Building an ointment base: matching petrolatum's occlusivity with plant materials
A plant based ointment at 12 percent wax aimed at petrolatum level occlusion, in a 50 ml jar poured at 72 to 78 C, with the water loss evidence shown.
Every plant based answer to petroleum jelly is sold on the promise that it does the same job. Most of them are ordinary balms in a different tin, and they do not. This page gives an ointment formula built specifically for occlusion rather than for feel, explains the structural reason it still falls short of petrolatum, and scores the two against each other on properties that can be checked.
Petrolatum cuts transepidermal water loss by roughly 98 percent, and no plant blend reaches that. A thick anhydrous ointment can reach the top of the plant band instead. This one is 12 percent beeswax, 8 percent castor wax, 45 percent castor oil, 20 percent shea and 14.9 percent jojoba, melted at 88 to 92 C, poured at 72 to 78 C, cured 48 hours.
What ointment means as a format
Ointment is not a marketing word for a thick balm. In pharmacopoeial usage it names a semi-solid dosage form meant to stay on the surface, classified by its base: hydrocarbon bases (petrolatum and its blends), absorption bases (petrolatum plus lanolin or a sterol fraction), water-removable bases and water-soluble bases. The formula below is an oleaginous base with no water in it, which puts it in the first class by behaviour despite sharing none of its chemistry.
Four properties define the format. It contains no water, so it needs no preservative and cannot evaporate. It is highly viscous, so it stays where it is put rather than flowing into skin creases. It spreads poorly, which is a feature: a film that spreads thin is a film that has stopped occluding. And it has a high yield stress, meaning it holds its shape until a real force is applied, which is measurable rather than a matter of opinion. If you want the boundaries between the formats set out properly, they are in balm, salve, ointment and cream.
The trade is explicit. Everything that makes an ointment occlusive makes it unpleasant somewhere, so only pay that price where water loss is genuinely the problem.
The occlusivity target, and how far short plant materials fall
Petrolatum's occlusivity is one of the few claims in cosmetics with unusually strong measurement behind it, going back to work in the 1970s. Applied as a film, it reduces transepidermal water loss by around 98 percent, which is higher than any other single material in routine use. Nothing plant-derived comes close. Waxes, butters and liquid oils are typically reported in the range of a 20 to 30 percent reduction, with enough variation between studies that a ranking is more defensible than a decimal.
| Material or format | TEWL reduction | Why it lands there |
|---|---|---|
| White petrolatum | about 98% | Continuous hydrocarbon gel film, no absorption, no polar groups |
| Anhydrous lanolin | high, below petrolatum | Complex ester and sterol mix, partly absorbed, holds water as well as blocking it |
| Wax and butter balm | roughly 20-30% | Discontinuous crystalline film with liquid oil between the crystals |
| Shea butter, neat | roughly 20-30% | Melts and thins at skin temperature, film breaks up |
| Liquid vegetable oils | roughly 15-30% | Spread thin, partition into the stratum corneum, stop being a film |
Read the gap honestly. A plant ointment that reaches the top of the third row is doing well, and the formula below is built to sit there rather than to leap into the first. No measurement exists for this exact blend, and there is no way to produce one on a bench without a chamber instrument. What can be said is where the mechanisms point. The methods themselves, including the 2 mg per square centimetre dose convention that makes any two figures comparable, are in measuring occlusivity and transepidermal water loss.
Why an oil blend cannot copy a hydrocarbon gel
This is the part most natural alternatives skip. Petrolatum is not a thick oil. It is a colloidal gel: liquid saturated hydrocarbons held inside a continuous network of microcrystalline waxes of a similar chemical family. The liquid and the solid are made of the same kind of molecule, so the network wets its own liquid perfectly, the gel is optically and physically continuous, and it does not phase separate over any timescale a shelf life covers.
Three consequences follow, and each is a reason a triglyceride blend behaves differently.
- Nothing is absorbed. Saturated hydrocarbons of that molecular size do not partition into the intercellular lipid lamellae in any quantity, so the film stays where it was put. Plant oils do partition, and a film that is partly absorbed is a film that is partly gone.
- The film is continuous. A balm sets as crystals of wax and butter with liquid oil between them, and water vapour takes the path through the liquid. Raising wax raises the crystal fraction but also raises the number of grain boundaries. That is the ceiling described in oleogels and wax networks.
- There are no polar groups. Triglycerides carry ester carbonyls, and ricinoleic acid carries a free hydroxyl, both of which give water molecules somewhere to hydrogen bond on their way through. Petrolatum offers nothing to bond to.
The practical route to closing part of the gap is therefore not a cleverer ingredient. It is more of the film, applied thicker, held together by a network that resists being spread thin. That is what the percentages below are doing, and it is why the result is much less pleasant to use than a body balm.
