Are actors who smoke 'at work', breaking the law?

Do you know for a fact that

* Smoking is banned in 100% of Britain with no work place exceptions

* The Soap Opera episode in question was filmed after that smoking ban went into effect

* The episode was filmed in Britain

Many TV shows for western audiences are filmed in Canada, various European nations, Australia etc. where the rules may be different. This is one reason why in some cop shows, they don't seem to follow the right rules for cautioning suspects. The reason is the writers and actors are in some nation with different rules, so it does not occur to anyone that their show is fiction in the nation they making it for.

In the USA, smoking is allowed in some work places.

The ban is not because of government regulations, but because of insurance rates ... companies can get the same insurance for less money if they ban smoking there. US government regulations against smoking are generally in public places where children can be present, such as restaurants.

In the USA, there are some very poorly enforced rules about not making movies with people doing things that children are not supposed to emulate, while at the same time there is a drive for realism. This leads to the vast majority of movies being rated X or R, or the mildest are PG, plus if the FCC still had any teeth to stop anything other than bare nudity and the filthiest of language, 90% of what we now see on US TV would be banned.