Is Borax Toxic?

Many people are concerned about whether borax is safe to use. There are many sites on the internet claiming borax is toxic. But there is a lot of better evidence that it is safe. Click to learn why...

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Many people are concerned about whether borax is a safe chemical. There are many sites on the internet claiming it is toxic. I disagree with these sites and believe that borax is as safe for household use as table salt or washing soda—in other words, the dose makes the poison. Here’s why…

History of Borax

chunk of borax on a blue table

Humans have mined and used borax (also known as sodium tetraborate) since its discovery in Persia more than 4,000 years ago. Borax is a naturally occurring mineral found in concentration in dried salt lake beds, and consists of water, sodium, boron and oxygen. That’s it. The main areas where borax is mined today are in Turkey and California.

Boron is an essential trace mineral nutrient required for many functions in the body, like rebuilding bone and teeth, hormone regulation, absorption and metabolism of calcium, magnesium and phosphorus, and maintaining communication between your cells.

In fact, boron is as essential for the parathyroid gland as iodine is for the thyroid.

Boron is ubiquitous in soil and water, and is required for plant growth. Diets with a fair amount of fruit and vegetables provide about 2 to 5 mg of boron per day, but this also depends on the region where the food was grown and how it was grown.

The Evidence on Borax

All of the studies that showed evidence of possible hormone disruption in animals either used ridiculously high doses of borax (many grams delivered intravenously), or they conflated borax with boric acid, which is NOT the same stuff.

Borax (sodium tetraborate) is used in the process of making boric acid, but there is a tremendous chemical difference between the two. Many of the studies used to demonstrate the alleged danger of borax often used boric acid instead, or were ambiguous about which was used.

Boric acid is toxic at far lower doses than borax, so any study that isn’t clear about which of the two is used for the data should not be considered credible. (This includes the EWG data.)

Borax can be toxic at the high doses used in animal studies. It has this effect at high doses is because it is essentially an overdose of the element boron. Iron, zinc and calcium are required by the body too, but an overdose of any of these will also send you to the hospital, or even kill you!

However, adults would never ingest anything even close to the amount of borax required to do harm—unless they worked unprotected for years in a borax mine or packaging factory. However, you will want to keep your small children and pets out of the borax, just as you would keep them away from the chewable vitamins. An overdose of boron can be as dangerous as an overdose of zinc or iron, especially for small bodies.

Borax is officially classified as non-carcinogenic and a mild skin irritant. The high alkalinity of borax (pH 9.5) is what causes skin irritation, which is the same reason that washing soda and even baking soda cause skin irritation, too. The alkaline pH of borax, washing soda and baking soda is what softens the water, and makes it possible for them to clean your clothes.

There are also several studies in the PubChem database that show borax is only a very mild lung irritant and causes no lasting damage. If ingested, it is quickly excreted in the urine. In addition, it does not really penetrate the skin well, and is not bio-accumulative.

Finally, the Material Safety Data Sheet lists borax as a health hazard of 1—the same as baking soda and salt. In other words, borax is toxic in the same way that salt is toxic (Actually ounce for ounce, salt is more toxic): A small amount can do great things; a huge amount will kill you and other living things.

You wouldn’t want to ingest large amounts of salt or baking soda, inhale them, or rub them in your eyes. Borax is no different.

Uses for Borax

Borax is used in laundry detergents, hair potions and skin lotions. Like diatomaceous earth, it also can help kill fleas and dust mites in your carpet by dehydrating them. It is also used as a safer ant and cockroach killer.

Borax is also naturally anti-fungal and anti-viral (but not anti-bacterial), and—here’s the neat part—through a chemical reaction with water, borax produces hydrogen peroxide (the main ingredient in OxyClean) to brighten and sanitize your clothes.

Because borax is made of just sodium, oxygen, hydrogen and boron, many people even ingest small amounts of borax mixed in water to self-treat various health conditions that supplemental boron can really help, like arthritis, fluoride detoxification, osteoporosis, prostate cancer, menopausal symptoms, psoriasis, and candida.

I do not recommend supplementing with borax because it’s very hard to regulate the dose, and you don’t want to overdo it. Use a high-quality boron supplement instead.

For external use, you should use the same precautions (gloves, dust mask or bandana) with borax that they would use around any dusty substance, like washing soda, bentonite clay, diatomaceous earth, or powdered soap. (Heck, even flour or powdered sugar would be irritating if inhaled!)

So, Is Borax Toxic?

In sum, borax is wholly natural and has no inherently toxic ingredients. It doesn’t cause cancer, accumulate in the body or in nature, or absorb through the skin.

Because the dose makes the poison, borax is not harmful to the body or the environment with normal, external usage any more than salt or baking soda is. In fact, the largest borax (borate) mine in the world—found in Boron, California—is considered to be one of the most ecologically sound and environmentally sustainable mines in the United States.

I consider borax a safe, effective cleaner, and I will continue to use it in my household green cleaning and safer pest control.

50 thoughts on “Is Borax Toxic?”

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  1. Hi. I saw you had proof that Borax isn’t toxic. Is there any information that zote soap is toxic? Please and thanks!