The formula
Weight percent of the total batch, adding to exactly 100. The 500 g batch fills about nine 50 ml jars at a 46 g fill, after a 10 percent allowance for what stays on the jug and the spatula.
| Phase and ingredient | % | 100 g (g) | 500 g (g) | What it is there for |
|---|---|---|---|---|
| A: beeswax, cosmetic grade | 12 | 12.0 | 60.0 | Primary structure, stops the film flowing off |
| A: hydrogenated castor oil | 8 | 8.0 | 40.0 | Fine crystal network, holds the oil load in |
| A: castor oil | 45 | 45.0 | 225.0 | The viscous, adhesive continuous phase |
| A: shea butter, refined | 20 | 20.0 | 100.0 | Solid fat body, softens the drag |
| A: jojoba oil | 14.9 | 14.9 | 74.5 | Oxidative stability, thins the castor enough to pour |
| B: mixed tocopherols | 0.1 | 0.1 | 0.5 | Antioxidant, added below 60 C |
| Total | 100 | 100.0 | 500.0 | About two 50 ml jars, or nine |
If you want to run it at a batch size that is not on the table, the arithmetic is a single multiplication per line and the batch calculator will do it without transcription errors.
Why each number is what it is
45 percent castor oil is the whole idea. Castor runs around 950 centipoise at 20 C against 60 to 80 for most seed oils, because the hydroxyl group on carbon 12 of ricinoleic acid hydrogen bonds molecule to molecule. That gives the nearest thing in the plant world to a continuous viscous phase that resists being wiped thin. In a lip product the tack ceiling sits somewhere between 15 and 25 percent, and 45 percent would be intolerable. Here the tack is the mechanism, not a fault.
8 percent hydrogenated castor oil is deliberately above the 1 to 5 percent window that page recommends, and you should know what that costs. At 1 to 3 percent castor wax is an anti-syneresis agent, raising yield stress at almost constant hardness. Push it to 8 percent and it starts contributing genuine stiffness as well, giving a mass that holds a peak on a spatula and does not slump out of a knuckle crease at 30 C. The penalty is a drier, shorter, slightly draggy afterfeel and a melt step the rest of the formula does not need.
12 percent beeswax supplies the coarse structure the castor wax does not. Beeswax crystallises into a forgiving, plastic network rather than a brittle one, which is why the finished ointment dents rather than cracks. 20 percent refined shea butter is there to keep the mass from feeling like grease over sandpaper; refined rather than unrefined, because the unsaponifiable fraction that people prize in shea contributes nothing to occlusion and brings a smell that gets stronger in a thick film.
14.9 percent jojoba oil does two jobs. It is a liquid wax ester rather than a triglyceride, which makes it one of the most oxidatively stable liquids on a balm bench, and it thins the castor enough that the melt pours rather than glugs. 0.1 percent mixed tocopherols is at the measured optimum for alpha-tocopherol in oil, around 100 parts per million, above which it can start acting as a pro-oxidant. The working range and the evidence are in vitamin E and antioxidants.
Hydrogenated castor oil melts at 83 to 88 C and will not dissolve in the 75 to 80 C bath most balm formulas use. Hold this batch at 88 to 92 C until the liquid is completely clear, then get it out of the heat. Beeswax darkens and tocopherol degrades with a long hot hold, so the hold should be minutes, not half an hour. Skipping the temperature gives you a batch that looks fine in the jug and grows specks in the jar, which is the mechanism behind undissolved wax specks.
Method, pour temperature and cure
- Weigh phase A into one jug. Beeswax, hydrogenated castor oil, castor oil, shea and jojoba, taring between each addition. Weigh the tocopherol separately.
- Melt at 88 to 92 C. Use a water bath and accept that it will be close to boiling. Hold until there is not a single crystal or haze left, which usually takes 8 to 12 minutes at 500 g. Stir slowly and constantly; the castor makes the melt sluggish and it will scorch on a hot spot if you leave it still.
- Cool to below 60 C and add phase B. Lift the jug out, stir, and add the tocopherol when the reading drops under 60 C.
- Bring it back to 72 to 78 C and pour. Sit the jug back in the bath for a minute or two if you have overshot down. Pour in one continuous movement into warm, dry jars.
- Leave it alone. Do not stir, scrape or move the jars while they set. A sheared castor wax network sets stringy, and it does not recover.
- Cure 48 hours at room temperature before capping tightly, labelling or judging the texture. 72 hours is better. Both networks are still building for the first two days.
The pour window is high because the blend is thick. Below about 70 C the melt is already stiff enough that it lands in the jar as a mound and sets with a lumpy surface and trapped air. Above 80 C you get a deep shrinkage dip and the beeswax darkens. The physics of the whole window is in pour temperatures.
