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Sodium Benzoate Nonsense

I don’t spend a lot of time on the blog swatting down idiotic ideas about chemicals. It’s a full time job, and (see next post) I already have a full time job. It’s also frustrating work, because the supply of idiocy is apparently beyond limit, and just when you think you’ve seen the most clueless thing yet, they somehow manage to remove another clue and come back around. But over the weekend, several people alerted me to one of the latest ads in Panera Bread’s long-running campaign to convince everyone that their food is chock-full of wholesome goodness. This one takes off after sodium benzoate, and there are little Twitter and Instagram animations talking about how this icky stuff belongs in fireworks, not in your Panera food, right, guys?

If you Google “sodium benzoate”, prepare yourself for a firehose of stupidity. There’s a long list of sites that are convinced that while benzoic acid is a fresh, healthy, natural ingredient, that sodium benzoate is a devilish industrial chemical that will rot your soul. No, really, that’s pretty much how it goes, and since I know that the great majority of the readers here have a good understanding of acid/base chemistry, you all must be furrowing their brows in puzzlement about that one. I’m with you. I think that my favorite, in a way, is the assertion that when sodium benzoate is exposed to ascorbic acid, that it immediately converts to benzene, which cues up a look at benzene’s (most definitely alarming) toxicity. The source for this would have to be this paper from 2008, which analyzed a long list of beverages for benzene contamination, and found that the only detectable levels were in carrot juice intended for infants. Benzene levels correlated with copper and/or iron levels, and the authors believe that the benzoic acid in carrots is catalytically decarboxylated to a small extent during the heat treatment of the juice. But even the sites that don’t bring that up generally work in something about how sodium benzoate causes Alzheimer’s, Parkinson’s, multiple sclerosis, cancers of all types, you name it. And you thought only aspartame could do it all. Somehow, turning fresh, pure benzoic acid into its sodium salt puts the Curse of the Vat onto it, and this evil stain can never be removed, as we all know.

The first idiotic part of this, as the chemists are well aware, is that in foods that contain benzoic acid, a goodly fraction of it is already present as the benzoate anion. In fact, “Determine the proportions of benzoate and benzoic acid in a 0.1M solution of sodium benzoate” is a perfectly good (and perfectly straightforward) problem for an introductory chemistry class. In food, the cation associated with the benzoate is going to be hard to put your finger on, the inside of cells (and food in general) being the gemisch that it is, but sodium is an excellent first choice, considering how much of it is found in living systems. Calcium, technically, is the most common cation in the body, but it gets that title because a lot of it is tied up in bone tissue. Sodium, magnesium, and potassium are probably better bets for intra- and extracellular fluids, although calcium’s definitely a player, too. But it really doesn’t matter much. Benzoic acid is in equilibrium with (whatever) benzoate, and at the likely pH readings in foods (it’s slightly more acidic than acetic acid), you’re going to have a decent amount of the latter.

Benzoic acid is found (as a completely natural metabolite and intermediate) in a huge variety of foods, especially fruits and vegetables – berries are particularly high in it, but it’s also found in aromatic spices such as cinnamon and allspice. There’s not much in meat, but it is found in seafood, and in milk, particularly in fermented milk products such as completely natural, non-GMO yogurt made by people wearing unbleached hemp clothing and singing to each other about their feelings. OK, I’ll try to resist going off like that again (it’s difficult), but it’s certainly true that the bacterial metabolic pathways in fermented milk products like cheese and yogurt produce a good amount of benzoate. (If you’re wondering, chemically, where it comes from, it’s apparently via the microbial breakdown of hippuric acid and phenylalanine, and indirectly from tyrosine as well).

We humans tend to clear benzoic acid out as its conjugate with glycine (which compound is the abovementioned hippuric acid), and I have seen a 1930s biochemistry text that gave this as a laboratory experiment for undergraduates. They suggested that each student drink a solution with several grams of sodium benzoate and then collect their urine over the next few hours, followed by an extractive workup and crystallization to see who produced the best yield of hippuric acid. Such a Urination Derby (or “Piss-off”) experiment is frowned on these days – I used to threaten my lab sections with this one when I was a teaching assistant, but the higher-ups wouldn’t have let me go through with it even if I’d tried. But that’s not because the benzoate is toxic.

This is a comprehensive review on the use of benzoic acids and benzoates in foods, and the folks at Panera could learn a lot from it. Although, it has to be noted, the ones who came up with their benzoate ads could apparently learn a lot from most anything, starting with children’s board books and working up from there. The review points out that benzoic acid is a widely used preservative, but its salts are preferred due to their greater solubility (just as in that old experiment above). It’s mostly used for acidic foods, since it seems to have its greatest antimicrobial effect at pH levels from 2.5 to 4.5 – that is, when the equilibrium is largely towards the benzoic acid side. Put in nonchemical terms, for anyone from Panera who might stumble across this, sodium benzoate turns into benzoic acid when it’s used as a preservative. It’s just a matter of pH, as any high school or freshman chemistry student should be able to explain.

