Two lip balms can carry the same twelve percent wax and behave nothing alike. One glides and sets with a grip; the other drags, then sweats oil in the tube after a month on a warm shelf. The percentage is identical. What differs is how the structurant crystallises, and crystal habit is a property of the molecule rather than of the number on the formula sheet.
This is a working guide to the five materials that build the oil phase of a stick, a balm, an ointment or a cream: what each one actually does at the level you would dose it, what processing each one demands, and which lines on the certificate of analysis confirm that the drum you received is the material you ordered. Wax esters used purely for texture and gloss have their own guide (Wax Esters for Texture Design), and the liquid hydrocarbon family has its own (White Mineral Oil Grades). This article covers the true waxes, the gellants and the occlusive.
The five structurants, side by side
Every figure below is a figure a supplier specification sheet actually carries. Where sources disagree, the range is shown rather than an average, because that disagreement is itself part of what you are buying.
| Material | CAS | Melt / drop point | How it structures | Typical use level | What it is for |
|---|---|---|---|---|---|
| Beeswax | 8012-89-3 | 62–65 °C | microcrystalline needle network, high oil binding | 3–15% | stick hardness, grip and gloss; the benchmark |
| PEG-8 Beeswax | 8012-89-3 | 59–70 °C | the same wax body with an ethoxylated head | 1–10% | beeswax that emulsifies itself |
| Trihydroxystearin | 139-44-6 | 85–89 °C | thixotropic fibre network through hydroxyl hydrogen bonding | 0.2–0.8% (gels); 0.5–2% (pressed powders) | gelling oil without a hard wax |
| Bis-Diglyceryl Polyacyladipate-2 | 82249-33-0 | ca. 35 °C | non-crystalline, fibre-forming paste | 0.5–2%; 2–10% in lip | vegan lanolin; cushion and gloss without wax bloom |
| Mono- and Diglycerides | 67254-73-3 | 55–70 °C | alpha-crystalline lamellae, non-ionic | 0.1–2% as co-emulsifier; more as a bodying agent | W/O co-emulsifier, lamellar gel, crumb softening |
| White Petrolatum | 8009-03-8 | 38–60 °C | microcrystalline semi-solid gel | to 100% in an ointment; 2–30% in creams | occlusion and barrier; the reference standard |
Drop point is only half of the specification
A drop point tells you when the structure lets go. It says nothing about what the material felt like before that, and the difference between two materials melting a few degrees apart sits entirely in the crystal habit.
Beeswax crystallises as fine needles. Those needles overlap and trap liquid oil in the gaps, which is why a beeswax balm feels firm without being brittle and why it holds its shape in the tube. The cost is a waxy, slightly draggy film and a tendency to bloom: over time the wax re-crystallises at the surface and the stick goes dull and grey. Roughly 35 to 45 percent of beeswax is linear wax monoesters and hydroxymonoesters in the C40 to C48 region, another 15 to 27 percent is complex wax esters built on 15-hydroxypalmitic acid, 12 to 14 percent is free fatty acids mostly in the C24 to C32 range, and 12 to 16 percent is odd-numbered hydrocarbons running from C27 to C33. That hydrocarbon fraction is the part that keeps beeswax slightly soft at body temperature while it still reads as a wax.
Trihydroxystearin works through a different mechanism altogether. It is glyceryl tri(12-hydroxystearate), a defined triglyceride of C57H110O9, and its three secondary hydroxyl groups hydrogen-bond to each other. Dispersed hot and cooled under shear it builds a three-dimensional fibre network that holds oil like a sponge, and the result is thixotropic: firm at rest, fluid under shear, firm again when the shear stops. That is the behaviour behind a balm that settles without running, and it arrives at 0.2 to 0.8 percent, an order of magnitude below the wax level a comparable structure would need. Read that number again when you plan the batch, because it also means a dosing error of 0.2 percent is a very large relative error.
Bis-Diglyceryl Polyacyladipate-2 does not crystallise at all. It is a partial ester of diglycerol with adipic acid and a mixture of caprylic, capric, isostearic, stearic and 12-hydroxystearic acids, supplied as a tacky, stringy, yellow paste that melts near 35 °C and reads as a viscous oil rather than a solid. Because there is no crystal to re-form there is no bloom and no sweating, and the datasheets make a concrete claim that follows from it: viscosity across 25 to 70 °C tracks lanolin closely, but unlike lanolin it does not drift with temperature cycling, light or long storage. It also takes up water to at least 170 percent of its own weight, which is why it doubles as a W/O structure builder. In practice it is the material you reach for when the brief says vegan and the reference product was built on lanolin or beeswax.
