Crowthorne FAQ’s 

What is a KI test?

The KI-Discus test ensures operator protection when using a microbiological safety cabinet, by producing a fine mist of potassium iodide at specific locations and monitoring the amount detected outside the open front of the cabinet. Test failure can be the cabinet, the filtration system or even the environment i.e. room air conditioning.


When testing LEV systems, what’s the difference between a standard test and thorough examination and test to HSG258?

Originally LEV systems were required to be tested under COSHH Regulation 9. This was a simple test and still has merit as a means of trending, air velocities, alarm function and evidence of containment. However, standards have moved on and with health and safety stricter, HSG258 is now applied and P601 too.

HSG258 examines the system from the LEV to the outlet after the fan

P601 examines the process the LEV is being used for, to ensure the system is appropriate for the process


What’s the difference between a scheduled fumigation and fumigation efficacy study of a CL3 laboratory?

A scheduled fumigation is undertaken to fumigate CL3/4 laboratories and has a documented procedure. An efficacy study provides evidence that the overall fumigation procedure provides a 106 log reduction, as preloaded plates are placed around the room ensuring the fumigation process is correct.


What’s the difference between a fumigation efficacy study and an emergency fumigation of a CL3 laboratory?

A scheduled fumigation gives access to the laboratory, so the placement of the vaporiser and equipment can be placed in the most efficient positions. Additional conditioning can also be added to the room, for example, heating to ensure the temperature is maintained during the entire fumigation process.

An emergency fumigation is different as entry to the room is not permitted without protective equipment, so you have restricted access to precondition the room. We recommend an efficacy study be undertaken in an emergency fumigation situation to confirm the efficacy of the process. We can document the process, so an emergency fumigation protocol can be produced, or we can issue a protocol for the client.


Do I need to containment test my fume cupboard on a routine basis?

This is a good and common question. We recommend that a new installation should be tested, together with the laboratory parameters. This provides a baseline and benchmarks test results for future testing. Also if something changes, for example Laboratory pressure, then you can evidence the original setup and know where to get back to.


Are all of your engineers qualified to P601 for LEV testing?

As P601 work is only part of what Crowthorne Group offers, not all engineers hold the same qualifications. However, those who do hold the qualification 10 – 15years experience of this work! We also have an on going training program for P601 engineers, at present approx. 30% of our engineers are qualified.


Can we still access the lab during a safety cabinet fumigation?

Depending on the process, using our peroxide systems, yes you can. The formalin fumigation needs a longer dwell time, so is usually undertaken over night.


How long does it take to fumigate a safety cabinet?

This dependant on the method selected:

For traditional formalin, this needs a saturation time of 10 hours, so usually undertaken over night.

For VHP fumigation, this depends on whether it is just the work area or full filter change, so ranges from 2 to 8 hours also depends on the size of the cabinet.


Do you stock spare parts to repair units when they fail?

For Microflow and Labcaire, the majority of parts are ex-works. We can obtain parts even for very old units or we can have old PCB’s tested and repaired. For other manufacturers we hold a number of parts in stock, some for obsolete units, so it’s always worth getting in touch to ask.


How often do I need to change my carbon filter in my recirculating fume cabinet?

It is recommended they are replaced every year as part of the annual service visit. However, certain applications place huge demands on the carbon filter, and they often become blocked quickly, in which case we’d recommend they are changed more regularly. If you are unsure and would like to speak to a specialist, you can contact us and we can advise.


Do you undertake remedial works?

We do offer a repair service to both contract and non-contract customers, either for items identified by ourselves, customers or third parties.


How often does my safety cabinet need to be tested?

For best operator protection, depending on its use, this should be undertaken including a containment test using a KI-Discus, a minimum of annually, and if used in a CL3/4 Lab this should be six monthly.


How many engineers do you have, and do you cover all of the UK?

We have a growing number of engineers, currently 30 covering the UK. Some are site based, but the majority are field based so travel extensively. We also cover other parts of Europe and also undertake work globally.


What’s the best method to test the sealability of a CL3 laboratory?

We always apply the latest methodology as laid out in an international, European or British standard when available, if not then the appropriate guidance. For this we would apply the test contained in the ACDP guidance, including the use of a smoke pencil with the Laboratory operating under its usual operating conditions.


Can you repair leaks detected in my CL3 lab?

Yes we can, and for a number of our clients we work with the site engineers, but minor leaks detected are often rectified during our routine annual visit. If for example a dado rail  needed to be removed we would work with the site electrician, so the repair can be completed in the most timely and cost effective way.


What’s your lead time on replacement filters?

This is dependent on the application and filter size.

HEPA filters - we hold a number in stock, so some would be Ex-stock, generally otherwise a 6 -8 week lead time, this can be reduced but if a production run has to be broken an additional charge is sometimes made.

Carbon filters – a number of more common sizes and types are held in stock, so can be turned around very quickly if they are in stock, these can generally be on site within 7 days, if not and have to be made or purchased then 3-4 weeks.