The clinical laboratory is an inherently dangerous place. Laboratorians face a variety of dangers working in an environment that contains biohazards. Utilizing standard precautions and correctly employing Personal Protective Equipment (PPE) are essential keys to ensure laboratorians’ safety. Maintaining a clean and orderly environment and employing good disinfection practices are vital as well. A cluttered workspace and an area contaminated with biohazards threaten the safety of both employees and visitors.
General disinfection tips
Lab directors should conduct audits of their department’s physical environment to identify safety hazards specific to their lab. Such audits typically do not need to interfere with the day-to-day lab processes, and they should be performed on a regular basis, at least monthly. Many changes can occur in a laboratory at any time, such as the movement of instruments, the placement of new equipment, or even the movement and stocking of lab supplies, and the implications of such changes for safety should be recognized.
When checking for physical environment safety, look to see that aisles are clear of boxes or other obstructions, especially if the pathway leads to a fire evacuation route. Loose wires from computers and keyboards need to be properly tied up. Make sure that lab floors are cleaned regularly; the U.S. Centers for Disease Control and Prevention (CDC) recommends that lab floors be wet-mopped at least daily in a biohazard area.1 Also, make sure anti-fatigue mats on the floor are replaced on a regular basis so that wear does not create slip or trip hazards. In histology areas, be sure to keep paraffin wax build-up from occurring on walkways in order to prevent dangerous falls. Use scrapers or other implements to remove any wax build-up as it occurs.
Ensure that laboratory safety equipment such as emergency eyewashes, showers, and fire extinguishers are unobstructed at all times. It is important to make sure there is easy access to bloodborne pathogen and chemical spill response kits. Electrical panels in the department should have three feet of clearance in front of them. Check all lab electric cords as well for fraying or other damage. Simple movement of equipment can easily damage a cord, and exposed wiring can be a cause of laboratory fires. Ensure that compressed gas tanks are secured to prevent tipping.
Cluttered lab work benches can also include hazards for workers. A messy workspace can contain hidden dangers such as contaminated sharps, infectious materials, and even unknown chemical hazards if there are unlabeled materials. Lab areas should be dusted regularly as well. Dust may contain molds and other air contaminants that can potentially interfere with laboratory testing, particularly in a microbiology laboratory. That is one reason why electric fans should not be used in a lab setting. Fans in the lab can circulate those air contaminants. Fans also interfere with safety airflow devices such as chemical fume hoods or biological safety cabinets, and they can even interfere with the lab room air flow that is maintained for staff protection.
Because of the nature of the biohazardous materials used in laboratories, lab benches should not only be orderly; they should be disinfected after every work shift and after any spill occurs.2 This disinfection should take place with the use of an intermediate-level chemical germicide. While the CDC recommends the use of a 10 percent bleach solution as the disinfection standard,3 there are other products that can be used in the lab setting.
Commercially available lab cleaning products can be purchased in the form of pre-filled spray bottles, large containers of fluids, or even canisters of single-use wipes. Be careful when selecting any commercial product to make certain it is effective enough to eliminate most bacteria (including Mycobacterium tuberculosis) and all fungi and that it inactivates viruses. Many products that are sold cannot perform all of those disinfection functions, and labs that use insufficient products may inadvertently place their staff at risk for infection. According to the CDC, some commercially available germicides can rapidly kill ordinary vegetative forms of bacteria such as staphylococci and streptococci, but only select brands are effective against more resistant organisms such as Mycobacterium tuberculosis, non-lipid viruses, and most forms of fungi. Check the information provided by the manufacturer to make sure that the disinfectant selected is potent enough for complete lab disinfection.
Some laboratory instrument manufacturers recommend the use of specific cleaners on their equipment because bleach products may harm instrument surfaces. These cleaners may not be effective for biohazard control in the lab setting, and while they may be used on the equipment, they should not be used for general counter or work bench disinfection as well. One good way to avoid harm to surfaces from repeated bleach use is to rinse the surface with water or even ethanol after the bleach has been used.
It is important to pay attention to the contact time needed for disinfectant chemical products to work effectively on laboratory surfaces. Whether using sprays or wipes, the disinfectant action does not occur immediately, and the wet product should be left on the counter or surface for a prescribed amount of time as designated by the manufacturer. Some products can take up to three to four minutes to kill the pathogens they are designed to eliminate. A common lab cleaning mistake is to wipe a disinfectant-treated area down with water or even paper towels to dry the area long before the contact time needed to complete disinfection has elapsed. This is a potentially dangerous practice that can lead to a laboratory-acquired infection. Staff education about the proper use of germicidal chemicals is critical for proper infection prevention in the work place.
Regular cleaning and disinfection of lab surfaces apart from those involved in testing per se are also necessary to maintain the safety of the physical environment. Routinely wipe down chairs, telephones, computers, and other small items such as timers and pens. These items can become contaminated when laboratorians handle them with gloves that were worn during patient sample handling. While PPE is designed for staff protection, studies have shown that contaminated surfaces and items also can lead to lab-acquired infections. A Salmonella typhimurium outbreak occurred in clinical and academic laboratories across the United States in 2017 that caused illness for 24 people. When affected lab staff were interviewed by the CDC, some stated they had not worn gloves or lab coats, and some said they used pens and notebooks at home that were used in the lab setting.4
Being prepared for an accident
To complete an assessment of the physical laboratory work space, correct any issues discovered and educate staff to prevent reoccurrences. Provide a review of good disinfection practices and the proper use of products if necessary. Putting those pieces together is important in creating a strong lab safety culture. Then, once the physical lab environment is in safe order, it is time to ensure that features are in place that will help staff to maintain safety in the event of an accident.
Accidents and spills of chemicals or biohazardous materials do occur, and it is necessary to have adequate spill clean-up supplies ready. Every clinical laboratory should have materials ready in the event of a spill of blood or body fluids. The spill kit should include absorbents, implements for handling broken glass, PPE, and disposal containers or bags. Place signs indicating the location of spill kits and check kits periodically to make sure all needed supplies are present. Chemical spill kits should also be available. Make sure sufficient amounts of absorbents and neutralizers are kept, based on the amount of chemicals stored and used in the department. All staff should be adept at spill clean-up procedures. Regular training is necessary, and conducting spill drills will enable staff to respond quickly and appropriately when an accident occurs.
A career in a laboratory setting involves working with complex procedures and hazardous materials. Regulatory agencies—and common sense—demand that staff be able to work safely every day. That can be accomplished by maintaining a clean and safe physical environment and by providing work practice procedures and education. Watch for physical hazards and for practices that are unsafe, and make immediate corrections so that a safe environment can be maintained.
- CDC: Infection Control, Disinfection and Sterilization.
- Bloodborne Pathogens standard 1910.1030(d)(4)(ii)(A).
- U.S. Department of Health and Human Services, Public Health Service, CDC, NIH. Biosafety in Microbiological and Biomedical Laboratories (BMBL). 5th ed. Washington, DC: US Department of Health and Human Services; 2011.
- CDC. Human Salmonella typhimurium infections linked to exposure to clinical and teaching microbiology laboratories.