How long should a patch test be performed before a chemical service?

A patch test should be performed 48 hours before a chemical service to ensure that the client does not have an allergic reaction to the product being used. This timeframe is critical because it allows enough time for any potential allergic reactions to manifest, providing a safe window for the hairdresser to assess the client’s sensitivity to the chemicals. A reaction could include redness, swelling, or irritation at the test site, indicating that the service should not be performed.

This practice is essential for safeguarding both the client’s health and the hairdresser’s professional responsibility. While some may consider shorter or longer durations, 48 hours is widely recommended across many state regulations and industry standards, ensuring that results from the patch test are reliable and comprehensive.