SOLVENT
Propanediol
- solvent
A corn-derived humectant and solvent, often chosen as a lighter-feeling alternative to propylene glycol.
- products in our library
- 908
- of researched products
- 13%
- on the label, in our shampoos
- usually #12
- most common in
- Shampoo
- in water
- Water-soluble
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.
How fast it leaves after the product is applied.
What is still on the hair once it has evaporated.
| Property | Level | Out of |
|---|---|---|
| Buildup risk | Low | 1 of 5 |
| Rinse-out behaviour | Rinses clean | 5 of 5 |
| Drying speed | Steady | 2 of 5 |
| Residue | Minimal | 2 of 5 |
What it does for a formula
What Propanediol does
The general function first, then how the role changes by product type where we have researched it.
What everything else is dissolved in before it reaches your hair.
Binds water and holds it against the hair rather than adding oil.
What a humectant does depends on the air around it as much as on the formula.
Water alone removes it, so it does not accumulate between washes.
Charge
Carries no charge, so it neither clings to hair nor is pushed away by it. Nonionic ingredients are the mild, pH-tolerant workhorses of a formula.
Solubility
Rinses out with water alone, so it does not build up on hair between washes.
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 ? |
|---|---|---|
Shampoo
205 products
|
secondary · #12 | |
Conditioner
140 products
|
secondary · #9 | |
Leave-in
102 products
|
supporting · #4 | |
Scalp treatment
90 products
|
leading · #3 | |
Mask / treatment
81 products
|
supporting · #8 | |
Styler: volumizer
35 products
|
supporting · #8 | |
Styler: gel
30 products
|
supporting · #4 | |
Heat protectant
29 products
|
supporting · #5 | |
Styler: curl cream
29 products
|
supporting · #4 | |
Styler: mousse
25 products
|
supporting · #8 |
12 more product types
| Product type | How common | Typical position on label ? |
|---|---|---|
Finisher: serum
24 products
|
leading · #3 | |
Styler: smoothing cream
20 products
|
supporting · #5 | |
Styler: hairspray
19 products
|
secondary · #12 | |
Styler: paste
16 products
|
secondary · #17 | |
Styler: texture spray
13 products
|
supporting · #4 | |
Co-wash
12 products
|
supporting · #8 | |
Finisher: shine spray
10 products
|
supporting · #7 | |
Styler: refresh spray
7 products
|
supporting · #4 | |
Dry shampoo
6 products
|
secondary · #10 | |
Styler: lotion
6 products
|
supporting · #7 | |
Finisher: oil
5 products
|
secondary · #10 | |
Finisher: anti frizz finish
4 products
|
supporting · #9 |
| Product type | Products | Share of category | Median position | Earliest position | Band |
|---|---|---|---|---|---|
| Shampoo | 205 | 13% | 12 | 3 | secondary |
| Conditioner | 140 | 12% | 9 | 2 | secondary |
| Leave-in | 102 | 15% | 4 | 2 | supporting |
| Scalp treatment | 90 | 31% | 3 | 1 | leading |
| Mask / treatment | 81 | 14% | 8 | 2 | supporting |
| Styler: volumizer | 35 | 24% | 8 | 2 | supporting |
| Styler: gel | 30 | 11% | 4 | 2 | supporting |
| Heat protectant | 29 | 14% | 5 | 2 | supporting |
| Styler: curl cream | 29 | 13% | 4 | 2 | supporting |
| Styler: mousse | 25 | 12% | 8 | 2 | supporting |
| Finisher: serum | 24 | 17% | 3 | 2 | leading |
| Styler: smoothing cream | 20 | 25% | 5 | 2 | supporting |
| Styler: hairspray | 19 | 8% | 12 | 2 | secondary |
| Styler: paste | 16 | 8% | 17 | 2 | secondary |
| Styler: texture spray | 13 | 13% | 4 | 2 | supporting |
| Co-wash | 12 | 12% | 8 | 2 | supporting |
| Finisher: shine spray | 10 | 10% | 7 | 3 | supporting |
| Styler: refresh spray | 7 | 20% | 4 | 2 | supporting |
| Dry shampoo | 6 | 5% | 10 | 6 | secondary |
| Styler: lotion | 6 | 17% | 7 | 5 | supporting |
| Finisher: oil | 5 | 2% | 10 | 5 | secondary |
| Finisher: anti frizz finish | 4 | 13% | 9 | 4 | supporting |
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 | 222 |
| 4-8 | Supporting | 296 |
| 9-15 | Secondary | 143 |
| 16-25 | Lower | 138 |
| 26+ | Trace | 109 |
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.
