All teachers have a responsibility to keep their students safe, which may in some instances mean that they are required to give first aid. While all schools will have designated first aiders who have qualifications, it's still beneficial for all teachers to understand at least the basics.
There needs to be one first aider for every 50 employees, and this person (or their substitute) must be available at very short notice during working hours. There should be a roster drawn up, with duties allocated (as well as substitutes should the primary first aider be absent).
The first aid qualification is a requirement for anyone who wants to be the nominated First Aider in their workplace. Only once a risk assessment has been carried out can it be determined how many employees require first aid training or if a qualified First Aider is needed.