Skin care products aid in maintaining the skin’s natural pH balance. Skin care products should balance the pH of natural skin (5.4 to 5.9) and should be measured frequently, particularly when new skin care products are introduced to people’s daily routines. To test the pH of skin care products a pH meter or pH strips can be directly inserted into the product. For solid skin care products, dilution with distilled water may be required.
So, you may be wondering what pH is and why it is important in cosmetics like skin care, when you should be measuring the pH, and how you go about it.
What Is pH?
The potential of hydrogen (pH) is a logarithmic scale that runs from 0-14. It gives us a chemical understanding of a solution or substance and is commonly used to ensure that skin care products are safe to use.
The pH scale allows us to identify if a skin care product is neutral, acidic, or alkaline. A neutral pH has a value of 7, anything acidic below 7, and anything above 7 is alkaline.
In the first decades of life, skin has a strong collagen and elastin production, making us look young, but as we age, this decreases. Therefore, by having a good skincare routine, you can keep your skin looking and feeling its best, while boosting regenerate skin cell production.
The balance of your skin care products matters, and with millions in today’s market, it can be challenging to know which product to choose. By selecting skin care products that have a similar pH to that of your skin, the healthy skin barrier will be maintained. This is essential for your health, as the skin barrier keeps skin hydrated, reducing water loss, and protecting against environmental pollutants and harmful microorganisms.
Typical pH For Common Skin Care Products
While many people are convinced that skin care products should have a neutral pH of 7.0, some disagree and believe it should be the same pH as our skin.
As mentioned, human skin is slightly acidic, so it is good to start here, however, the pH of natural skin care products depends on the ingredients in the product.
So, don’t worry too much about using a skin care product that doesn’t have the same pH as your skin, as human skin is fairly neat! The skin can maintain its natural balance – so if you wash your face with a skincare product that has a slightly acidic pH, it will restore over time to the skin’s natural pH level.
Below are the typical pH ranges for the most common skin care products:
Moisturizers: 5 – 7
Skin Serums: 4 – 6
Cleansers: 4.5 – 7
Toners: 5 – 7
Exfoliants: 3.2 – 3.9
Sunscreens: 5 – 7.5
Vitamin C-Based Products: 2.6 – 3.2
Retinol Products: 4 – 6.6
Using Skin Care Products That Have A Too High Or Too Low pH
Using a skin care product that is extremely acidic or alkaline can cause issues, however. For example, using a skincare product that has a very low pH can over-exfoliate the skin and damage the skin barrier. On the other hand, if you use a skin care product with a very high pH level (alkaline), it can strip your skin of the natural oils and sebum, leaving the skin looking and feeling dry and red. High-alkaline skin care products can also cause skin inflammation/irritation, and in some cases cracking. To prevent these issues from occurring, it is super simple – get into the routine of measuring the pH of your favorite products!
The Importance Of Measuring & Adjusting The pH Of Skin Care Products
When using pH-sensitive ingredients in the production of natural skin care products, it’s important to measure the pH, as even though they are ‘natural’ they still contain preservatives or active ingredients.
Just like food products, cosmetic products also need to be preserved to prevent microbial spoilage that could make the skin care product unsafe to apply on the skin. Preservatives are common in skin care products that contain water-based ingredients like rose water, aloe vera, etc. to prevent microbes from taking over.
In comparison, skin care products that are anhydrous or water-free typically do not need preservatives, as they are not prone to microbial growth and contamination. Common products include whipped body butters and lip balms. However, some anhydrous products can come into contact with water when applied with wet fingers such as a cleansing cream/balm or a body scrub. When using these products you should avoid applying them with wet hands, or you should introduce a preservative.
The majority of naturally derived preservatives such as potassium sorbate, salicylic acid, and sodium benzoate have specific pH requirements to ensure they are safe and working properly in the product. This includes measuring the pH of the skin care product and if needed, adjusting the pH.
Low-pH preservatives can lose efficiency if the pH increases. For example, potassium sorbate becomes active at approximately 70% at a pH of 4.5 and 35% at a pH of 5. Therefore, most natural preservatives in skin care products require a pH lower than 5.
On the other hand, if active ingredients are used, the pH of the product requires special attention. For example, skin care products containing alpha hydroxy acids (AHAs) need a pH of 4 or lower to remain active as a chemical exfoliant. Products containing Vitamin C (ascorbic acid) are active at 3.5, and Vitamin B3 (niacinamide) is best kept at a pH of 6. When adding active ingredients to skin care products, contacting the supplier is recommended to clarify what pH levels are required for specific product ingredients.
Should Skin Care Products Be Diluted Before Test pH?
