How to Stay Safe in a Microbiology Lab

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-08-27

Quick Answer

• Master the four biosafety levels and match your daily practices to the BSL designation of your specific laboratory space before handling any microorganism.
• Build a personal protective equipment routine that covers correct donning and doffing order, glove changes, and eye protection for every procedure that can generate splashes or aerosols.
• Treat every spill and sharp as a potential exposure event, use the facility spill kit and sharps container, and report all incidents to your supervisor even when no injury is visible.

Understanding Biosafety Levels and Your Work Environment

Microbiology laboratories are classified into biosafety levels based on the agents handled, the procedures performed, and the facility design. The Centers for Disease Control and Prevention and the National Institutes of Health publish the Biosafety in Microbiological and Biomedical Laboratories guidance that defines these levels, and your employer must follow those standards. As a new worker, your first responsibility is to identify which biosafety level applies to your specific laboratory room, beyond to the building or the institution.

Biosafety Level 1 laboratories handle well-characterized agents that do not consistently cause disease in healthy adults. These facilities require standard microbial practices but do not demand special containment equipment beyond a sink for handwashing. BSL-2 laboratories handle agents associated with human disease through percutaneous injury, ingestion, or mucous membrane exposure. These facilities require restricted access during work, decontamination of waste, and the use of biological safety cabinets for procedures that generate aerosols. BSL-3 laboratories handle agents that can cause serious or potentially lethal disease through inhalation, requiring controlled access, directional airflow, and respiratory protection in defined situations. BSL-4 laboratories handle dangerous agents with high individual risk and no available treatment, requiring maximum containment and full-body suits with dedicated air supplies.

The U.S. Bureau of Labor Statistics Occupational Outlook Handbook describes the work environments for biological technicians and medical scientists, noting that laboratory work involves performing experiments and recording data under controlled conditions. The same source explains that biological technicians typically work in laboratories and must follow strict safety protocols to avoid contamination. Your employer must provide the facility design, equipment, and training that match the biosafety level of the agents you handle, and you must confirm that you understand the specific requirements before starting any procedure.

Personal Protective Equipment Selection and Use

Personal protective equipment forms the physical barrier between you and the biological materials you handle. The selection of PPE depends on the risk assessment for the specific procedure, not on a universal standard that applies to every task. Your laboratory safety manual should specify the minimum PPE for each procedure, and you should follow that specification without substituting equipment that is not approved for the task.

Gloves

Gloves are the most frequently used PPE in microbiology laboratories. You must select glove material based on the chemicals and biological agents you handle. Nitrile gloves provide protection for most laboratory work and resist punctures better than latex gloves. Latex gloves offer high dexterity but can cause allergic reactions in some workers. You must inspect each glove for visible tears, holes, or degradation before donning. Double gloving is appropriate when you work with sharp instruments or when the procedure involves high-risk agents. You must change gloves when they become visibly contaminated, when you move from a contaminated area to a clean area, and after any glove failure. Remove gloves by peeling them from the wrist without touching the bare skin to the contaminated outer surface.

Laboratory Coats and Gowns

A dedicated laboratory coat or gown protects your clothing and skin from contamination. The coat must be long enough to cover your arms and torso, and it must have a closure that keeps the front covered. You should wear the coat only in the laboratory and remove it before entering common areas, break rooms, offices, or restrooms. The coat should be laundered by the facility or through an approved service, and you should not take it home for cleaning. Disposable gowns are appropriate for procedures with high contamination risk, and you should remove them carefully to avoid transferring contamination to your skin or clothing.

Eye and Face Protection

Safety glasses, goggles, or face shields protect your eyes and face from splashes, aerosols, and flying debris. You must wear eye protection whenever you perform procedures that can generate droplets, including vortexing, opening cultures, pipetting, and centrifugation. Safety glasses with side shields provide basic protection, while goggles provide a seal around the eyes. A face shield protects the entire face and should be worn when you work with large volumes of infectious material or when you perform procedures that generate significant aerosols. You should clean and disinfect reusable eye protection after each use and inspect it for scratches or damage that could reduce visibility.

