The test

Occupational inhalation testing looks at what happens when you breathe in certain substances at work. 

By watching how your respiratory system responds during the test, we can usually identify the substances that are causing you problems.

In some cases we may need to carry out other tests, such as blood tests and peak flow tests, before making a diagnosis. 

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

During your test

The test exposes you 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 five days (Monday to Friday). You will need to stay in hospital for most of this time. 

Before the occupational inhalation test, we will use a histamine or methacholine reactivity test to see how responsive or reactive your airways are. 

This test is given through a face mask. During the test, you may experience symptoms such as coughing, wheezing, shortness of breath and chest tightness. The test is generally very safe.

Once the reactivity test is completed, we will carry out an inhalation test.

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

We will not tell you which substances you have inhaled until we have finished all of our tests. This is to make sure that each substance is tested fairly. 

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

Measuring lung function

A spirometer 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 pen, or a phone to record the times and readings of your blows. The team will then analyse these readings to get the results of your inhalation test.

Risks and side effects

The chance of a serious reaction to the inhalation test is very low. 

Side effects may include a mild asthmatic reaction, and symptoms such as coughing, wheezing, shortness of breath and chest tightness. The symptoms may be similar to those you may experience at work. 

If needed, we may give you medicine (such as salbutamol) which works by relaxing the muscles of the airways into the lungs, making it easier to breathe.

Any potential risk of an adverse allergic reaction is monitored at all times. We have measures in place to make sure any risk is as low as possible.