Laboratory Safety


Developing a Culture of Safety

Successful establishment of a Culture of Safety requires that laboratory safety become an integral and apparent priority to the organization, embraced first and foremost by the top management and with the infrastructure support required to foster behaviors among its employees. As required by the Clinical Laboratory Improvement Amendments, the College of American Pathologists, and other accrediting agencies, a laboratory director needs to assume the responsibility for:

  • Establishing and enforcing a policy for a Culture of Safety within the lab
  • Identifying as many hazards as possible and specifying practices and procedures that will eliminate those hazards
  • Ensuring that all personnel are instructed and engaged in performing risk assessments and demonstrating that they can identify laboratory hazards in their individual work environments
  • Ensuring that all personnel are trained and competent in the standard practices and techniques that minimize identified workplace hazards
  • Provide an avenue for personnel to identify hazards and present risk-mitigation strategies to the management
  • Educate clinicians and nurses regarding safe specimen procurement and transport to ensure their safety and that of the laboratory personnel who receive the clinical specimens

Improving Biosafety in Our Nation's Laboratories - APHL Position Statement

Biorisk Management

Biorisk Management is the buzz word of the day. Biorisk is the system or process to control the safety and security risks associated with the handling or storage and disposal of biological agents and toxins in laboratories and facilities.

  • How do you identify these risks?
  • Which steps do you take to manage these risks?
  • How do you know your risk management is working and will continue to work?

The questions above may be answered by establishing a laboratory policy and procedure for assessing, mitigating and performing checks on activities that pose hazards in the workplace. Implementation of a comprehensive biorisk management system is critical to reduce both the safety and security risks associated with biological agents. Some key factors for establishing and implementing a successful program include commitment by top management and a focus on continual improvement. Biorisk management is not static, but fluid in nature and specific to each individual laboratory.  

Risk Assessment Templates

Updated 11/2022


  • Decontamination-The removal or inactivation of biological agents by physical or chemical means.
  • Disinfection-A procedure, usually chemical, that inactivates viruses or kills vegetative bacteria, but not necessarily resistant forms such as spores.
  • Sanitize-An agent that reduces the numbers of vegetative bacteria.
  • Sterilize-The complete elimination or destruction of all forms of life by a chemical or physical means.

Disinfection suffixes

-cide- Kills (determined by specific testing)


  • Bactericide (= germicide)-Destroys vegetative bacteria only.
  • Tuberculocide- Destroys Mycobacterium tuberculosis.
  • Sporocide-Destroys spores.

-static- Prohibits growth but may not kill.


  • Bacteriostatic - prevents growth of vegetative bacteria
  • Tuberculostatic - prohibits growth of Mycobacterium tuberculosis

In the U.S. manufacturers must register disinfectants. The United States Environmental Protection Agency (EPA) maintains 12 lists of chemical disinfectants. The listing is by product, not by active chemical. EPA listings:

Desirable disinfectant characteristics (no one disinfectant possesses all these):

  • Broad spectrum
  • High efficiency
  • Not affected by organic matter
  • Non-toxic, non-corrosive, non-flammable
  • Odorless
  • Inexpensive
  • Environmentally friendly

In order to effectively eliminate pathogens it is important to:

  • Select the appropriate disinfectant for the agent to be killed or inactivated
  • Use the proper amount of disinfectant and allow sufficient contact time
  • Remember that the physical act of wiping is an important part of disinfection


  • There is no universal decontamination method for biological materials
  • It is important to know and understand decontamination definitions
  • Disinfection efficacy can be influenced by concentration, contact time, etc.
  • Selection of an appropriate decontamination method may be a trade-off (the perfect disinfectant does not exist)

Biological Spill Preparedness in the Laboratory

Advanced preparedness and training for management of spills in the laboratory is essential. Spill kits should be strategically located throughout each laboratory section and should contain all items needed for the clean up to be performed expeditiously. Only trained staff should be responsible for spill clean-up.  

Biological Spill Procedure Example

Biological Spill Kits should contain:

• 1 gallon of undiluted EPA approved disinfectant
• 2 cloth towels (bath size or larger)
• Latex/ nitrile gloves
• Warning signs and tape
• Dust pan
• Autoclave bags
• Booties
• Tongs
• Spill dedicated bucket and mop
• Written instructions for spill clean-up

MALDI-TOF Technology and Safety Considerations

Matrix Assisted Laser Desorption Ionization - Time of Flight – Mass Spectrometry (MALDI-TOF)

MALDI – Irradiation of the sample matrix by a laser produces ions

TOF – Electro-magnetic force is applied to the ions simultaneously, resulting in ionic acceleration in a flight tube. Ions travel through the flight tube at speeds based on mass. Lowest mass ions will reach the detector first - heaviest mass ions reach the detector last.

MALDI-TOF analysis creates a protein fingerprint spectra unique to the organism and the spectra is compared to a known spectral database for the organism identification. Prior to  implementation of the testing, a safety risk assessment should be completed for the MALDI-TOF instrumentation set up, use and clean up procedure. With the increasing use of MALDI-TOF technology it is important to be aware of safety and misidentification concerns.

