Biosafety & Primary Biocontainment In BSL-2 & 3 Conditions

  • A common question in BSL-2, when assessing the risk and identifying potential solutions for primary biocontainment, is the selection of the most relevant IVC system, either a “standard” one, such as NexGen or EasyCage (the latest disposable) in negative mode, or a “sealed” one such as BCU (designed primarily for BSL-3 applications).

    When referring to the main biosafety standards, “non-certified” primary biocontainment systems can be used for rodent caging, in the same way that certified BSC-I, BSC-II and BSC-III, if they are demonstrated as a suitable solution (EU directive 2000/54/EC, BMBL Manual – CDC, WHO Manual and Canadian Biosafety Standards). This includes IVC systems. The main issue is to guarantee that the system selected is safe for personnel and laboratory environment through a relevant risk analysis and mitigation, according to the nature of the activities, the nature of the biological agent concerned, e.g. the potential routes of infection. The integrity of primary containment devices other than BSCs, e.g. primary containment caging, should also be qualified in accordance with testing procedures and acceptance criteria appropriate for the equipment and design.

    Safe” can be translated into “appropriate to the risk” as demonstrated through a comprehensive, multi-component risk analysis and mitigation, which is too long to detail in this short paper but available from our Veterinary & Professional Services Department. Whatever the biocontainment system, only projects / protocols with an acceptable risk level and control will be initiated and, in addition, suitable procedures must be defined and personnel competency must be guaranteed in all cases.

    The use of a primary biocontainment IVC system such as BCU, designed for work in a ABSL-3 environment, or a standard IVC system (NexGen or EasyCage) in negative mode in ABSL-2 environment are all potentially safe, reliable, compliant and practically suitable solutions, fully adapted to small rodent care and use if all required conditions are implemented.

    • The BCU sealed IVC system has been purposefully designed for stringent BSL-3 work, including the rack ventilation system and control, allowing its use with airborne or aerosol transmitted agents.
    • NexGen and EasyCage systems used in negative mode for biocontainment in BSL-2 conditions (as well as with radio-isotopes or chemical risk), use the same high-performing rack ventilation and Eco-Flo system, allowing maximum versatility and biosafety (please ask for details) when compared with other IVC systems.

    Disposable cages may also be an interesting option with categories of agents not requiring a sealed IVC system but very resistant to decontamination / disinfection (prions, spores, parasite eggs, fungi, some viruses…) allowing to send infected cages and bedding to incineration, after leaving the biocontainment area according to applicable barrier procedures.

    The disposable caging solution (EasyCage) presents other potential advantages such as:

    • Better control of personnel and environment exposure in washing area, due to absence of cleaning.
    • Easier waste management: no need to decontaminate if packed in a suitable way before shipment to incineration.

    If useful, Allentown Veterinary & Professional Services Department can contribute to the risk analysis and mitigation and to the definition of an appropriate solution.