Now to the toxicology and the regulatory aspects. The EC considers benzoic acid together with the benzoate salts, benzaldehyde, and benzyl alcohol, since they are readily interconverted in living systems. They are all GRAS, “generally recognized as safe”. In more detail, that means that (using the regulatory phrasing) “There is no evidence in the available information on the substance that demonstrates, or suggests reasonable grounds to suspect, a hazard to the public when they are used at levels that are now current or might reasonably be expected in the future“. Classic toxicology on benzoic acid/sodium benzoate is not easy, because it’s so nontoxic. Values up to 5 to 10 grams per kilo have been reported as the median lethal dose in rats, which is a huge, whalloping amount. If true, that’s less acutely toxic than table salt; sodium chloride has an LD50 of about 3 grams/kilo in the rat. Chronic toxic effects, though, most certainly show up if you feed rodents a diet that’s 1% or more benzoic acid by weight (still a mighty dose indeed – see below). There are effects on cells in culture as well, although at levels that would seem difficult to achieve in vivo.

Limits for it in foods are generally set to several hundred mg/kilo (a very generous amount – those are levels that you won’t find for too many other things). You can legally go up to 6000 mg/kg for cooked shrimp and 3000 mg/kg for “vegetable pulps”, though. Average daily intake is recommended as around 5 mg/kilo of body weight per day or less, so you’d think that you might want to lay off the cooked shrimp in vegetable pulp. Actual commercial levels of the compound tend, apparently, to be far lower than those legal upper limits. Studies from Australia, New Zealand, Turkey, Hong Kong and many other countries have found that the actual daily intake is a factor of five or less than that ADI value. There are exceptions, though, particularly with concentrated fruit products and with cheeses and yogurt-like products, which has led to some to call for a re-evaluation of all these intake levels. To give you an idea, the estimate from the review linked to above is that perhaps 5% of the population might be over the 5 mg/kg/day limit, averaged over a typical lifetime. In case you’re wondering, that 1%-by-weight in the food that causes problems in rats would equal some 10 to 20 grams per day in an average human’s diet, a brutal amount that would be impossible to reach in anything approaching a normal diet.

But all that is sanity, backed up by hard data. Panera’s ad is a cute graphic is all about how sodium benzoate is found in fireworks, so it shouldn’t be in your delicious food. The problem is, a goodly number of Panera’s menu items – such as all the ones with cheese, and all the ones with berries – contain plenty of sodium benzoate already, in some proportion with benzoic acid. It’s stupid and disingenuous of them to pretend that they’re protecting their customers from evil industrial chemicals, when the same stuff is found in their own ingredients. As many readers will appreciate, you can play the same game with all sorts of other ingredients. Lactic acid (found in milk) is used in tanning leather. Palmitic acid, found in meats, coconut oil, sunflower seeds and many other foods, is used in making soap. 2,3-butanediol (a flavor component of many cheeses) is used in making printing ink and as antifreeze. I could go on all day; any organic chemist could. The entertainment value goes down after a while, because the fundamental premise (Good Healthy Natural Stuff versus Toxic Sludge) is stupid to start with.

So Panera, you’re playing on people’s lack of knowledge of chemistry in order to make yourselves look good. Your reasoning is faulty and your science is wrong. Your ads are offensive to anyone who actually understands chemistry, not that you care much, and you’re claiming a halo for yourselves that you don’t have. Do go on, though.



88 comments on “Sodium Benzoate Nonsense”

  1. Dietmar says:

    “A close relative of sodium benzoate is pottasium benzoate (E212), also known as benzoic acid.”

  2. Chris says:

    Derek I applaud your efforts but I fear that you will make no progress with those who want to live in a “chemical-free” world.

    I spent an hour watching my wife arguing with a sales assistant who was trying to sell a “chemical-free” cosmetic.

    I think we have to concentrate on the next generation.

    1. colintd says:

      When people talk about wanting to live chemical free, I offer to allow them to experience the inside of a large UHV chamber I have access to.

      Obviously I’ve been lucky that no-one has wanted to take up the offer (the cleaning and bakeout from finger prints is bad enough, evacuate a whole person and we’d have to scrap the rig), but it does help illustrate what “chemical free” really means.

      1. Chris says:

        When people say they want to live “chemical free” I have been known go shout “Elon! Elon I need a rocket!” In the hope that we could end their suffering quickly.

    2. MTK says:

      Don’t know who said it, but it’s true:

      “You can’t fight beliefs with facts.”

      1. tkeru408 says:

        I learned a while back (from Derek) that “you can’t use reason to talk someone out of a position that they didn’t arrive at by reason.” I use that quote on a regular basis now.

    3. fajensen says:

      Look at the Bright Side: It’s a sign of progress.

      The reason behind is that we now have such an abundance of resources and possibilities that we have to creatively invent problems / threats in our lives rather than dealing with the very stark problems of the “Ye Good Olde Days”, Starvation, Diseases, Malnutrition, ….

