No but you need a licence when teach as a dance instructor
Answer:
The scale is represented by numbers ranging from 0 to 14 where 7 is neutral. Greater than 7 on the pH scale is more alkaline and less than 7 is more acidic. The pH of hair ranges between 4.5 – 5.5. Lye relaxers range from 12 – 14 and no-lye relaxers range from 9 – 11
