Do Sodium Benzoate And Citric Acid Form Benzene?
Written by Irina Webb
No. Sodium benzoate and citric acid do not form benzene when you mix them. The benzene worry comes from a different pair: sodium benzoate plus ascorbic acid, which is vitamin C. And even that pair only makes a trace of benzene when heat, light, and a little metal like iron or copper are also present. Citric acid is safe to use next to sodium benzoate.
Here is the quick version:
- Sodium benzoate + citric acid: no benzene.
- Sodium benzoate + vitamin C (ascorbic acid) + heat, light, and metal: a tiny amount of benzene is possible.
- Citric acid by itself: safe. Some studies show it can even help break benzene down.
Below, I break down the studies and the chemistry behind why sodium benzoate paired with citric acid is not a concern.
The Sodium Benzoate And Citric Acid Myth
Maybe you scanned the label on a pack of baby wipes, a face cleanser, or a lotion and stopped at citric acid and sodium benzoate. You are not the only one. You may have read that these two ingredients form benzene when used together. Benzene is a chemical that can increase the risk of cancer, so the worry makes sense. But the claim does not hold up. Here is what the science actually shows.
Sodium benzoate is the salt form of benzoic acid. It’s a common preservative in food, cosmetics, and personal care products. It fights mold and bacteria, and it’s generally considered safe at the small amounts used. For the full safety picture, see my post Is Sodium Benzoate Safe?.
Citric acid is a mild acid found in citrus fruit. In skincare and baby wipes, it is used in tiny amounts, mostly to set the pH. It’s a safe, well-studied ingredient. I cover it in depth in Is Citric Acid Safe?.
Is Benzoate The Same As Benzene?
No. Benzoate and benzene are not the same thing. The names look alike, but they are two different chemicals.
Benzene is a pollutant found in gasoline, crude oil, and cigarette smoke. Benzoate, as in sodium benzoate, is a preservative made from benzoic acid. Benzoic acid shows up naturally in foods like cranberries, prunes, and cinnamon. So, an ingredient name that sounds like “benzene” is not a reason to worry on its own.
What Happens When You Mix Sodium Benzoate And Citric Acid?
Nothing harmful happens when you mix sodium benzoate and citric acid. Together, these two ingredients simply help keep a product fresh. Citric acid lowers the pH, which helps sodium benzoate work as a preservative. No benzene forms from this pair.
The reaction that makes benzene needs vitamin C, not citric acid. Citric acid is not part of it. The next sections explain where the worry came from and why citric acid stays out of the reaction.
Where The Benzene Worry Started
Benzene is a known human carcinogen. It’s found in crude oil, gasoline, and cigarette smoke, and it can form during some industrial processes (the National Cancer Institute and FDA guidance).
The concern about benzene in products started in the early 1990s. Some soft drinks tested positive for benzene. These drinks had both sodium benzoate and ascorbic acid (vitamin C), and they were exposed to heat, light, and metal ions like copper or iron (a benzene-in-foods review). In the mid-2000s, the FDA and the American Beverage Association looked into it, and drink makers changed their recipes and their guidelines.
In 2006, the American Beverage Association shared guidelines to lower or stop benzene from forming in drinks that had both benzoic acid and ascorbic acid. The main tips were to replace the vitamin C, add a chelating agent like EDTA to block the metal triggers, and store products away from heat and light.
Sodium Benzoate + Ascorbic Acid Can Form Trace Benzene
A few studies confirm that sodium benzoate and ascorbic acid (vitamin C) can react to form benzene.
One study tested 25 popular Ayurvedic supplements that used ascorbic acid and sodium benzoate. About 36% had some benzene. The levels stayed within safety limits but finding it in daily-use supplements still gives pause.
Another study looked at 28 drinks that tested positive for trace benzene. The higher levels showed up in drinks that had both sodium benzoate and ascorbic acid.
A third study found that some benzene occurs naturally in foods like eggs and butter. Higher levels appeared in products that had both benzoates and ascorbic acid.