Respiratory Protection

Respiratory protection is required in BSL-3 laboratories and in certain BSL-2 procedures where the risk assessment identifies an aerosol hazard. You must be fit-tested for the specific respirator model you will use, and you must complete medical clearance before fit testing. N95 respirators provide filtration but do not provide a full seal, while elastomeric half-face respirators and powered air-purifying respirators provide higher levels of protection. You should not use a respirator that has not been fit tested for your face, and you should perform a user seal check each time you don the respirator.

Donning and Doffing PPE in the Correct Order

The order in which you put on and remove PPE affects your safety. The correct donning order is designed to keep the most contaminated items on the outside and to protect your skin and clothing. The correct doffing order is designed to prevent contamination of your skin, clothing, and mucous membranes during removal.

Donning Sequence

The standard donning sequence begins with hand hygiene, followed by the laboratory coat or gown, then the mask or respirator, then eye protection, and finally gloves. You should perform hand hygiene before you put on gloves so that your hands are clean when you touch the inside of the gloves. The gown should be tied securely at the back or side, and the mask should be positioned over your nose and mouth with the straps secured. Eye protection should be placed over the mask and adjusted for a comfortable fit. Gloves should be the last item you put on, and they should cover the cuffs of the gown to prevent skin exposure at the wrist.

Doffing Sequence

The doffing sequence is designed to remove the most contaminated items first while protecting your hands. Gloves are removed first, followed by eye protection, then the gown, and finally the mask or respirator. You should remove gloves by grasping the outside of one glove at the wrist and peeling it off, then using the bare hand to peel the second glove from the inside. You should remove eye protection by handling the straps or the sides of the device, not the front. The gown should be untied and peeled away from the body, and the mask or respirator should be removed by handling the straps or ties, not the front. You must perform hand hygiene immediately after removing each item and again after removing all items.

Biological Safety Cabinets and Aerosol Control

Biological safety cabinets are the primary containment device in microbiology laboratories. These cabinets protect you, the environment, and the sample by directing airflow through high-efficiency particulate air filters. You must understand the type of cabinet you are using and the limitations of that cabinet before you work in it.

Cabinet Types

Class II biological safety cabinets are the most common in microbiology laboratories. These cabinets provide personnel protection through inward airflow, product protection through downward airflow, and environmental protection through exhaust filtration. Type A2 cabinets exhaust air back into the laboratory through a HEPA filter, while Type B2 cabinets exhaust air to the outside through a dedicated duct. You must confirm which type of cabinet you are using because the procedures you can perform depend on the cabinet type. Type B2 cabinets are required when you work with volatile chemicals or radionuclides in addition to biological agents.

Working in the Cabinet

You should place all materials inside the cabinet before starting work and arrange them to minimize the movement of your arms across the work surface. The front grille of the cabinet must remain unobstructed to maintain proper airflow. You should work at least six inches inside the front edge of the cabinet to stay within the protected airflow zone. You should avoid rapid arm movements that can disrupt the airflow, and you should not place objects over the front grille. The UV lamp, if present, should be used only when the cabinet is not in use and the sash is closed, because UV light can damage your skin and eyes.

Cabinet Certification and Maintenance

Biological safety cabinets must be certified by a qualified technician at least annually and after any move or repair. The certification verifies the airflow velocity, the integrity of the HEPA filters, and the performance of the cabinet. You should not use a cabinet that has not been certified or that has an alarm indicating airflow failure. You should also decontaminate the cabinet work surface before and after each use with an appropriate disinfectant, and you should allow the cabinet to run for several minutes before you begin work to purge the air.

Spill Cleanup and Decontamination Procedures

Spills are the most common exposure event in microbiology laboratories. You must know the spill cleanup plan for your laboratory before you need it, and you must be able to execute the plan without hesitation. The response to a spill depends on the agent, the volume, and the location of the spill.

Small Spills Inside a Biological Safety Cabinet

A small spill inside a biological safety cabinet can be managed by the worker who caused the spill. You should keep the cabinet running and cover the spill with absorbent material. You should then apply disinfectant to the absorbent material and allow it to sit for the contact time specified by the disinfectant manufacturer. You should then clean the spill area and the surrounding surfaces with the disinfectant. You should place all contaminated materials in a biohazard waste container and decontaminate the cabinet work surface.