      …. Of course the anti-vaxxers and anti-chemicals could spend their time better on helping the rest of the planet leave “Ye Good Olde Days”. But, since they are sectarian idiots the lot of them, it is probably better they fight it out on “SoMe”!

    4. CM says:

      Water is a chemical. Let’s see how long someone can live in a chemical-free world.

      1. Terry says:

        Actually, water is a compound…

        1. TMcG says:

          It’s a chemical compound

    5. David Rowley says:

      Hi Chris,

      Those who want to live in a chemical-free world will need to leave the world (and their body) behind. The very home they live in regardless of construction materials, is 100% chemical, from top to bottom. Every element found in the basic structure of every piece of wood, drywall, concrete, shingle, tile, stone, bamboo, etc., etc. is found on the Periodic Table of Chemical Elements. Every last particle in their bodies, as well is a chemical element.

  3. Jon says:

    Okay, you may not like video links, but I had to post this one:

    It’s noisy, but worksafe.


  4. Photoredox says:

    Some blue light will convert your sodium benzoate to benzene, this will not happen with benzoic acid.

  5. Anonymous says:

    I am as mortified by the lack of lack of knowledge of the simplest chemical principles as any chemist. And here comes the but. A routine allergy skin test showed my wife has a strong reaction to sodium benzoate. I was initially skeptical for after all don’t you need a protein to provoke an allergic reaction? Then we started reading food labels. A few sips of any soft drink or some bottled ice teas (looking at you Lipton) induce hives in her after a few minutes. She has had hives after eating food made with Kikoman but not other brands of soy sauce. Sure enough there it is on the label. Lately she has been occasionally reacting after eating shrimp or canned crab. I just learned from your article that sodium benzoate may be the explanation, not a protein allergy as I supposed.

    All I’m saying is while we can deplore and laugh at the chemical ignorance you discuss, the phenomenon is real.

    1. Vader says:

      We all understand the perils of small number statistics and no control group, until we’re part of the small number.

    2. T says:

      Your wife may well have a sensitivity/allergy to sodium benzoate. People can develop allergies to almost anything. Many people are also allergic to eggs/wheat/milk/nuts/tomatoes. That doesn’t mean that these are nasty dangerous additives that should be banned from all food.

    3. Chris Phoenix says:

      Is your wife sensitive to the foods listed in this article which naturally contain sodium benzoate?

      1. Anonymous says:

        Yes, I learned from Derek’s post that shrimp and presumably crab can contain sodium benzoate. These have been a hit or miss cause of hives for her. We couldn’t figure it out but now avoid canned or frozen seafood from Asia. The tricky part is in restaurants when they are included in a sauce.

    4. I think, and correct me if I’m wrong, that if you had a salicylate intolerance (which involves an inadequate ability to conjugate acetyl-CoA to hydroxyphenols for excretion) you might find benzoic acid problematic, but then, given the high amounts of other salicylates in foods, it would not be your only worry. Salicylate reactions are often seen in the skin and lips, which can be exposed to higher concentrations than other tissues.

      1. No, I was wrong. Benzoic acid is excreted as a glycine conjugate, acetyl-CoA is needed for an intermediate step.

        Some drugs and supplements interfere with conjugation (valproate, and lipoic acid here)
        Lipoic acid decreases conjugation by depleting acetyl-CoA; what would have the opposite effect? Probably a low carb diet, where an excess of acetyl-CoA produces ketosis. Add some proteins high in glycine (ox tail, beef tendon, pig’s trotter) – if this syndrome is modifiable these seem like the rational things to try. (you could try supplementing pantethine and glycine instead, but then you’d miss out on identifying the metabolic basis of the reaction)
        Or just don’t eat the benzoic foods.

        1. Lana says:

          George Henderson, your comments are very interesting!! Since 2011 I have struggled with a severe reaction to benzoates (including benzoic acid) when applied to my skin (lotion, serums, deodorant, etc). I DO take alpha lipoic acid, and am wondering if that is interfering with the glycine process to get it out of my system. Bone broth and supplemental glycine does help, but each accidental exposure is worse than before, and I have to go off of benzoate foods for a few weeks. My theory is that when applied to the skin, the glycination process in the liver is by-passed. ?? I have a bachelor’s in biology and a master’s in counseling, so my science background is less than sufficient to help me figure this out on my own. The recent episode was the result of a well-intentioned massage therapist trying a new lotion without mentioning the change to me. The resulty was general lethargy, cognitive sluggishness, and then the telltale severe (SEVERE) eye irritation. I am beyond retirement age and must continue to work full time. I work with teenage kids and would like to not be the counselor with the “ugly eyes.” The trouble I’m having is the food lists I find are not consistent, and I would like a good list that truly omits the problem foods. Can you help? Also, what do you think about the supplements we take with hopes of them being life-enhancing, but interfering with this process of eliminating the benzoates before they cause problems? Sorry for this confusing comment. I am heading to a spa to spend a few hours in a sauna so that I can feel better. By the way, at the spa there is a mugwort infusion for the women to splash on themselves, as mugwort is said to be good for females. Well, being female, I tried it. Within 20 minutes, my eyes were itching and I knew I was on my way back to hell. Hurried home and googled mugwort, only to find that it is high in benzoic acid. If you have any help for me I would deeply appreciate it. Thank you very much!