Mono- and diglycerides structure through lamellae rather than fibres. The free hydroxyl groups left on the glycerol backbone give an otherwise fat-like molecule a polar end, and the monoester fraction arranges into alpha-crystalline bilayers that gel water and oil at the same time. The same polarity is what forms a helical inclusion complex with amylose in bread. In a cosmetic or pharmaceutical cream the practical effect is a bodying lamellar gel that reinforces the interface without an extra emulsifier.
Petrolatum is the odd one out, because it is not a structurant you add, it is a structure you buy. It is a purified mixture of semi-solid hydrocarbons forming a microcrystalline gel matrix, and its defining property is occlusion. A petrolatum film reduces transepidermal water loss by roughly 98 percent while still permitting barrier repair, the number that explains why it has stayed the dermatological reference for a century despite contributing nothing beyond the film.
Replacing beeswax: three routes, and what breaks in each
The pressure to reformulate away from beeswax comes from cost volatility, from a supply that depends on a single animal source, and from briefs that ask for vegan or clean-label positioning while still demanding the firm set of a beeswax stick. Three routes work, and each one fails somewhere different.
- PEG-8 Beeswax: keep the wax, change the head. Esterifying the free fatty acids of beeswax and reacting them with ethylene glycol keeps the crystalline body and adds a non-ionic hydrophilic head. Suppliers publish a melting point of 59 to 70 °C, a saponification value of 77 to 90 and an HLB of 9, with use levels of 1 to 10 percent. The gain is that one material does the job of wax and emulsifier at once, which shortens the oil phase list in a cream or a lotion. The caveat is that HLB figure: 9 sits in the middle of the scale, and the same datasheet that quotes it describes the material as a self-emulsifying wax for stable oil-in-water emulsions. Treat 9 as a bench starting point rather than a prediction, and be explicit with the factory, because an ethoxylated material is excluded on principle from any brief that says PEG-free.
- Bis-Diglyceryl Polyacyladipate-2: change the structure mechanism. Because it never crystallises it solves both failure modes of a beeswax stick at once, no bloom and no oil migration, and it brings lanolin-like cushion. Dose it at 0.5 to 2 percent for a soft solid and 2 to 10 percent in a lipstick or lip balm. What it will not give you is beeswax hardness; if the original brief rested on the mechanical grip of a wax needle network, expect to add a small amount of a hard high-melting material or to accept a softer stick.
- Trihydroxystearin: replace the wax with a gellant. If the goal is simply to keep the stick firm, a fibre gellant at 0.2 to 0.8 percent carries the structure that would otherwise need several percent of hard wax, and it leaves a cleaner, less waxy film. The trap is entirely in the process, not the formula. Trihydroxystearin must be dispersed into oil already at 55 to 60 °C, held under high shear for 10 to 20 minutes to activate, and then kept under blade stirring all the way down to about 40 °C. Cut the shear short, or let the batch cool undisturbed, and you get graininess, uneven crystallisation and a gel thinner than the one you made last week. Where a production line has no cooling-under-shear step, this route will disappoint and the fault will be blamed on the raw material.
The processing windows that actually decide the batch
| Material | Add at | Mixing | What goes wrong if you rush it |
|---|---|---|---|
| Beeswax | melt into the oil phase at 70–75 °C, well above its 62–65 °C melting range | simple agitation | cold dosing leaves grit; surface bloom on cooling |
| PEG-8 Beeswax | 60–70 °C | simple agitation | an incomplete melt gives a lumpy emulsion |
| Trihydroxystearin | 55–60 °C | high shear for 10–20 min, then blade stirring down to 40 °C | graininess, a weak gel, batch-to-batch variation |
| Bis-Diglyceryl Polyacyladipate-2 | oil phase, 60–70 °C for full clarity | simple agitation | little; stringy handling is normal |
| Mono- and Diglycerides | into the fat phase at 65–75 °C; hydrated alpha forms need no melting step | dispersed hot under shear | beta-crystal conversion during a long hot hold |
| White Petrolatum | 70–80 °C to blend, or cold as the ointment base | simple agitation | entrained air if stirred cold |
The line above worth memorising is the one on mono- and diglycerides. The alpha-crystalline form is the functional one and it is metastable; a long hot hold converts it to the beta form, which is more stable and much less effective as a gel. When a lamellar gel fails to build, check the time in the hold tank before you blame the raw material.
