Make Your Selection Below


Containment Level 3 (CL3) facilities

Containment Level (CL) 3 laboratories offer two physical levels of containment from harmful pathogens. Although routine fumigation of CL3 laboratories is not mandatory within the UK government’s Advisory Committee on Dangerous Pathogens (ACDP) guidance, there is a requirement to be able to safely fumigate a facility in the event of a spillage or leakage which could lead to widespread contamination.

Fumigation using Formaldehyde is still known to be highly reliable and effective for room decontamination due to its broad antimicrobial efficacy and log reduction. Crowthorne offer both hydrogen peroxide and formaldehyde fumigation dependant on your requirements and preference. To discuss your individual requirements, get in touch

When to Fumigate?

Fumigation may be required under any of the following circumstances:

  • To ensure a laboratory is decontaminated before the annual inspection and verification
  • Following a spillage or leakage
  • To prevent cross and background contamination
  • To create a sterile environment
  • During the decommissioning of a CL3 facility
  • As part of a fumigation efficacy study.

Fumigation Validation

It is important to validate the fumigation using Biological Indicators (BIs) to verify effectiveness. There are various types of BIs available depending on the type of fumigant used.

Sealability of CL3 and CL4 Facilities

All laboratories which require fumigation will need to provide evidence to the Health and Safety Executive (HSE) that sealability tests using smoke pencils have been undertaken and any identified leak paths adequately rectified.

Emergency CL3 Fumigation Scheme

Advisory Committee on Dangerous Pathogens (ACDP) guidance stipulates the requirement to be able to safely fumigate a facility in the event of a spillage or leakage which could lead to widespread contamination (routine fumigation is not stipulated).

In addition, a documented fumigation protocol is required for every CL3 laboratory, which should include a fumigation efficacy study which is validated using biological indicators, to ensure the effectiveness of an emergency fumigation.

In the case of a spillage in your CL3 laboratory Crowthorne Group offer an emergency fumigation scheme. Our highly trained engineers will attend your site within 24 hours to fumigate the potentially contaminated facility, dramatically reducing any downtime.

Biosafety Cabinet Fumigation

Routine Fumigation

According to BS EN 12469:2000 and the Advisory Committee on Dangerous Pathogens (ACDP), Biosafety Cabinets should be fumigated:

  • Before any work on the safety cabinet where access to potentially contaminated parts is necessary, including pre filter and main filter changes
  • Before undertaking in situ HEPA filter leak integrity testing
  • After a spillage where inaccessible surfaces may have become contaminated
  • Before maintenance engineers are permitted to work on the equipment


Crowthorne Group offer Equipment Bio-Decontamination Service (EBDS) specifically designed to fumigate microbiological safety cabinets, incubators, robotic enclosures and similar laboratory equipment.

Where there are a number of safety cabinets to service, we perform an overlapping fumigation and service schedule to drastically reduce laboratory downtime.

Emergency Fumigation

Emergency fumigation can also be arranged under a regular schedule contract or ad-hoc dependant on the requirements of your facility.

Formaldehyde vs. Hydrogen Peroxide Fumigation

Whilst hydrogen peroxide fumigation has been proven to be a safe and efficient method of fumigation, many users prefer to stick with the ‘tried and tested’ solution of formaldehyde decontamination for its highly reliable and effective results, its broad antimicrobial efficacy and its log reduction.

As formaldehyde requires a lengthy contact time, fumigation is generally run overnight. Your engineer will return to site the next morning to complete the fumigation process, making sure the safety cabinet is fully decontaminated and ready for use, ensuring minimal disruption and downtime of the safety cabinet.