Notice the pattern. The benzene formed when sodium benzoate met ascorbic acid, not citric acid. And even though both are acids found in fruit, citric acid and ascorbic acid are not the same. They do different jobs and cannot swap places.
Why Ascorbic Acid Can Form Benzene And Citric Acid Can’t
Here is the simple reason ascorbic acid can form benzene and citric acid can’t. Vitamin C is a reducing agent, which means it gives away electrons easily. When trace iron or copper is around, that electron-giving power creates reactive bits called radicals. Those radicals knock a piece off benzoate and leave benzene behind. Gardner and Lawrence first mapped this reaction in 1993.
Citric acid cannot do any of that. It has no reducing power, so it does not make radicals. Instead, it grabs onto the iron and copper the reaction needs and helps shut it down. That is why chemists call it a chelator (citric acid chemistry and ascorbic acid chemistry).
I looked hard for evidence that citric acid and sodium benzoate form benzene in food or skincare. I found none. In fact, the studies point the other way. Several environmental studies show citric acid can even help break benzene down in soil and water treatment. That is a bonus, not the main point. The main point is simple: citric acid is not part of the benzene reaction.
The Bottom Line: Do You Need To Worry?
I have not found any evidence that citric acid and sodium benzoate form benzene in food or skincare. The reaction that forms benzene involves sodium benzoate and ascorbic acid (vitamin C), and it needs heat, UV light, and metal traces.
You put skincare on your body often, sometimes on large areas, and sometimes on babies. So, I would skip products that have both ascorbic acid and sodium benzoate. This matters most if the product sits in a warm place or comes in packaging that lets light through.
It’s fine to use ascorbic acid (vitamin C) and sodium benzoate separately. Sodium benzoate is a safe, well-studied preservative. Vitamin C is a nutrient your body needs, and as an antioxidant it helps protect and refresh your skin. To find a good option, take a look at my post What Is a Vitamin C Serum?.
Frequently Asked Questions
What Ingredient Forms Benzene With Sodium Benzoate?
Ascorbic acid, better known as vitamin C, forms benzene with sodium benzoate. Even then, it needs heat, light, and metal ions like iron or copper.
Is It Safe To Use Citric Acid And Sodium Benzoate Together?
Yes, it is safe to use citric acid and sodium benzoate together. Citric acid is used in tiny amounts, mainly to adjust pH. Some studies even show citric acid helping to preserve products or break benzene down.
Can I Use Vitamin C And Sodium Benzoate In The Same Product?
I would avoid using vitamin C (ascorbic acid) and sodium benzoate in the same product, especially if it is stored in heat or light. Using them in separate products, or at different times of day, is not a concern.
Do Potassium Benzoate Or Potassium Sorbate Form Benzene?
Potassium benzoate and potassium sorbate do not form benzene with citric acid. In skincare, you will most often see sodium benzoate and potassium sorbate, which are commonly paired together. Potassium benzoate is used more in foods and drinks, so you may rarely see it on a skincare label. It is a close cousin of sodium benzoate, and like all benzoates, it can form a trace of benzene only if it meets vitamin C (ascorbic acid) under heat and light. Potassium sorbate is a different type of preservative and does not turn into benzene at all. In every case, citric acid is not the trigger.
Is Citric Acid Safe?
Yes, citric acid is safe. It is a mild, natural fruit acid and a normal part of your body’s own metabolism, and it is accepted by strict natural standards. For the full picture, including the mold question and its role as an exfoliating acid, see my Is Citric Acid Safe? post.
Is Sodium Benzoate Safe?
Yes, sodium benzoate is generally considered safe at the levels used in cosmetics. It is a widely used, well-studied preservative, and it is far gentler than preservatives like formaldehyde-releasers. For a full breakdown, see Is Sodium Benzoate Safe?.
