Sodium Benzoate and Potassium Sorbate: Gentle Preservatives Explained

The world of food and cosmetics wouldn't be the same without preservatives today. Preservatives extend shelf life by limiting spoilage from bacteria and mold. Sodium benzoate and potassium sorbate are two more commonly found preservatives you may see on the ingredient label of packaging. They are both effective and have gentle properties. In appropriate levels, they are considered safe for consumers. Most of us are aware of the benefits of things like hyaluronic acid, niacinamide, or retinol for our skin.

What about the ingredients that preserve our skincare products? Here comes sodium benzoate and potassium sorbate! These preservatives are still common preservatives, but are gentler than others, and can be found in most natural and clean beauty products.
So what are sodium benzoate and potassium sorbate? How do they work? Why are they used more frequently than other preservatives? This post will go over sodium benzoate and potassium sorbate in fuller detail. We hope to shed understanding around their safety & effectiveness, as well as their important role in your daily and skincare products.

What are Sodium Benzoate and Potassium Sorbate?

Sodium benzoate and potassium sorbate are both preservatives that are synthetically produced and accepted as preservatives in either a natural or standard skin care formulation. They serve as preservation from bacteria, yeast, and mold, which eventually spoil these products, or can elicit an adverse reaction on your skin. 

Sodium benzoate is the sodium salt of benzoic acid and occurs naturally in various things, but principally in certain fruits, such as apples and cranberries. 
Potassium sorbate is the potassium salt of sorbic acid and is derived from the berries of the mountain ash tree. 

It is interesting, both of these preservatives are synthetically manufactured, but both would be categorized as low-toxicity products, and are deemed safe by co-regulatory organizations worldwide, regarding use in foods and cosmetics. 

Why Are Preservatives So Important in Skin Care? 

Preservatives are important for all skin care products containing a water base (which is most). Without a preservative anything with a water base will additionally act as a bacteria, mold, or fungi breeding ground. Imagine opening your jar of moisturizer to see black spots or smelling something that seems to be spoiling- that is usually not safe for your skin. Preservatives prevent this from occurring, and help with the shelf life of your product.

Mechanism of Action for Sodium Benzoate and Potassium Sorbate

Sodium benzoate and potassium sorbate can be said to stop the growth of microorganisms by cutting off their metabolism. Under a pH of 7 sodium benzoate is still effective, which together with potassium sorbate is good because many skin-care products have a soft-acidic pH. Potassium sorbate acts the same way and is frequently combined with other preservatives to gain a wide range of anti-microbial action. 

It is the case that both preservatives are especially sought in products with any clean beauty, natural skincare, and paraben-free claims.

Sodium benzoate and potassium sorbate have the following contributions to skincare:

1. Gentle and Non-Irritating: These two preservatives are generally very well tolerated, even with sensitive skin, in contrast to very harsh preservatives like formaldehyde releasers. 

2. Widely Approved in Natural Products: Their low toxicity and biodegradability are the reasons for them being permitted in the production of COSMOS and ECOCERT-certified skincare products.

3. Work Effectively in Low Concentrations: From my experience, they are usually added at low percentages (0.1% to 0.5%), so unlikely to irritate while still providing good protection from growth. 

4. Safe and Approved: Both preservatives are also well studied and approved by FDA regulations, EU Cosmetic Regulation, and Health Canada. 

5. Non-Comedogenic: Both are non-comedogenic, which is beneficial for oily and acneic skin types. 

Are Preservatives in Skin Care Safe?

Yes, sodium benzoate and potassium sorbate are considered safe for sensitive, acneic, and even rosacea-prone skin when within regulated concentrations. As with any ingredient, though, it is always wise to patch test first, especially for known allergies.

Additionally, both preservatives are non-sensitising and less likely to cause contact allergies compared to methylisothiazolinone or the like.

Myths About Sodium Benzoate and Potassium Sorbate

Let’s dispel some common myths:       

Myth 1: These are toxic chemicals.    

Reality: Although they are synthetic, they have a very low risk and are highly regulated. The concentration in skincare is low enough for them to be harmless.      

Myth 2: Natural products don't need preservatives.      

Reality: Every product, no matter how "natural", will need preservation if there's water in the product (unless it's 100% oil-based). Water and no preservatives = mold.       

Myth 3: They cause irritation.      

Reality: Irritation is very rare and usually associated with overuse or an incorrect formulation. Most people have great tolerability to these ingredients.    

Where to Find in Skincare Products       

Look on your ingredient list for any of the two, usually nearer the end (indicating lower concentration). 

• Sodium Benzoate     
• Potassium Sorbate     

Products That May Contain:      

• Cleansers     
• Toners      
• Moisturizers     
• Face masks       
• Serums     
• Natural deodorants       

These preservatives may sometimes pair together or with another mild preservative (such as phenoxyethanol) for broader protection.       

Questions About Sodium Benzoate & Potassium Sorbate

Question 1. Are sodium benzoate and potassium sorbate natural?

Answer. Sodium Benzoate and Potassium Sorbate are synthetic derivations of naturally occurring substances, so they are okay in many natural formulations.

Question 2. Can Sodium Benzoate and Potassium Sorbate preservatives cause allergies?

Answer. Allergic reactions are uncommon but not impossible! It is always a great idea to patch test the product before putting it in the full area if you have sensitive skin.

Question 3. Do these preservatives have an impact on the texture/wateriness/scent?

Answer. No, they are neutral in scent and do not change the feel of the product.

Question 4. Are sodium benzoate and potassium sorbate safe during pregnancy?

Answer. Yes. They are generally considered safe for use during pregnancy at the low levels that typically occur in cosmetics.

Question 5. Can I use products with these preservatives every day?

Answer. Yes. Sodium benzoate and potassium sorbate can be used every day in the products that contain them.