FILM FORMER
sodium laneth-40 maleate/styrene sulfonate copolymer
- film former
A synthetic film-forming polymer. Polymers of this kind dry to a continuous film on the hair, which is how a styling product holds a shape.
- products in our library
- 22
- of researched products
- 0.3%
- on the label, in our heat protectants
- usually #9
- most common in
- Heat protectant
- in water
- Water-dispersible
At a glance
Four things worth knowing about how this ingredient behaves on hair.
How much of it is left on hair between washes.
What it takes to get it off the hair again.
What the polymer class can do, not what any bottle claims.
How well the film survives damp air, as a class.
| Property | Level | Out of |
|---|---|---|
| Buildup risk | Low | 2 of 5 |
| Rinse-out behaviour | Rinses with shampoo | 4 of 5 |
| Hold | Firmest | 5 of 5 |
| Humidity resistance | Holds up | 4 of 5 |
What it does for a formula
What sodium laneth-40 maleate/styrene sulfonate copolymer does
The general function first, then how the role changes by product type where we have researched it.
The film is what holds a shape once the water has gone.
How firmly depends on the polymer class and how much of it is used.
A long-chain molecule that stays behind as the product dries.
It does not truly dissolve, and ordinary shampooing removes it.
Charge
Charge is not recorded for this ingredient.
Solubility
Spreads through water without truly dissolving, and normal shampooing removes it.
Where it appears
Where it appears
One row per product category in our library: how many products list it, what share of that category that is, and where it typically sits on the label.
| Product type | How common | Typical position on label ? |
|---|---|---|
Heat protectant
5 products
|
secondary · #9 | |
Leave-in
4 products
|
secondary · #22 | |
Finisher: shine spray
3 products
|
secondary · #31 | |
Mask / treatment
2 products
|
supporting · #6 | |
Styler: hairspray
2 products
|
secondary · #10 | |
Scalp treatment
1 product
|
secondary · #25 | |
Shampoo
1 product
|
secondary · #25 | |
Styler: curl cream
1 product
|
secondary · #31 | |
Styler: lotion
1 product
|
secondary · #11 | |
Styler: mousse
1 product
|
secondary · #15 |
1 more product type
| Product type | How common | Typical position on label ? |
|---|---|---|
Styler: texture spray
1 product
|
secondary · #14 |
| Product type | Products | Share of category | Median position | Earliest position | Band |
|---|---|---|---|---|---|
| Heat protectant | 5 | 2% | 9 | 3 | secondary |
| Leave-in | 4 | 1% | 22 | 16 | secondary |
| Finisher: shine spray | 3 | 3% | 31 | 18 | secondary |
| Mask / treatment | 2 | 0% | 6 | 2 | supporting |
| Styler: hairspray | 2 | 1% | 10 | 5 | secondary |
| Scalp treatment | 1 | 0% | 25 | 25 | secondary |
| Shampoo | 1 | 0% | 25 | 25 | secondary |
| Styler: curl cream | 1 | 0% | 31 | 31 | secondary |
| Styler: lotion | 1 | 3% | 11 | 11 | secondary |
| Styler: mousse | 1 | 0% | 15 | 15 | secondary |
| Styler: texture spray | 1 | 1% | 14 | 14 | secondary |
We have not researched differences by product type yet. The reading below comes from where it sits on the labels in our library.
Position footprint
Every listing in our library, by position on the label.
| Positions | Zone | Listings |
|---|---|---|
| 1-3 | Leading | 2 |
| 4-8 | Supporting | 2 |
| 9-15 | Secondary | 8 |
| 16-25 | Lower | 6 |
| 26+ | Trace | 4 |
How to read this
US labelling rules put ingredients above 1% in descending order of amount; below 1% they may be listed in any order.
So position tells you about relative amount only above that line, and we never convert a position into a percentage.
Who should pay attention
Formulation guidance for specific hair conditions, limited to the label positions where it applies. It is not a conclusion about any finished product, or about you.
A set polymer film is a physical barrier to humidity, so a style keeps its shape longer in damp conditions.
Synthetic film formers dry into a continuous film, which is what holds a shape against movement and against humid air.
Some acrylate copolymers rinse with water and some need a detergent; the label alone does not say which one a formula used.
It sets firm on its own. Whether the curl stays flexible depends on the plasticisers and oils the rest of the formula carries.
Read from this ingredient’s chemical class. Where we have researched the ingredient itself, that reading replaces the class one.
Why it matters to shoppers
What seeing this ingredient tells you, what it does not, and the limits of our own method.
