Ingredient review
Phenylbenzimidazole Sulfonate
INCI: POTASSIUM PHENYLBENZIMIDAZOLE SULFONATE
A widely used, water-soluble UVB filter that offers effective sunburn protection without a heavy feel.
In plain English
This is a sunscreen ingredient that absorbs UVB rays—the kind that cause sunburn and contribute to skin cancer. Unlike many sunscreens that are oily, this one dissolves in water, so it feels light on the skin and works well in formulas that don't leave a white cast. It's often combined with other filters to provide broader protection.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is relatively strong for its common cosmetic role.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- synthetic
- Evidence
- strong
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Phenylbenzimidazole Sulfonate is generally a lower-concern ingredient when the full formula suits your skin.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging Phenylbenzimidazole Sulfonate.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
strongThere is a stronger practical or research basis for the ingredient role described here.
What it is
A synthetic, water-soluble organic compound that absorbs ultraviolet B (UVB) radiation. It is a common active ingredient in sunscreens worldwide.
How it works
When applied to the skin, it absorbs UVB light energy and converts it into heat, which is then released from the skin. This prevents the UV rays from penetrating deeper and causing sunburn or cellular damage.
Pros
Lightweight feel
Because it's water-soluble, it doesn't add greasiness, making it ideal for daily wear under makeup or for oily skin types.
No white cast
Unlike mineral sunscreens, this ingredient doesn't leave a chalky residue, so it's great for deeper skin tones.
Cons and cautions
No UVA protection
It only blocks UVB rays, so it must be paired with a UVA filter like avobenzone or zinc oxide for complete protection.
Potential eye irritation
Some people experience stinging or burning if the product gets too close to the eyes, especially when sweating.
Best for
- People who prefer lightweight, water-based sunscreens
- Those with oily or acne-prone skin looking for non-comedogenic sun protection
Use caution if
- Anyone seeking broad-spectrum UVA/UVB protection on its own
- Individuals with known sensitivity to organic UV filters
Usage tips
Safety summary
Extensively tested and considered safe for topical use at regulated concentrations. Rare reports of skin irritation or eye stinging exist, but it is generally well-tolerated.
Research notes
Decades of use and numerous studies confirm its efficacy as a UVB filter. It is a standard ingredient in sunscreen formulations worldwide.
Common label clues
- Typical concentration
- Up to 4% in the US, up to 8% in the EU and other regions
- Regulatory status
- Approved as a safe and effective sunscreen active ingredient by the US FDA (up to 4%) and the EU Cosmetics Regulation (up to 8%).
- Common uses
- Sunscreens, Daily moisturizers with SPF, Makeup with SPF
- Environmental note
- Some studies suggest organic UV filters may impact marine life, but this ingredient is less commonly associated with coral bleaching than others like oxybenzone.
Good to know
- This ingredient is often listed as 'Ensulizole' on labels in the US.
- It is approved by the FDA and is considered safe and effective when used as directed.
- Because it's water-soluble, it can be easier to rinse off than oil-based sunscreens.
Common questions
What is Phenylbenzimidazole Sulfonate in beauty products?
This is a sunscreen ingredient that absorbs UVB rays—the kind that cause sunburn and contribute to skin cancer. Unlike many sunscreens that are oily, this one dissolves in water, so it feels light on the skin and works well in formulas that don't leave a white cast. It's often combined with other filters to provide broader protection.
What does Phenylbenzimidazole Sulfonate do in a beauty product?
When applied to the skin, it absorbs UVB light energy and converts it into heat, which is then released from the skin. This prevents the UV rays from penetrating deeper and causing sunburn or cellular damage.
Is Phenylbenzimidazole Sulfonate safe for most people?
Extensively tested and considered safe for topical use at regulated concentrations. Rare reports of skin irritation or eye stinging exist, but it is generally well-tolerated.
Who should be careful with Phenylbenzimidazole Sulfonate?
Anyone seeking broad-spectrum UVA/UVB protection on its own Individuals with known sensitivity to organic UV filters
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.