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Water, Glycerin, Cocamidopropyl Betaine, Sodium Methyl Lauroyl Taurate, Glycol Distearate, Sclerotium Gum, Sodium Benzoate, Cocamide MEA, Citric Acid, Lauric Acid, Sodium Methyl Aurate, Guar Hydroxypropyltrimonium Chloride, Sodium Hyaluronate, Stearic Acid, Panthenol, Sodium Cocoyl Alaninate, Cetrimonium Chloride, Sodium Hydroxide
this is the ingredients list of my face wash
it’s safe please reply
Hi Abhi! Regarding your question about the safety of your face wash, we realize that it’s not easy to read and understand the ingredients. For this reason, we kindly offer a service called “product ingredient review” to help you understand the safety of your product. Please, follow the link to use the service: https://ireadlabelsforyou.com/services/ingredient-review/
Just found you blog, I found a produte Gooya marinade has sodium benzoate and edta with citric essence oils. My search has found nothing about these two together with citric acids. Along benzoate and citric asics are not good. Put with Edta? Edta is a good metal tetox and more. Bensese/ carcinogen/ be efected in a good way with edta?
Hi Carolinah! Our post is not about sodium benzoate and citric acid. It is about sodium benzoate and vitamin C combination. Citric acid is not vitamin C.
I am breastfeeding and very careful about what I put on and in my body. The one treat I allowed myself (with doctor’s OK) is an almost daily latte. I just discovered this place uses Torani vanilla syrup which has sodium benzoate and citric acid. I am panicking that I’ve inadvertently harmed my baby by drinking this regularly…
Hi, Ali! Our “Sodium Benzoate & Citric Acid Myth” blog post emphasizes in the introduction and conclusion that “Benzene may form only when sodium benzoate and ascorbic acid are present in the same product. It must be ascorbic acid for this to occur, NOT citric acid.” May we ask about the cause of your anxiety?
Thank you for this! I was afraid to drink my Aloe Vera juice because it contains Sodium Benzoate and Citric Acid. Thanks for clearing everything up!
Thank you for your kind feedback, Kaylee! You are very welcome!
Hello Irina!
I was so interested to read this article as I have been studying Sodium Benzoate and how it interacts with Ascorbic Acid for some time now. I’m a skincare enthusiast and I’ve been obsessed with ingredients for a while. I try my hardest to only use the purest products (no parabens, alcohols, overall harsh ingredients etc.) Thus, once I learned how the two ingredients (in the same formulation) could cause Benzene, I was FLOORED and I instantly put it on my list of bad ingredients (based on individualized situation), mainly because I use A LOT of Vitamin C (in the form of ascorbic acid) products daily. After doing some research I learned that not only do A TON of products contain Sodium Benzoate, but also ingredients like: Benzoic Acid and a number of other “Ben” ingredients (many having a Benzene ring in their core or makeup). I was overwhelmed by how many products I had to eliminate and even more alarmed by a few VITAMIN C products that had the both ingredients inside. All that being said, I would love to hear your thoughts on the following question: In your opinion should I be concerned about using products with Sodium Benzoate in them since I would more than likely follow up with an Ascorbic Acid product? Wouldn’t that be similar to mixing the two ingredients and creating the cocktail on the surface of skin that would be absorbed?
Any advice would be more than appreciated! I’ve been racking my brain over this question for the longest time and constantly eliminating products with Sodium Benzoate in them.
Thank you so very much for your time and assistance!
Hi, Brittany! Thank you for reaching out to I Read Labels for You! Good job with your healthy living journey! As for your question, we have talked to chemists and did research into scientific sources, but we have not found any evidence proving that benzene formation on the skin after the subsequent use of ascorbic acid is possible. We hope this helps!
Hello Maria!
Thank you, thank you, thank you so very much for your kind words and reply! This information definitely helps!!
I TRULY appreciate your time and assistance!!
Sincerely,
Brittany B.
Of course! You are so very welcome!
Hi Irina,
I was wondering, is there a concern for the combination of Ascorbyl Palmitate and Sodium Benzoate in skincare products? I was unable to find any research about this form of Vit C.
Hi, Raza! Thank you for the question! Ascorbyl Palmitate is a kind of Vitamin C, and we do not recommend the combination of Vitamin C with Sodium Benzoate. I hope this helps!
How about the sodium benzoate in novaferrum liquid iron supplements for kids? Pediatricians recommend taking novaferrum with vitamin c foods like oranges for iron absorption. Does the combination result in the formation of carinogenic benzene?
