Three events have come together in the past few years that codified a need for rapidly deployable, mobile and cost effective containment equipment. First, there was recognition that many regions and countries in the world did not have adequate infrastructure, reliable power, or primary containment to provide a safe environment when working with emerging, re-emerging and dangerous infectious agents. In the US and elsewhere following the 2001 anthrax letters Public Health Labs and First Responders began experiencing an increase in their mission scope to collect, transport and perform analysis on unknown samples that may contain biological or chemical hazards. That mission had increased significantly due to copycat, hoax and criminal activity. In the same timeframe, advances in biomedical research created a need to move samples, animals and materials from room to room, or into and out of imaging suites and equipment while maintaining containment. In response to these needs portable Class III Biosafety Cabinets, flexible film isolators and compact, easily deployable hybrids were developed and refined.
Portable Class III Biological Safety Cabinet
Small, bench top units were developed that provide safe, effective and affordable primary containment (i.e. SEA) enabling flexibility for laboratory use or field deployment. It was originally developed for diagnostic screening of unknown and highly pathogenic samples in facilities, laboratories or field settings that lack reliable secondary containment controls. The closed system decreases the chance of aerosol escape, resultant accidental exposure and potential laboratory acquired illnesses.
In animal research, portable battery powered Class III BSCs are increasingly being used to move animals from holding rooms to procedure rooms. The supply is single HEPA filtered, the exhaust is double HEPA filtered as required by the CDC (Download BMBL 5th Ed. pdf). By use of large RTPs integrated into transporter carts of Class III design, the walls of animal holding rooms, and stationary Class III systems, scientists can safely transport exposed animals from holding rooms to procedure areas equipped with devices such as magnetic resonance imaging (MRI), positron emission tomography (PET), and other non-invasive scanning devices. The systems reduce personnel and environmental exposure and reduce the time the animal must be handled and anesthetized.
Transportable Class III BSC
Transportable Class III Biological Safety Cabinets are used in Public Health Laboratories for the receipt of unknown hazardous samples associated with chemical or biological terrorism or criminal activities. Workers use the transport BSCs to move the unknown hazardous sample from the loading dock area or other delivery site used by the First Responder, to the containment lab without risking contamination of non-contained and public areas, as well as the containment lab itself.
Taken together, the advent of the use of transport and mobile Class III BSCs provides a significantly safer way of moving and handling infected animals or unknown samples than any past capability.
Flexible Film Isolator
The negative-pressure flexible-film isolator is a self-contained primary containment device that provides maximum protection against hazardous biological materials. Isolators can be placed on a counter top or on a mobile cart. The workspace is enclosed in a transparent polyvinylchloride (PVC) film that suspended from a plastic or steel framework. Like Class III BSC, the supply air passes through one HEPA filter and exhaust air passes through two HEPA filters.
WHO recognizes the double HEPA exhaust obviates the need to duct exhaust air outside the building. Flexible-film isolators are used frequently and very successfully in animal containment, field work and other instances where it is not feasible to install or maintain conventional BSC. Hybrids (semi-flexible film isolators) exist where some of the panels are made of a rigid material such as polycarbonate, and typically the front panel is soft PVC.
The deployable isolator unit is a self-contained negative pressure filtration system that operates on two standard D cell batteries. Supply air is HEPA filtered. Exhaust air is double HEPA or double HEPA and carbon filtered. All filters are readily available and easily replaceable by First Responders and those involved in field collection and preliminary screening and triage. It is a rapidly deployable, light-weight, disposable system that comes in a compact transport case and sets up much like a dome tent. The isolator is made of durable 15mil polyurethane to withstand field use, repeated assembly/disassembly, and can be assembled and operational within minutes for on-demand use requirements. Large samples and equipment are introduced through a zipper system similar to those on a BSL-4 suit. Sampling ports are provided for use with external detectors and analytical equipment.
The diversity in containment equipment is almost limitless and depends on user requirements and design team innovation and advances in materials.