          1. Liz Lee says:

            I have recently been diagnosed as having a contact allergy to sodium benzoate (in addition to 5 other substances) but as I have been reading up on this chemical, I came across your post.
            Lana, I have found the 11/21/16 article “Update on Benzoates” from the Dermatologist very helpful as well as the website for Contact Dermatitis Institute for identifying sources of benzoate/benzoic acid.
            Also, thanks to the many others here who have posted regarding sensitivities to sodium benzoate. Though we may be a small number, I find it very helpful to share information.

    5. Carlene says:

      I stumbled across this comment by accident while looking for information online about sodium benzoate and rash. Like your wife I’ve learned by process of elimination that foods or drinks containing sodium benzoate cause red bumps on my face. Until now I’ve never heard of anybody else with a similar reaction. I’m very careful when it comes to buying drinks and soy sauce in particular since so many have it.

    6. Amy U says:

      Myself as well. If I ingest sodium benzoate (and some of its close relations-potassium benzoate), it’s not my urine that is interesting…get my drift? I can not leave the house (read bathroom) and for approximately a week my old injuries (sprains, bone spurs etc) are inflamed and move out of place-I go have a chiropractor “pop me back in”. It’s no picknic. Just because science has answers doesn’t mean it has ALL the answers (yet). It is the arrogance of some that creates the ignorance and distrust of the uninformed masses. Let’s agree that there is more to know.

  6. a. nonymaus says:

    Aside from rare cases of allergy (possibly to some benzoic acid protein conjugate?), it seems like a classic case of an appeal to vitalism by these sandwich-makers. It is a seductive fallacy that there can be two benzoates of different origin, alike in their accidents but differing in their essences. Perhaps I could put some robes on and offer my services to transubstantiate the bad benzoate into good.
    Can I get any money out of Panera for deceptive advertising if I find some unprotonated benzoate in their cheese or fruits? What if I feed same to the above poster’s wife and she develops an allergic reaction?

    1. Anonymous says:

      She also develops hives with potassium benzoate. I have considered getting some benzoic acid and spreading a few milligrams on her merienda just to see what happens. Both my marital vows and self preservation have prohibited the experiment.

  7. Kyle MacDonald says:

    “Gemisch”. Good word, I’ll be using that one.

    Question from someone with only foggy memories of first-year chemistry: is the concentration of the cation the main thing that determines how much of its salt will be formed? Do you ever get a solution containing cations X+ and Y+ and anion Z- where X+ is at, say, 50 times higher concentration than Y+, but more of the YZ salt forms than the XZ?

    1. Barry says:

      For salts in solution, the proportion of total cations present is the proportion of partners for any given anion. That’s no longer so when you hit the solubility limit of any of the combinations. So e.g. Iodide will glom onto Ag+ even in the presence of much more e.g. Na+ or K+

    2. NJBiologist says:

      The situation you describe applies around the cell membrane: outside, there’s much more Na+ than K+; inside, that reverses.

  8. Anon says:

    I’m going to offer a service to remove all the toxic and unnatural hydrogen hydroxide from these guy’s bodies, and basically shove ’em in a freeze-dryer.

  9. Food bro says:

    Obviously, your new job is at a sodium benzoate plant, shill!

  10. ScientistSailor says:

    Derek, you are too generous to say their science is wrong. They are not doing science. I’s not even wrong…

  11. milkshaken says:

    I actually dislike the taste of benzoate ever since my grandma ruined a batch of homemade cherry compot and jam with it, being overly generous with the preservatives that summer. As I can usually tell the presence of high-levels benzoate (Lipton ice tea, shame on you), and for me the off-taste of benzoate is bothersome, I ended up avoiding sodas, ice teas and juices that list benzoate on the ingredient list. (Sorbate is slightly less atrocious taste-wise but I can still tell apple cider with sorbate, by blind testing.)

    I am not against benzoate in general – it is better than food poisoning – but I think it has been overused and given the choice I would rather buy food that is preserved by sterilization or refrigeration

  12. CR says:

    To quote a Letterman Top 10 from quite some time ago….M’m! M’m! SODIUM BENZOATE!

    1. CreezusMan says:

      I just remembered how abjectly humorless those top 10 lists became, to the point that they seemed like a cry for help from the writer’s room.

  13. Young Padawan says:

    Just checked out the ingredient list of some of their breads. Microcrystalline Cellulose!!! Isn’t that a bad chemical??? Or maybe it is just a fancy name for chopped up firewood… Why would you eat your fireplaces food?
    So why could one ingredient possible be that bad according to their logic and the other is perfectly fine? Didn’t they find any a llitle more NATURAL sounding source of dietary fiber? How about some bran???

