In 1941 the Auxilliary Fire Service and the professional local fire services were brought together as a single organisation called the National Fire Service. The new organisation adopted a traditional eight pointed star, topped with a crown and with the letters ‘NFS’ as its badge. As well as being worn on the fireman’s peaked cap, the badge could be seen on the side of appliances, as a transfer marking on helmets and on small pin badges designed to be worn when a firefighter was in civilian clothing to show that he or she was employed on vital war work. This little badge was made of a gold coloured metal, with details picked out in red enamel:

The rear of the badge has a brooch type pin fastening, suggesting it was for wear by a woman:

I am assuming that a similar version with a half moon fastener was produced for wear by male staff in the lapel button of their suits, although the only examples I have come across so far are the pin back type. These little badges seem to be pretty common and this one only cost a couple of pounds.