Biosafety Levels A Key Factor in Critical Airflow Space Design
Biocontainment is the critical factor distinguishing between a hospital operating regularly and one having to perform a total decontamination because of lack of containment of dangerous fumes, gases, airborne infections or bacteria.
As a result, the Centers for Disease and Control and Prevention in the United States has established criteria levels of biocontainment in order to ensure public safety in critical airflow spaces such as: hospitals, research facilities, chemistry laboratories. These levels include a set of mandatory precautions and procedures, which range from level 1, the lowest and least dangerous level, to level 4, which is the highest and most active.
The lowest level involves activities such as washing hands and using minimal protective equipment whereas the higher you go, the more protective equipment you have to wear, such as positive pressurized personnel suits, multiple containment rooms and airflow systems, extensive personal training, and required protocols.
Specifically, Biosafety Level 1 involves working with well-characterized non-pathogenic agents that do not cause disease to humans, eating or drinking is not permitted in the space, working with open laboratory benches without need for special containment equipment. In contrast to the other levels, a BSL-1 is the only environment where isolation from the general building is not required. These are the typical labs you will see in colleges and university teaching spaces.
A BSL-2 laboratory requires a bit more precaution. Such an environment requires limited access during occupied hours as well as additional training provided to personnel in handling pathogenic agents. These spaces are designed for moderate exposure to hazards that are difficult to transmit by air, such as Hepatitis A, B & C, as well as HIV.
A BSL-3 laboratory is a designation given to spaces where bacteria that can produce potentially lethal airborne disease to humans, such as the West Nile Virus, for example exist. The precautions involved in a BSL-1 and BSL-2 laboratory are applicable to BSL-3 spaces as well, in addition to a few extra protocols. These protocols include the use of solid front protective equipment as well as keeping all dangerous material in a biological safety cabinet.
Belnor Engineering Inc. provides these safety cabinets through their Air Master Systems fume hood product line, through their range of available lab furniture. In addition, the space must abide to the drafting and use of a laboratory-specific manual that demonstrates compliance to necessary safety measures. The construction of the laboratory should be such that the entrance would be isolated from the building in case of contamination and that the windows be sealed.
The ventilation system also has to be designed to account for the case of decontamination, where air in all areas must be purged and replaced with 100% outside air. In general, recirculated air needs to be filtered anyways for BSL-3 environment.
A BSL-4 laboratory is the most stringent case of all the above. This is due to the fact that the work performed in these spaces usually involve highly dangerous, infectious or toxic agents that cause disease in humans for which there is no current cure, such as the Ebola virus. In these areas, the use of a full positive pressure personnel suit is required.
Usually the construction of the laboratory accounts for various ultraviolet rooms, interlocks, shower rooms, and a vacuum ventilation systems. In addition, all the water and air entering or exiting the area must be subject to HEPA filtering, and the entrances must be such that the lab is completely isolated from the general building in the case of widespread contamination.It is critical to understand these designations when dealing with the construction of a critical airflow space such as a surgery suite or a laboratory.
Belnor Engineering Inc. does a great job in ensuring that the lab exhaust and supply air systems in place are conforming to these standards in order to avoid any costly spills or decontamination scenarios where precious downtime results in significant losses for the owner. By specifying the correct venturi valves and monitoring accessories for each application, Belnor helps to provide a reliable VAV system that saves on headaches for critical airflow projects.