  2. My great grandma used boric acid as an eye wash and my mom uses it on her dog for skin irritations. I use it to make my laundry cleaner. People read or study things until they find what agrees with their world view.

  3. As a chemist, I must say that borax (actually the tetraborate ion in it) is easily converted in boric acid, e.g., by adding acetic acid or citric acid (typical ingredients of homemade cleaning liquids), or any other acid that is stronger (in chemical terms) than boric acid. The tetraborate ion is always in equilibrium with boric acid, and one form converts into another by simply changing pH. Anything the brings pH down will convert part of tetrabortate (borax) into boric acid. At neutral pH (around 7), you have around 50% of borax converted into boric acid. Just bear in mind that the two forms are always present in solutions, and pH is the factor that determines the ratio between them.

  4. The use of Synthetic Chemical Fertilizer’s inhibits food crop’s from absorbing boron… so there is a deficiency of this mineral with most people who eat a processed food diet…

  5. Hi. First, I loved this article. Second, I have used borax in my home made soap, shampoo and body spray for 6 years with no irritations or side effects.

  6. I know someone who tested with immeasurably low boron who is scheduled for an operation on the parathyroid to correct ‘unhealthily high blood calcium levels’. Has teeth issues and bone issues. This person has, until recently, been very wary of borax while now they’re taking it as part of a supplement.
    People fulmenating about so called scientific studies pointing to the danger of boron related compounds in general really would do well to apply a bit of science to themselves and see what their levels are. In today’s environment i would be far more concerned about a lack of it. I also recommend to anyone interested googling a uni of florida study on bone denisty and prune intact. And lo! Prunes are one of the best dietary sources of boron…

  7. Good for you, I use Borax all the time and even exfoliate with it and I am 57. I am with you. People are either meaning boric acid which can be dangerous or in my opinion are just alarmist. I think we have to stop throwing the baby out with the bath water. Just so you know I was touting organic long before it was popular, but well I leave it there. Thanks for trying to make people aware.

    1. Boric Acid is not dangerous, it is an ingredient in Visine and used alone with water as an eyewash. Boric Acid is also used to cure some vaginal problems as a suppository. If it is used in that respect how dangerous could that be? My grandmother would always put boric acid on us in a little paste with water for any skin rashes we ever had. So no it is by no means dangerous no more than table salt.

    1. Johnny McQuinn

      I put a 1/4 of a cup in my bathwater. It really works great for skin. Borax will make you look younger and your skin glow.

  8. Thank you for this factual info on Borax! Borax has been used for a long time and has a proven safety record. Not sure why some forces want to malign it so much now. It used to be used for food preservation and is making a comeback (as boracare) in the building industry to prevent rot and insect damage on timber. The human body needs small amounts of boron. Boron compounds have fungicidal properties.

    1. I’ve been dealing with demodicosis for 6 months. I’m dealing with naturally, staying away from all prescriptions, the odds aren’t very convincing for the amount of chemicals that are going on & in me.
      I’ve recently been reading articles on borax so I’m going to give it a try. Ha, my problem now is trying to find it.

  9. I just used borax to scrub my skin with. I have very dry, rough skin on my legs. After one scrub I cannot believe how soft my skin is! That’s when I went online to research how safe borax is and found your article. This makes great sense to never and I will keep using it in the laundry and on my skin.

    1. Please be careful. Borax works because it is highly alkaline, which can burn or irritate your skin as much as a mild acid like salicylic acid can. That’s why it smoothed out the rough, dry skin so well. I wouldn’t recommend it straight for regular skin usage!

  10. Would you say the UK and Europe are wrong to have banned Borax as because it can be harmful to female fertility?

    1. I think borax is the very least of our worries when it comes to chemicals that can effect female fertility.

      1. You have not read the medical studies HAVE YOU? They used small amounts of borax in the 1920’s in milk products, and the studies confirmed it unsafe and extremely unsafe for children. It has caused deaths!

        1. I suggest you read the article a little more thoroughly. It specifically states, “However, you will want to keep your small children and pets out of the borax, just as you would keep them away from the chewable vitamins. An overdose of boron can be as dangerous as an overdose of zinc or iron.”

          For external household use (not ingestion), I consider borax to be extremely safe.

          1. Borax is not safe for children to be used without adult supervision and if people use borax they have to be very careful not to use to much.

  11. Borax is about as poisonous as salt.
    You do not want to take too much of either.
    Both are required for good health, but you can get all you need by eating a healthy diet.

    Our cotton clothes seemed to wear out much faster with borax.

  12. I just saw an article on a friends fb page stating that we should Beware of Homemade Slime which is made by using borax along with shaving cream, glue, soap, water and food coloring or paint. My daughter and her friends love making slime and up until today I had not heard any concerns with it. What are your thoughts on this concern? After reading your article above and some other articles I have found – I am not sure there is really anything to be concerned about – but would welcome your thoughts. Thanks.

    1. I have no problem with my daughter making slime. I don’t really want her to inhale powders of any kind, so I supervise a bit there, but otherwise I have no worries!

