What should be done if a client is allergic to a product used during a service?

Stopping the service and informing the client is the correct approach when a client is allergic to a product used during a service. This response prioritizes the client's health and safety. Allergic reactions can vary in severity, and it is crucial to address any potential issues immediately to prevent adverse effects. By halting the service, the professional can assess the situation more thoroughly and determine the best course of action, such as providing the client with medical attention if necessary.

Additionally, informing the client allows for transparency and promotes trust in the client-provider relationship. Educating the client about their allergies and ensuring that alternatives are safe for them is an important aspect of maintaining a professional and responsible practice.