Study into the ability of patients with impaired lung function to use breath alcohol testing devices

A subject who fails to provide an adequate breath sample for a breath alcohol measuring device under the provisions of Road Traffic Act 1988 may be charged with refusing to supply a sample unless the police officer believes the person is genuinely unable to do so. Subjects who are confronted with this situation may approach their general practitioner or chest physician for advice on whether they are medically able to provide adequate breath samples to satisfy the breath testing devices. There is currently no guidance available for medical practitioners concerning respiratory performance or lung function which will impair the use of such breath testing devices. This paper describes experiments with human volunteers suffering from respiratory illnesses and their ability to provide adequate breath samples to satisfy the requirements of the breath alcohol testing devices used in Great Britain. It was found that the most suitable parameters for determining whether a subject was capable of using a breath alcohol testing device were spirometry measurements of Forced Expired Volume in one second (FEV1) and Forced Vital Capacity (FVC). In this study subjects with a FEV1 less than 2.0 litres and a FVC less than 2.6 litres were generally unable to use all the devices.