    2. My son starts to make home made slime with borax, shaving cream, soap… My friend warned me about the use of borax as she said it is very toxic, I however said that I think borax is natural and safe to use for laundry and a little bit for slime (I supervise my 8 year old son when he wants to use borax in slime) because I even bought it at Whole Foods. This led me to search online and saw your article.

  13. Thanks for the post! Just cruious, if borax + acid = boric acid, is there a risk that you can inadvertently ‘make’ boric acid by using borax with another ingredient, such as apple cider vinegar which has hydrochloric acid?

    1. You need a very strong acid to make boric acid from borax. Apple cider vinegar contains acetic acid at a very low concentration, not hydrochloric acid. You won’t need to worry about accidentally making it with vinegar, or orange juice, or any other food grade acid.

    1. This is a classic example of the bait and switch I see in article after article. You’d think people would do more fact checking. The beginning of the article talks about borax, and then it goes on to warn about the dangers of exposure to boric acid.

      Borax and boric acid ARE NOT THE SAME THING. Boric acid can only be made by reacting borax (sodium tetraborate decahydrate) with a strong mineral acid, such as hydrochloric acid, which simply doesn’t happen in a household cleaning or crafting setting. Boric acid is much more of a concern than household borax, and conflating the two only confuses people and leads to unnecessary precaution.

      Ounce for ounce, borax is as dangerous as table salt, and less toxic than caffeine.

  14. Bernadette Tran

    Fantastic! Really interesting information. I know that Borax is not toxic but I can`t give you a reason. I just know it. Now I know why. Thank you for sharing this article! Best regards!

  15. Thank you for such an informative article! I’ve been using borax, vinegar, etc, instead of store-bought cleaners for awhile, & had just read some questionable articles regarding the “toxicity” of borax, which I’d never heard before, so I looked further & found this article. I feel better now!

    1. Me too! Just made several batches of cleaning products with it, and then started reading that it may be toxic. Thank you so much for this very informative article. Makes perfect sense, and I feel much better now that I have the facts. Thank you!!

  16. Great write up. I agree with you on the “toxicity” of borax. It’s simple science, really. If borax is as natural as methane gas (also non-carcinogenic), then it’s perfectly safe to wash clothes with borax as it is to be in the same room with someone who is prone to flatulence.

    Odd, I know, but the truth can’t be denied.

    1. Arsenic and cobra venom are also just as natural as methane gas, so that’s not a good indicator. Just because something is natural doesn’t make it safe

      1. True, but that’s not the argument I’m making for borax. The MSDS safety data specifically states borax is rated a 1 for safety, which is the same safety rating as baking soda and table salt. Borax is equivalent to table salt, not to cobra venom.

        1. It goes further, if you look at some MSD sheets it goes so far as to say that table salt is markedly more toxic by oral consumption than borax with 3000 mg/kg of table salt being toxic and 4500 – 6000 mg/kg of borax being toxic for rats.

  17. Thank you, at last someone offering a rational informative answer to the question on many early years practitioners lips right now ( following current trend of slime recipes). Every other site I have looked at, while researching this, offered only fear inducing warnings or irrational objections; yet offered me no real advice or evidence that i could use as a basis for opinion. Of course I understand the need for caution when creating an environment safe for children to explore but I firmly beleive it is possible to do so in such a way that avoids blindly erradicating everything not guaranteed 100% chilld friendly. It harks back to the shaving foam panic we endured a few years ago, did we not then conclude that although there may be an element of concern in using it to enhance provision, the dangers are minimal and therein lies the exact reason we impliment thorough risk assessments. My manager calls it the double a, vital in early years, “awareness = avoidance”. This view, in my mind, is synonimous with lazy thinking,; not only does it markedly diminish a childs potential to develop critical thinking in a practical context, we are underestimating their innate capacity to manage danger for themselves as they seek out new and challenging experiences. Thanks again, I shall be sharing your advive with friends and colleagues so they too are able to make informed decisions re balancing safety with stimulation thus creating a future generatoon of innovative free thinking individuals (as opposed to worryworts who stick to what they know, or worse have been told by others!)

    1. The author’s emphasis in writing this article is the safety of borax for household use, although she hints at being read up on borax as a supplement and cure for some ailments. Here is an interesting article by an Australian naturopathic kind of physician where he makes some astounding claims for the curative uses of borax: That man tells us that the European Union totally and completely banned the sale of borax (and boron too, I think) a few years ago so as not to threaten the profits of the drug companies.

      1. The article blatantly conflates boric acid (which is not sodium borate and is toxic in low doses) with borax (which is sodium tetraborate and is not toxic at low doses) to make its case, which is totally dishonest.

        I also think, however, that any borax in vaccines is probably of relatively less concern compared to the many other significantly toxic ingredients in vaccines.

        1. I don’t know what idiot is now spouting that boric acid is toxic, no more than table salt. Look at your Visine bottle for ingredients. Women use boric acid in suppository form to cure BV. Please stop and study this, the pharma companies don’t want you using Borax nor boric acid cause they lose money.


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