Bowie and Dick tests: which one is right for me?

Bowie and Dick tests are routinely used in Sterile Service Departments (SSDs) of hospitals to check the functionality of an autoclave. It is imperative that this is done every day because if a fault has developed in the autoclave, the sterility of the contents being decontaminated will be compromised. As a result, this can lead to Healthcare Associated Infections (HCAIs), which in turn can lead to patients contracting illnesses, or in extreme cases, lead to death.

Types of Bowie and Dick tests available

Single use pack

This consists of a paper pack around 12cm by 12cm. The paper pack has a Bowie and Dick test sheet in the middle and is packed out on either side with paper.

The advantage of the single use test pack is that they are very cheap and easy to use. However, they also take up a lot of space. Users should remember that a test needs to be carried out every day meaning that some SSDs may have hundreds of these test packs in stock. Furthermore, test sheets should be kept on file in the event of an investigation or external audit. These test sheets can also take up space.

Paper test pack and clamp

Similar to the single use test pack, a sheet is placed inside a metal clamp. The test sheet is then padded out with blank test packs. The advantage of this method is that the test packs can be used around 10-15 times and the metal clamp can be used hundreds of times. This reduces wastage and minimises storage space.

Bowie and Dick Helix test

The Bowie and Dick Helix test consists of a small metal box with an inlet holes. Steam is drawn through the holes and it passes through a compacted helix spiral which is 2.1m long. When the steam has finished passing through the condensed spiral, it is ejected through a nozzle where a thin indicator strip has been placed. The indicator strip will turn a different colour in the same way the test sheet does.

The advantage of the Helix test is that it saves a lot of space. Furthermore, the little indicator strips can be placed in a book and these also take up minimal space when compared to larger test sheets.

When can I use a Bowie and Dick test?

Bowie and Dick tests should be carried out daily and they can be used for all types of sterilisation. Steam, plasma, gamma, formaldehyde and ethaline oxide are all compatible with the Bowie and Dick test, regardless of which one you use.

Bowie and Dick tests should always be carried out in an empty autoclave. This is because you are testing the functionality of the autoclave, not the efficiency of the sterilisation process on the contents.

If users wish to see how efficient the sterilisation process is, then a Batch Monitoring System (BMA) would be carried out.  Unlike the Bowie and Dick test, BMAs are carried out with a full load and test to see that the sterilisation (be it steam, plasma etc) is reaching all the nooks and crannies of the chamber. Class 6 emulators can also be used for this purpose.

What to do if there is a problem

If there is a problem with your autoclave, the Bowie and Dick test sheet will turn a different colour. For example, Stericlin test sheets use blue ink. The ink turns pink if everything is functioning as it should be. If there is a problem, it will turn brown. Sometimes, the test sheet will turn pink, but is will have some brown spots. This also means that the autoclave is not functioning quite as well as it should be.

For example, common problems with autoclaves are:

• Leaky door seal
• Problem with the water supply
• Pump malfunction

Of course, there are a variety of other issues that can manifest themselves in an autoclave. If you find that your autoclave is faulty, it is always best to contact a service engineer to help.

Above all, it is recommended that you stop using that particular autoclave immediately if the Bowie and Dick test shows that there is a fault.

How Henderson Biomedical can help

Henderson Biomedical is the official UK distributor of Stericlin. In addition to this, our staff are trained to give advice on the different types of Bowie and Dick tests that are available to users.

Stericlin manufacture all the different types of Bowie and Dick tests mentioned above. Furthermore, we are able to advise on the service and repair of autoclaves.

For more help and advice, please contact our team on 020 8663 4610 or via email: info@henderson-biomedical.co.uk.