Light and water-binding rather than oily, so it adds less weight than oils or butters do.
A small water-binding solvent. It holds moisture and helps the rest of the formula spread evenly over the strand.
A humectant follows the air: it holds water in humid conditions and can give it up in very dry ones. Climate decides what it does more than the label does.
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.
- a light, fast-drying formula
- hydration rather than oil
- a rinse-clean feel
- body without weight on fine hair
- 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 solvent, listed below the main ingredients in our shampoos
- it was on the printed ingredient list of every product we counted (we read labels, not marketing copy)
- 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.
- Ethylhexylglycerin · 412
- Caprylyl Glycol · 366
- Tocopherol · 352
- Benzyl Alcohol · 265
- Guar Hydroxypropyltrimonium Chloride · 250
- Cetrimonium Chloride · 243
- Sodium Hydroxide · 229
- Behentrimonium Chloride · 224
- Butylene Glycol · 202
- Aloe Barbadensis Leaf Juice · 199
The number beside a name is how many products in our library list both.
These ingredients tend to appear together to soften the strand, hold on to water, and deliver a stated effect.
Found in these products
The most prominent placements first. The badge is the position on that product’s own ingredient list.
As I Am · Scalp treatment
Dry & Itchy Scalp Care Itch Soothing Drops
#1 on the label · $5.50/oz
AAVRANI · Scalp treatment
Hair Density Boosting Treatment
#2 on the label · $23.65/oz
AAVRANI · Mask / treatment
Intensive Repair Conditioning Hair Mask
#2 on the label · $4.62/oz
AAVRANI · Scalp treatment
Scalp Rescue Serum
#2 on the label · $18.66/oz
Act+Acre · Scalp treatment
3% Stem Cell Peptide Treatment
#2 on the label · $40.00/oz
Aveda · Leave-in
be curly advanced™ curl perfecting primer
#2 on the label · $6.12/oz
Aveda · Finisher
botanical repair™ strengthening overnight serum
#2 on the label · $20.00/oz
Aveda · Styler
brilliant™ universal styling creme
#2 on the label · $6.20/oz
Aveda · Styler
invati ultra advanced™ thickening foam
#2 on the label · $9.33/oz
Aveda · Leave-in
Nutriplenish™ Daily Moisturizing Treatment
#2 on the label · $9.40/oz
Aveda · Leave-in
Nutriplenish™ Leave-In Conditioner
#2 on the label · $14.00/oz
Aveda · Styler
Nutriplenish™ Styling Treatment Foam
#2 on the label · $5.82/oz
Identity
What this entry is, and what our references call it.
Propanediol
- CAS 26264-14-2
- PubChem 134919
- humectant
- 1,3-propanediol
- propanediol
- propanediol (plant-derived preservative)
- propanediol (vegetable)
For your hair?
Whether Propanediol matters for your hair depends on your hair.
the 6th most-listed solvent or propellant in our libraryWhat 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
Sourced Backed by a manufacturer or regulatory source.
This ingredient
- Manufacturer or regulatory PubChem : Compound identity: CID 134919, CAS 26264-14-2, C3H8O2 · accessed 2026-08-28
How this page was made
- Every number above is counted from the ingredient lists in our own product library: 908 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.
