What Is Oxyquinoline Benzoate?
Oxyquinoline Benzoate is the salt that forms when benzoic acid reacts with 8-hydroxyquinoline, also called oxyquinoline. The result is a stable white to off-white powder that dissolves well in alcohol and certain oily ingredients but only sparingly in water. Because it merges the preservative traits of benzoic acid with the germ-fighting ability of oxyquinoline, chemists saw early on that the compound could help keep cosmetics fresh and safe.
The ingredient first appeared in personal care labs in the mid-1900s as brands searched for alternatives to older, harsher preservatives. By combining two well-known antimicrobial agents into a single salt, formulators could use lower levels while still controlling the growth of bacteria and fungi. Production is straightforward: benzoic acid is dissolved and neutralized with oxyquinoline under controlled pH, then the mixture is cooled, filtered and dried to yield a fine crystalline powder.
Today you will most often spot Oxyquinoline Benzoate in leave-on and rinse-off products that need robust microbial protection. Common examples include facial creams, body lotions, sunscreens, clay masks, foot powders, deodorant sticks and certain makeup items like liquid foundation. Its broad-spectrum action allows brands to simplify preservative systems or reduce the amount of other synthetic preservatives in a formula.
Oxyquinoline Benzoate’s Cosmetic Benefits/Uses
The main reason this ingredient shows up on labels is its strong antimicrobial activity. By hindering the growth of bacteria, yeast and mold it helps keep products from spoiling too quickly, protects the user from potential skin irritations linked to contaminated formulas and extends shelf life so creams and lotions remain effective until the last drop.
Who Can Use Oxyquinoline Benzoate
Because it sits on the skin rather than sinking deeply, Oxyquinoline Benzoate is generally well tolerated by most skin types including normal, oily, combination and mature skin. Sensitive skin can usually handle it too since the ingredient is used at very low levels, though very reactive complexions should still watch for any redness or stinging that could indicate an intolerance.
The compound is made from benzoic acid and 8-hydroxyquinoline, both sourced through synthetic routes, so it contains no animal-derived materials. For that reason it is considered suitable for both vegetarians and vegans provided the finished product is certified cruelty free.
No data suggest that topical use poses special risks during pregnancy or while nursing. Still, personal hormone shifts can make skin more reactive during these times, and for legal safety anyone who is pregnant or breastfeeding should ask a health professional before introducing a new product that lists this preservative.
Oxyquinoline Benzoate does not absorb UV light and is not known to trigger photosensitivity. Users do not need to take extra sun-care steps beyond normal daily SPF use.
Potential Side Effects/Adverse Reactions
Responses to any skincare ingredient vary by person. The points below outline possible reactions to Oxyquinoline Benzoate, but they are uncommon when the preservative is used at the low levels allowed in cosmetics.
- Skin irritation Mild burning or itching can occur on very sensitive or compromised skin
- Contact allergy Rare cases of allergic dermatitis have been linked to quinoline compounds in leave-on products
- Dryness In higher concentrations the ingredient may disrupt the skin’s surface oils leading to tightness or flaking
- Eye stinging If a formula accidentally gets into the eyes it can cause temporary discomfort or watering
If any of these reactions appear stop using the product and consult a healthcare professional if symptoms do not clear up quickly.
Comedogenic Rating
Rating: 1 out of 5. Oxyquinoline Benzoate is used at very low levels and does not have an oily or waxy texture that would sit in pores and block them. Its job is to fight germs, not act as an emollient or thickener, so it is unlikely to create the kind of film that encourages blackheads or pimples. People who are prone to acne can generally use products containing this preservative without added worry. In formulas with heavy oils the overall product could still clog pores, but that would be due to the base oils rather than this ingredient.
Summary
Oxyquinoline Benzoate serves mainly as an antimicrobial agent in cosmetics, teaming the preservative power of benzoic acid with the germ fighting skills of 8-hydroxyquinoline. By stopping bacteria yeast and mold it keeps creams lotions and makeup safe and effective for longer periods. Though it delivers solid protection it is not a headline ingredient, so you will see it far less often than big name preservatives like phenoxyethanol or parabens.
Safety data show a low risk of irritation or allergy when used within the small percentages allowed by regulations, and its comedogenic rating of 1 makes it a low-clog option for most skin types. As with any new skincare item it is smart to patch test a product that contains Oxyquinoline Benzoate just to be sure your skin approves.