Universal Precautions are suitable for laboratory procedures outlined in the CDC/NIH guidelines and represents the laboratory safety level Biosafety Level 2 (BSL 2). Universal precautions are generally prudent good laboratory practices to follow regardless of the BSL of the laboratory.
Universal precautions are considered adequate to protect workers involved in small volume production, diagnostic activities and research involving non-pathogenic or low level pathogens. Most recombinant DNA work can also be safely conducted using universal precautions. Respiratory pathogens, potentially lethal, or exotic agents likely will require greater levels of protection. All work using potentially biohazardous materials needs to be reviewed and approved through the
Institutional Biosafety Committee (IBC) before being initiated.
Controlling biohazards at the BL-2 level is accomplished by use of standard microbiological practices, engineering controls, and personnel protective equipment (lab coat, eye protection, and gloves). A risk assessment will identify the required measures beyond the outlined universal precautions.
BL-2 laboratories should apply the practices listed in this section to comply with established guidelines for biological safety:
- Treat all specimens as if they are infectious and capable of transmitting serious infection.
- Workers who work with blood and blood products should follow BSL-2 practices when handling clinical specimens, blood, body fluids, or tissues.
- BSL-2 protection is advisable when working with unknown environmental samples as they may contain infectious agents.
Personal Protective Equipment:
- Use of nitrile gloves is recommended when working with infectious agents. Gloves should be removed before touching common objects in public areas. Wash hands each time gloves are changed.
- Contaminated clothing will be decontaminated and laundered on-site or by a commercial laundry service.
- Typically gloves should be removed prior to removal of other PPE. Gloves should be removed before leaving the laboratory.
Lab Design and Engineering Controls:
- Hand washing facilities are required and should be conveniently located.
- Laboratory surfaces, counters, and floors should be made of impervious materials allowing for easy and effective disinfection.
- Restrict laboratory access to authorized personnel only.
- Biohazard containers for disposal of contaminated materials should be readily accessible. Covered containers are preferred but circumstances may warrant open containers.
- Class 2 Biological Safety Cabinets (BSC) should be utilized when processes such as centrifugation, blending, vortexing, sonicating, and homogenizing, may aerosolize infectious materials.
- Good laboratory techniques should be exercised to minimize the formation of aerosols, droplets, spatters, splashes. Other primary containment devices (e.g., centrifuge safety cups) may be substituted used when handling concentrated infectious organisms outside a BSC.
- Remember to decontaminate all applicable equipment should it need to be repaired or transported to the manufacturer.
Good Laboratory Practices:
- Wash hands immediately after gloves are removed and just prior to leaving the laboratory.
- Mechanical pipetting devices must be used. Mouth pipetting is prohibited.
- Be vigilant when using sharps and never re-sheath needles. Accidental penetration of the skin caused by needles, scalpel blades, laboratory instruments, broken glass, etc. is a common cause of Laboratory Acquired Infections. Place used needles, disposable syringes, lancets, scalpel blades, and other sharp items into a puncture-resistant biohazard container (sharps container) for disposal.
- Maintain good housekeeping and provide adequate space to minimize laboratory accidents.
- Eating, drinking, smoking, or any direct or indirect hand-to-face contact should be avoided.
- Visitors or non-laboratory personnel should be closely supervised and provided proper personal protective equipment.
Signs and Labels:
Emergency Notification Signs should be posted on the entry doors listing the names of persons who should be contacted in the event of any emergency.
- Refrigerators, microwaves, and other similar equipment and supplies in the lab area should be labeled for "lab use only" or "food prohibited".
- Entrances to laboratories, storage areas, etc. must have signs warning visitors, emergency personnel, custodians, etc. of the potential hazards of the area.
- Safety equipment should be easily accessible and safety signs clearly visible.
Decontamination and Transport:
- All specimens should be stored or transported in sturdy containers with secure leak-proof lids.
- Laboratory work surfaces should be decontaminated after a spill of potentially infectious materials and at the completion of work. Contact time and effectiveness of the chosen disinfectant should be researched prior to an incident so .
- Contaminated material will be properly segregated and ideally will be decontaminated in the laboratory before disposal. If the material must be transported to another laboratory for decontamination should be handled according to institutional policy. It should be placed in a closed, leak-proof, biohazard container. All waste should be handled according to the
Biohazard Waste Disposal Guidelines.
- Decontamination, disinfection, and sterilization protocols should be documented to facilitate training and demonstrate proper precautions.
Final Note on Universal Precautions:
Each worker is ultimately responsible for their own safety. Enforcement of the universal precautions in the laboratory is the primarily the responsibility of the principal investigator. Administrators must support programs for educating, training, monitoring, inspecting, and risk assessment. All workers should be diligent and encouraged to report unsafe working conditions.