The test

Occupational inhalation testing allows us to carefully recreate what happens to you when you breathe in certain substances at work. By watching how your respiratory system responds during the test, we can usually identify any substances that are causing you problems.

In some cases, however, we may need more information and will look at other tests, such as blood tests and peak flow tests before making a firm diagnosis. This happens especially when you have not been exposed to the substance for some time.

The occupational inhalation test is also known as ‘bronchial provocation testing’ or ‘occupational challenge testing’.

During your test

The test aims to recreate, in a laboratory setting, exposure to specific substances that you have come across in your working environment. We closely monitor how your lungs react to these substances throughout the test.

The test is usually conducted over a period of five days (Monday to Friday). You will need to stay in hospital for most of this time. 

Each day at about 9am we will give you a histamine reactivity test in the laboratory. Histamine is a substance naturally produced by the body. You will be asked to breathe in some histamine via a face mask so we can measure how irritable your airways are on that day. This test is painless.

About an hour later, the inhalation test will be performed.

Each day you will be asked to breathe in a substance and we will measure what happens. On some days you might breathe in substances that we suspect may be causing you difficulties. On other days we will use harmless substances.

So we can make sure that the test is scientifically valid, we will not tell you which substances you have inhaled until we have finished all of our tests.

After the tests are finished, we will explain and give you a full written copy of the results.

How lung function is measured

A spirometer (or vitalograph) is used to monitor your lung function. We will ask you to blow into this machine every hour throughout the day until you go to bed.

You will need to bring a watch and a pen to record the times and readings of your blows. The team will then analyse these readings to get the results of your inhalation test.

Occupational lung disease covers a broad group of conditions caused by the inhalation of dusts, chemicals, or proteins.

Your hospital stay

You are going to be in hospital for up to a week while we carry out the test. 

You will stay on Victoria ward which is on the second floor of Royal Brompton Hospital's south block. 

You will have a lot of spare time during the tests, so it's a good idea to bring things to do and read. You will also be able to use your mobile phone so that you can make calls if needed. . 

Please do not drink caffeinated drinks (tea, coffee, cola or hot chocolate) throughout your stay as these can affect the results.

Royal Brompton is a teaching hospital and takes part in the ongoing education of nurses, doctors and other health staff. Sometimes students or health professionals will be in the laboratory to learn about Occupational Inhalation Testing. If you do not want to have students present during your tests please let us know before you arrive on the ward. 

For more information about being an inpatient at Royal Brompton Hospital, please read our essential information for patients.

Test risks

The chance of a serious reaction to the inhalation test is very low. However, it is common for people to have a mild asthmatic reaction similar to that which they may experience at work.

If you do experience a reaction we will give you a drug to reverse the effects such as salbutamol, which opens up the airways and normally works very quickly. Although there is a potential risk of a more serious allergic reaction, your safety is our main concern and measures are taken at all times to make sure any risk is as low as possible.

Your appointment

In our clinic, the clinical nurse specialists and doctors work together to deliver the best possible care. You will be seen by one of our clinical nurse specialists, Julie Cannon or Bernadette Fitzgerald, who will ask some general questions and, if appropriate, carry out routine tests to assess your lung function (spirometry) and allergic status (using skin prick tests).

You will then be seen by one of the following doctors specialising in the assessment and care of occupational and environmental lung diseases:

Professor Paul Cullinan
Consultant in occupational lung disease 

Dr Jo Szram
Consultant in occupational lung disease 

Dr Johanna Feary 
Consultant in occupational lung disease and asthma

We are a teaching hospital and one of only a few occupational lung disease specialist services in the UK. We often have visiting doctors, nurses and students in our clinic, but you can let us know at any time if you would prefer not to have visitors present during your consultation.

Further information

  • We are available to offer advice and support: please phone and ask to speak to one of our clinical nurse specialists or doctors on 020 7351 8341
  • Visit the Lungs at Work website
  • Your trade union or professional association will be able to offer you support and legal advice

This booklet gives general information on some of the lung function tests available to see how well your lungs work:

Your lung function tests - Royal Brompton Hospital - December 2015 (PDF, 353KB)