggs.

When a high concentration or large volume source of infection is involved, if a sealed rotor or a centrifuge with a safety cage is used, if the rotor or safety cage is only opened in the biological safety cabinet, it can be centrifuged in an open laboratory.

(2) When the microorganisms must be handled outside the biological safety cabinet, facial protection measures (glasses, masks, masks, or other anti-splash devices) must be taken to prevent sources of infection or other harmful substances from splashing or spilling on the surface.

(3) In the laboratory, special protective protective clothing, gowns, smocks or uniforms must be used. When personnel go to non-laboratory areas, protective clothing must remain in the laboratory. Protective clothing can be handled in the laboratory or in the laundry room, but it cannot be taken home.

(4) Wear gloves when you may come into contact with potential sources of infection, contaminated surfaces, or equipment. Wearing two gloves is more appropriate. Obviously contaminated gloves should be handled. When the source of the infection is finished or when the gloves are damaged, remove the gloves. Disposable gloves do not have to be cleaned or reused. They should not be used to contact "clean" surfaces (keyboards, telephones, etc.), nor should they be worn outside the laboratory. Glue gloves with talcum powder should be provided. Wash your hands after removing your gloves.

(5) The surface of the bench should be waterproof, heat resistant, organic solvent resistant, acid and alkali resistant, and other chemical substances that are used to disinfect work surfaces and facilities; there should be an eye washing device; if the laboratory faces the outside window, it should be Install screens to prevent flies.

(6) When installing the biological safety cabinet, the ventilation and exhaust of the room shall be taken into account, and the biological safety cabinet will not be operated beyond the normal parameters. The biological safety cabinet should be far away from the door, away from the window that can be opened, away from the walking area, away from other equipment that may cause the wind pressure to be confusing, and ensure that the biological safety cabinet airflow parameters are within the valid range.

Need to remind everyone (microblogging) is that for the new laboratory design and construction must meet the requirements of laboratory safety; for the already built laboratory, even if the pattern can not be changed, it should strive to the work area and rest Zone separation, and as far as possible meet other requirements of the biosafety laboratory.

III. Personal Protection and Laboratory Safety Behavior

While participating in emergencies emergency treatment, we must ensure the safety of the CDC personnel to prevent laboratory infections and leakage.

1. First-Class Biosafety Laboratory (BSL-1)

(1) Wear lab coats, coats, and uniforms to avoid contamination and dust on clothes.
(2) Wear gloves if there is injury or rash on the skin.
(3) Protective eyewear should be worn when it is estimated that microorganisms or dangerous substances will spill out during operation.

Secondary Biosafety Laboratory (BSL-2)

(1) The laboratory director shall prohibit or restrict the entry of personnel into the laboratory when carrying out work on infectious disease sources. In general, susceptible individuals or persons who have serious consequences after infection are not allowed to enter the laboratory. For example, people with immunodeficiency or immunosuppression are at increased risk of infection. The laboratory director has the ultimate responsibility for estimating each situation and deciding who can enter the laboratory.

(2) Laboratory personnel receive appropriate immunizations or tests (eg, Hepatitis B vaccination or TB skin test) related to the source of treatment or to be treated in the laboratory; collect and store, as appropriate, the source of the disease being treated Suitable for use by laboratory personnel and at-risk personnel for basic serum samples. Depending on the function of the source or facility being treated, other serum samples should be collected periodically.

(3) Biosafety procedures should be included in the standard operating procedures or biosafety manuals specially developed by laboratory directors for laboratory personnel. For people with special risks, ask to read and follow the work and procedures.

(4) The laboratory director ensures that the experiment and its support staff receive appropriate training, including possible work-related risks, necessary measures to prevent exposure, and exposure assessment procedures. When the procedure must change, the personnel must update their knowledge every year and receive additional training.

(5) In the presence of an exogenous source, a biohazard symbol should be attached to the entrance of the laboratory and the following information should be displayed: relevant origin, biosafety level, immunization requirements, researcher's name, telephone number, must be worn in the laboratory Personal protective equipment, procedures required by the laboratory

(6) Do not eat, smoke, clean contact lenses, and makeup in the work area. It is not allowed to store food and daily necessities in the work area. In the laboratory, people wearing contact lenses also wear masks or masks. Food should be stored in a dedicated cupboard or refrigerator outside the work area.

(7) Do not use mouth to pipette liquid. Only use mechanical device to transfer liquid; set safety requirements for sharps. Contaminated sharps must be kept vigilant at all times, including needles, syringes, slides, pipettes, capillaries, and scalpels; other instruments can be used without sharps. When possible, use plastic utensils instead of glass utensils. Broken glassware cannot be handled directly by hand and must be handled with other tools such as brushes and rakes, clips, or tweezers. Containers containing contaminated needles, sharps, and broken glass should be sterilized as required before they are removed.

(8) All operations should be as careful as possible to avoid spills and aerosols; disinfecting should be performed at least once a day (microblogging) and when the living body is spilled, countertop disinfection should also be performed in time. In cases of spills or accidents that are apparently exposed to the source of infection, immediately report to the laboratory director. Perform appropriate medical evaluations, observations, treatments, and keep written records.

(9) All cultures, stores, and other prescribed wastes should be disinfected using a viable method of disinfection, such as autoclaving, prior to release. The materials transferred to the nearest laboratory should be placed in a durable, leak-proof container, sealed and transported out of the laboratory, and their packaging should comply with relevant national regulations.

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