Ingredient review
Polyquaternium-98
INCI: Polyquaternium-98
Polyquaternium-98 is a gentle, film-forming polymer that smooths hair and skin without heavy buildup, making it a good choice for sensitive scalps and fine hair.
In plain English
Polyquaternium-98 is a synthetic polymer that forms a thin, flexible film on hair or skin. This film helps reduce static electricity, smooths the hair cuticle, and locks in moisture. It's designed to be lightweight and less likely to cause buildup than older conditioning polymers, so it works well for fine or easily weighed-down hair. In skincare, it can improve the feel of a product and help other ingredients spread evenly.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Polyquaternium-98 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 Polyquaternium-98.
- 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
moderateThere is useful support, but formula details and claim strength still matter.
What it is
Polyquaternium-98 is a cationic (positively charged) polymer created through chemical synthesis. It belongs to the polyquaternium family, which are widely used in personal care for their conditioning and film-forming abilities. This specific variant is engineered to be more biodegradable and to deposit more evenly on hair and skin.
How it works
The positive charge on Polyquaternium-98 is attracted to the negatively charged surfaces of hair and skin. This electrostatic attraction allows the polymer to form a thin, even film that smooths the hair cuticle, reduces friction, and prevents static flyaway. On skin, it can help other ingredients adhere better and create a soft, non-greasy feel.
Pros
Lightweight conditioning
Forms a thin film that smooths hair without heavy buildup, ideal for fine or limp hair types.
Gentle on sensitive skin
Low irritation and comedogenic risk make it suitable for sensitive scalps and skin.
Cons and cautions
Synthetic origin
Not natural or biodegradable in the same way as plant-based alternatives, which may matter to eco-conscious users.
Less research than classics
While safe, there is less independent long-term safety data compared to older polyquaterniums like PQ-10.
Best for
- People with fine or easily weighed-down hair
- Those looking for a gentle conditioning agent for sensitive scalps
Use caution if
- Individuals who strictly avoid synthetic ingredients
Usage tips
Safety summary
Polyquaternium-98 is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential. As with all polyquaterniums, avoid eye contact in concentrated form.
Research notes
Research on Polyquaternium-98 is primarily from manufacturer studies and industry reports. It is designed to offer better deposition and less buildup than earlier polyquaterniums. Independent peer-reviewed studies are limited, but the ingredient class is well-established in safety assessments.
Common label clues
- Typical concentration
- 0.1% to 2%
- Regulatory status
- Approved for use in cosmetics in the EU, US, and many other regions. Generally recognized as safe at typical use levels.
- Common uses
- Conditioners, Shampoos, Leave-in treatments, Styling products, Moisturizers
- Environmental note
- This polymer is designed with improved biodegradability compared to older polyquaterniums, though it is still synthetic and not fully biodegradable in all conditions.
Good to know
- Polyquaternium-98 is designed to be more biodegradable than some earlier polyquaterniums.
- It is often used in 'low-poo' and sulfate-free hair care systems.
Common questions
What is Polyquaternium-98 in beauty products?
Polyquaternium-98 is a synthetic polymer that forms a thin, flexible film on hair or skin. This film helps reduce static electricity, smooths the hair cuticle, and locks in moisture. It's designed to be lightweight and less likely to cause buildup than older conditioning polymers, so it works well for fine or easily weighed-down hair. In skincare, it can improve the feel of a product and help other ingredients spread evenly.
What does Polyquaternium-98 do in a beauty product?
The positive charge on Polyquaternium-98 is attracted to the negatively charged surfaces of hair and skin. This electrostatic attraction allows the polymer to form a thin, even film that smooths the hair cuticle, reduces friction, and prevents static flyaway. On skin, it can help other ingredients adhere better and create a soft, non-greasy feel.
Is Polyquaternium-98 safe for most people?
Polyquaternium-98 is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential. As with all polyquaterniums, avoid eye contact in concentrated form.
Who should be careful with Polyquaternium-98?
Individuals who strictly avoid synthetic ingredients
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.