What Is Sodium Borate?
Sodium borate, more popularly known as borax, is a naturally occurring mineral made up of sodium, boron and oxygen. Chemically it appears in two main forms: disodium tetraborate anhydrous and disodium tetraborate decahydrate. Both forms deliver the same practical effect in cosmetics, just with different water content. Large deposits of sodium borate are mined from dry lake beds in places like California’s Mojave Desert and parts of Turkey, where ancient lakes evaporated and left concentrated borate crystals behind.
Historically people used borax as a household cleaning booster long before scientists understood its chemistry. By the early 1900s formulators noticed that small amounts helped stabilize creams and lotions, paving the way for its adoption in personal care. Modern cosmetic grade sodium borate is produced by refining mined borate ore, dissolving it in water, filtering out impurities, then crystallizing the purified compound. The result is a white, odorless powder that dissolves easily in water.
You will most often spot sodium borate in rinse-off products like cleansers, scrubs and masks, but it can also appear in some moisturizers, shampoos, conditioners and styling gels. Its role is subtle yet important: it fine-tunes the pH of a formula so other ingredients perform at their best and keeps the product stable while it sits on your bathroom shelf.
Sodium Borate’s Cosmetic Benefits/Uses
Sodium borate plays a behind-the-scenes role that supports the overall feel and effectiveness of a product.
Buffering: The ingredient keeps a formula’s pH within an optimal range. By preventing the product from becoming too acidic or too alkaline, it protects sensitive skin from irritation, ensures preservatives work properly and maintains the texture and consistency that make a cream glide smoothly or a gel stay clear.
Who Can Use Sodium Borate
Sodium borate is generally considered suitable for most skin types because it is used at very low levels and mainly serves as a pH balancer rather than an active treatment. People with normal, oily or combination skin are unlikely to notice its presence at all. Those with very dry or highly sensitive skin may prefer to limit exposure since any alkaline-leaning buffer can sometimes disrupt an already fragile barrier, especially if the product stays on the skin for long periods.
The compound is mineral-derived, not animal-derived, so it is typically acceptable for both vegans and vegetarians. Always check the full ingredient list though, as other components in the same formula could be animal sourced.
Pregnant or breastfeeding individuals can usually use products that contain sodium borate in rinse-off or leave-on formats, as the cosmetic concentrations are low and absorption is minimal. This is not medical advice; anyone who is expecting or nursing should review all skincare products with a qualified healthcare professional to be safe.
Sodium borate does not increase photosensitivity, so there is no special need to alter sun protection habits because of its presence. It also plays nicely with most other cosmetic ingredients and does not interfere with common actives like vitamin C, niacinamide or retinoids.
Potential Side Effects/Adverse Reactions
Reactions to sodium borate applied on the skin differ from person to person. The points below describe potential side effects, yet most users will not experience them when the ingredient is used at standard cosmetic levels in a well-formulated product.
- Skin irritation – a mild burning or stinging sensation can occur, particularly on compromised or freshly exfoliated skin
- Dryness or tightness – rare but possible if the buffer shifts the formula slightly toward the alkaline side and disrupts surface lipids
- Allergic contact dermatitis – very uncommon but may present as redness, itching or small bumps
- Eye irritation – tearing or discomfort if the product accidentally gets into the eyes
- Increased absorption through broken skin – cuts or abrasions could allow more of the compound to penetrate, which may elevate the likelihood of irritation
If any of these effects develop while using sodium borate or a product containing it, stop use immediately and seek guidance from a healthcare professional.
Comedogenic Rating
Rating: 0 out of 5
Sodium borate is an inorganic mineral salt that dissolves fully in water and leaves no oily or waxy residue on the skin, so it has no tendency to clog pores. It is used at very low levels purely to balance pH, which further limits any chance of buildup inside follicles.
Because of this, the ingredient is generally fine for people who are prone to acne or breakouts.
One extra note: if a formula containing sodium borate also includes heavy oils or butters, the product’s overall pore-clogging potential will depend on those richer ingredients, not on sodium borate itself.
Summary
Sodium borate’s main job in cosmetics is to act as a buffer that steadies pH so preservatives work correctly and textures stay consistent. By keeping a formula from drifting too acidic or too alkaline, it quietly protects both the product and your skin.
While borax once enjoyed wide use, newer buffering systems have taken center stage and today you will mostly find sodium borate in a limited range of cleansers, masks and a few creams. It still earns a place on the ingredient list when a formulator wants a dependable mineral pH adjuster.
At the low concentrations allowed in cosmetics sodium borate is considered safe for most users, with irritation being uncommon. As with any new skincare product though, doing a small patch test first is a smart way to check how your own skin responds.