The target for the cured product is specific: at 18 C it must still take a fingernail or a small spatula without effort. That is the coldest a bathroom shelf usually gets in a temperate winter, and an ointment that has to be dug at is one that will not be applied thickly enough to work. If it fails that test, drop the hydrogenated castor oil to 6 percent and put the two points into jojoba.
Jar or squeeze tube
A 50 ml wide-mouth jar is the easier container: it lets a user take a large dose in one movement, which matters when the correct dose is a visible layer rather than a smear, and it tolerates the yield stress of the formula as written.
A squeeze tube is better hygiene and better for oxidation, because the headspace does not grow as the product is used, but it needs the formula softened or it will not extrude. Take the beeswax to 9 percent and the hydrogenated castor oil to 6 percent, and put the five recovered points into jojoba. Test the tube cold: one that dispenses fine at 22 C can be immovable at 10 C in a coat pocket. Closure and material compatibility are covered in packaging compatibility.
Where this format is right, and where a balm is better
An ointment earns its greasiness on small areas of thickened, fissured or wind-exposed skin, at a dose most people find excessive. The convention in the occlusivity literature is 2 mg per square centimetre: roughly 0.3 to 0.4 g over both heels, roughly 0.2 g over the backs of both hands. That is a layer that stays visible, not something rubbed in until it disappears. Dosing in practice is worked through in how much balm to apply.
| Site and situation | Better format | Dose per use | Reason |
|---|---|---|---|
| Cracked heels, overnight under socks | Ointment | 0.3-0.4 g | Thick skin, high water loss, occlusion held in place by the sock |
| Knuckles and fingertips in cold wind | Ointment | 0.1-0.2 g | Small area, repeated wetting, film needs to survive |
| Hands between shifts at work | Balm | 0.1 g | Has to be usable in two minutes without transferring to everything |
| Whole body after a bath | Balm or lotion | 10 g and up | An ointment at that area is unusable and expensive |
| Face, day use | Balm or cream | 0.02-0.05 g | 45 percent castor is far too tacky for facial skin |
| Lips | Lip balm | 0.01 g | Above the castor tack ceiling and unpleasant to taste |
Occlusive ointments are the format people reach for when skin is broken, and that is exactly where a cosmetic stops. Broken skin, weeping eczema, burns and open wounds are outside what a homemade anhydrous product should be used on or described for. In the United States a skin protectant claim puts a product under an OTC drug monograph, in which petrolatum is a listed active at 30 to 100 percent; a plant ointment has no such route. Where the line falls in each market is set out in cosmetic versus drug claims, and the general limits of what a page like this can tell you are in the disclaimer.
Failure modes
| Symptom | Mechanism | Fix |
|---|---|---|
| Stringy, cohesive, pulls into threads | The castor wax network was sheared while it set, and hydrogen bonded gels do not re-form after shear | Pour and walk away. If it has already happened, remelt to 90 C and re-pour undisturbed |
| Tack that never fades | Working as designed. 45 percent castor is above any lip or face tack ceiling | Reduce castor to 30 percent and add 15 to jojoba, accepting a thinner, less durable film. See sticky and tacky balm |
| Hard white specks in the jar | Hydrogenated castor oil never fully dissolved and seeded on cooling | Hold at 88 to 92 C to a clear melt, not 80 C |
| Oil standing on the surface | Liquid load beyond what the two networks can hold, usually after a warm delivery | Raise hydrogenated castor oil by one point, taken from jojoba. See balm sweating |
| Rancid or crayon smell inside a year | A large oil mass in a jar with a growing headspace, opened daily with wet fingers | Tube rather than jar, tocopherol at 0.1 percent, and a 12 month date rather than 18 |
| Immovable at 18 C | Both structurants at the top of their range in a cool room | Hydrogenated castor oil to 6 percent, beeswax to 11, difference into jojoba |
Oxidation deserves its own note, because the oil load here is unusually high. Castor and jojoba are both stable and refined shea is unremarkable, so the blend is not intrinsically fragile. The risk is physical: a jar dipped into daily has a wet finger in it, an expanding air space above it and often a warm bathroom around it, and that shortens shelf life more than the fatty acid profile does.