Large Spills Inside a Biological Safety Cabinet

A large spill inside a biological safety cabinet requires a more extensive response. You should keep the cabinet running and notify other workers in the laboratory. You should cover the spill with absorbent material and apply disinfectant, allowing the contact time to pass. You should then clean the spill and decontaminate the cabinet, including the catch basin below the work surface. You should remove all contaminated materials and place them in biohazard waste. You should also notify the laboratory supervisor and the biosafety officer, and you should document the spill in the laboratory incident log.

Spills Outside the Cabinet

A spill outside the biological safety cabinet is a more serious event because it exposes the laboratory environment and personnel. You should immediately alert other workers in the laboratory and evacuate the immediate area. You should allow aerosols to settle for at least 30 minutes before you begin cleanup. You should then put on the appropriate PPE, including gloves, a gown, and eye protection, and cover the spill with absorbent material. You should apply disinfectant and allow the contact time to pass. You should clean the spill and dispose of all contaminated materials in biohazard waste. You should report the spill to the laboratory supervisor and the biosafety officer, and you should document the event.

Sharps Handling and Disposal

Sharps are needles, scalpels, broken glass, and other items that can puncture or cut the skin. Sharps injuries are a major route of exposure to bloodborne pathogens and other infectious agents. You must handle sharps with care and dispose of them in the correct containers.

Safe Sharps Practices

You should use sharps only when no alternative exists. You should use needleless systems and blunt needles whenever possible. You should not recap needles, bend needles, break needles, or remove needles from syringes by hand. You should place sharps directly into a puncture-resistant sharps container immediately after use. You should not overfill the sharps container, and you should replace the container when it is three-quarters full. You should never reach into a sharps container, and you should never attempt to retrieve an item that has fallen into the container.

Sharps Injury Response

If you sustain a sharps injury, you must immediately wash the wound with soap and water. You should report the injury to your supervisor and seek medical evaluation as soon as possible. The facility must have a post-exposure plan that includes medical evaluation, testing, and follow-up. You should document the injury in the incident log and complete the required incident report. You should not delay reporting a sharps injury, because prompt medical evaluation is important for your health.

Waste Segregation and Disposal

Microbiology laboratories generate several types of waste, and each type requires a different disposal path. You must segregate waste at the point of generation to ensure that each waste stream is treated correctly.

Biohazardous Waste

Biohazardous waste includes cultures, stocks, and other materials that contain infectious agents. This waste must be placed in red biohazard bags or containers that are labeled with the biohazard symbol. The waste must be decontaminated before disposal, typically through autoclaving or incineration. You should not place biohazardous waste in regular trash, and you should not place regular trash in biohazardous waste containers.

Sharps Waste

Sharps waste includes needles, scalpels, broken glass, and other items that can puncture the skin. This waste must be placed in puncture-resistant sharps containers that are labeled with the biohazard symbol. The containers must be sealed when they are three-quarters full and decontaminated before disposal. You should not place sharps in regular trash or in biohazardous waste bags.

Chemical and Radioactive Waste

Chemical and radioactive waste require separate handling and disposal procedures. You must follow the facility chemical hygiene plan and the radiation safety plan for these waste streams. You should not mix chemical or radioactive waste with biohazardous waste, and you should not pour these materials down the drain unless the facility has approved that disposal path.

At a Glance

Records and Incident Reporting

Accurate records are essential for laboratory safety and for the continuous improvement of your practices. You must maintain records of your training, your work, and any incidents that occur. These records serve as evidence that you have received the required training and that you have followed the correct procedures.

Training Records

You must document the safety training you receive, including the date, the topic, and the instructor. You should retain copies of your training certificates and your respirator fit test records. You should also document any refresher training you receive. The U.S. Bureau of Labor Statistics Occupational Outlook Handbook notes that biological technicians typically need a bachelor's degree and that they receive on-the-job training. The same source indicates that medical scientists typically need a doctoral degree and that they may receive training in laboratory safety as part of their education.

