Check that fires can be readily detected and that your staff can be warned promptly.
In small open-plan single storey offices and shops, fire can usually be detected in enough time for everyone to escape safely, but there may be some places where fire could go undetected for some time.
If so, a smoke alarm or some other automatic fire detection and warning may be required.
Example - in a small workplace a shout of "Fire!" or perhaps a hand bell may be enough, provided it can be heard throughout the workplace.