The subject title of this article can easily be misinterpreted as an introduction to a complicated set of guidelines and directives that require overly specialized safety equipment, voluminous documentation, and extensive time to develop. As with any compliance standard, much of this is dependent upon the specifics of the workplace and the potential airborne hazards within. In the basic clinical and anatomic pathology laboratory much of this has already been developed and exists within the Personal Protective Equipment (PPE) and related safety recommendations. Developing a more specific and efficacious Airborne Infection Control Policy (AICP) for your lab can be simply achieved by adding basic PPE equipment (such as facial masks) and extending the recommendations to a mandated imperative with routine monitoring and accountability.

While one of the most basic and common items in airborne infection control, the facial mask, has become a personal and/or political option in society, crises in healthcare such as the current Covid-19 novel virus pandemic, now requires healthcare to take leadership in removing the option component and developing separate mandatory compliance standards specific to each individual laboratory. Facial masks provide a ‘first line of defense’ protective barrier that blocks or significantly hinders the expulsion and transmission of minute oral fluid droplets or spray into the

World Health Organization (WHO) studies show that facial masks reduce the incidence of airborne transmission and infection by more than 80%. It is accepted that even though facial masks do not eliminate the possibility of airborne transmission, the amount of fluid/aerosol droplets and the distance they travel can be reduced from 12 feet to 3feet from person to person.

As previously stated, developing a compliance standard for the workplaces requires specificity. Cloth masks provide some degree of barrier protection but are not specifically designed for this purpose. The surgical mask (left image) designed for healthcare are a loose-fitting item that provides more of a physical barrier from the wearer to others in the environment. It is accepted for standard laboratory and limited patient exposure use, and filters 3.0 – 0.1 micron size particles. The N95 respirator (right image) is a tight-fitting mask that forms a seal around the mouth and nose. It is a much more efficient filtration system that filters as much as 10x fewer size minute particles, and provides dual exposure protection from wearer to the environment and better filtration from environment to the wearer. It is used for more critical care direct patient use, as in the front-line workers dealing directly with the patient.

Understandably an individual laboratory will determine which mask is more appropriate for their environment, but a new AICP standard should always state the specific item in use and a statement on monitoring and accountability. It should also be signed off by the laboratory or department safety officer.

There has been much discussion on the need and efficacy of facial shields in the laboratory as an added protection. Facial shields were designed as a safety barrier for the eyes and partial face. While they can be an essential PPE device used to enhance personal safety, facial shields are more specifically designed to protect the eyes and face from debris or flying objects. By itself it is not an effective device for an AICP standard. Airborne particles, particularly in aerosol form, easily spread beyond the material barrier of the shield and disperse themselves into the environment. There is little to no protection for the wearer from aerosol particles coming from the environment and do not effectively block transmission. If used, facial shield should always be used in conjunction with a surgical or N95 mask and when appropriate with safety glasses.

In closing, it is unfortunate that the subject of mask wearing and the proven success that it has demonstrated in reducing airborne viral transmission, has been compromised by other biases and objectives having little to do with safety. Optimal patient care and the personal safety of healthcare workers must always be the prime objective to ensure a healthy and safe environment. Patients depend on those who are their trained and skilled caregivers to do the patient no harm in the care they provide. Healthcare workers must also be able to depend on their institutions to ensure the best safety protection and conditions they need to carry out their role. Hopefully through developing new AICP standards we will help keep the focus on the prime objective.

In Part 2 of this subject of developing an AICP standard we will further discuss how to draft a simple policy standard for your laboratory, as well as introduce other low-cost aerosol control filtration systems that can be used in the lab environment.


  • Brown, S., ‘Enhancing PPE Methods Amidst Covid-19 Crisis’ , article,, 2020.
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