The biological safety cabinet represents a primary containment barrier that allows working safely with biological agents such as the virus that causes COVID-19. It is equipment designed to prevent the escape of bioaerosols from the work area and, therefore, protects people and the environment from possible exposure to these agents. There are three types, known as: class I, class II and class III.
It provides protection to the user and the environment but does not protect the product from possible contamination.
Provides protection to personnel, the environment and the product.
It is totally closed and offers the maximum degree of protection to the user and the environment. It is designed to work with highly dangerous biological agents.
Currently, various doctors from different hospitals and health centers are wondering which is the ideal cabin when they are handling samples that could potentially be contaminated with the COVID19 virus.
More specifically, the question is: wouldn’t using a Type B1 Biosafety Cabinet be safer against the virus than a classic Type A2?
In Europe, type II Biological Safety cabinets only differ in type A and type B. The differentiation of type B into two subtypes, B1 and B2, emanates from an American standard.
Safety levels with a Cabinet
A Biosafety Cabinet provides security for both the user and the samples, whatever the type. Regarding the management of COVID-19, it is suggested for SARS-CoV-2 to use a safety level 2 for diagnosis and a level 3 for manipulation or more detailed studies.
Although the Coronavirus family is generally considered to be Biological Hazard 2, it is the type of manipulation that is made of it and the circumstances that force it to be handled in BSL-2 or BSL-3 biohazard laboratories. Moreover, microorganisms up to risk level 3 are also to work with Class II, regardless of whether it is TYPE A or TYPE B.
What are the differences between Class II A and B Biosafety Cabinet?
Biological Safety Cabinets. Class II Type A Neither of the two types described (A and B) prevents contact exposures to hazardous materials. Approximately 70% of the total volume of air is recirculated over the work area, while the remaining 30% is extracted. The air inlet velocity for 20 cm front openings must be at least 0.4 m / sec.
Biological Safety Cabinets. Class II Type B Approximately 30% of the total volume of air is recirculated over the work area, while in this case the remaining 70% is extracted. The air inlet velocity for 20 cm front openings must be at least 0.5 m / sec. The downflow air velocity, on average, should be 0.25 m / sec.
The reason why users feel more confident in using a Type B when it comes time to acquire new equipment to work with COVID-19, are very subjective criteria, which apparently give a greater sense of security.
Our recommendation is to use Type B cabinets for the usual use that has always been given, which is the management of cytostatics; because that is its base application, and its design with a lower HEPA filter under the work zone is the most correct. And we do not recommend extreme use where it is not applicable.