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The Key Differences in Containment Laboratory Security Levels

The coronavirus pandemic has put the spotlight on laboratory work – and the accompanying issue of biosecurity – over the past two years. Here Arena Instrumentation, who offer high-quality CL3 room testing services across the UK, highlight the differences between the various categories.

Containment Laboratories – Level 1

Containment level 1 (CL 1, although in many other countries this is abbreviated to BSL-1 or Bio Safety Level 1) is used for work with low-risk biological agents and hazards, genetically modified organisms, animals and plants, and as such don’t need any special biosecurity features.

There still needs to be risk assessments in place, access should be strictly controlled (any guests or visitors should be supervised) and the premises need to be locked if they are not being used.

All the surfaces should be impervious to water, resistant to acids and solvents and easy to clean. The ventilation systems and safety cabinets should be inspected and tested at least once a year. All staff should know what to do in the event of an emergency, such as a spillage of chemicals.

Containment Laboratories – Level 2

CL2 rooms and labs are a step up in protection because they handle ‘medium-risk’ biological agents and hazards, genetically modified organisms, animals and plants. All of the protections in place for CL1 rooms and labs apply here, along with some additional safety measures. The increased risk means special equipment, such as safety cabinets and centrifuges with sealed rotors, should be used in these environments.

Greater stress is placed on user cleanliness with hand sanitisers and eyewash stations provided, as well as personal protective equipment. If there are any potentially harmful pathogens present they are not generally transmitted through the air, but in a CL2 lab care should be taken to avoid any splashes as these can settle on surfaces and be transferred through the hands.

The use of sharps – any instruments which could puncture the skin – should be avoided where possible.


Containment Laboratories – Level 3

CL3 rooms and labs work with ‘high risk’ biological agents and hazards, genetically modified organisms, animals and plants and represents a step up in biosecurity from level 2. There should be even stricter access controls in place than for levels 1 or 2, and all waste and clothing should be decontaminated within the lab before it is either disposed of or washed. Fumigation procedures should be used on a regular basis to ensure that the areas remain ‘clean’.

Yellow fever, West Nile virus and the COVID-19 coronavirus are examples of the types of virus which need to be handled with biosafety level 3 protocols.

A level 3 laboratory may also contain a separate lobby, which helps to contain the spread of any harmful pathogens. Both rooms should have self-closing double-door access separated from general building corridors, and the air should be drawn into the lab from clean areas and with no recirculation. This is in part because many of the agents which are present could transmit infection via the airborne route.


Containment Laboratories – Level 4

This is the highest level of biosecurity which is currently available. CL4 labs and rooms are not as common as their CL3 counterparts, as they handle only the most hazardous and exotic microbes which pose a serious risk to human health, and for which no treatment may be available. These include the Ebola and Lassa Fever viruses, as well as any materials which have been brought back to Earth from a space exploration programme.

CL4 protocols mean that staff should be able to completely seal off the lab, room or suite where the pathogen or material is present and wear high-level PPE, such as positive-pressure, air-supplied full-body suits.


CL3 Room Testing Services from Arena Instrumentation

Arena Instrumentation offer high-quality CL3 room testing services across the UK. We use a mixture of integrity testing and fumigation to ensure that the lab is operating safely and efficiently. The tests can be done annually, as part of a regular maintenance schedule or immediately after any spillage or leak of a potentially harmful pathogen.

The integrity test involves using a smoke-generating device which is operated from outside the room. Inside, our engineers create a constant positive pressure which will ensure the smoke reaches every corner and surface. They can then identify any leaks – either visually, or with smoke-detecting equipment – and report back to the client.

If there is a spillage, it is essential that the room or lab is decontaminated as quickly as possible. Our Emergency CL3 fumigation protocols involve using formaldehyde to ensure the labs and lobby are safe to enter again and to prevent the spread of any biological agents into neighbouring areas.

If you would like to know more about our CL3 room testing – or any of our other services –  follow this link to our contacts page.