Skin care products generally do not need diluting unless they are solid like a bar of soap. pH probes and pH strips are more than capable of reading the pH of the skin care product perfectly fine without interfering with its consistency and adding water. Solid products are however an exception as you cannot test the pH of a solid object. So, to test the pH of a solid skincare product, we recommend a 10% dilution (10g of the skin care product with 90g/90mL of distilled water).
While pure distilled water is considered neutral (a pH of 7), when exposed to air, the water can absorb carbon dioxide (CO2) and form carbonic acid (H2CO3), causing it to become slightly acidic. Therefore, if you were to dilute your skin care cream, the pH measurement would be the dilution measurement, not the measurement of the actual product.
Testing The pH In Skin Care Products
Just like when measuring the pH of grapes when harvesting, you should also be frequently testing the pH of your skincare products, particularly if you are using a new product, or if you are noticing issues with your skin’s condition.
There are two main ways to measure the pH of skin care products:
pH Strips
pH Meters
How To Measure Skin Care Products Using pH Strips
pH strips are a simple and easy way to measure the pH of skin care products. As the name suggests, they are small strips that have a pH-sensitive end, which changes color based on the pH of the product.
A step-by-step guide:
Scoop some of the product to one side and insert one pH test strip directly into the product
Push some of the product onto the stip, ensuring that your fingers are not wet (wetness can alter the pH)
Gently wipe off excess product on the sides of the container
To obtain the pH reading, the color of the strip is compared with a color chart from the pH test kit
Write down the pH reading and adjust the pH if needed (see steps below)
Advantages of using pH strips:
Inexpensive
Easy to use
Fast results
Easily accessible
Can be used for all skin care products including emulsions
pH meters are also better when working with natural preservatives as these products require highly precise pH measurements for them to be effective.
How To Adjust The pH Of Skin Care Products?
Testing the pH of your skin care product is just the beginning, next is adjusting it (if needed). To adjust the pH of skin care products, you will need to select the appropriate pH increasers or decreasers.
Increasing pH Levels In Skin Care Products
If your skin care product’s pH level is acidic (too low), you can easily increase it by adding small amounts of sodium bicarbonate (NaHCO3). As it has a pH of 8.4, it will nicely balance the pH of the product. When adding harsh chemicals, we recommend mixing the NaHCO3 with distilled water – 10% of NaHCO3 and 90% of distilled water or 1g/mL of NaHCO3 and 90g/mL of distilled water.
Next, add the solution to the product. We recommend starting with a few drops (you can always add more later if needed). After adding the NaHCO3 solution, check the pH level again to check it is within the range of the skin’s natural pH (5.4-5.9). When adding NaHCO3 to skin care products we recommend using cosmetic, food, or pharmaceutical grade as household versions like baking soda may have impurities that could irritate the skin.
Decreasing pH Levels In Skin Care Products
To lower the pH level in a skin care product, citric acid (pH: 3-6) or lactic acid (pH: 2.4) are the best choice.
Citric Acid:
Start by adding small amounts to your skin care product – mix 10% of the acid and 90% of distilled water or 1g/mL of citric acid and 90g/mL of distilled water. Once the mixture is ready, add a few drops to the skin care product and mix well. As acid is involved and can be very corrosive, we recommend using the correct PPE such as gloves to prevent skin irritation.
Lactic Acid:
Start by adding small amounts to your skin care product. – mix 10%, 10% of lactic acid, and 90% of distilled water or 1g/mL of acid and 90g/mL of distilled water. As lactic acid is very strong, we suggest diluting it further than citric acid to 25% or 40%.
Once the mixture is ready, add a few drops to the skin care product and mix well. As acid is involved and can be very corrosive, we urge extra care when handling and highly recommend using the correct PPE such as gloves to prevent skin irritation and goggles to protect the eyes.
After mixing, check the pH level again, adding more acid if required.
Can You Balance Skin At Home?
Absolutely! There are many ways to balance your skin if you notice symptoms of unbalanced pH skin conditions – you can:
Use a pH-balanced cleanser
Use a pH-balanced toner
Wash your face with lukewarm water
Use an organic/100% cotton cloth to wash your face
Use diluted apple cider vinegar as a toner
Eat a healthy diet with plenty of vitamins, minerals, and antioxidants
Summary
Maintaining the pH of skin care products is essential for optimal skin health. Testing the pH of skin care products to ensure that they are safe for use is critical to this booming billion-dollar industry. With the ease of testing with pH strips and pH meters, customers can enjoy caring for their largest bodily organ, and producers can sleep easy knowing that their skin care products are safe and beneficial for skin surfaces.
If you have any questions about testing the pH of skin care products or what pH strips or pH meter will best suit your productional needs, do not hesitate to contact the world-class team at Atlas Scientific.
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