Final answer:
Chemical relaxers and permanent wave solutions may begin to smoke if there are flammable residues or incompatible chemicals on the hair. It is vital to start with clean hair to avoid adverse reactions, and professionals should follow safety precautions to control the chemical reaction and avoid harmful fumes.
Step-by-step explanation:
Chemical relaxers and permanent wave solutions may begin to "smoke" on a client's head if there are flammable residues or incompatible chemicals present on the hair. When applying perms or relaxers, which involve a chemical reaction that disrupts and reforms the hair's disulfide bonds, it's crucial to start with clean hair to prevent any adverse reactions. Typically, the smoking is due to the reaction of the relaxing or waving agents with substances already on the hair, which could include styling products or build-up from previous chemical treatments.
It's important for professionals to ensure the hair is thoroughly washed and that any flammable products are removed before the application of chemicals. Additionally, the reaction can be carefully controlled by adhering to professional guidelines for application, including the use of safety apparatus like fume hoods when necessary to avoid the inhalation of harmful fumes.