Medical Air Technology (MAT) has designed a scheme for the major refurbishment of an existing laboratory at University Hospital Crosshouse – a large district general hospital near Kilmarnock in south-west Scotland.
The company has worked successfully with the hospital’s operator, NHS Ayrshire & Arran, on earlier operating theatre projects at the hospital, which provides a wide range of services.
The upgraded laboratory increases the hospital’s Containment Level 3 (CL3) capacity, allowing it to work with a wider range of pathogens, including coronaviruses. CL3 is the highest containment level in common use in the UK, and laboratories of this type require certain features to be incorporated into the design to ensure appropriate containment.
After receiving the design order, MAT developed and submitted several different room layouts, each of which met the hospital’s key requirement to enlarge the lobby leading into the laboratory. Following an option appraisal, MAT and its supply chain mobilised to site to carry out the entire refurbishment. This included a full strip-out of the existing laboratory, taking it right back to bare brick, before the installation of a new ventilation system, control panel, furniture, drainage, domestic water, and decoration.
MAT explained: “The lobby is a vital element of CL3 laboratory design. It marks the start point of the controlled airflow. The HVAC monitored pressure control system supplies air to the lobby, and then draws the air through to the laboratory via a combination of safety cabinet extract and HEPA filtration of exhausted laboratory air, creating a gradation of negative pressure.”
On this project, MAT took air from the existing corridor and introduced it to the lobby via a pressure stabiliser. The laboratory door contained a door transfer grille to allow the pressure regime and design airflow to be met. The air was then extracted via two microbiological safety cabinets, procured by MAT from Contained Air Solutions (CAS).
In addition to designing and installing the laboratory, MAT had to meet two specific challenges. The first involved working on the roof to install the ventilation system, which had to be undertaken out of hours to minimise disruption to the hospital’s day-to-day running, so the installation team was often working under floodlighting. MAT also had to ensure that all guidelines were followed to provide a COVID-secure workplace.
A Category 3 or CL3 laboratory is an airtight, gas-tight, leak-proof room that uses specialised airflow design to ensure biocontainment. Conceptualising and designing a safe and compliant CL3 laboratory requires expert knowledge of the importance of room structure, and a thorough and advanced appreciation of the way airflow operates.
Control of Substances Hazardous to Health (COSHH) regulations require that at CL3 the workplace must be maintained at an air pressure negative to atmosphere to stop the escape of hazardous pathogens. This is achieved by the specialist airflow created by the HVAC system, a critical part of the containment process, which establishes and maintains the negative pressure, and thus ensures containment and operator safety.