It is unlikely that the use of devices such as these would be considered an infringement to the smoking regulations as the definition of ‘smoking’ in legislation is defined as:
“Smoking tobacco or anything which contains tobacco, or smoking any other substance and includes being in possession of lit tobacco or of anything lit which contains tobacco or being in possession of any other lit substance in a form in which it could be smoked’.
Although electronic cigarettes emit vapour they are not ‘lit’ and do not contain tobacco and so they would not be covered by the legislation. However, there is a potential issue which you will need to consider that concerns the method of enforcement used with these regulations.
If an authorised local authority officer witnesses a driver smoking in his cab, the officer can ask the company to provide the driver’s details so that a fine can be issued. It is extremely difficult to demonstrate that the ‘cigarette’ was an electronic device.