Incident Records

You must document every incident, including spills, sharps injuries, exposures, and near misses. The incident record should include the date, the time, the location, the procedure, the materials involved, and the actions taken. You should also document any medical evaluation and follow-up. Incident records are used to identify patterns and to improve safety practices. You should report all incidents to the laboratory supervisor and the biosafety officer, and you should follow the facility incident reporting procedure.

Equipment Maintenance Records

You must maintain records of the certification and maintenance of your biological safety cabinets, autoclaves, and other safety equipment. These records verify that the equipment is functioning correctly and that it provides the required protection. You should not use equipment that has not been certified or that has failed a maintenance check.

Common Failure Patterns and How to Avoid Them

New microbiology laboratory workers often make predictable errors that increase their risk of exposure. Understanding these failure patterns can help you avoid them.

Failure to Confirm the Biosafety Level

The most common failure is assuming that all laboratory work is the same. You must confirm the biosafety level of your specific laboratory space and the agents you handle. Working at the wrong biosafety level can expose you to agents that require higher containment. You should ask your supervisor to confirm the biosafety level and the required practices before you begin work.

Failure to Wear the Correct PPE

Workers sometimes skip eye protection or respiratory protection because they do not perceive the risk. You must wear the PPE specified in the risk assessment for each procedure. You should not substitute PPE that is not approved for the task, and you should not reuse disposable PPE.

Failure to Work Correctly in the Biological Safety Cabinet

Workers often block the front grille of the cabinet or work outside the airflow zone. These errors reduce the containment provided by the cabinet and can lead to exposure. You should arrange your work to keep the grille clear and to keep your work at least six inches from the front edge.

Failure to Respond Correctly to a Spill

Workers sometimes clean up a spill without waiting for aerosol dispersal or without the correct PPE. This can lead to exposure to the spilled agent. You must follow the facility spill cleanup plan and wait for the specified time before you begin cleanup.

Failure to Report Incidents

Workers sometimes do not report near misses or minor exposures because they do not think the event is important. This prevents the facility from identifying hazards and improving safety. You must report all incidents, including near misses, to the supervisor and the biosafety officer.

Professional Escalation Criteria

You must know when to escalate a safety concern to a supervisor, the biosafety officer, or the facility safety committee. Escalation is appropriate when you encounter a situation that you cannot resolve with the training and resources you have.

You should escalate when you do not know the biosafety level of your laboratory or the correct PPE for a procedure. You should escalate when you find that safety equipment is missing, damaged, or not certified. You should escalate when you have a spill that you cannot clean up safely or when you have an exposure that requires medical evaluation. You should escalate when you observe a coworker who is not following the safety procedures and you cannot correct the behavior yourself. You should escalate when you have a question about the correct waste disposal path for a material.

The National Institutes of Health Office of Intramural Training and Education provides career development and training resources for research professionals, including laboratory safety training. The American Society for Microbiology Career Services provides professional development resources for microbiologists, including information about laboratory practice and safety. These organizations can help you understand the professional expectations for laboratory safety and the resources available for your training.

Safety and Regulatory Context

Microbiology laboratory safety is governed by a framework of regulations and guidelines that protect workers and the public. You must understand the regulatory context for your work and the responsibilities that apply to you and your employer.

The Occupational Safety and Health Administration regulates laboratory safety through the Occupational Exposure to Hazardous Chemicals in Laboratories standard and the Bloodborne Pathogens standard. These regulations require your employer to provide a written safety plan, to train you on the hazards, and to provide the required PPE. The regulations also require your employer to provide medical evaluation and follow-up after an exposure.

The Centers for Disease Control and Prevention and the National Institutes of Health publish the biosafety guidelines that define the biosafety levels and the required practices. These guidelines are not regulations, but they are the standard of practice for microbiology laboratories. Your employer must follow these guidelines to maintain accreditation and to protect the safety of workers and the public.

The U.S. Department of Transportation regulates the transport of infectious substances. You must follow the DOT requirements if you ship or transport biological materials. The requirements include the correct packaging, labeling, and documentation for the materials.

