A ban on smoking in the workplace is being put to the test in Spain as staff resume work after the New Year holiday.
Spain ranks among the EU's biggest tobacco consumers
The ban went into effect on Sunday, when many businesses were closed for the holiday.
The new law bans smoking in offices, shops, schools, hospitals, cultural centres and on public transport.
Businesses occupying more than 100sq m have eight months to set up a separate smoking area. Smaller premises have to indicate whether they are smoke-free.
The government says the ban is necessary because smoking is the biggest killer in Spain, with 50,000 smoking-related deaths annually.
Surveys show that about 30% of Spaniards smoke.
A government-sponsored opinion poll released in December showed more than 70% of respondents backed the ban.
A current ban on tobacco advertising on TV will be extended to billboards.
The law was passed by the Spanish parliament on 15 December, with 297 of the 350 deputies in the lower house voting for it.
Similar bans have been imposed in Ireland, Italy and Norway.