Ingredient review
Nonyl Nonoxynol-5
INCI: Nonyl Nonoxynol-5
Nonyl Nonoxynol-5 is a synthetic surfactant that can help cleanse and emulsify, but it has raised environmental and skin irritation concerns.
In plain English
Nonyl Nonoxynol-5 is a man-made ingredient that helps water and oil mix together, making it useful in cleansers and creams. It belongs to a group of chemicals called nonylphenol ethoxylates, which have been studied for potential environmental effects. In skincare, it can be effective at removing dirt and oil, but it may also be drying or irritating for some people, especially with frequent use.
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
Nonyl Nonoxynol-5 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 Nonyl Nonoxynol-5.
- 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
Nonyl Nonoxynol-5 is a synthetic nonionic surfactant and emulsifier derived from nonylphenol and ethylene oxide. It is part of the nonylphenol ethoxylate family, which has been used in cosmetics and industrial applications for decades.
How it works
It works by reducing the surface tension between oil and water, allowing them to mix into a stable emulsion. In cleansers, it helps lift dirt, oil, and makeup from the skin so they can be rinsed away. In creams, it helps keep the water and oil phases from separating.
Pros
Effective cleanser
Nonyl Nonoxynol-5 efficiently removes excess oil, makeup, and impurities from the skin, making it useful in deep-cleansing products.
Good emulsifier
It helps create stable mixtures of oil and water, which is important for the texture and performance of creams and lotions.
Cons and cautions
Potential irritant
This surfactant can strip the skin's natural oils and cause dryness, redness, or irritation, especially with frequent or leave-on use.
Environmental concerns
Nonylphenol ethoxylates like this one have been shown to be persistent in the environment and may have toxic effects on aquatic life, leading to restrictions in some regions.
Best for
- People with oily or normal skin looking for a strong cleanser
- Those using rinse-off products occasionally
Use caution if
- People with sensitive, dry, or compromised skin
- Those concerned about environmental impact of nonylphenol ethoxylates
Usage tips
Safety summary
Nonyl Nonoxynol-5 is considered safe for use in rinse-off cosmetics at low concentrations, but it can cause skin irritation with frequent use. Environmental concerns have led to reduced usage and regulatory scrutiny.
Research notes
Studies indicate that nonylphenol ethoxylates can be irritating to skin and eyes at higher concentrations. Environmental research shows they degrade into nonylphenol, which is toxic to aquatic organisms. Human health risks from cosmetic use are considered low when used as directed.
Common label clues
- Typical concentration
- Typically used at 1–5% in rinse-off products
- Regulatory status
- Approved for use in cosmetics in many regions, but subject to restrictions in the EU under the REACH regulation due to environmental concerns. Not recommended for leave-on products.
- Common uses
- Cleansers, Emulsions, Industrial cleaners
- Environmental note
- Nonylphenol ethoxylates are known to be persistent in water and can act as endocrine disruptors in aquatic wildlife. Many manufacturers have voluntarily phased them out.
Good to know
- Nonylphenol ethoxylates are restricted or banned in some countries for certain applications due to environmental concerns.
- This ingredient is more common in industrial or household cleaners than in modern skincare.
Common questions
What is Nonyl Nonoxynol-5 in beauty products?
Nonyl Nonoxynol-5 is a man-made ingredient that helps water and oil mix together, making it useful in cleansers and creams. It belongs to a group of chemicals called nonylphenol ethoxylates, which have been studied for potential environmental effects. In skincare, it can be effective at removing dirt and oil, but it may also be drying or irritating for some people, especially with frequent use.
What does Nonyl Nonoxynol-5 do in a beauty product?
It works by reducing the surface tension between oil and water, allowing them to mix into a stable emulsion. In cleansers, it helps lift dirt, oil, and makeup from the skin so they can be rinsed away. In creams, it helps keep the water and oil phases from separating.
Is Nonyl Nonoxynol-5 safe for most people?
Nonyl Nonoxynol-5 is considered safe for use in rinse-off cosmetics at low concentrations, but it can cause skin irritation with frequent use. Environmental concerns have led to reduced usage and regulatory scrutiny.
Who should be careful with Nonyl Nonoxynol-5?
People with sensitive, dry, or compromised skin Those concerned about environmental impact of nonylphenol ethoxylates
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.