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Lab Safety Practice in Microbiology

Safety in the laboratory—for many, it’s a topic that tends to have a forbidding, preachy air about it. For others, it can seem superfluous, as anyone with minimal training and a dash of common sense should be able to avoid hazardous complications in the lab—or so it may seem. In reality, however, danger can easily strike due to the all-too-common inattentiveness that comes from “going through the motions” and underestimating the imminent likelihood of harm. With that in mind, let’s take a look at safety principles that should be observed in a microbiology lab environment.

There are a number of safety standards, regulations, and recommendations that have been published by various organizations, including the Occupational Safety and Health Administration (OSHA). As a comprehensive exploration of lab safety would take up far more space than we have here, we’ll restrict ourselves to an overview of tips and procedures that can significantly reduce the likelihood of injury in the laboratory.

Follow the Hierarchy of Controls

Promoted by the Centers for Disease Control and Prevention as well as a number of other health organizations, the Hierarchy of Controls is a simple standard by which one can judge the relative efficacy of various safety protocols. It ranks safety measures in order of preference. The idea behind the Hierarchy of Controls is that lab managers should consider more effective safety measures first, before opting for less effective ones. These five “Controls” are arranged in descending order, as follows:

  • Elimination – It's best to remove a hazardous threat from the lab area to ensure optimal safety. If this is not possible—which, considering the nature of lab work, holds true in many cases—supervisors and managers should consider Substitution.
  • Substitution – The hazardous substance should be replaced with less hazardous material. If this is not possible, it’s time to consider Engineering Controls. 
  • Engineering Controls – This strategy involves constructing the lab area in a way that isolates lab personnel from hazards as far as possible—for example, by building permanent enclosures or installing Plexiglas splatter guards.
  • Administrative Controls – This refers to safety procedures that lab workers are expected to comply with. As this type of control can be compromised by human error, it is less desirable than the measures listed above.
  • Personnel Protective Equipment (PPE) – The least effective control, PPE refers to the safety gear that lab workers are expected to wear, such as protective goggles.

Fire Safety

Fire is one of the more serious hazards that laboratory workers face. To decrease the chances of an uncontrollable fire, lab workers should minimize the amount of materials in the area, as unneeded objects and substances can help cause or spread fires. On a similar note, it’s best to clean the lab area on a routine basis, ensuring that no clutter develops; unused materials should be returned to storage until it is necessary to retrieve them. Remember also that doorways and areas where emergency equipment is maintained (e.g., fire extinguishers) should be easily accessible and unhindered by extraneous objects—when putting out a fire or escaping from one, every second counts. Finally, keep in mind that laboratory barriers such as shields and fume hoods are there for a reason, and they should not be moved without urgent cause.

Avoid Eating in the Lab

In any lab where pathogens may be present, eating and drinking are highly inadvisable behaviors, as is storing food in containers where infectious materials can be found. Similarly, putting on cosmetics or contact lenses should also be discouraged

Dealing with Exposure to Common Chemicals

It’s certainly no big secret that microbiology labs tend to contain a variety of hazardous chemicals—the list is obviously far too long to explore here. Proper handling of these kinds of chemicals, including correct procedures in the event of accidental exposure, is a paramount concern for lab workers. For example, toluene—a colorless solvent—can trigger a variety of health problems, from headaches to liver damage, if it is inhaled, ingested, or absorbed through the skin. Another common solvent, xylene, can cause similar ailments, including severe skin irritation and vomiting. Both chemicals will induce serious illness with chronic exposure.
So what should workers do if they are exposed to dangerous levels of these chemicals?

  • If the chemicals have made contact with the worker's eyes, it is imperative to wash out their eyes immediately, for at least 15 minutes. For this reason, there should be an eye-wash fountain in the lab for incidents such as these. Make sure that their contact lenses are removed first—in fact, workers should be discouraged from wearing contacts in the lab.
  • The worker should remove any clothing that the chemicals have touched, and these garments should be immediately placed in closed containers.
  • Exposed skin should be thoroughly washed with soap and water.
  • If the worker has inhaled unsafe amounts of a chemical, get them out of the area and into fresh air. It's important to be aware of the safe concentration level of the chemical in question—for example, toluene is considered unsafe if present above 200 ppm over an eight-hour lab shift.
  • If the worker has ingested the chemical, call for medical help.
  • In addition, make sure that the area is properly ventilated before cleaning up chemical spills.

Provide Adequate Ventilation

Keeping the laboratory properly ventilated is another important issue. Note that this does not just refer to the importance of preventing dangerous airborne chemicals from escaping the room—it’s also important to keep lab workers from becoming exposed to these substances. Chemical hoods and vented storage cabinets are valuable accessories in preventing personnel exposure to hazardous substances. This equipment must be kept clean at all times, which includes ensuring that all exhaust ducts are free from blockage.

On a related note, the lab’s HVAC system should provide acceptable cooling and heating capabilities in order to ensure that personnel can benefit from a comfortable working environment. The system should be periodically inspected by an HVAC professional. Negative room pressure should be maintained, and no area of the lab should have static air.