In that situation it is essential, as those dangerous gases are part of the work being done.
If I were an employer (and I'm not) why should I spend hard-to-come-by funds on facilities for smokers, when them smoking contributes in no way at all to the success of the organisation? If I was to give money away it would be better to donate it to charity, where it would be beneficial to worthwhile causes.
And if those smokers can't do a decent days work without needing to go outside for cigarettes for more breaktime than a non-smoker needs, then they're not fit for the job and I would replace them with someone who is.
No objection whatsoever if someone wants to smoke. But like any other addiction when it starts to affect people around them or prevents them from doing their job then it has gone too far and they need to wise up.
Like any addict, though, they can't accept any of this. Their minds are closed to all reason. Woe betide anyone who gets in the way or suggests the addict is wrong. They find anyway possible to justify to themselves and others that to be addicted is normal and is their right.