Hi Rajam! We appreciate your interest! Irina will be happy to help you with your question in a private consultation: https://ireadlabelsforyou.com/services/
Ever since the reports of Benzene have been in suncreen, I’ve been on the look out for Sodium Benzoate everywhere!
Lately I’ve been using two Mario Badescu products and I’m a bit nervous they’re unsafe. Typically I use the Witch Hazel Toner, Cellufirm Drops and Vitamin C Serum – and they all have Sodium Benzoate. Although my skin has been looking *great* lately, I DEFINITELY do not want to continue usage if they’re cancer causing.
The product I guess I’m most concerned about is the Vitamin C serum? Here are the ingredients:
Propylene Glycol, Aqua (Water, Eau), Aloe Barbadensis Leaf Juice, Hexylene Glycol, Pentylene Glycol, Tetrahexyldecyl Ascorbate, 3-O-Ethyl Ascorbic Acid, PEG-25 Hydrogenated Castor Oil, PEG-40 Hydrogenated Castor Oil, Cucumis Sativus (Cucumber) Extract, Panax Ginseng Root Extract, Sodium Hyaluronate, Soluble Collagen, Lavandula Angustifolia (Lavender) Oil, Hydroxyacetophenone, Triethanolamine, Citric Acid, Potassium Sorbate, Caprylyl Glycol, Phenoxyethanol, Silver Citrate, Zeolite, Sodium Benzoate
What are your thoughts? Cease and desist?
Hi Emma! The product you mentioned contains ethoxylated ingredients, namely PEG-25 and PEG-40, that we do not recommend on our website. If you need a more detailed consultation, Irina will be happy to help you: https://ireadlabelsforyou.com/services/
Hello. Is it okay to use this face wash that has this ingredients
Ingredients
Aqua (Water)
, Sodium Laureth Sulfate, Glycerin, Cocamidopropyl Betaine, Sodium Chloride, Benzyl Alcohol, Glycol Distearate, PEG-40 Hydrogenated Castor Oil, Laureth-4, Sodium Benzoate, Dipropylene Glycol, Tocopheryl Acetate, PEG-120 Methyl Glucose Dioleate, Sodium Citrate, Propylene Glycol, Citric Acid, Tetrasodium EDTA, Parfum (Fragrance), Retinyl Palmitate, Disodium Phosphate, Hexyl Cinnamal, Hydroxycitronellal, Citronellol, Sorbitol, Sodium Hydroxide, Limonene, Linalool, Cucumis Sativus (Cucumber) Fruit Extract, Denatonium Benzoate, Tocopherol, Benzoic Acid, Ci 19140 (Yellow 5), Ci 42090 (Blue 1)
Hi, Tanzila: this product does not adhere to the safety standards of my blog. For more information, please take advantage of my inexpensive email product review service: https://ireadlabelsforyou.com/services/ingredient-review/ ~Irina
For the Mad Hippie Vitamin C
Water Deionized, Vitamin C (Sodium Ascorbyl Phosphate), Alkyl Benzoate, Vegetable Glycerin, Water, Glycerin, Sodium Levulinate, Sodium Anisate, Clary Sage (Salvia Sclarea), Grapefruit (Citrus Grandis), Hyaluronic acid, Amorphophallus Konjac Root Powder, Aloe Barbadensis Leaf, Vitamin E (Tocotrienol), Ferulic acid, Chamomile Flower Extract (Recutita Matricaria), Sodium Phytate, Xanthan Gum, Hydroxyethylcellulose
Is this safe?
The 2nd ingredient is Sodium Ascorbyl Phosphate and the 3rd ingredient is Alkyl Benzoate, so high amounts of both. Reached out to the company and they said the Alkyl Benzoate is derived from coconut. Not sure if that makes a difference.
