Patch Test

What is it & why is it carried out?

Patch testing is a simple safety procedure used within the beauty industry to identify whether a client may have an allergic reaction to a product before a full treatment is carried out. It involves applying a small amount of the product to the skin—usually on the inner arm or behind the ear—and monitoring the area for any signs of irritation such as redness, itching or swelling. This process helps detect contact allergies caused by ingredients commonly found in cosmetics, such as dyes, fragrances or preservatives.

Patch testing is carried out to protect both the client and the practitioner. Allergic reactions can be severe, particularly with treatments like hair colouring, lash tinting or chemical peels, so early identification of sensitivity reduces the risk of harm and ensures treatments are safe to perform. In the UK, including Scotland, there is no single law that explicitly states “patch testing must always be done”; however, it is strongly supported by legislation such as the Health and Safety at Work Act 1974, which requires businesses to ensure the safety of clients as far as reasonably practicable. Additionally, under the UK Cosmetic Products Regulation (EC) No. 1223/2009, all cosmetic products must be proven safe for human health before use, reinforcing the importance of procedures like patch testing as part of risk assessment and safe practice.

Overall, patch testing is considered industry best practice and is often required by insurance providers and treatment guidelines, helping therapists meet their legal duty of care while maintaining professional standards.