Short answer: choose dicaprylyl ether where the formula is aggressive — antiperspirant, depilatory, oxidative hair colour — or where a dry, powdery after-feel is the whole point. Choose dicaprylyl carbonate where you need to dissolve organic UV filters or wet out pigments. Plenty of formulas use both: carbonate in the pigment or filter phase, ether in the dry-down.
Side-by-side comparison
| Property | Dicaprylyl Ether | Dicaprylyl Carbonate |
|---|---|---|
| INCI name | Dicaprylyl Ether | Dicaprylyl Carbonate |
| CAS number | 629-82-3 | 1680-31-5 |
| EC number | 211-112-6 | 605-498-9 |
| Molecular formula / weight | C16H34O / 242.44 g/mol | C17H34O3 / 286.45 g/mol |
| Functional group | Dialkyl ether (C–O–C) | Carbonate ester (C–O–C(=O)–O–C) |
| Density (20–25 °C) | ≈ 0.81 g/cm³ | ≈ 0.89 g/cm³ |
| Skin feel | Dry, powdery, almost weightless | Dry but with more cushion; velvety |
| Spread rate | Very fast | Fast |
| Polarity | Essentially non-polar | Weakly polar |
| Solvency for UV filters and pigments | Moderate at best | Good — its main technical advantage |
| Hydrolytic stability | Not hydrolysable | Ester bond; can hydrolyse at extreme pH over time |
| Typical use level | 2–10 % (20 %+ in anhydrous formats) | 2–10 % |
| Strongest fit | Antiperspirant, depilatory, hair colour, silicone-free skin care | Sun care, foundation and BB cream, primers, cleansing oils |
Same feedstock, different molecule
Both products start from a C8 alcohol. In dicaprylyl ether, two octyl chains are joined through a single oxygen atom, which gives a compact, highly non-polar molecule of 242 g/mol. In dicaprylyl carbonate, the same octyl chains are joined through a carbonate group, which adds a carbonyl and a third oxygen, raises the molecular weight to 286 g/mol and puts a small permanent dipole into the molecule.
That is the whole story, and it explains almost every difference on the table. A molecule with no dipole and no hydrolysable bond behaves like a very light mineral oil that never reacts. A molecule with a carbonate group behaves like a light ester: still dry, but able to interact with polar surfaces, and susceptible to hydrolysis under conditions an ether simply ignores.
What the carbonate group changes in practice
It dissolves things the ether cannot
Organic UV filters — avobenzone, octocrylene, octyl methoxycinnamate — are polar, crystalline solids. They need a solvent with some polarity to stay in solution through the life of the product, otherwise they recrystallise and you lose SPF and gain visible crystals. Dicaprylyl carbonate is a recognised solubiliser for these filters, which is why it appears in so many sun-care oil phases. Dicaprylyl ether, being non-polar, is a poor solvent for them and is used there for feel rather than function.
The same property makes the carbonate a better wetting agent for treated pigments and mineral UV filters: it coats the particle surface more readily and reduces the viscosity rise you get when you load 15–25 % pigment into an oil phase.
It gives the formula a little more body
At 0.89 g/cm³ versus 0.81 g/cm³, and with a slightly higher refractive index, dicaprylyl carbonate feels marginally richer. On skin the difference is subtle but measurable: cushions slightly more, spreads a fraction slower, and leaves a soft rather than powdery finish. In a foundation or a night cream that reads as “more expensive”; in a light serum or an antiperspirant it reads as “too heavy”.
It can hydrolyse — the ether cannot
Carbonate esters resist hydrolysis far better than ordinary triglycerides or fatty-acid esters, which is why the material is stable through normal storage. But at pH above roughly 10 or in strongly acidic systems, held for months at elevated temperature, the carbonate bond will slowly cleave and the acid value of the batch will climb. This is why an acid-value specification matters for carbonate and is meaningless for an ether.
Where dicaprylyl ether is the better choice
- Antiperspirant and deodorant. Aluminium salts make the system acidic and electrolyte-rich, and the product sits at skin temperature for months. An ether has no hydrolysable bond and no ester to saponify, so the emollient does not change while the rest of the stick does.
- Depilatory creams. These run at pH 11–12,5 — a range that destroys most esters. This is one of the few applications where an ether is not merely preferable but close to mandatory.
- Oxidative hair colour. Peroxide plus ammonia at pH 9–10 will attack ester bonds over the shelf life of the dye. An inert ether stays inert.
- Powdery, weightless skin feel. If the brief is “disappears on the skin”, the ether's lower density and non-polar character deliver it with less sensory work.
- Anhydrous formats at high loading. Facial oils, cleansing oils and body oils often carry 20 % or more; at that level the difference in richness between the two becomes obvious.
Where dicaprylyl carbonate is the better choice
- Sun care. Filter solvency is a functional requirement, not a sensory preference. If your oil phase has to hold avobenzone without crystallisation, the carbonate is doing a job the ether cannot do.
- Colour cosmetics. Foundations, BB creams, tinted primers and pressed powders all benefit from faster pigment wetting, lower viscosity at high pigment load, and a soft-focus finish.
- Cleansing oils and balms. The weakly polar character helps dissolve sunscreen and pigment films while still rinsing cleanly — an ether is too non-polar to lift them efficiently.
- Emulsions that need a richer cushion. When the sensory target is “nourishing” rather than “weightless”, the carbonate closes the gap without going as far as a triglyceride.
A decision list you can hand to a formulator
Is the finished pH outside 4–9?
Use dicaprylyl ether. Above pH 10 or in strongly acidic systems the carbonate's ester bond becomes a shelf-life question, and you do not want an emollient that changes while the product sits.
Does the oil phase have to dissolve a UV filter or wet out pigment?
Use dicaprylyl carbonate, at least for that part of the oil phase. Non-polar ethers will not keep crystalline filters in solution.
Is the sensory target “powdery and weightless”?
Dicaprylyl ether. If it is “soft and cushioned”, carbonate.
Is this an anhydrous product at 20 %+ loading?
Ether for lightness, carbonate for body. At that level you are choosing the product's entire skin feel, so bench both.
Everything else being equal?
Split the oil phase: carbonate where the functional work happens, ether where the dry-down is judged. This is what most commercial sun and colour formulas do.
Using both in one formula
A typical sunscreen oil phase might carry 3–5 % dicaprylyl carbonate purely to keep the filters in solution, plus 3–5 % dicaprylyl ether to pull the after-feel back towards dry. A foundation might use carbonate as the pigment carrier and ether to cut the drag during application. In both cases the two ingredients are not competing for the same job, which is why the “which one is better” question usually has a false premise.
Where you should be careful is total emollient load. Both are light, but stacking 8 % of each still gives you 16 % oil phase, and the sensory gain from the ether can be lost if the carbonate level creeps up during development.
Specifications, packaging and what to ask for
Our dicaprylyl ether is supplied at ≥ 99.0 % (GC) and our dicaprylyl carbonate at ≥ 98.0 % (GC); the carbonate specification sits lower because it is an ester and the residual alcohol and acid are part of the normal balance, not a quality failure. Both ship from 1 kg for evaluation.
When you write the purchase specification, ask for different things for each product. For the ether: colour (APHA), water content and a peroxide value, since ethers can slowly form peroxides if stored warm and exposed to air. For the carbonate: colour (APHA) and acid value, because a rising acid value is the first analytical sign that the batch has hydrolysed. Neither parameter tells you anything useful about the other product.