The Sweet Smell of Success |
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The Sweet Smell of Success
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| In any busy histopathology department, staff comfort and safety is important in ensuring efficiency, productivity and ultimately, accurate results. We are, after all, providing vital information that medics must rely on for patient diagnosis and treatment. At the Princess Margaret Hospital in Swindon, the Histopathology Department produces some 40,000 slides each year acting as a central resource for processing tissue samples from inpatients, outpatients, local GPs, various clinics and out-lying hospitals. |  |
Having been at the Princess Margaret for over 26 years, I have lived through many changes within the laboratories. The most dramatic occurred in the seventies, when the department underwent a major renovation and modernisation scheme that included an open-plan style of laboratory. Although initially viewed very favourably, and highly suited to some types of laboratories, over the years we have experienced the downside of this type of layout when chemical processes are at work. For us, the impact was noticed during microscopical slide processing.
The department usually processes 150 to 200 slides in a batch. Although a significant number, this amount is insufficient to justify automated equipment and all slide preparation is performed manually. Preparing the sections manually means that the xylene vapour, the solvent used in mounting the slide coverslips, is released into the working environment. In contrast, larger laboratories, typically working with batches of 200 to 300 slides, tend towards the use of automated coverslip machines that contain the toxic xylene fumes in a totally enclosed system. Our open-plan layout exacerbates the problem by being draughty and completely free of any barrier to the dissipation of the fumes. In addition, the laboratory is also south facing and becomes very warm, creating a problem with the evaporation of solvents. This combination of conditions creates an uncomfortable working environment with staff forced to work with the constant odour of solvents in the atmosphere, and obvious concerns for the health risks involved.
In an attempt to improve conditions, we started to prepare slides within a downflow workstation to try to control the solvent fumes. However, with its open fascia, this unit was unable to perform adequately in the draughty laboratory and the smell of xylene still filled the room.
Our second effort involved the use of alternative mounting products, including Clearene, Histoclear and Citroclear. These xylene substitutes do not present a safety problem, however, in our experience, they do not work as well as xylene and we had concern for the quality of slide preparations obtained. In addition, although the pungent, orangey scent of the Histoclear and Citroclear is not hazardous, some staff still found it overpowering, nauseating, and just as irritating as the xylene odour.
It became obvious that a major re-vamp in working procedures was needed. The proper containment of fumes, in an enclosed cabinet, seemed to be the only answer to safeguard the health and comfort of the staff whilst still permitting use of the preferred xylene.
We looked at the various models of fume cabinets available on the market, but having been impressed with previous products and service from Labcaire Systems, decided to make an in-depth investigation of their new Aura range of filtration fume cabinets. A factory visit followed, where we were helped to assess possible solutions to our problems.
Immediately, a major attraction of the new Aura cabinets was evident – the ability to easily transfer working samples in to and out of the cabinet without stopping on-going work. Most enclosed fume cabinets make this operation problematic due to their small working apertures. With the Aura design, airflow is automatically adjusted to maintain a pre-set level of airflow whenever the door is opened, thus allowing easy sample manipulation and transfer. This capability is achieved through sensors that continuously monitor the face aperture velocity and regulate the fan speed to ensure safe airflow conditions are maintained at all times.
Other attractive features of the Aura range include the EverSafeTM system that guarantees operator protection by monitoring airflow and filter efficiency and automatically signalling any maintenance requirements. We were also impressed with the recirculating filtration design that promised no disruptive or expensive installation and the convenience of being able to move the cabinet if required.
Such features arise from Labcaire’s clean sheet design for the Aura units, developed to meet the increased safety demands of forthcoming European legislation. It convinced us that Aura could provide the answers we were looking for, in our bid to improve our working conditions.
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We purchased two units, serving a specific function in the processing of the departments slides. The Aura 250E unit is used for mounting of the samples, and its excellent fume containment means that we can use xylene again without the problem of vapour release into the laboratory atmosphere. Our existing Labcaire WS6 downflow workstation is now used for air drying of the slides, since the action of drawing air through its perforated stainless steel worksurface provides ideal drying conditions together with sufficient fume containment for this purpose. |
A new, larger Aura 550E cabinet is used for manual slide staining techniques and reagent handling; troughs of reagents are stored in the cabinet making them readily available for dipping slides without exposing the user to fumes.
Both cabinets are fitted with Labcaire’s EverSafe™ system to monitor air flow and filter performance. The warning of approaching filter saturation enables us to prepare for filter change and eliminates down time for the cabinets. The carbon filters themselves are the largest fitted to any filtration cabinet, and feature Labcaire’s FiltrakTM easy filter installation and sealing system. These main filters are protected from particle contamination by removable pre-filters, which are accessed from below without disturbing the main carbon filters. A measure of their size and capacity may be seen in the fact that we have been using the units for several months and have not seen any drop in the filtration rate or compromise in the filtration efficiency.
The large filters and powerful motors within the Aura cabinets also ensure low noise levels of less than 55 dB and allow the largest working aperture of any available cabinet. This is proving popular with all the staff as it provides easy access to the workspace. Ease of use is further enhanced by the excellent visibility within the units, achieved by elimination of the front support struts on the cabinet and good illumination of the working area by a dual fluorescent lighting system.
Most importantly, the efficient fume containment systems have achieved our objectives. The department is now comfortable to work in and we are no longer constantly breathing in the odour of hazardous solvents.
