Polymer Waxes (PE, OPE, Fischer-Tropsch, Montan): 6 Wax Types, Dosage and Selection

Polymer waxes are low-molecular-weight hydrocarbon and ester waxes, from paraffin wax at about 200 g/mol to polyethylene wax at up to 10,000 g/mol, that are compounded into plastics at roughly 0.07 to 3 parts to cut friction between the melt and the metal, carry pigments and fillers, and release the part from the tool. They are the external half of almost every rigid PVC lubricant package and the standard carrier in filler masterbatch, so which of the six wax classes belongs in which compound?

Waxes are one of the oldest and cheapest groups of plastic additives, and the only one measured in tenths of a part. A rigid PVC pipe compound carries 0.6 to 1.5 phr of paraffin wax plus 0.1 to 0.2 phr of oxidized PE wax, while a 60 wt% calcium carbonate masterbatch can carry 3 wt% of PE wax or Fischer-Tropsch wax as its dispersant and carrier. That range is what makes wax selection a compound-by-compound decision rather than a fixed recipe.

This page defines a polymer wax and how it lubricates a melt, sets out the six wax classes (paraffin, Fischer-Tropsch, polyethylene, oxidized polyethylene, polypropylene and montan wax), compares PE wax against paraffin wax and Fischer-Tropsch wax on molecular mass and die-drool behaviour, gives the phr and wt% levels each polymer and process needs, explains what goes wrong at the wrong dosage, shows how a wax is specified and tested, lists which waxes are cleared for food contact under EU and US law, and names the producers who supply them.

Key figures

• 6 wax classes used in plastics: paraffin wax, Fischer-Tropsch wax, PE wax, oxidized PE wax, PP wax and montan wax
• 0.07 to 0.3 phr: the oxidized PE wax level in rigid PVC, the lowest dosage of any lubricant in the family
• 200 to 10,000 g/mol: the molecular-mass span across the six classes
• FCM 549, 811, 93/94, 529 and 550: the EU food-contact entries covering PE wax, oxidized PE wax, paraffin wax and montan wax

What Are Polymer Waxes in Plastics?#

A polymer wax is a low-molecular-weight hydrocarbon or long-chain ester that melts well below the processing temperature of the plastic and then does three jobs at once: it lubricates the melt, it wets and disperses pigments and fillers, and it releases the part from hot metal. Internal lubricants reduce friction between polymer chains and lower melt viscosity, while external lubricants reduce adhesion between the melt and the metal surfaces of the screw, die and calender roll, and prolong fusion (Baerlocher, 2017 lubricant brochure). Almost every wax in this family acts externally. Waxes also work as dispersants that wet pigment and filler surfaces and as the carrier resin in masterbatch, and where a part must release from a mould, wax is one of four mold-release classes alongside fatty esters, silicones and metallic soaps.

The hub on processing lubricants for plastics sets out the internal and external balance that waxes sit inside, and it is the starting point for choosing a lubricant package before narrowing down to a single wax class.

How does a wax lubricate a polymer melt?#

A wax lubricates by separating surfaces that would otherwise stick: its non-polar hydrocarbon chains sit between the melt and the hot metal of the screw, die or calender roll, while polar waxes anchor to the metal itself. The chain-length and polarity rule sets which behaviour a wax shows: polar groups such as hydroxyl, carboxyl and calcium carboxylate on C14 to C18 chains act internally, while non-polar chains above C20 and up to about C100 act externally, and a reduction in polarity gives more external action (Baerlocher lubricants brochure; Peter Greven plastics brochure, 09/2025).

Rabinovitch, Lacatus and Summers (1984, Journal of Vinyl Technology) tested differential thermal analysis, haze, microscopy, metal-release and Brabender fusion data and concluded that the internal and external classification is "deficient in explaining performance." Their finding: polar lubricants such as calcium stearate wet the metal preferentially, non-polar paraffin wax does not wet the metal at all but instead makes the calcium stearate layer more fluid, and lubrication between PVC primary particles follows the same physics as lubrication at the metal wall. That result is why paraffin wax and calcium stearate are dosed together in a PVC pipe formulation rather than substituted for one another.

Internal, external and combined lubrication: where each wax sits#

Every wax in this family is an external lubricant, which means it builds a release film between the melt and the metal, prolongs fusion and, at too high a level, turns a clear compound hazy. Table 1 lists twelve lubricants by melting or dropping point and lubrication mode, with the wax classes set alongside the metal soaps and esters they are commonly dosed against.

Table 1. Lubrication mode and melting range

Source: Baerlocher lubricants brochure, 2017.