Career Context and Professional Development

Microbiology laboratory safety is a core competency for a career in the life sciences. The U.S. Bureau of Labor Statistics Occupational Outlook Handbook describes the education and training pathways for biological technicians, medical scientists, and other laboratory professionals. The same source indicates that biological technicians typically need a bachelor's degree in biology or a related field, and that medical scientists typically need a doctoral degree. The handbook also describes the work settings for these occupations, including laboratories and research facilities.

The American Society for Microbiology Career Services provides resources for microbiology professionals, including job listings, career development, and professional networking. The NIH Office of Intramural Training and Education provides training and mentoring for students and researchers. The U.S. National Science Foundation Careers page describes the work of scientists and program staff in a federal research organization. The Association of American Veterinary Medical Colleges provides career resources for veterinary professionals, including those who work in laboratory animal medicine.

Safety training is a continuous process. You should seek opportunities to refresh your safety knowledge and to learn about new hazards and new practices. You should participate in the safety training your employer provides, and you should ask questions when you do not understand a procedure. You should also stay current with the biosafety guidelines and the regulations that apply to your work.

Frequently Asked Questions

What is the first thing I should do when I start working in a microbiology laboratory?

Confirm the biosafety level of your laboratory and the specific procedures you will perform. Ask the supervisor to review the facility safety plan and the PPE requirements for your tasks. Complete the required safety training before you begin any work.

How do I know which biosafety level applies to my laboratory?

The biosafety level is determined by the agents you handle and the procedures you perform. The facility biosafety officer or the laboratory supervisor can confirm the biosafety level for your specific space. You should not assume that all laboratories in the facility have the same biosafety level.

What PPE do I need for routine microbiology laboratory work?

The minimum PPE for most microbiology laboratory work includes a laboratory coat, nitrile gloves, and eye protection. The specific PPE for your procedure depends on the risk assessment. You should confirm the required PPE with the supervisor before you begin work.

How do I clean up a spill in a biological safety cabinet?

You should keep the cabinet running and cover the spill with absorbent material. Apply the disinfectant and allow the contact time to pass. Clean the spill and the surrounding surfaces, and place all contaminated materials in biohazard waste. Report the spill to the supervisor and document the event.

What should I do if I have a sharps injury?

Wash the wound with soap and water immediately. Report the injury to the employer and seek medical care as soon as possible. Document the injury in the incident log and follow the facility exposure plan.

How do I dispose of biohazardous waste?

Place the waste in a labeled biohazardous waste container. The waste must be decontaminated before disposal, typically through autoclaving or incineration. Do not place biohazardous waste in regular trash.

What should I do if I see a coworker who is not following the safety procedures?

You should speak to the coworker directly if you feel comfortable doing so. If the behavior continues or if the situation is serious, you should report the concern to the supervisor or the biosafety officer. You should not ignore a safety concern because you do not want to cause conflict.

How often should I receive safety training?

You should receive safety training when you start work and when you are assigned to a new procedure or a new laboratory. You should also receive refresher training on a regular schedule, as defined by the employer and the regulations. You should ask for additional training if you do not understand a procedure.

Using the Evidence

Related Articles

• Laboratory Careers List: Exploring Diverse Roles in the Lab
• Veterinary Diagnostic Laboratory Careers: From Bench to Leadership
• Medical Laboratory Careers: A Practical Guide to Roles, Education, and Advancement
• Laboratory Technician Career Progression: From Entry-Level to Specialist
• Pathology Laboratory Careers: Roles, Education, and Professional Opportunities

References and Further Reading

• Occupational Outlook Handbook. U.S. Bureau of Labor Statistics.
• O*NET OnLine. U.S. Department of Labor.
• Office of Intramural Training and Education. National Institutes of Health.
• Careers at NSF. U.S. National Science Foundation.
• Career Services. American Society for Microbiology.
• AAVMC Career Resources. Association of American Veterinary Medical Colleges.
• NCBI Literature Resources. National Center for Biotechnology Information.
• PubMed. National Library of Medicine.

This article is educational and does not replace institutional policy, professional advice, or applicable safety and regulatory requirements.