Never said there had to be be a first aider. The guideliens [although its been a while since i seen them] recommend a first aider or appointed person if there were more than 5 persons?
For clarity - an appointed person is someone responsible for taking charge in an emergency, and does not have to be a fully qualified first aider. I would suspect in most salons the owner would automatically assume this role.
Im basing this on the salons risk assessment deeming it to be a high risk [owing to the potential chemicals, equipment and even UV tanning]
Low risk i believe the recommendations were for 25 staff not 5
But I am no expert, however i would agree a risk assessment would be an appropriate start. It would probably be difficult to justify yourself after any accident without having done a risk assessment. At least armed with this you can say - we did not need a first aider as per our risk assement, as apose to, i didnt think i needed one.