External effects at working dosage include strong metal release and prolonged fusion, and at high dosage, haze, exudation and reduced printability and weldability. Baerlocher classes calcium stearate as internal and zinc stearate as external, and that classification is the supplier's own functional grouping rather than a physical law: as the Rabinovitch critique above shows, calcium stearate's real role is to wet the metal wall, which is an external-type action, so the internal and external labels describe typical formulation behaviour more than a fixed mechanism. The full balance for each PVC process is on lubricants for PVC compounding, which sets out how wax, ester and metal-soap levels move together across pipe, profile, injection moulding and calendering.

Is wax the same thing as plastic?#

No, but polyethylene wax and polyethylene are the same chemistry at different chain lengths: PE wax is polyethylene with an average molecular mass of up to about 10,000 g/mol, low enough to melt and flow like a wax instead of behaving like a moulding resin. PE wax is made either by direct polymerization of ethylene or by breaking down high-molecular-weight polyethylene, and it is this short chain length, not a different chemical structure, that separates a wax from a resin.

What Are the 6 Types of Wax Used in Plastics?#

The 6 types of wax used in plastics are paraffin wax, Fischer-Tropsch wax, polyethylene wax, oxidized polyethylene wax, polypropylene wax and montan wax, and they are best understood in order of molecular mass, which runs from about 200 g/mol for paraffin wax to about 10,000 g/mol for PE wax. Table 2 sets out the identity, molecular mass, melting or dropping point, lubrication mode and EU food-contact entry for each class before the sections below examine each one individually.

Table 2. The 6 wax classes: overview

Order rule: the three hydrocarbon waxes (paraffin, Fischer-Tropsch, PE wax) come first, then the oxidised polyolefin wax, then the polypropylene wax, then the fossil ester wax.

1. Paraffin wax (macrocrystalline and microcrystalline)#

Paraffin wax (CAS 8002-74-2) is the classic external lubricant of rigid PVC: a mixture of n-alkanes of about 200 to 1,000 g/mol that melts at 54-56 °C and is used at 0.6-1.5 phr in pipe compounds. Its EC number is 232-315-6, its formula is written CnH2n+2, and a fully refined grade such as Struktol PE(H)-165 has a dropping point of 67-72 °C and a specific gravity of 0.92. ECHA CHEM lists 100 active REACH registrations under EC 232-315-6 (queried 2026-09-22), reflecting how widely paraffin wax trades across industries beyond plastics. Struktol's technical data states that paraffin wax is "not recommended for articles that are to be printed," because its non-polar surface film resists ink and coating adhesion.

Microcrystalline wax (EC 264-038-1) is the branched, higher-viscosity variant of the same petroleum-refining family, carrying 30 active REACH registrations. In rigid PVC pipe, paraffin wax delays resin particle breakdown and fusion (Krzewki and Collins, 1981, Journal of Macromolecular Science, Part B), which is why it is dosed together with calcium stearate rather than alone: the two lubricants are retrialled as a pair whenever either level changes. Grades, specifications and the full regulatory matrix are on paraffin wax, the substance page for this class.

2. Fischer-Tropsch wax (synthetic paraffin)#

Fischer-Tropsch wax is a synthetic paraffin with a very narrow molecular-mass distribution, which is what separates it from petroleum paraffin: one experimental Sasol grade measured a number-average molecular mass of 776 g/mol and a mass-average of 786 g/mol, a polydispersity of 1.01, while a commercial PE wax in the same study measured 4,715 and 14,960 g/mol respectively (Radebe, Wesley-Smith, Focke and Ramjee, 2022, University of Pretoria, Journal of Polymer Engineering). Fischer-Tropsch wax is made by the Fischer-Tropsch synthesis route and "is mainly produced by Sasol, South Africa" (Mhlabeni, Jamiru and Mhike, 2024, Frontiers in Chemical Engineering). Baerlocher's synthetic paraffin grade, Baerolub L-KO, melts at 100-105 °C, and its linear chains, unlike branched petroleum paraffin, can co-crystallise with HDPE. A verified CAS or EC number for the wax used by producers such as Sasol is not established, so none is stated here, and its REACH status is not established either.

Fischer-Tropsch wax wins where paraffin's broad distribution becomes a liability: lower-molecular-mass waxes "tend to exacerbate die drool" relative to PE wax (Mhlabeni, Jamiru and Mhike, 2024), and grade data for Fischer Tropsch wax sits on its own substance page. Why low-molecular-mass waxes feed die build-up (die drool) is explained there, with remedies.

3. Polyethylene wax (PE wax)#

Polyethylene wax (CAS 9002-88-4) is low-molecular-weight polyethylene, with a broad molecular-mass distribution averaging up to 10,000 g/mol, used as an external lubricant in rigid PVC, as a dispersant and carrier in masterbatch, and at 1-4% of compound in elastomers. Its formula is written (C2H4)n. Struktol's PE(H)-100 grade melts at 90-105 °C with a specific gravity of 0.91, and Baerlocher's Baerolub PA-L melts higher, at 102-110 °C.