- hold that survives humidity
- a style that holds
- a product ordinary shampooing removes
- results that hold as the weather changes
- an exact safety score (we do not publish one for any ingredient)
- how a finished product performs, which depends on the whole formula, not one line of it
- the exact percentage in a bottle, because label position never converts into a number
- a secondary film former, listed below the main ingredients in our heat protectants
- it was on the printed ingredient list of every product we counted (we read labels, not marketing copy)
- a stiff, crunchy result on its own
- that a product is right or wrong for you
We do not publish safety scores or hazard grades. Where a regulator has published a restriction or a use condition, we state it and cite it; otherwise we describe what the ingredient does and stop.
Commonly paired with
The ingredients that most often appear alongside this one in our library. We leave out the near-universal ones, because they pair with everything and tell you nothing.
- Benzyl Benzoate · 10
- Alcohol Denat. · 10
- Benzoic Acid · 9
- Ethylhexylglycerin · 9
- Sorbic Acid · 8
- Cetrimonium Chloride · 8
- Polysorbate 20 · 7
- Benzyl Alcohol · 7
- Chlorphenesin · 6
- Cyclopentasiloxane · 6
The number beside a name is how many products in our library list both.
These ingredients tend to appear together to give it a scent, carry the formula and let it dry, and keep the formula stable.
Found in these products
The most prominent placements first. The badge is the position on that product’s own ingredient list.
UNITE Hair · Mask / treatment
BLONDA Fix Treatment
#2 on the label · $10.63/oz
Mixed Chicks · Heat protectant
Straightening Serum (Straight)
#3 on the label · $2.50/oz
CHI · Heat protectant
Royal Treatment Royal Guard Heat Protecting Spray
#5 on the label · $3.17/oz
Kenra Platinum · Styler
Hot Spray 20
#5 on the label · $3.13/oz
ghd · Heat protectant
Straight & Smooth Spray
#9 on the label · $6.28/oz
UNITE Hair · Mask / treatment
RE:UNITE Treatment
#10 on the label · $9.00/oz
Kenra Platinum · Heat protectant
Blow-Dry Mist
#11 on the label · $8.24/oz
Kevin Murphy · Styler
ANTI.GRAVITY
#11 on the label · $7.30/oz
Kenra Platinum · Heat protectant
Blow-Dry Spray
#12 on the label · $8.24/oz
Alterna · Styler
Caviar Anti-Aging Universal Heat Styling Spray
#14 on the label · $8.10/oz
Kevin Murphy · Styler
ANTI.GRAVITY.SPRAY
#15 on the label · $6.61/oz
Rizos Curls · Styler
Curl Defining Mousse - 6.8 oz
#15 on the label · $3.38/oz
See all 22 products in the library that list sodium laneth-40 maleate/styrene sulfonate copolymer
Identity
What this entry is, and what our references call it.
No public-domain structure depiction is available for this entry.
sodium laneth-40 maleate/styrene sulfonate copolymer
- polymer
- sodium laneth-40 maleate/ styrene sulfonate copolymer
- sodium laneth-40 maleate/styrene sulfonate copolymer
For your hair?
Whether sodium laneth-40 maleate/styrene sulfonate copolymer matters for your hair depends on your hair.
22 products in our library list itWhat this ingredient does, and where it sits on the labels we have researched.
A verdict on any product that contains it, and never a safety grade.
We do not physically test your hair. Everything above comes from the ingredient lists in our library and from published references. The consultation is what turns it into a plan.
References
Seed entry, sourcing in progress Written from our reference work; primary sourcing is still being attached.
No published source is attached to this entry yet.
How this page was made
- Every number above is counted from the ingredient lists in our own product library: 22 of 6816 researched products list this ingredient. Nothing on this page is written per ingredient.
- The dots are levels, not scores. Each one comes from what kind of ingredient it is (its chemical class, charge and solubility) or from where it sits on the labels we have.
- US labelling rules put ingredients above 1% in descending order of amount; below 1% they may be listed in any order. Position tells you about relative amount only above that line, and we never convert a position into a percentage.
- The prominence bands (leading, supporting, secondary) are the same ones the product pages use to read a single label, applied here to the median position across a category.
- We do not publish safety scores or hazard grades. Where a regulator has published a restriction or a use condition, we state it and cite it; otherwise we describe what the ingredient does and stop.
- Identifiers and references appear only when a published source is attached to this entry. Without one, we leave the row out rather than fill it in.
- This is cosmetic information, not medical advice, and nothing here diagnoses or treats a health condition.
- Entry last updated 2026-09-22. Product-page methodology: the product library.
