Borax and boric acid are often confused as being the same thing, but while they share some similarities, they are distinct chemical compounds with different properties and uses. In this article, we’ll examine the differences between borax and boric acid to gain a clearer understanding of what sets these two substances apart.
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What is Borax?
Borax, also known as sodium borate, sodium tetraborate, or disodium tetraborate, is a compound made of sodium, boron, oxygen, and water. Its chemical formula is Na2B4O7•10H2O. Borax contains boron, a nonmetallic element, combined with mineral salts. In its powdered form, borax is white, consisting of soft colorless crystals that can appear from transparent to opaque.
Borax has been used for a variety of purposes throughout history. In nature, it’s found in arid regions such as desert areas. Borax can also be produced synthetically from other boron-containing minerals. Some key characteristics and uses of borax include:
- Natural cleaning agent – Borax can help remove stains, whiten laundry, and eliminate odors
- Preservative – Borax can keep foods from spoiling by inhibiting microbial growth
- Buffering agent – Borax helps maintain proper pH levels in cleaners and other solutions
- Flux for soldering – Borax lowers the melting point when soldering metals
- Insecticide – Borax can kill ants, roaches, and other bugs
- Fertilizer ingredient – Borax provides boron, an essential micronutrient for plants
- Wood preservative – Borax protects wood against fungus and insects
- Anti-fungal agent – Borax inhibits the growth of molds and fungi
Due to its versatility, borax can be found in a wide range of commercial and consumer products including laundry boosters, all-purpose cleaners, cosmetics, enamel glazes, fertilizers, and pesticides. It’s recognized as generally safe for most uses by the FDA when used appropriately.
What is Boric Acid?
Boric acid, also known as orthoboric acid, is a weak acid that combines boron with oxygen and hydrogen. Its chemical formula is H3BO3. Boric acid takes the form of colorless crystals or a white powder that dissolves easily in water.
Like borax, boric acid has antiseptic, antifungal, and insecticidal properties. Some primary uses of boric acid include:
- Pest control – Boric acid kills roaches, ants, termites, and other insects
- Preservative – Boric acid keeps foods from spoiling due to its anti-fungal abilities
- Antiseptic – Boric acid has antimicrobial activity against bacteria and fungi
- Cleaning agent – Boric acid can remove stains and odors as a laundry whitener
- Wood preservative – Boric acid protects wood against insect damage and decay
- Eye wash – Diluted boric acid can be used as an eye wash or eyewash
You’ll often find boric acid used in insecticides, antiseptic creams, eyewashes, wood preservatives, livestock feed, and other industrial products. It’s also commonly used as an acne treatment due to its antiseptic properties. While it has many uses, boric acid can be hazardous if swallowed in large amounts.
Similarities Between Borax and Boric Acid
Despite their distinct chemical makeups, borax and boric acid share the following similarities:
- Contain boron – Both contain the element boron as a key component
- White appearance – They are typically white powders or crystals in their pure form
- Water-soluble – Borax and boric acid readily dissolve in water
- Toxicity at high levels – They can be toxic when ingested in large quantities
- Antimicrobial properties – Both have antibacterial and antifungal abilities
- Preservatives – They help prevent spoilage and decay
- Pest control – Borax and boric acid can eliminate insects and other pests
- Cleaning agents – They have uses as laundry and household cleaners
- Flame retardants – Both can be used as fire retardants
The main similarity between borax and boric acid is that they both contain boron, which gives them many shared properties and uses. However, the specific chemical composition of each compound results in some differences as well.
Differences Between Borax and Boric Acid
While borax and boric acid have overlapping uses and qualities, there are some key differences between the two substances:
- Chemical structure – Borax is a compound while boric acid is an acid
- pH – Borax is basic while boric acid is acidic
- Toxicity – Boric acid is more acutely toxic if ingested in excessive amounts
- Solubility – Borax is moderately soluble in water while boric acid is highly soluble
- Uses – Some applications differ, with borax used in soldering and boric acid used as an eyewash
- Potency – Boric acid is stronger as an insecticide and antiseptic
In summary:
| Property | Borax | Boric Acid |
|---|---|---|
| Chemical Formula | Na2B4O7•10H2O | H3BO3 |
| pH | Basic | Acidic |
| Toxicity | Low | High |
| Solubility in Water | Moderate | High |
| Common Uses | Cleaning, soldering flux, insecticide | Eyewash, insecticide, preservative |
As this table illustrates, the distinct chemical makeup of borax (Na2B4O7•10H2O) and boric acid (H3BO3) result in differences in properties like pH, toxicity, and solubility, as well as their specialized uses.
Can Borax and Boric Acid Be Substituted for Each Other?
Because borax and boric acid share so many similar properties and uses, some people consider them interchangeable and substitute one for the other in recipes and applications. However, there are some important caveats to keep in mind when substituting borax for boric acid or vice versa:
- Substitution may change the pH of cleaners and solutions. Borax is alkaline while boric acid is acidic, so substituting one for the other can alter the pH balance of a product.
- Effects may not be equal when substituted 1:1 by weight. Due to differing levels of boron content, you may need more or less of one versus the other to achieve the same effect.
- Toxicity levels differ between borax and boric acid if ingested. Boric acid is more acutely hazardous if swallowed.
- Specialized uses may not carry over. For example, borax works as a soldering flux whereas boric acid does not.
Therefore, substitution is not always straightforward. The effectiveness when substituting borax for boric acid or vice versa can depend on the specific application and the relative amounts used. It’s recommended to consult recipes and safety guidelines for a given project before substituting one for the other.
How to Make Boric Acid from Borax
While not a highly recommended DIY project due to toxicity concerns, it is chemically possible to make boric acid at home from borax. Here is an overview of the process:
- Obtain borax (sodium tetraborate decahydrate). This is commonly available as a white powdered laundry booster.
- Dissolve the borax in hot distilled water to make a saturated solution. Use a 2:1 ratio of borax to hot water.
- Allow the borax solution to fully cool down. White boric acid crystals should begin to form as the solution cools.
- Filter out the boric acid crystals using paper filters or coffee filters.
- Spread the filtered boric acid crystals on towels to dry.
- Store the dried boric acid in clearly labeled, sealed containers kept out of reach of children and pets.
This DIY process takes advantage of the differing solubilities of borax vs. boric acid. As the saturated borax solution cools down, the boric acid becomes less soluble and crystallizes out. The boric acid crystals can then be filtered from the remaining borax solution.
However, making your own boric acid is not recommended for the average consumer. Inhaling boric acid dust can be hazardous, and ingesting homemade boric acid could be poisonous due to potential contaminants or improper dosing. It’s best to purchase commercially manufactured boric acid from a trusted supplier.
Conclusion
While borax and boric acid have many overlapping uses and qualities thanks to their shared boron content, they are distinct chemical compounds with important differences. Borax is a basic compound with the formula Na2B4O7•10H2O while boric acid is an acidic compound with the formula H3BO3. Boric acid is more toxic if ingested and more potent as a pesticide and antiseptic. Substituting borax for boric acid or vice versa is not always straightforward and could alter the pH balance of solutions. Although it’s possible to make boric acid from borax, this is not recommended due to potential toxicity concerns. When using either of these boron-containing substances for cleaning, pest control, or other applications, it’s best to follow recipes and guidelines specifying the exact compound to use.