Scoring it honestly against petroleum jelly
| Property | White petrolatum | This ointment | Winner |
|---|---|---|---|
| TEWL reduction | About 98 percent | Top of the plant band, unmeasured | Petrolatum, clearly |
| Film durability through handwashing | Very high | Good, better than a balm | Petrolatum |
| Shelf life | Effectively indefinite | 12 to 18 months | Petrolatum |
| Cost per gram | Very cheap | Several times higher | Petrolatum |
| Contact allergy risk | Among the lowest of any cosmetic material | Beeswax and propolis traces are a known, if uncommon, sensitiser | Petrolatum |
| Supplies barrier lipid precursors | None | Free fatty acids and unsaponifiables | This ointment |
| Skin feel and finish | Slippery, sits on top, transfers heavily | Tacky, grips, transfers less | Preference, not performance |
| Renewable sourcing and biodegradability | Fossil, poorly biodegradable | Renewable, biodegradable | This ointment |
| Route to a skin protectant claim | US OTC monograph active at 30 to 100 percent | No monograph route | Petrolatum |
That is six rows to petrolatum, two the other way and one a matter of taste, and pretending otherwise would be dishonest. The case for making this ointment is not that it beats petroleum jelly. It is that it gets close enough for ordinary dry skin while being renewable and supplying fatty acids an inert hydrocarbon cannot. Whether that trade is worth making is argued from both sides in natural versus petroleum, and the safety questions people actually have about the fossil option are answered in is petroleum jelly bad for you.
The decision rule, and what this formula cannot do
Use this base when the site is small, the skin is thick or fissured, the film has to survive water, and the user is prepared to accept a greasy, tacky product. Use a normal balm everywhere else, because a balm that gets applied five times a day will beat an ointment that gets applied once and then abandoned for being unpleasant.
What it cannot do: it cannot substitute for petrolatum where a clinician has specified petrolatum, it cannot be used on broken skin, and it cannot carry a claim about protecting or treating anything. It also cannot be validated on a home bench. Every occlusivity figure on this page comes from published work on other materials, and the honest statement about this particular blend is that its mechanisms point in the right direction and nobody has put it in a chamber. If you need a measured number, you need petrolatum, or you need a laboratory.
Frequently asked questions
Is there a plant based alternative that works as well as Vaseline?
Not on raw occlusion. Petrolatum reduces transepidermal water loss by around 98 percent and plant waxes, butters and oils are usually reported at 20 to 30 percent. A thick anhydrous ointment closes part of that gap by being applied heavily and resisting spread, but no published plant blend matches a hydrocarbon gel. Choose one for sourcing reasons, not performance reasons.
Why does this formula use 45 percent castor oil when lip balms cap it at 25?
Because tack is the point rather than the fault. Castor is roughly 950 centipoise at 20 C against 60 to 80 for most seed oils, thanks to the hydroxyl group on ricinoleic acid, and that viscosity is what stops the film being wiped thin. On lips or facial skin the same property is unpleasant, which is why an ointment at this loading belongs on heels, knuckles and fingertips.
Can I use hydrogenated castor oil at 8 percent when everyone says 1 to 5?
Yes, as long as you expect a different result. At 1 to 3 percent it holds oil in without adding hardness. At 8 percent it becomes a genuine structurant and the product turns firmer, drier and slightly draggy. It also needs a melt held at 88 to 92 C rather than the usual 75 to 80, or it will not dissolve and will grow specks in the jar.
Does an anhydrous ointment need a preservative?
No, because there is no water for bacteria or mould to grow in. It still needs an antioxidant, since rancidity is a chemical process rather than a microbial one, and 0.1 percent mixed tocopherols covers that. The real risk in a wide-mouth jar is water introduced by wet fingers, which is a reason to prefer a squeeze tube for a product used daily.
Why does it have to be poured so much hotter than a normal balm?
Two reasons. Hydrogenated castor oil melts at 83 to 88 C and will not clear in a 75 to 80 C bath, so the melt hold has to reach 88 to 92 C. And the blend is thick enough that below about 70 C it lands in the jar as a mound instead of levelling, trapping air and setting with a lumpy surface. The pour window is 72 to 78 C.
Can I put this on eczema, a wound or a nappy rash?
No. This is a cosmetic for intact skin. Occlusive products for broken skin, weeping eczema, burns or nappy rash sit on the drug side of the line in most jurisdictions, and petrolatum has an OTC monograph route in the United States that a plant ointment does not. Follow a clinician's instructions for those situations rather than a formula from a website.
Sources and further reading
- United States Pharmacopeial Convention, USP General Chapter <1151> Pharmaceutical Dosage Forms, Rockville, for the classification of ointment bases.
- European Directorate for the Quality of Medicines, European Pharmacopoeia monograph: Paraffin, white soft (Vaselinum album), Strasbourg.
- European Directorate for the Quality of Medicines, European Pharmacopoeia monograph: Ricini oleum hydrogenatum (hydrogenated castor oil), Strasbourg.
- US Food and Drug Administration, 21 CFR 347, Skin Protectant Drug Products for Over-the-Counter Human Use, eCFR.
- Rawlings A.V. and Lombard K.J., A review on the extensive skin benefits of mineral oil, International Journal of Cosmetic Science, 2012.
- Cosmetic Ingredient Review, Final report on the safety assessment of Ricinus communis (castor) seed oil, hydrogenated castor oil and related ingredients, International Journal of Toxicology, 2007.
Reviewed and updated 6 September 2026. Spotted an error? Tell us and we will fix and log it.