Ingredient review
PEG-25 PABA
INCI: PEG-25 PABA
PEG-25 PABA is an older UV filter that effectively absorbs UVB rays but has fallen out of favor due to potential skin sensitivity and environmental concerns.
In plain English
PEG-25 PABA is a chemical sunscreen ingredient that works by absorbing ultraviolet B (UVB) rays from the sun, converting them into less harmful heat. It is a modified version of PABA (para-aminobenzoic acid), which was once common in sunscreens but is now rarely used because it can cause skin irritation and allergic reactions. The 'PEG-25' part makes it water-soluble and less likely to stain clothes, but it still carries some of the same concerns as its parent compound.
Review score
Safety, usefulness, and evidence
Higher-caution ingredient
The evidence base is useful, but some claims depend heavily on the formula.
Main practical flags: irritation is moderate; clogging risk is low.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- moderate
- Clogging risk
- low
Quick decision guide
Read the cautions before using
PEG-25 PABA can be useful, but watch for some irritation potential.
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 PEG-25 PABA.
- 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
moderateCan bother some users, especially with frequent use, damaged skin, or strong companion ingredients.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
PEG-25 PABA is a synthetic compound created by attaching polyethylene glycol (PEG) chains to PABA. This modification improves water solubility and reduces the staining and irritation potential of plain PABA, while retaining its ability to absorb UVB radiation.
How it works
In a cosmetic product, PEG-25 PABA sits on the skin's surface and absorbs UVB light (wavelengths 290–320 nm). It converts the high-energy UV radiation into lower-energy heat, which is then released from the skin. This prevents the UV rays from penetrating deeper and causing sunburn or DNA damage.
Pros
Effective UVB protection
PEG-25 PABA absorbs UVB rays efficiently, helping prevent sunburn and reducing the risk of skin damage from short-wave UV radiation.
Water-soluble formulation
Unlike plain PABA, PEG-25 PABA dissolves in water, allowing for clear, non-greasy sunscreen formulations that are less likely to leave white residue or stain clothes.
Cons and cautions
Potential skin irritation
PEG-25 PABA can cause stinging, redness, or allergic reactions in some people, especially those with sensitive skin or a history of sunscreen sensitivity.
Environmental concerns
Like many chemical UV filters, PEG-25 PABA may persist in water and harm marine ecosystems. Some regions have restricted its use due to environmental impact.
Best for
- People looking for a water-resistant UVB filter in a sunscreen
- Those who tolerate chemical sunscreens well
Use caution if
- Individuals with sensitive or reactive skin
- Those with a history of PABA allergy or sunscreen reactions
Usage tips
Safety summary
PEG-25 PABA is considered safe for topical use in regulated concentrations, but it carries a moderate risk of skin irritation and allergic reactions. Its environmental impact and potential for systemic absorption have led to reduced usage in favor of newer UV filters.
Research notes
Research shows PEG-25 PABA effectively absorbs UVB rays, but studies also indicate it can cause contact dermatitis and photoallergic reactions in some individuals. Environmental studies raise concerns about its persistence and toxicity to aquatic organisms.
Common label clues
- Typical concentration
- Up to 10% in rinse-off products; lower in leave-on products
- Regulatory status
- Approved as a UV filter in some countries (e.g., Japan, Australia) but not in the EU or USA for sunscreen use. In the US, PABA itself is no longer generally recognized as safe and effective (GRASE) by the FDA, and PEG-25 PABA is not listed as an approved sunscreen active ingredient.
- Common uses
- Sunscreens, Moisturizers with SPF, Makeup with SPF
- Environmental note
- PEG-25 PABA may be persistent in aquatic environments and has been detected in water samples. Some studies suggest it can harm coral reefs and marine life, contributing to its declining use.
Good to know
- PEG-25 PABA is less common in modern sunscreens, as many brands have moved to newer, less irritating UV filters.
- It is not approved for use in all countries; check local regulations if traveling.
- The 'PEG' part means it may be contaminated with ethylene oxide or 1,4-dioxane during manufacturing, though levels are typically low.
Common questions
What is PEG-25 PABA in beauty products?
PEG-25 PABA is a chemical sunscreen ingredient that works by absorbing ultraviolet B (UVB) rays from the sun, converting them into less harmful heat. It is a modified version of PABA (para-aminobenzoic acid), which was once common in sunscreens but is now rarely used because it can cause skin irritation and allergic reactions. The 'PEG-25' part makes it water-soluble and less likely to stain clothes, but it still carries some of the same concerns as its parent compound.
What does PEG-25 PABA do in a beauty product?
In a cosmetic product, PEG-25 PABA sits on the skin's surface and absorbs UVB light (wavelengths 290–320 nm). It converts the high-energy UV radiation into lower-energy heat, which is then released from the skin. This prevents the UV rays from penetrating deeper and causing sunburn or DNA damage.
Is PEG-25 PABA safe for most people?
PEG-25 PABA is considered safe for topical use in regulated concentrations, but it carries a moderate risk of skin irritation and allergic reactions. Its environmental impact and potential for systemic absorption have led to reduced usage in favor of newer UV filters.
Who should be careful with PEG-25 PABA?
Individuals with sensitive or reactive skin Those with a history of PABA allergy or sunscreen reactions
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.