Thank you for this article! It’s wonderful 🙂
Hello Rose! We appreciate your interest! Irina will be happy to help you with your question in a private consultation: https://ireadlabelsforyou.com/services/
Recently we bought a gripe water for our 2 month old with following inactive ingredients
Citric acid, potassium benzoate , potassium citrate and potassium sorbate..is it safe to use for my son? Or should I worry about formation of benzene in this? Thank you
Hi Anusha! We appreciate your interest! Irina will be happy to help you with your question in a private consultation: https://ireadlabelsforyou.com/services/
Hello,
What about nail polish.
Should I be concerned about this nail polish
Ingredients : BUTYL ACETATE, ETHYL ACETATE, NITROCELLULOSE, ADIPIC ACID/NEOPENTYL GLYCOL/TRIMELLITIC ANHYDRIDE COPOLYMER, PLANT BASED NON DENATURED ALCOHOL ETHYL ACETATE, TRIBUTYL CITRATE,ISOSORBIDE DICAPRYLATE/CAPRATE, BUTYL ACETATE, STEARALKONIUM BENTONITE, ISOPROPYL, PLANT BASED NON DENATURED ALCOHOL, PHOSPHORIC ACID, ACETYL TRIBUTYL CITRATE, CAPRYLIC/CAPRIC TRIGLYCERIDE, PRUNUS CERASUS (BITTER CHERRY) FLOWER EXTRACT (PRUNUS CERASUS FLOWER EXTRACT), CITRIC ACID, DIACETONE ALCOHOL, WATER (AQUA), GLYCERIN, PUNICA GRANATUM FRUIT EXTRACT, PRUNUS AMYGDALUS DULCIS (SWEET ALMOND) OIL (PRUNUS AMYGDALUS DULCIS OIL), PERSEA GRATISSIMA (AVOCADO) OIL (PERSEA GRATISSIMA OIL), POTASSIUM SORBATE, EQUISETUM ARVENSE LEAF EXTRACT, PROPYLENE GLYCOL, SILICA, SODIUM BENZOATE, TOCOPHEROL
Hi, Marija: from the perspective of sodium benzoate and ascorbic acid interaction, I believe that this product is okay. ~Irina
Would the body shop strawberry shampoo be a problem cause it has strawberry juice and sodium benzoate and I’m guessing strawberry juice has Vit C.
Aqua/Water/Eau, Sodium Laureth Sulfate, Citric Acid, Cocamidopropyl Betaine, Ammonium Hydroxide, Sodium Chloride, Propylene Glycol, Parfum/Fragrance, Sodium Benzoate, Hexylene Glycol, Polyquaternium-10, Glycerin, Fragaria Vesca Juice/Strawberry Juice, Salicylic Acid, PPG-5-Ceteth-20, Aloe Barbadensis Leaf Juice Powder, Limonene, Sodium Acetate, Isopropyl Alcohol, Sodium Hydroxide, CI 14700/Red 4, CI 17200/Red 33.
That’s an interesting one. I am not so sure how much of that strawberry juice is actually in the shampoo and how much of vitamin C is preserved in the juice. But the way, this shampoo does not adhere to the safety standards that I set up for I Read Labels For You. ~Irina
Hi! Thank you so much for this, it’s been so helpful. Would taking an iron supplement with sodium benzoate and also eating vitamin c -rich foods to help with absorption be problematic?
Thanks,
Kathleen
Hi, Kathleen: I don’t recommend taking sodium benzoate internally. Could you find a supplement without sodium benzoate preservatives? ~Irina
Hello, i use sunscreen that contains benzoic acid, on mornings. İs it okay to use vitamin c on evenings after cleaning sunscreen from my face?
Yes, I believe so. ~Irina
Irina, what wipe preservative would you recommend in this case? I followed this article from your previous post on Phenoxyethanol – which is a common preservative,
Would sodium benzoate be alright i.e if not better than phenoxyethanol? Maybe the better question is what preserve should I look for in wipes?
Hi, KenStacey! I believe that sodium benzoate is safer than phenoxyethanol in baby wipes. Have you considered getting the Baby Wipes Rating List ebook? https://ireadlabelsforyou.com/ebooks/baby-wipes/ ~Irina
Hi Irina,
I was wondering, given more Vitamin C derivatives are now used in skincare some of them actually mix with sodium benzoate and/or benzoic acid with these latter being listed near the bottom of the list. Do you know if derivatives like ethyl ascorbic acid are safe to layer with other products containing them. Is there a skin reaction that occurs that makes us known to the danger? I’ve only used the derivative and have tried to research and most articles note that skin penetration has low risk for any danger.
