24/04/2009High containment biological safety cabinet

Telstar has broadened its offering of Biological Safety Cabinets (BSC) with a range of high containment equipment including Class III models and isolators. Thanks to these latest additions, Telstar now offers to the market a wide range of Biological Safety Cabinets of classes I, II and III and Pharmacy Isolators. The new cabinets are the result of the experience and reputation of the recently acquired Clean Air Techniek B.V., from The Netherlands, well-renowned for the manufacture of high-level bio-containment equipment for the northern European market.

The applications, operating criteria and specifications of the new BSCs and Isolators from Telstar have been defined by considering the requirements of the leading centres handling bio-active substances.

A great number of systems are available which provide biological protection, be it personal, for the environment or for the product itself. These systems are given the generic name of "safety barriers" and depending on the level of biological risk one or more of these safety barriers must be used.

The barriers used to eliminate or minimize exposure to biological materials are called Primary Safety Barriers. Within this category are the class I, II and III biological safety cabinets, isolators, protective suits, breathing apparatus, masks, safety goggles, etc.

In order to correctly choose the class of BSC required, it is essential to know the risk level of the biological agents that are to be handled inside the unit. Several levels of containment exist, depending on the virulence of the pathogenic biological agent that is being handled.

The United States Center for Disease Control and Prevention (CDC) classifies various diseases according to their level of biological risk: BSL 1 represents minimum risk and BSL 4 extreme risk.

The Class III Biological Safety Cabinets have been especially designed for the handling of microbiological agents classified as Biosafety level 4 (BSL-4), offering maximum protection to both the environment and the user.

The pathogenic agents in group 4 are those microorganisms that can cause serious illness in humans and as such constitute a grave danger to personnel, with a high possibility of spreading to other people and for which there are generally no effective prophylaxis or treatments. This group includes diseases such as Marburg virus, Ebola virus and other haemorrhagic diseases.

The Class III Biological Safety Cabinets from Telstar feature a totally sealed, air-tight working area which keep the user completely separated from the product by a physical barrier, with the sample being handled using gloves attached through the sealed window of the cabinet. A HEPA-14 filter located in the rear part of the cabinet continuously supplies filtered air to the working chamber and the evacuated air is passed through another HEPA-14 filter, preventing the release of microorganisms into the environment. In accordance with the cabinet design, the HEPA-14 supply filter provides turbulent flow within the cabinet. Materials are placed inside the cabinet using a pass-through box with a double sealed door, which can be decontaminated between uses.

To complete the range of laboratory equipment offering protection for the product, user and environment, Telstar has a range of positive- and negative-pressure isolators to meet the different needs of its clients.

Telstar is committed to helping pharmacists ensure the sterility of drugs, the safety of patients, and the health of pharmacy personnel, in order to follow the last tendencies of the new USA standard USP Chapter 797. This standard is focused in the health & hospital field and recommends the use of negative pressure isolators with the third filter stage for chemotherapy preparations like handling cytotoxic or other hazardous drugs. Also is recommending the use of positive pressure isolators for handling samples that requires greater sterility assurance.

The positive-pressure isolators provide laminar flow in the working chamber, making them ideal for products which have no biological risk but require high sterile conditions. The Isolator main chamber pressure is positive to the room. The main chamber is slightly higher pressure than the pass-through box to maintain aseptic conditions in the main chamber. The pass-through box is positive, but slightly lower pressure than the main chamber to assure aseptic conditions within the main working chamber. This equipment not only provides a high level of containment against external contamination, but avoids the risk of cross contamination as they provide laminar air flow to the working chamber.

The negative-pressure isolators also provide laminar airflow within the working chamber and are used for products biologically hazardous that also required minimized cross contamination. The barrier isolator pass-through box and main chamber pressure are negative to the room. In the standard configuration the pass-through box is slightly more negative than the main chamber to prioritize cleanliness in the main chamber while ensuring containment of hazardous compounds within the main work area. An additional third HEPA H14 prefiltration stage right below the workbench adapts the isolator to the requirements in the manipulation of hazardous substances like the preparation of cytotoxic medicines as prescribed in some countries recommendations.

This high containment equipment has flexible gloves for handling materials within the working chamber, adjusted to the size and shape of the opening in the front window. They can be replaced from outside the cabinet in such a way that the old gloves are pushed into the interior of the working chamber and the new ones are attached whilst the unit is in use.