What the certificate of analysis can and cannot tell you
None of these five materials is a single compound, and that has a practical consequence: identity cannot be read from appearance, and it often cannot be read from any one number. Two identities do the heavy lifting here, and one of them is counter-intuitive.
Beeswax: acid value plus ester value equals saponification value. That is arithmetic, not a specification. The published beeswax profile is an acid value of 17 to 24, an ester value of 70 to 80 and a saponification value of 87 to 104, and the arithmetic closes because saponification value is defined as the sum of the other two. Use the identity as an integrity check: a certificate whose three figures do not reconcile is not describing beeswax. Then use drift in the profile as an adulteration check. Cut with paraffin and all three fall together while the hydrocarbon content climbs past the 18 percent ceiling; cut with a cheap free fatty acid and the acid value jumps while the ester value and saponification value lag behind. The acid value also says something concrete about composition: 17 to 24 corresponds to roughly 12 to 17 percent free acids on a C26 to C30 basis, which matches the 12 to 14 percent JECFA reports for genuine beeswax. A figure outside that window is a reformulation, whether or not anyone labelled it as one.
Trihydroxystearin: the saponification value is an identity number, and the CAS is a specification decision. Because Trihydroxystearin is a defined triglyceride, C57H110O9 with a molecular weight of 939.5, its saponification value can be calculated rather than merely quoted: three ester bonds, one molecular weight, so saponification value = 3 × 56,106 ÷ 939.5 = 179. That is exactly what suppliers report, which means a certificate showing a value far from 179 is describing a mixture rather than the defined triester. Which brings up the CAS. Trihydroxystearin carries CAS 139-44-6, the defined pure triester. Generic hydrogenated castor oil carries CAS 8001-78-3, and it is frequently the same molecule from the same hydrogenation route, but it is not the same specification, because the generic grade is not required to hit the melting point or the saponification value that the defined INCI implies. Write the INCI and CAS 139-44-6 on the purchase order, and check the drop point against the 85 to 89 °C window when the goods arrive.
Mono- and diglycerides: the saponification value moves the wrong way. This is the one that catches buyers out. Our standard identity is saponification value = number of ester bonds × 56,106 ÷ molecular weight, and applied to a glyceryl stearate it gives a clear and unwelcome trend. Monostearin, C21H42O4 at 358.6, carries one ester bond: saponification value 156. Distearin, C39H76O5 at 625.0, carries two: 179. Tristearin, C57H110O6 at 891.5, carries three: 189. As monoester content rises, the saponification value falls. A standard glycerolysis grade at 40 to 55 percent monoester and a distilled grade at 90 percent monoester can both land inside the same 150 to 180 window, so a buyer who reads a high saponification value as evidence of rich monoester content has it backwards. Monoester content is a gas chromatography figure. Order total monoester content explicitly, specify 40 percent or 90 percent, and use the saponification value only as a check that the material is a partial glyceride at all.
Bis-Diglyceryl Polyacyladipate-2: the iodine value is the tell. The published profile is a saponification value of 270 to 290, an acid value of 2 maximum and an iodine value of 3 maximum. That last figure is the informative one. An iodine value that low means a fully saturated acid profile, and it is a large part of why the material is oxidatively stable and resists yellowing. A vegetable lanolin quoting a materially higher iodine value is a different ester blend, whatever the label says.
White Petrolatum: the grade is the test battery, not the melting range. This is the clearest example on the list of two grades that look identical on the front of the pack and are separated entirely by what the laboratory has to prove. The USP monograph for White Petrolatum and the European monograph for white soft paraffin both set the melting range at 38 to 60 °C. The same melting range. Everything else differs: consistency measured with a 150 g cone penetrometer at 25 °C, reading between 100 and 300; organic acids, no more than 400 microlitres of 0.1 N sodium hydroxide; residue on ignition, no more than 0.05 percent; a colour test against a standard; and an ultraviolet absorbance ceiling of about 0.5 on a solvent extract for the white grade. A cosmetic grade need not run any of it. So when a formulator asks whether cosmetic and pharmaceutical petrolatum differ, the honest answer is that they may be the same material from the same refinery and they may not, and the pharmacopoeial grade is the one where you can tell.
