The Importance Of Patch Testing
Patch testing should be a non-negotiable part of every salon's routine. If you're not already incorporating this vital step into your services, it’s time to ask yourself why. This article aims to address any questions or concerns that might be holding your salon back from conducting patch tests, and why it's crucial for both your clients’ safety and your business's success.
For those of you who are already conducting patch tests in your salon, consider this a refresher, packed with additional tips and tricks to enhance your technique and ensure you’re delivering the best service possible.
What Is Patch Testing?

To put it simply, a patch test is a safety measure where a small amount of hair dye or tint is applied to a client’s skin to check for any allergic reactions. This practice is something we all learned about in college, but unfortunately, it’s often overlooked or deemed less important as time goes on. However, it remains a crucial step to ensure not only the safety and well-being of your clients, but a secure future for your business.

Step 1 - Mix 10ml colour and 10ml of the desired developer, or the manufacturer’s recommended ratio.
Step 2 - Use a cotton bud or tint brush and place a small amount of the formula either behind the clients ear or inner elbow. (These areas are easy and quick to clean)
Step 3 - Leave for 48 hours to see if any allergic reactions happen.
In general, an in-salon patch test typically takes about 15 to 30 minutes depending on the client.
How to Patch Test?
When a client books a hair color service, taking the right precautions ensures both their safety and a flawless result. First and foremost, always confirm that the client is at least 16 years old. Your staff should be well-trained and fully knowledgeable about patch testing procedures for clients over this age. A patch test is now a mandatory requirement and must be performed at least 48 hours before any new colour treatment. This crucial step helps prevent potential allergic reactions, ensuring a safe experience for the client.
If a client wishes to switch to a different shade, brand, or type of color service for their next appointment, it's vital to follow your insurer’s guidelines and salon protocols. Adhering to these procedures keeps your business compliant and maintains the highest standard of care. By following these essential steps, you can provide a seamless, professional, and safe hair coloring experience for every client.
For returning clients, it’s also important to conduct a new patch test if it has been more than six months since their last one, if they’ve recently had a tattoo or black henna tattoo, or if they’re using a new colour brand or product in the salon. Following these steps ensures a safe, positive experience for your clients and protects your salon's reputation.
Why Is Patch Testing So Important?
Ensuring the client's safety, comfort, and well-being is a top priority, but patch testing is also a crucial insurance requirement that helps protect your business's reputation. If a client experiences a reaction to a tinting treatment without a prior patch test, some insurance providers may deem your policy invalid, potentially refusing coverage or denying any claims made against you. While this may be a one off for your salon, clients tend to make more nose about a bad experience, meaning that this one off client could not only ruin your chances to obtain future insurance coverage, but ruin your reputation as a safe professional hairdresser.
As a professional, your insurance provider may cover claims if an issue arises due to your negligence, especially if you failed to perform a required patch test. However, this can come at a cost. A claim against you could lead to higher monthly insurance premiums, impacting your business financially.
In short, a patch test isn’t just about client safety, it’s essential for protecting your reputation, your company, and your bottom line. Prioritising this simple step helps you avoid unnecessary risks while maintaining trust and professionalism in your salon.

What Will Happen To My Client If I Don't Do
a Patch Test?
There are several reactions that may occure if someone is allergic to hair dye. Some individuals are prone to a skin reaction known as contact dermatitis, which can cause redness, dryness, scaliness, bumps, blisters, or irritation when exposed to certain substances. These substances can either be irritants that directly damage the skin or allergens that trigger an allergic reaction.
Many permanent and some semi-permanent hair dyes contain paraphenylenediamine (PPD), a chemical known to cause irritation and allergic reactions. Darker hair dyes tend to have higher levels of PPD, making them more likely to cause a reaction. PPD is the most common culprit behind hair dye-related skin sensitivities.

If you have a mild sensitivity to PPD, you may notice irritation and inflammation on your scalp, neck, forehead, ears, or eyelids after using hair dye.The affected skin may become red, swollen, blistered, dry, thickened, or cracked, often accompanied by a burning or stinging sensation. Symptoms typically develop within 48 hours, though stronger irritants can trigger an immediate reaction.
If your client is allergic to PPD, you may experience itching and swelling on your scalp and face. In some cases, PPD can cause a reaction throughout the body, leading to itching, hives, and an overall feeling of being unwell.
These symptoms may not appear immediately and can take several hours or even days to develop. If any of these do appear on your client druing a patch test do not proceed with the treatment as this puts the client at extreme risk of a severe reaction.
It’s essential to ask your client if they’ve had a black henna tattoo since their last allergy alert test. Black henna often contains dangerously high levels of PPD. Clients who have previously had a black henna tattoo may develop an increased sensitivity to PPD in hair dye, even if they’ve used the same color safely before. The NHS has issued warnings about the risks, including a tragic case where a woman suffered a fatal anaphylactic reaction while colouring her hair, five years after having a black henna tattoo.
What Should I Do If a Client Can't Come In For a Patch Test?
It is important that you do not allow your client to proceed with the appointement without a Patch test. If your client isn't able to come into the salon for any reason The Patch Test Kit is a great way to ensure that you do not miss out on this crucial step.
The Patch Test Kit includes 2 x syringes & end caps, 1 x mixing tube, 1 x applicator, 1 x plaster, 1 x postal box, seals and full instructions. By following these steps below, you client will be able to safely preform a patch test at home.
Step 1: Prepare the Kit - Fill and seal each syringe with 1ml dye in one and 1ml developer in the other. (Check colour manufacturer's patch test instructions.)
Step 2: Post the Kit - Send the kit to your client using a large letter stamp. Let them know it is on the way!
Step 3: Test at Home - Your client does the test at home at least 48 hours before their appointment.
Step 4: Keep Evidence - Your client brings their signed declaration and photo evidence to their appointment.
This can be a key practice for a busy salon, mobile hairdressers, and for clients who may travel far for your services. You can also earn extra revenue by using these kits by charging your clients £9.99 (the RRP) for using this method of patch testing.
