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Potassium benzoate is a preservative commonly added to food, beauty, and skin care products to increase their shelf life.

While this compound is approved for use in many countries, it has come under scrutiny for its possible side effects. These range from severe allergic reactions to hyperactivity to an increased risk of cancer.

Yet, you may wonder whether these side effects are backed by research.

This article reviews potassium benzoate, which foods contain it, and its possible side effects.

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What is potassium benzoate, and how is it used?

Potassium benzoate is a white, odorless powder that’s obtained by combining benzoic acid and potassium salt under heat (1).

Benzoic acid is a compound naturally found in plants, animals, and fermented products. Originally derived from the benzoin resin of certain tree species, it’s now mostly industrially produced.

Potassium salts are typically extracted from salt beds or certain minerals.

Potassium benzoate is used as a preservative, as it prevents the growth of bacteria, yeast, and particularly mold. As such, it’s often added to food, beauty, and skin care products to extend their shelf life (1).

A few beauty and skin care items that may harbor this ingredient are shampoos, conditioners, facial cleansers, and moisturizers.

Potassium benzoate is a preservative commonly found in food, beauty, and skin care products. It helps extend shelf life by preventing bacteria, yeast, and mold growth.

Which foods contain it?

Potassium benzoate can be found in a variety of packaged foods, including (2, 3, 4):

• Beverages: soda, flavored drinks, and certain fruit and vegetable juices
• Sweets: candy, chocolate, and pastries
• Condiments: processed sauces and salad dressings, plus pickles and olives
• Spreads: certain margarines, jams, and jellies
• Processed meats and fish: salted or dried fish and seafood, as well as certain cold cuts

This preservative is also added to some vitamin and mineral supplements. Additionally, it’s used as a sodium benzoate alternative in foods that require a lower sodium content (3).

You can tell whether a food contains potassium benzoate by looking at the ingredient list. It may also be called E212, which is its European food additive number (3).

Keep in mind that foods made with potassium benzoate are generally heavily processed and contain fewer nutrients and beneficial compounds than minimally processed ones. Therefore, it’s best to limit your intake of these items — regardless of their potassium benzoate content.

Many packaged and processed foods, including certain sweets, drinks, condiments, and meats, contain potassium benzoate. You can look for this preservative on the ingredient list.

Is potassium benzoate harmful or safe?

The European Food Safety Authority (EFSA) and World Health Organization (WHO) both consider potassium benzoate to be a safe food preservative (3, 5, 6).

In the United States, the Food and Drug Administration (FDA) considers the related compound sodium benzoate safe but has yet to take a clear stance on the safety of potassium benzoate (7).

Possible side effects

That said, this compound comes with potential side effects.

When a food or beverage containing both potassium benzoate and ascorbic acid (vitamin C) is exposed to heat or light, it may form the chemical benzene (2).

Benzene-containing foods may cause hives or severe allergic reactions, especially in people prone to eczema, itchy skin, or a chronically stuffy or runny nose (3, 4).

Environmental exposure to benzene from factors like motor vehicles, pollution, or cigarette smoke is also linked to an increased risk of cancer. However, more research is needed to determine whether ingesting small amounts carries the same health risks (1, 2, 7).

Some research further suggests that young children exposed to benzene or benzoic-acid-containing compounds like potassium benzoate may have a higher risk of attention deficit hyperactivity disorder (ADHD). However, more studies are needed (8).

Overall, further research is necessary to determine this preservative’s health effects.

Intake limits

The WHO and EFSA have defined the maximum safe acceptable daily intake (ADI) of potassium benzoate as 2.3 mg per pound (5 mg per kg) of body weight. To date, the FDA has yet to define any intake recommendations for potassium benzoate (3, 5).

The maximum permitted levels of potassium benzoate vary based on the type of processed food. For instance, flavored drinks may contain up to 36 mg per cup (240 mL), while fruit jams may only harbor up to 7.5 mg per tablespoon (15 grams) (3).

For reference, a 155-pound (70-kg) adult would have to drink around 10 cups (2.4 liters) of soda to surpass the ADI. Keep in mind that drinking this much soda is never recommended.

Though there’s little risk of adults exceeding the ADI, the best way to avoid high levels of this additive is to limit your intake of processed foods. Limitations are particularly crucial for infants, toddlers, and children, as they may exceed the ADI if following a highly processed diet (3).

Potassium benzoate is generally considered safe. However, more research is needed on the long-term health effects of ingesting this compound.

The bottom line

Potassium benzoate is a preservative used to increase the shelf life of various packaged foods, as well as beauty and skin care products.

It’s generally considered safe when ingested in small amounts, although some people may experience an allergic reaction. More research is needed to determine whether it increases ADHD or cancer risk.

Although potassium benzoate is unlikely to be harmful in small amounts, foods containing it are generally heavily processed. Thus, it’s best to limit these foods in your diet regardless of their potassium benzoate content.