    1. Another Guy named Dan says:

      microcrystalline cellulose is used as a “flow agent” to keep powdery ingredients like flour and confectioner’s sugar from getting clumpy in humid conditions

      1. Isidore says:

        Some months ago I saw published the results of analyses, conduced by the FDA in response to complaints, of various grated packaged parmesans sold by different stores. They all contained microcrystalline cellulose, some as much as >10% by weight, and some contained no parmesan at all. I wonder what’s the composition of the parmesan Panera’s uses in salads.

      2. Kevin S. says:

        When i need cellulose fiber, i go gnaw on the old cottonwood in my backyard ;-D

  14. As others have mentioned above, sodium benzoate can be a trigger for allergies. Drinking soda that contains it will cause me and several people I know to sneeze profusely. It would be good if Panera replaced their shoddy science rationale with “we removed sodium benzoate because some of our customers are allergic to it”.

    1. Anonymous says:

      Amen. We applaud what Panera is doing and urge them to do it faster. We’ve had too many single blinded allergy trials with sodium benzoate when eating

  15. Paul Winalski says:

    I actually participated in the Urination Derby as an undergrad back in 1975. Our Biochem professor divided the lab into partners. One had to do the biosynthesis by drinking a measured amount of sodium benzoate, collecting urine over the next hours, and isolating the hippurate. The other had to do a chemical synthesis of hippuric acid from glycine and benzoyl chloride. You could tell the students doing the biosynthesis by their pale faces and stoic expressions–the human stomach is not particularly happy with benzoate solutions. The big problem with the experiment was that we were using a Bio Department lab that had only one fume hood. This was used to dispense the benzoyl chloride, which is a potent lachrymator. This meant that over the course of the experiment there were students carrying around open beakers of both urine and benzoyl chloride. The air in the lab got pretty foul!

    1. Chemcat says:

      I enjoy reading lab stories from “back in the day”. It sounds like your Biochemistry professor did a good job of making the content relatable, and certainly memorable!

      1. Emom6 says:

        This is hilariously fun science. I am in love with you guys!

  16. anon says:

    People believe in supernatural beings, miracles, gods…There is no need to fight against commercials. Such a waste of time.

    1. Vader says:

      Are you suggesting that, if we could just get rid of religion, all other forms of human nonsense would recede into significance?

      Or merely that, given that religion is extremely popular in spite of All The Right-Thinking People regarding it as nonsense, we’ll never be rid of human nonsense and it’s pointless to try?

      1. fajensen says:

        Witchcraft never went away, never will!

        Anyone on need of confirmation can just fire Google right up and learn that about 97*% of all advice on how to fix any given computer problem involves a series of “try …” steps, making up an incantation, which, it is hoped, makes whatever it is, “go away”.

        It’s “Try, try, try and Try” …. hardly anyone will write anything remotely suggesting a model or even the thinking behind the “Trying”. The old: “… X is caused by A or B or perhaps D …. To determine A or B do …. then …. If D then … ” is gone / dead. Magick and Invocations is where we are!

        *) and learn that 99.7% of all statistics on the Internet are made up on the spot!

        1. Sacha says:

          Go back 25-30 years and you could get detailed troubleshooting steps (except you wouldn’t easily have been able to get them from the internet). Computers now are so complex, with dozens of hidden processes doing mysterious things in the background that neither you nor the manufacturer knows anything about, that it’s very difficult to analyse the specific cause of a problem without spending hours or days debugging things at the kernel level – which is neither possible nor desirable for most people. At the same time, there’s been a concerted effort to make interfaces cleaner and simpler, so users don’t even see what limited technical information is available. So there really is little recourse left than to try the most likely things. Fortunately, this has a high success rate.

  17. Bill Smathers says:

    Fun fact: that benzoate to hippuric acid experiment you mentioned is also in Laboratory experiments in organic chemistry, 5th edition by Adams, Johnson and Wilcox. This was published in the mid-50s. I can upload the relevant pages if there’s any interest here.

    1. AlphaGamma says:

      Not in Vogel’s Practical Organic Chemistry (at least not my copy, which is 5th edition from the 1980s), even though that gives a prep of cysteine starting from “500g of washed, dried human hair”.

      “Raw material can usually be obtained from barbers’ shops.”

      1. Scadriel says:

        Panera also claimed their competetors were using cysteine sourced from human hair in one of their ads. They are the worst.

    2. Pascal says:

      Bill, I would be interested in said pages!

  18. anonymous says:

    I think you missed the lowest hanging fruit in your ingredient naming game.

    Palmitic acid was used in WWII (well the aluminum salt of it) to make napalm (with the “-palm” part of the name from Palmitic acid…)

    1. Chris Phoenix says:

      Actually no, see page 29 of

      The soap used was incorrectly thought to be based on palmate. So it is the source of the name, but not the actual chemical used.

  19. Noni Mausa says:

    Reading my 1939 “Fortunes In Formulas for Home, Farm, and Workshop” where they describe how to test for sodium benzoate, using chloroform (!) mixed into the sample and allowed to evaporate out on a handy windowsill. The list of chemicals used in this book is as long as my arm, and the authors assume the reader can pick them up easily at the local chemist. Oh how dumb Americans have gotten in a mere 78 years.