The regulatory layer that sits on petrolatum
Petrolatum is the only material on this list with a conditional prohibition attached to it in the European Union. Under Regulation (EC) 1223/2009 it appears in Annex II, the list of substances cosmetic products must not contain, with an exception permitting it where the full refining history is known and it can be shown that the substance from which it is produced is not a carcinogen. Read that again, because it is unusual: very few cosmetic ingredients are prohibited by default and permitted only on proof of provenance.
The proof has a number attached to it. Under Note L of the CLP Regulation a petroleum-derived substance need not be classified as a carcinogen if it contains less than 3 percent by weight of dimethyl sulphoxide extractables measured by the IP 346 method. That threshold is the practical dividing line between the material IARC placed in Group 1, untreated and mildly treated mineral oils, carcinogenic to humans on the strength of occupational exposure in cotton spinning and metalworking, and the highly refined material in Group 3.
The distinction that gets lost in consumer argument is the one between MOSH and MOAH. Both are analytical categories rather than ingredients. Mineral oil saturated hydrocarbons accumulate in tissue, but the 2023 EFSA update concluded that accumulation at current dietary exposures is not a health concern. Mineral oil aromatic hydrocarbons are the concern, and specifically the fraction carrying three or more aromatic rings, which includes genotoxic carcinogens. Regulators are already acting on that fraction in adjacent areas: under France’s AGEC law, mineral oils have been banned from packaging and printing inks since 1 January 2025 above 0.1 percent MOAH, or above 1 ppm for the three- to seven-ring compounds, and above 0.1 percent MOSH. That is packaging law rather than cosmetics law, but it is the direction of travel, and it explains why the question a customer will ask in two years is not whether your petrolatum is refined but whether you hold the document that says how.
The procurement answer is short. Buy the pharmacopoeial grade, and ask for two documents alongside the certificate of analysis: the refining history, and an IP 346 result. A supplier who can produce both has answered the European question before it is asked.
Choosing by brief
| If the brief says | Reach for | Because |
|---|---|---|
| firm stick, classic waxy grip, cost secondary | Beeswax | the needle network gives the hardest set per percent and the familiar feel |
| one material that is both wax and emulsifier | PEG-8 Beeswax | self-emulsifying at 1–10%; removes a separate emulsifier from the list |
| vegan, no bloom, no oil sweating | Bis-Diglyceryl Polyacyladipate-2 | non-crystalline paste; viscosity stable from 25 to 70 °C |
| clean film, low wax load, thixotropic set | Trihydroxystearin | fibre gel at 0.2–0.8%; needs cooling under shear |
| lamellar body plus a W/O interface | Mono- and Diglycerides | alpha-crystalline bilayers; supplies the interface, not just the body |
| maximum occlusion, dermatological reference, lip products | White Petrolatum | about 98% reduction in water loss, with purity documented at pharmacopoeial grade |
Grades we supply
We supply all six materials discussed above, quoted against the specification you write rather than a catalogue number:
- Beeswax (CAS 8012-89-3), cosmetic grade for lipstick, lip balm, creams and ointments
- PEG-8 Beeswax (CAS 8012-89-3), emulsifier and viscosity modifier for creams, makeup and sun care
- Trihydroxystearin (CAS 139-44-6), thickener and structuring agent for lipstick, lip balm and colour cosmetics
- Bis-Diglyceryl Polyacyladipate-2 (CAS 82249-33-0), emollient ester for lipstick, lip balm, makeup and skin care
- Mono- and Diglycerides (CAS 67254-73-3), 40 percent or 90 percent monoester, for creams, lotions and food-grade emulsions
- White Petrolatum, cosmetic grade (CAS 8009-03-8), for lip balms, hand creams, baby care and colour cosmetics
- White Petrolatum, pharmaceutical grade (CAS 8009-03-8), ointment and cream base to USP and Ph. Eur.
Tell us the brief - how hard the stick has to be, what film you want, whether the label has to say vegan or PEG-free, and whether the product touches lips - and we will confirm the structurant, the use level and the goods-in specification before you place the order.