What Is Ammonium Benzoate?
Ammonium benzoate is the ammonium salt of benzoic acid, a compound that occurs naturally in some fruits like cranberries and prunes. It appears as a white crystalline powder that dissolves easily in water, making it handy for liquid and gel formulas. The cosmetic world first turned to benzoic acid salts in the early 20th century when manufacturers looked for safer ways to keep products fresh without relying on heavy metals or high alcohol levels. Today ammonium benzoate is made by reacting benzoic acid with ammonium hydroxide, then purifying the result to remove leftover reactants and moisture.
You will most often spot ammonium benzoate in water-based items such as facial toners, sheet masks, lightweight moisturizers, leave-on hair treatments and some rinse-off cleansers. Brands like it because it blends in smoothly, has no strong scent and stays stable across a wide pH range.
Ammonium Benzoate’s Cosmetic Benefits/Uses
Its main job in beauty formulas is as a preservative. By slowing the growth of bacteria, yeast and mold it helps products last longer, keeps textures consistent and protects users from unwanted microbes.
Who Can Use Ammonium Benzoate
Because it is generally mild and water-soluble, ammonium benzoate suits most skin types including normal, dry, oily and combination. Sensitive or compromised skin can usually tolerate it as well since the ingredient is used at very low levels, though people with a known benzoate allergy should avoid it.
The compound is made through a lab process that involves no animal-derived materials so it is suitable for both vegetarians and vegans.
Current safety assessments have not raised specific concerns for pregnant or breastfeeding women when ammonium benzoate is used in cosmetics. This is not medical advice and anyone who is pregnant or nursing should show the full product ingredient list to a qualified health professional before use to be safe.
The ingredient does not make skin more prone to sunburn and causes no known photosensitivity. It is also fragrance-free and colorless so it will not interfere with other actives or change a product’s scent profile.
Potential Side Effects/Adverse Reactions
Reactions to topical ammonium benzoate vary from person to person. The points below describe potential side effects that could occur, but they are uncommon when the ingredient is used at standard cosmetic levels and produced under good manufacturing practices.
- Mild skin irritation
- Transient stinging on broken or freshly shaved skin
- Contact allergy in individuals sensitive to benzoates
- Eye irritation if the product accidentally gets into the eyes
If any discomfort, redness or swelling develops stop using the product and consult a medical professional.
Comedogenic Rating
Rating: 0/5
Ammonium benzoate is fully water soluble and leaves no oily or waxy residue on skin. Because it does not sit on the surface or clog pores it earns a non-comedogenic score of 0. This makes it suitable for people who are prone to acne or frequent breakouts.
No data links this preservative to increased sebum production or blackhead formation. It is also used at very low percentages, further lowering any clogging risk.
Summary
Ammonium benzoate’s main role in cosmetics is as a preservative that holds back bacteria, yeast and mold so products stay fresh and safe. It does this by disrupting the microbes’ internal balance, stopping them from growing.
While benzoic acid salts have been around for decades, ammonium benzoate itself is not a headline ingredient so you will see it more in the fine print than in ads. Brands choose it because it blends well into water-based formulas, has no scent and works over a broad pH range.
Current research shows it is low risk for most users when used at the small amounts allowed in personal care. Still, skin can react to anything so it is smart to do a quick patch test when trying a new product that lists ammonium benzoate.