Hi, Angela: I agree with you that the risks are very minimum. ~Irina
Is there a concern about products combining sodium benzoate with sodium ascorbyl phosphate?
And does this apply to C12-15 alkyl Benzoate? What about benzyl alcohol?
Thanks.
There is only concern when it is combined with a form of a vitamin C. ~Irina
Hi & thank you for such a clarifying post. If I’m understanding correctly, it would not be wise to mix a vitamin c serum – ascorbic acid as the active with a hydrating serum that contains sodium benzoate? This might create a “benzene situation?”
Thank you!
Yes, you are correct, Lena. Thank you for clarifying. ~Irina
Should I be concerned by the combination of sodium benzoate and E-ascorbic acid used in this product ?
Sunscreen-ingredients list.
Aqua, Titanium Dioxide, Suncat DE TM, Sodium Polyacrylate, Glycerin, Zinc Oxide, Xylitol, Phospholipids, Caprylic Acid, Glyceryl Stearate, Dicaprylyl Carbonate, Hyaluronic Acid, Helianthus Annuus (Sunflower) Seed Oil, D-Alpha Tocopheryl Acetate, Calendula Flower Extract, Aloe Barbadensis Leaf Juice, Himalayan Thermal Water, SODIUM BENZOATE, E-ASCORBIC ACID, Sodium Levulinate, Phenoxyehtanol, IFRA Certified Allergen Free Fragrance, Allantoin, Melanin.
Thank you!
Hi, Geethika! Thank you for your interest and trust! Please, consider taking advantage of our e-mail consultations for ingredients of a specific product: https://ireadlabelsforyou.com/services/ingredient-review/
Thanks a lot gor your detailed explanation. The ginger garlic paste i use for cooking has sodium benzoate and citric acid. Though it increases temperature while i cook, can i assume this combination as safe?
Hi, Rupa! We appreciate your interest and trust! If you want to know the details that are not described in the post, you are more than welcome to book a consultation with Irina: https://ireadlabelsforyou.com/services/
Thanks a lot for your valuable information
Should I be concerned by the combination of benzoic and citrus acid used in this product?
Shampoo – ingredients list.
aqua
decyl glucoside
xanthan gum
aloe barbadensis leaf juice powder
citric acid
benzoic acid
dehydroacetic acid
organic simmondsia chinensis oil
d-panthenol (pro vitamin b5)
phenoxyethanol
inulin (aqua alpha-glucan oligosaccharide pre biotic)
Thank you! ( just purchased your consumer superpower)
Hi, Leah: that combination is okay. ~Irina
Hi,
Im thinking of trying this product that has the following ingredients:
Triticum vulgare/aestivum (wheat) sprout extract, purified water, fructose, glycerol, sodium benzoate, potassium sorbate.
My question is that wheatgrass contains vitamin C and whether it is a concern since sodium benzoate is added in.
Thanks!
Lin
Hello Hui Lin! We appreciate your interest! Irina will be happy to help you with your question in a private consultation: https://ireadlabelsforyou.com/services/
Thank you for this, much appreciated!
This is such wonderful news. Thank you for this info Irina. It is invaluable! I have a query though, so one should stay away from personal care products with sodium benzoate & Vit C in it, but can you layer or use different products on let’s say your face where one contains Vit C and another sodium benzoate? 🤔
That’s a good point, Martie. Less is more. 🙂 ~Irina
So sodium benzoate is 100 % safe correct?
Especially in deodorants mixed with essential oils? Directly in contact with our lymph nodes.
Because essential oils do contain vitamin c.
I would just like to make sure.
I appreciate your help.
Stephanie: there is no such thing as 100% safe. What can be safe for one person can be poison for others. With this said. I don’t think there is any concern about mixing essential oils with sodium benzoate. ~Irina