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MAT delivers a CL3 laboratory for a leading UK university

Medical Air Technology (MAT) recently completed a high specification Containment Level 3 (CL3) facility for a leading UK university that wanted to expand its research capability. The new laboratory, situated on the top floor of the ten-storey faculty building, was partially funded by charitable donations and is part of a major ongoing refurbishment programme.

The biological research programmes planned for the suite using known CL3 pathogens meant that compliance with Advisory Committee on Dangerous Pathogens (ACDP) and Specified Animal Pathogens Order (SAPO) standards and the Security of Laboratories (part 7 of the Anti-terrorism, Crime and Security Act 2001) was paramount. MAT was involved from design through to commissioning and handover, working closely with the client to ensure that the design was tailored to suit their particular requirements and the limitations of the site

The turnkey suite comprises a dedicated LPS 1175 SR4 high security lobby and CL3 anteroom leading to a 75m2 CL3 laboratory. A new CL2 laboratory of 47m2 also forms part of the suite.

The ventilation design was for a 100% fresh air-conditioned air supply plant. integrated with microbiological Class II safety cabinets incorporating automatic air bypass to ensure a constant negative pressure suite.

An emergency fail-safe air bypass arrangement linked to the

roof-mounted AHU air supply plant ensures that in the event of an AHU shutdown, the suite is able to maintain negative pressure airflow. MAT also installed dedicated CO2 supplies for incubators. full system controls and integrated building security systems. Integrated formaldehyde cabinet and laboratory fumigation systems enable the client to fumigate the safety cabinet and laboratories independently. CCTV, intruder and personnel safety alarms were included for extra security. The laboratory suite was also modified to suit disabled workers, with the addition of a washroom with disabled access.

The job presented particular challenges due to the location of the new laboratory on the top floor, for example the cabinet extract ductwork had to be installed through the roof of the facility, and much of the ductwork throughout the suite had to be fire rated. In addition, all work had to be undertaken around active laboratories within the faculty.

Stringent health and safety and installation methods ensured the works were carried out safely and the project completed on time and to budget.


“Containment Laboratories must be designed and built so as to prevent or control the exposure of Laboratory workers, other persons and the environment to the biological agent in use.”

The Medical Research Council

A CL3 laboratory is required when handling human pathogens that may be transmitted via inhalation, that often have a low infectious dose to produce effects and that can cause serious or life-threatening disease. These pathogens include HIV, hepatitis B, yellow fever and rabies. CL3 laboratories are the highest containment level laboratories in common use in the UK and the point at which certain features to ensure appropriate containment must be incorporated into the design.

CL3 containment features primary and secondary barriers to minimise the release of infectious organisms into the immediate area and the environment. Every CL3 laboratory has two physical layers of containment:

  1. The primary barrier, which contains the hazard at source through the use of equipment such as microbiological safety cabinets.
  2. The secondary barrier, which protects the people and the environment through a combination of design and operating procedures such as air handling and restriction of access.

The CL3 laboratory is an airtight. gas-tight. leak-proof room that uses specialised airflow design to prevent the escape of hazardous pathogens. Design and maintenance of these spaces is complex, and should only be carried out by a specialised contractor like MAT, with a thorough and proven understanding of the myriad of requirements and regulations and the ability to deliver a safe and compliant facility.

Upon completion, the CL3 laboratory must be commissioned to ACDP guidance and COSHH requirements to ensure it is operating correctly. MAT FM can undertake this. carrying out pressure decay testing at both negative and positive pressures and leak testing prior to handover. In line with COSHH requirements, an ongoing service and maintenance plan from MAT FM then provides full verification of the critical ventilation system and an annual major service.

For more information, please email: or call 0844 8712100

Written and distributed by:

Medical Air Ltd

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Further information:

Stephen Taylor

Call: 0844 871 2100




In 2020, Imperial College London approached Medical Air Technology (MAT) to discuss the provision of two new ISO Class 6 cleanrooms. The cleanrooms, located within the Sir Michael Uren Hub, would allow the university to further extend the range of research that could be carried out within its new White City campus.

