New rules have come into effect in Scotland extending the mandatory wearing of face coverings.
They will now be required in workplace settings such as canteens.
Other areas such as corridors and other communal facilities will be included in a further extension of the rules coming into force on Monday.
The first minister told MSPs at Holyrood that the measures were part of the response needed at a “critical moment” in the pandemic.
Ms Sturgeon said: “The new rules are a proportionate additional step which will help employees keep themselves and their colleagues that bit safer.”
Face coverings are already required in a number of public settings, including shops.
They are also mandatory on public transport.
Exemptions are place, including for young children and people with certain health conditions.
There has been one significant easing of the rule on face coverings, however.
The first minister said couples would no longer have to wear them during wedding or civil partnership ceremonies.