  20. David Borhani says:


    Panera bread makes another set of disturbing statements in their video, “Preservatives with Purpose.” They state: “We’ve removed all artificial preservatives from our food / Now we’re putting them back where they belong”.

    They have removed three other GRAS preservatives from their food: “BHT Butylated Hydroxytoluene / Found in: … paint”, “BHA Butylated Hydroxyanisole / Found in: … rubber”, and “TBHQ Tertiary Butylhydroquinone / Found in: … varnish”,

    The important and useful purpose of including small amounts of these GRAS preservatives in foods, especially those containing unsaturated fats, is laid out well by the Wikipedia article on BHA:

    “Since 1947, BHA has been added to edible fats and fat-containing foods for its antioxidant properties as it prevents rancidification of food which creates objectionable odors. Like butylated hydroxytoluene (BHT), the conjugated aromatic ring [*] of BHA is able to stabilize free radicals, sequestering them. By acting as free radical scavengers, further free radical reactions are prevented.”

    So, if you like to eat rancid bread, go to Panera Bread!

    * A small quibble: the phenoxy radical, created when BHA and especially BHT donate their O-H H atom to a (often peroxy) radical on the fat, is what is “stablize[d]”. BHA, BHT, and also TBHQ, break the radical chain reaction by acting as chain terminating agents.

  21. LiqC says:

    This is in “Experiments in Organic Chemistry” by Fieser 2nd Ed 1941, experiment 22, pp 114-115. A book on Scribd comes up if you google it.

    Copy-pasting from the book, pardon the formatting:

    Ingest a solution of 5 g. of pure sodium ben-zoate in 200-300 cc. of water (or increase the hippuric acid out-put through special, measured diet), and collect the urine voidedover the following twelve-hour period. If it is to be kept for more than an hour or two before use, add 5-10 cc. of toluene toprevent decomposition, and then separate this when ready toproceed further.For every 100 cc. of urine add 4 cc. of concentrated hydro-chloric acid and note if a precipitate forms. (If some acidseparates at this point, collect it and combine it with any furthermaterial obtained by the following procedure.) Now add am-monium sulfate (25 g. per 100 cc. of urine) in portions, stirringwell so that it will all dissolve. The hippuric acid may separateeven before all of the added solid has dissolved, or it may depositonly after the solution has been well cooled and allowed to standfor several hours. Collect the precipitated material by suctionnitration, wash it with a small quantity of cold water, and crystal-lize it from water, using a little animal charcoal to decolorizethe solution. Since hippuric acid is fairly soluble in cold water,avoid an excess of solvent and cool the solution at o° beforecollecting the crystals. Record the melting point and the yieldof the purified product (m.p., pure, 187.5C). The average yield is 3 g

  22. Allan says:

    A true story, again about the difference a single proton in a conjugate acid-base pair can make. Many years ago, here in New Zealand, we had a list of potential chemical weapons circulated around all labs in the country every year, and you had to confirm if you had any of them in your lab. One year, tris(2-chloroethyl)amine, the well-known nitrogen mustard, was on the list. As we made lots of the ligand tren (tris(2-aminoethyl)amine) in my lab, we happened to have lots (200 g) of tris(2-chloroethyl)amine.HCl in the lab, so I ticked the box saying ‘yes’. Big mistake. Next moment, government officials were in touch, telling me a 3 member United Nations Chemical Weapons inspection team would be visiting my lab, all the way from The Hague, to inspect this material (not kidding). They duly did – they flew halfway around the world, stayed for three days, wrote a report, and here’s me thinking I’m going to suffer the same fate as Saddam Hussein. Anyway, it transpired that, while tris(2-chloroethyl)amine was a chemical weapon, the hydrochloride salt tris(2-chloroethyl)amine.HCl wasn’t. Because, obviously, it’s not simple to turn the latter into the former…..

  23. Joe Blow says:

    Panera’s logic might have been off, but benzoic acid/sodium benzoate in beverages, particularly in combination with ascorbic acid, has been shown to decarboxylate to give ppb levels of benzene, when exposed to heat/light.

    It is my tendency to react just as most of the people here have, i.e. to ridicule pseudoscience and popular misinterpretations of science. But experience has shown me that it is important to consider the scientific questions carefully, as a scientist, rather than to give in to my impulse to ridicule. We know far more than the average person does about chemistry and science in general. But it’s too easy to fall into the trap of overconfidence and overinterpretation of data. We lose credibility with the public. Look at how the public views nutritional advice on dietary fat, or how much of the public doesn’t believe in climate change–I think this is a direct result of scientists overplaying their hand in their attempts to guide policy (however well-intentioned they might be).

  24. Anonimix the Gaul says:

    I’m surprised nobody played the trump card yet. Maybe because it’s old news to most people here?

    But seriously, this reminds me of this very dangerous chemical that

    – is a major component of acid rain.
    – can cause severe burns when in gaseous form.
    – contributes to soil erosion.
    – leads to corrosion and oxidation of many metals.

