In the last week I have had two health and safety representatives ask me the same question. Are electronic cigarettes banned in the workplace?
Part of the problem is that, because they are new, the health effects of e-cigarettes are pretty unknown. The manufacturers seem reluctant to fund proper independent research, although that does not stop them selling them. When e-cigarettes were first introduced the World Health Organisation cautioned against their use saying there was a lack of evidence. More recently the US Food and Drug Administration publicly discouraged the use of e-cigarettes.
Certainly e-cigarettes do contain a number of carcinogens and toxins, but these are likely to be at much lower levels than with cigarettes made with tobacco. So one thing is pretty clear. If you already smoke, e-cigarettes are likely to be much safer than tobacco ones. They may also help you give up the habit, although the evidence is not clear on that yet.
In answer to the specific question about their legality, e-cigarettes are not covered by the ban on smoking in enclosed workplaces and public places, but an employer does have control over whether their employees can smoke them while at work. Given that the long term effects of the fumes are an unknown, then it could be argued that employers should not be allowing a potentially harmful substance to be used in the workplace under COSHH (the Chemicals regulations).
However in practical terms it is often difficult to tell the difference at first sight between an electronic and a real cigarette. There has been such a change in attitudes since the smoking ban that most people are genuinely shocked if they see someone light up in a pub or on a train. The use of electronic cigarettes threatens to muddy the waters and could make it much more difficult to enforce the current ban.
It also gives the wrong message about exposure to chemicals in the workplace. Even if they are much safer, no-one should have the right pollute the air that other people with chemicals.
Allowing smoking of e-cigarettes in places where smoking real cigarettes is banned will also make it less likely that people will give up as the e-cigarettes are likely to be used in addition to the tobacco cigarettes that they use outdoors or at home, rather than instead of them.
So I reckon that the advice to health and safety representatives is that they should try to ensure that the employer does not allow the use of e-cigarettes in enclosed places or anywhere that smoking tobacco is prohibited, but, as part of a health promotion campaign, might want to work with their employer to encourage smokers to switch to e-cigarettes and use them instead of tobacco cigarettes, but only in places not covered by the smoking ban.