Safety Considerations:

· Safe handling of organism isolate during sample preparation, extraction and target slide preparation including proper PPE (face shield) and / or engineering controls such as Class II Biosafety Cabinet (BSC)
· Proper PPE, use of fume hood and safe handling of hazardous chemicals such as Acetonitrile (ACN)
· Complete Inactivation of organism – verify inactivation protocols - some organisms may survive extraction method Avoid analysis of suspected high-risk infectious agents (Brucella spp., Francisella tularensis, Coxiella burnetii, etc.)
· Consult with LRN reference lab
· Look for trigger points prior to analysis on MALDI
· Follow ASM protocols for ruling out and referring potential select agents
· Gram stain and biochemicals
· Patient history- travel?

Missed Identification Concerns:

· Laboratories must be aware of software limitations
· Result limited by the database (library)
· Multiple libraries improve capability
· Beware of results that do not make sense – question
· Potential for exposure to highly infectious disease
· MALDI not reliable for identification of select agents

MALDI is cheaper, faster, and simpler than conventional microbial identification methods. It requires less labor and is generally accurate. It is important to educate those who are using this new technology to be aware of the limitations and be respectful of the potential safety hazards. 

MALDI-TOF Instrument Considerations

Does your lab have a Matrix Assisted Laser Desorption Ionization —Time of Flight, or MALDI-TOF, instrument? If you have one in use or plan to purchase one in the future, it is important to perform a biological risk assessment prior to testing. With increasing workload and staffing concerns in the microbiology laboratories MALDI is a very useful piece of equipment; however with any new technology there are safety concerns to be considered and mitigated.

During 2019 to date, 24 microbiologists have been exposed to either Brucella melitensis or Francisella tularensis during test procedures involving MALDI-TOF technology. Sentinel laboratory costs for post exposure surveillance and prophylaxis can add up quickly with multiple exposures. These exposures may have been avoided had American Society for Microbiology protocols  for handling bio-threat agents been followed. These guidelines include examination for trigger points by examination of growth characteristics, gram stain, biochemical reactions and patient history. Despite biosafety education, improved lab safety protocols, better engineering controls and biocontainment equipment laboratory acquired infections, or LAIs, continue to pose a risk. 

2018 Biothreat Agent Sentinel Lab Benchcards



What do we do to make the Biosafety Cabinet ineffective?
1.   Walk past it
2.   Open a door near it
3.   Overcrowd it
4.   Cover the front grill
5.   Move hands in a sweeping motion through the sash opening (barrier)

How should we clean a spill in the Biosafety Cabinet?
1.   Leave the BSC running
2.   Cover spill with absorbent material
3.   Carefully apply effective disinfectant and allow appropriate contact time
4.   Flood the catch basin if contaminated
5.   Decontaminate objects within the BSC before removal
6.   Allow the BSC to run for 10 minutes before resuming work

What about the Ultra Violet light in the BSC?
1.   UV light is not recommended as the sole disinfectant for decontamination
2.   UV has limited penetrating power – surface or air only
3.   UV light intensity decreases with
       a. Time
       b. Dirt and Dust
       c. Distance from the bulb
4.   If you do not maintain the UV light bulb and use it correctly, it will not be as effective as you think!


Biosafety Cabinet Training

Fundamentals of Working Safely in a Biological Safety Cabinet

This Center for Disease Control and Prevention Laboratory Training is Free and On-Line. It is a great way to allow for convenient training and certificate documentation for safety competencies in the laboratory.


For the safety of laboratorians, their family, and the laboratory, the use of any personal electronic device* should be prohibited in the technical work area of the laboratory under the following circumstances:
1.   During work with any category of hazardous materials,**
2.   If Personal Protective Equipment is being worn,
3.   During work on specimens or data or any process that may affect accuracy of results,
4.   During work in any area in which PED may distract or interrupt others,
5.   During work in any area in which accidental release of protected health information could occur,
6.   If PED cannot be worn without posing a hazard due to dangling wires or other accessories, and
7.   If PED interferes with the worker’s ability to detect potential hazards, such as an approaching obstacle or hearing an alarm

*Cell phones, portable music players, radios with headphones, personal digital assistants, test messaging or other wireless devices
**Chemical or Biological

Reference: Clinical Laboratory Standards Institute (CLSI) - GP17-A3 (Clinical Laboratory Safety)


Interim Clinical Laboratory Guidelines for Biological Safety

Interim Clinical Laboratory Guidelines for Biological Safety webpage is a valuable resource available from American Society for Microbiology. This resource contains guidance on Laboratory Risk Assessment, Sentinel Laboratory Biosafety, Biosecurity and Biomedical Waste Management.

The Biosafety section includes guidance for MALDI-TOF MS Identification Systems, Molecular Identification Methods and Total Laboratory Automation in the microbiology lab. As more labs implement these cutting edge technologies, it is important that safety risk is carefully considered through an assessment prior to initiation of testing. Once risk assessment is completed and safety mitigation plans are approved, the plan should be written into the SOP. Training should include safety and competency to perform the test safely, and should be confirmed and documented.  The Interim Clinical Laboratory Guidelines for Biological Safety may be downloaded free of charge from ASM .