After completing several previous cleanroom and containment laboratory projects at Imperial College London, MAT was proud and excited to once again have the opportunity to work in partnership with such a prestigious institution to deliver the new research environments.

After initial designs were developed and approved, building work began in summer 2020 and the new cleanrooms were handed over in June 2021, the entire project having taken just 11 months.

The The Sir Michael Uren Hub at Imperial College London

Imperial College London is a global top ten university with a world class reputation. Its alumni include 14 Nobel Prize winners, including Sir Alexander Fleming.

To enable the highest level of research, the university offers the best

possible facilities. One of its flagship buildings is the £90m Sir Michael

Uren Hub, located at the White City campus. Designed as a

collaborative facility, the 13-storey Hub provides space for Imperial’s

world-leading researchers, engineers, scientists and clinicians to work

alongside one another to investigate some of the twenty first century’s

most urgent biomedical and healthcare problems.


  • High standard ISO Class 6 clean areas with air change rates from 50 to 70 per hour
  • High load bearing raised and ventilated floor
  • Modular cleanroom ceiling with HEPA fan filter units
  • Complex CMR airflow and room pressure controls.
  • Complete mechanical and electrical installation including air handling units, HEPA filtration and specialist airflow and pressure controls
  • Piped specialist, hazardous and house gases, including vacuum systems
  • Hazardous gas emergency release abatement systems

What is Meant by ISO Class 6?

The new cleanrooms MAT was commissioned to design and build both had to be ISO Class 6 standard to safely accommodate the semiconductor research that would be carried out in them. Class 6, as defined in ISO 14644-1:2015 Cleanrooms and Controlled Environments, refers to the cleanliness levels that must be met within the cleanroom.

In addition to having a high air change rate, an ISO 6 environment must be accessed through airlocks to preserve pressurisation differentials and prevent the migration of particles from outside into the cleanroom space, increasing one class at a time. So, users should pass through an ISO 8 environment, then an ISO 7 environment, before entering the ISO 6 cleanroom.

MAT – Designer and Main Contractor

MAT acted as the designer and main contractor on the cleanroom project, working closely with the university to ensure minimum disruption to the other activities being carried out in the Sir Michael Uren Hub.

The team developed a design built around the complex research equipment and specialist tools that would be housed in the new cleanrooms. Work included final services connections and extensive bottled and house gases installation to several hazardous gases and associated gas detection systems.

The HVAC System

HVAC design is complex and requires a highly skilled delivery team.

MAT is an expert in the provision of specialist HVAC systems. The HVAC system is at the heart of cleanroom design. Cleanroom HVACs differ from standard systems in that they have an increased air supply, different airflow patterns, use of high efficiency particulate air (HEPA) filters, and room pressurisation, and clean to dirty room air cascades.

In order to meet the required air cleanliness, the air must pass through HEPA filters. The lower the ISO class, the more often the air must pass through the HEPA filter. This ‘air changes per hour’ rate (ACH) and the room volume are used to calculate the HVAC’s required airflow. A conventional HVAC system usually makes two to four air changes per hour, whereas in a cleanroom it can range anywhere from 10 to 250 or even more.

The ISO Class 6 cleanrooms at Imperial College London require air change rates from 50 to 70 per hour.

A Specialist Contractor

MAT designs, manufactures and installs bespoke critical ventilation systems and turnkey project solutions for new build and refurbishment projects. As a specialist contractor with many years’ experience, we are passionately committed to improving patient protection and end-user safety in demanding clinical, research and drug production arenas.

We have extensive experience of working in live environments and understand the challenges around delivering a project within an operational scenario.

In addition, MAT FM provides a range of competitively priced and highly effective service and maintenance packages for all core products and turnkey solutions offered by MAT or other suppliers, ensuring that equipment is maintained, serviced and validated correctly for optimum performance.

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For more information, please contact Will Evans:


Tel: 0844 871 2100

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