    It’s everywhere. Its many uses include:

    – as a spray-on fire suppressant and retardant,
    – as a major ingredient in many home-brewed bombs,
    – in spray-on oven cleaners,

    And wouldn’t you know, the stuff is used as an additive to food products!

    Including jarred baby food and baby formula!

    I mean, won’t somebody think of the children?!


    …and yes, some politicians did in fact try to ban DHMO, may Azathoth have mercy on their souls.

    1. Kevin S. says:

      Would you be referring to H2O? Lol.

    2. Dave says:

      Forget DMHO, have you heard about Hydro-oxic Acid?!! Panera still puts it in their bread!!

  25. doc says:

    “Gemisch” as a new word: how we have fallen. No chemist prior to -perhaps- 1990 would fail to know this perfectly common (in the lab, anyway) German word. Like the correct pronunciation of “unionized”, it was pathognomonic for a background in chemistry.

    Penicillamine, mw 149 ish, was the smallest hapten I ever encountered shown unequivocally to lead to allergic reactions. It would appear that benzoic acid has extended that lower limit, at least by a few amu.

    1. tangent says:

      Are you counting nickel?

    2. Anonymous says:

      Nitrophenols (nitrophenols MW 139, DNPs MW 184) are also antigenic. A large fraction of the entire human population has circulating antibodies reactive towards nitrophenols. (If I had lit access, I’d provide more specific numbers.) Spiegel (Yale) couples nitrophenols to targeting ligands to bind to specific receptors that will then recruit the nitrophenol existing Abs to kill the targeted cells.

  26. MoMo says:

    In a world where pharmaceutical organic persistors such as tricyclic antidepressants and Prozac cycle in the environment and your fat tissues and Ben and Jerrys ice cream has unacceptable levels of glyphosate worrying about benzoate advertising seems and is petty.

    At least Panera is trying to limit exposure and provide healthy foods. All Pharma wants to do is keep you, your children and grandma saturated with neuroleptics so you don’t notice how much you are saturated with useless drugs.

  27. cynical1 says:

    I have to say that I see this a little bit different. Statistically, there are far, far, far fewer people knowledgeable about science/organic chemistry in the general public than there are chemo-phobic and scientifically illiterate people in the general public. So, if you are trying to market to the masses, you wouldn’t advertise that you actually left sodium benzoate in your bread because it is completely benign and keeps your bread fresh longer. That would not sell any additional product if you are Panera (or any other retailer). However, if you reassure the idiotic masses that you removed a “chemical” from their food, then they all jump up and down with joy and think it must be “safe and natural”. You can’t blame Panera for marketing to the knuckle-dragging masses. If they want to move product, all they have to do is look at the masses. They are, for the most part, a pretty unenlightened bunch. I would like to coin a new phrase: symmetrically stupid.

    So, maybe the people who are in marketing at Panera are completely scientifically ignorant or completely the opposite. Who knows. But I would say they do, however, have the correct approach to marketing to the masses. It’s one thing to “know your product”. But it’s a different thing to “market your product”.

    I don’t much like Panera anyway.

  28. Steve Dutch says:

    There’s a pink mined salt from Utah that my wife likes. I found some at a health store. The clerk gushed “I love this! It has MINERALS in it!” [Bangs head slowly on counter]

    1. Laurel says:

      Salt is a mineral……

    2. loupgarous says:

      A friend of ours gave us some pink “snob salt” in a big plastic grinder. Anyone have an idea what makes it pink? I’m curious.

      1. Martin says:

        Mostly iron oxide, with traces of calcium, magnesium, potassium, copper. For Himalayan Pink salt, that is.

  29. Dave says:

    When Panera first posted their ‘unwanted/unnatural ingredients’ list, I had conniptions. Sometimes, I think I ought to contact the company- but decide that it would be a waste of time.

    PS… You know, that salad is still alive when you eat it.

  30. crni says:

    p-phenylenediamine, PPD, MW 108. Allergen of the year in 2006.

  31. eric says:

    I am a chem student in NC, whenever I drink a lot of stuff with benzoate I get psychotic. The stuff is bad for me, and that is a fact. I was reading it is a potent inhibitor of some neurochemical in the brain. Actually it was thought it helped schizophrenia, regardless I avoid the stuff now and always check my labels. Probably have to avoid a lot of fruits as well.

  32. Harvey Black says:

    I’m admittedly late to the party, but I would like note the famous paper by Ames et al about natural carcinogens. Perhaps the powers that be at Panera should at least scan it.

  33. Jo says:

    Hi all

    I have a severe allergic reaction to sodium benzoate and even though I try my best to avoid products (especially sauces) containing this preservative, it’s not always possible.

    I start to show flu like symptoms including fever and then begin to cough a lot – I basically bark non-stop like a dog for a whole month. Nothing helps cause even the cough syrups contain it.

    This has happened a few times and I was able to trace it back with each occurence. The reaction is consistent every time so the allergy test was accurate.

