A skin compatibility test is also known as a patch test. It is an essential step to take when working with special effects makeup and hair colouring products. Ultimately, it tells you whether or not the product is going to cause irritation or a reaction to someone’s skin. Here’s our guide to doing a skin compatibility test with an actor and what products should always be tested.
What is a Skin Compatibility Test?
A skin compatibility test tells you whether someone will react negatively to a cosmetic product. It is a way for makeup artists, beauty therapists and hairdressers to see if a product they intend to use will cause a problem. It is also known as a patch test.
A bad reaction to a product includes itching, burning, stinging, heat, redness, blistering, swelling, and any other such obvious reactions. This means that the product is not suitable for use on this person and a suitable alternative needs to be found.
What Products Need Testing?
Regular makeup products such as foundation and eyeshadow go through a lot of testing to ensure they are safe to use. Unless someone has a known allergy to a specific ingredient or has particularly sensitive skin, you can generally use most everyday cosmetic products safely without the need for a skin test.
However, some special effects makeup and hair colouring products can contain strong chemicals that can cause a serious reaction in a small number of people. Therefore, a skin compatibility test is essential. It is carried out to see if that product is safe to use on that person.
Products that should always be skin tested:
- Adhesives, solvents and removers
- Eyelash glue and lash extensions
- Brow and eyelash tints
- Eyelash perming
- Spray tanning
- Hair colouring products including semi, demi and permanent tints
Likewise, it is prudent to test any special makeup product if you are not sure. It is better to be safe than cause a reaction.
How Often to Skin Test
General guidance is to patch test a product every 12 months. However, even if a product has been tested recently or used on the person before with no reaction, it is still prudent to do a skin test. This is because formulations and ingredients change all the time. Likewise, people’s personal circumstances (like medication or medical condition) can change, so it is always best to do a skin test.
How to do a Skin Compatibility Test
You need the following to carry out a skin compatibility test – warm/tepid water, cotton pads, cotton buds or spatula, and the product to be tested and its appropriate remover.
- Carry out the skin compatibility test at least 24 hours before filming, though 48 hours is better. This gives you time to see if there is a reaction and to plan accordingly.
- Follow the manufacturer’s guidelines on any skin testing, including preparation and application.
- Do the test on an area of skin that is appropriate. For example, use the inside of the elbow or the wrist for body makeup. For makeup to be used on the face or scalp, behind the ear is always a good place to skin test. Do not test the product on the face.
- Gently wipe the area of skin to be used with a cotton pad/warm water to ensure the skin is clean bare and free from any other products.
- Apply a small amount of the product to a small patch of skin by using something suitable like a cotton bud or spatula.
- Wait at least 15 minutes with the actor. If there is any adverse reaction such as itching, stinging, burning, redness, swelling, and so on – the product must be carefully removed right away. If there is a serious reaction, seek medical attention.
- After 24 hours, if there is no reaction, carefully remove the product using the appropriate removal method. Lastly, gently pat/wipe the skin with a cotton ball dipped in warm water to remove all traces of the product.
- Record the skin test date, the product used and the result in the actor’s notes.
Good to Know
- Any reaction means the person is allergic to, irritated by, or sensitive to that product and a suitable alternative must be found.
- If there is no reaction after 24 hours, the tested product is fine to use on that person. However, normal health and safety precautions still need to be taken with the product. For example, if it is a product that needs using in a well-ventilated area, then ensure there is efficient ventilation.
- Temporary redness is quite normal for some products on removal. For example, Collodion and latex can leave a red mark on removal. This should fade and go away after a short time, and there should be no heat, itchiness, or stinging with the redness. It is always best to inform the actor that some redness may occur, so there is no undue worry or panic.
- Use a barrier cream as this will put a protective layer between the skin and the makeup. A non-greasy cream is best. Apply a barrier cream after using moisturiser and allow it to fully dry and go into the skin before applying anything on top.