Phosphate Buffered Saline: What Is It, Cosmetic Uses, Benefits & Side Effects

Curious about this ingredient? In this article we're explaining exactly what it is and why it's used within cosmetic formulations.
Updated on: July 1, 2025
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We verify all information on this page using publicly available nomenclature standards from The Personal Care Products Council (PCPC), the European Commission's CosIng database and documentation provided directly by ingredient manufacturers. Our analysis is based on technical data from these sources to ensure accuracy and reliability.

What Is Phosphate Buffered Saline?

Phosphate Buffered Saline, often shortened to PBS, is a clear water-based solution that holds a balance of simple mineral salts such as sodium chloride, sodium phosphate, potassium chloride and potassium phosphate. These salts are mixed in purified water and adjusted to a skin-friendly pH that sits close to the natural pH of human tears and skin. PBS was first made for biology labs where it helped keep cells comfortable outside the body. Because the solution is gentle, stable and easy to make, cosmetic chemists soon saw its value for skin care formulas.

Making PBS is straightforward. Each salt is weighed, dissolved in high-grade water then the pH is fine-tuned with tiny amounts of acid or base until it rests around 7.4. The finished liquid is filtered so it stays crystal clear and free of microbes.

Today you will spot Phosphate Buffered Saline in a wide range of rinse-off or leave-on products. It shows up in facial mists, sheet masks, soothing serums, micellar waters, after-sun gels, eye area treatments and exfoliating pads where a mild salt solution is needed to carry other active ingredients without stressing the skin.

Phosphate Buffered Saline’s Cosmetic Benefits/Uses

In beauty formulas Phosphate Buffered Saline serves one key purpose that brings several quiet advantages to the finished product.

Solvent: PBS acts as a gentle carrier that dissolves and evenly distributes other ingredients so they spread smoothly across the skin. Because its salt levels mirror natural body fluids it helps keep formulas comfortable, minimizes stinging and supports a balanced pH which can improve overall skin tolerance of the product.

Who Can Use Phosphate Buffered Saline

PBS is gentle enough for all skin types including oily, dry, sensitive and mature skin because its salt balance is close to that of natural skin fluids. It does not clog pores or leave a residue so it fits well into acne prone routines too. No particular skin type needs to avoid it unless there is a personal sensitivity to one of the individual salts, which is very rare.

The solution is made only from mineral salts and purified water so it is suitable for vegans and vegetarians. Nothing in its recipe comes from animals or is processed with animal by-products.

Pregnant and breastfeeding women can normally use products containing PBS since it is not absorbed into the bloodstream in any meaningful amount. This is not medical advice and anyone who is expecting or nursing should confirm all skin care choices with a doctor just to be safe.

PBS does not make skin more sensitive to sunlight and it does not interfere with sunscreen performance. It is also fragrance free and dye free which lowers the chance of cross reactions with other ingredients in a routine.

Potential Side Effects/Adverse Reactions

Reactions to topical Phosphate Buffered Saline differ from person to person. The points below list potential side effects that could occur, but most users will not experience them when the ingredient is blended and used correctly.

  • Mild stinging on freshly exfoliated or broken skin
  • Temporary dryness if applied in large amounts without a follow-up moisturizer
  • Rare local redness or itching in individuals who are sensitive to one of the salts
  • Very rare allergic reaction presenting as swelling or rash

If any unexpected irritation or discomfort appears stop using the product and seek advice from a healthcare professional.

Comedogenic Rating

Rating: 0/5 PBS is nothing more than purified water plus fully dissolved mineral salts so it leaves no oily or waxy residue that can plug pores.

Because of this it is suitable for people who are prone to acne or frequent breakouts.

Its water based nature can even help thin heavier formulas making them less likely to cause congestion.

Summary

Phosphate Buffered Saline is used as a solvent that keeps actives evenly dispersed, supports a skin friendly pH and delivers a gentle feel. By mirroring the salt balance of natural fluids it helps products stay comfortable for all skin types.

Though it rarely gets a spotlight in advertising, PBS is a behind the scenes staple in mists, serums and sensitive skin products because chemists value its reliability.

The ingredient is considered very safe with a low chance of irritation or pore clogging. As with any new product a quick patch test is wise to be sure your skin agrees with the full formula.

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