    Any advice on how to treat the allergic reaction as I haven’t had any success thus far.

    Much appreciated


  34. Nancy says:

    Hi Jo,

    I too have reactions to sodium benzoate, what you experience plus severe hives. Recently, I had severe hives due to oral flouconozale and have had anaphylactic reactions to other meds not realizing that sodium benzoate is an inactive ingredient. I have found Benadryl provides the best relief and for my recent whole-body hives a prescription steroid topical creme was helpful.

    To Derek Lowe, this article’s author, while your scientific perspective is appreciated, to criticize Panera is unfair. As you can see from reader comments, people experience real sensitivity and let me tell you that it sucks to break into hives after drinking a Bloody Mary at a high-end restaurant or using beauty products that you bought at Whole Foods thinking they are cleaner. Perhaps Panera linked reports of “food poisoning” or allergic reactions to its recipes and traced it to sodium benzoate.

  35. whatiscausingmybodytoreactthisway says:

    buy some sodium benzoate and mix a little in a glass of water and drink it, see if that is really what you are allergic to. It’s a naturally occurring preservative made by microbes.

    It’s known that people can become sensitized to many different compounds. I had a labmate that would go nuts if someone just even opened a bottle of DCC in the lab, he could feel it on the top of his head as a burning sensation.

    I myself have broken out into hives and blisters from working with allopurinol intermediates.

    If it really is sodium benzoate, try exposing yourself to very small amounts of it and see if you can become less sensitive to it.

    With regards to the “salt” argument posed by the author of this blog, MSG is just the sodium salt of glutamic acid, a naturally occurring amino acid in the body. Why do so many people have a reaction to MSG? Is it all in their minds??

    1. Derek Lowe says:

      To the best of my knowledge, no well-controlled blinded test of MSG sensitivity has ever shown it to be real.

  36. FPK says:

    It’s probably not just sodium benzoate that your wife reacts to, but all benzoate, including chemical crapola benzoate derivatives (all that crap with a -benz in the name on labels) AND unfortunately also many lovely fruit and vegetables that have a lot of naturally occurring benzoate in them (tomatoes, stone fruit/drupes, soy beans). She probably also reacts to chemically similar substances like vanilla, chocolate, cinnamon and cinnamonish sweet spices, and Balsam of Peru (plus flavorings derived from Balsam of Peru which are nefariously labeled as “artificial flavor” or “natural flavor”). Soy beans are naturally high in benzoate. Capsicum has chemical components that are similar to benzoate so chiles can irritate some people. It’s a lot to avoid. All of the stuff on the avoid list, both chemical garbage preservative benz stuff and natural benz stuff derived from cinnamon and Balsam of Peru are in many, many household and grooming products, too. That’s your pesticides and your face wash and hair spray and so on. 🙁

  37. Marilyn says:

    Snobs. Derek Lowe/ Frazier Crane “character”. Look at me, I like to use “big” words to impress. Snobs

    1. Barry says:

      You may have noticed that this is Derek’s ‘blog. You can read it, you may even learn from it. But if you’ve come to criticize our host, you’re in the wrong place.

      1. Kent G. Budge says:

        It’s not even a coherent criticism.

    2. loupgarous says:

      Marilyn, the grown-ups are talking about chemistry. I had enough chemistry in college to get me through two years of pre-med biochemistry before I changed majors, but I can follow along without too much Googling. Derek’s not trying to impress anyone, he’s just explaining himself in the language of chemistry.

      I don’t know if you are interested in anything that requires a special set of words to understand. Imagine trying to explain football without talking about “off-sides”, “clipping”, “grounding”, and other special words (I use football as an example, because here in the South everyone, men, women, and kids, follows football). Of course, feel free to think about knitting, fishing, contract bridge – whatever you enjoy that has its own set of special words.

      As the guy here with a degree in technical writing, it’s nice to use my education now and then.

  38. loupgarous says:

    One way to get through to Panera is for some med-chem and other pharma guys to show up in their kitchens with sheaves of papers about how leavening and other biochemical processes work and which have little or no relevance at all to actual baking. Feel free to make fatuous remarks about cooking in general, until the endpoint is reached where the Panera people lose patience with you.

    Listen to their complaints about how you have absolutely no idea about baking, then calmly reply “Now you know how we feel when you talk about the toxicity of sodium benzoate.

  39. As a Vape shop owner I am trying to get good information about sodium benzoate. It has become the newest fad in E-liquids (salt Nic) and I don”t see anyone publishing the concentration levels and can’t help but be concerned about people inhaling it all day everyday. As of now I have refused to sell it in my shop. Are my fears well founded or am I being overly cautious for no reason.

  40. loupgarous says: says there have been no studies on human inhalation of benzoic acid (sodium benzoate’s a salt of that), and just one study in male rats, so the EPA doesn’t even publish data on how toxic it is when inhaled.

    I’d say in the absence of data, you’re being reasonably cautious. The tobacco industry sat on data about how bad the various cyclic hydrocarbons in cigarette smoke were for you, and we know what happened there.

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