PE wax is made by three routes.

1. Direct polymerization of ethylene, which builds the wax at its target chain length from the start.
2. Thermal or mechanical degradation of high-molecular-weight polyethylene, breaking a resin down into wax-length chains.
3. Separation of the low-molecular-weight fraction from a polyethylene process stream.

The two degradation routes need the lightest fraction removed before the wax is sold, because leaving it in lowers the flash point, raises migration and increases build-up on processing equipment.

As a polymer, PE wax is exempt from REACH registration under Article 2(9), which is why no dossier appears under CAS 9002-88-4. The EU lists it for food contact as FCM 549 (Ref 80000), with no specific migration limit, and the US PVC pressure pipe industry's own range composition (PPI TR-2 Appendix C) allows 0.0-0.3 phr of PE wax alongside paraffin wax. Properties, grades and food-contact status of polyethylene wax are covered in full on its substance page.

4. Oxidized polyethylene wax (OPE)#

Oxidized polyethylene wax (CAS 68441-17-8) is PE wax that has been oxidised to carry polar carboxyl groups, and those groups anchor it to metal so firmly that 0.07-0.3 phr gives more release than a full part of paraffin wax. Its EC number is 614-498-8. Table 3 compares the two Struktol grades most often specified.

Table 3. OPE grade comparison

OPE is dosed at 0.07-0.3 phr across rigid PVC pipe, profile, injection moulding, calendering and clear extrusion, always as the trace, high-efficiency component of a larger package. The EU lists it as FCM 811 (Ref 80077) with a specific migration limit of 60 mg/kg, and the US clears it under 21 CFR 177.1620 for a number-average molecular mass of at least 1,200, plus 21 CFR 172.260 as a direct food additive at the same specification. A related use, E 914, covers only the surface treatment of certain fruits (EFSA re-evaluation, 2015) and sits outside plastics processing entirely. Grade-by-grade data for oxidized polyethylene wax sits on its substance page.

5. Polypropylene wax (PP wax)#

Polypropylene wax (CAS 9003-07-0) is the polypropylene analogue of PE wax, listed for EU food contact as FCM 550 (Ref 81060) with no specific migration limit. Melting point, molecular mass, typical dosage and producer are not established in our source library for this class, so none of those figures is published here; the entry is limited to its identity and its regulatory listing until further data is verified.

6. Montan wax and montanic acid esters#

Montan wax (CAS 8002-53-7), also called lignite wax, is the only fossil ester wax in this family: it is solvent-extracted from lignite, mainly at Amsdorf in Germany, and consists of 62-68% long-chain esters, 22-26% acids and 7-15% alcohols and hydrocarbons. Its EC number is 232-313-5, and it is also traded as "OP wax." Further deposits sit at Ione in California and in Yunnan and Jilin in China. The crude wax melts at 82-95 °C.

• Long-chain esters: 62-68% of the crude wax.
• Free acids: 22-26% of the crude wax.
• Alcohols and hydrocarbons: 7-15% of the crude wax.

Refining follows the Gersthofen oxidative process, which converts crude montan wax to montanic acids. Those acids are then partially esterified with ethylene glycol or 1,3-butanediol, with or without calcium neutralisation, to give the ester grades used in plastics. The US clears those partial esters under 21 CFR 178.3770 as lubricants for PVC food-contact articles, with a required dropping point of 76-105 °C. The EU lists crude montan wax as FCM 529 (Ref 67850) and montanic acids and their esters with ethylene glycol, 1,3-butanediol or glycerol as FCM 67 (Ref 67840); neither carries a specific migration limit. ECHA CHEM records 3 active REACH dossiers for montan wax, all registered as Article 18 intermediates.

"Montan Wax E" and "Montan Wax OP" are legacy grade names used generically across the market rather than the products of a single supplier. Struktol markets V-Wax E (dropping point about 80 °C) and V-Wax OP (about 101 °C) as 1:1 replacements for those legacy names. No montan-wax producer is named here beyond that replacement relationship, since the only other candidate identified in research could not be verified. Refining routes and derivative esters are covered in full on the montan wax substance page.

PE Wax vs Paraffin Wax vs Fischer-Tropsch Wax: Which One to Use?#

Polyethylene wax and paraffin wax differ by an order of magnitude in molecular mass, and almost every practical difference follows from that: PE wax melts near 100 °C and stays in the compound, while paraffin wax melts near 55 °C, fluidises the metal-soap layer and delays fusion. Table 4 lines up the three hydrocarbon-family waxes against eight criteria.

Table 4. PE wax vs paraffin wax vs Fischer-Tropsch wax

Lower-molecular-mass waxes tend to exacerbate die drool relative to PE wax, a published finding from Mhlabeni, Jamiru and Mhike (2024, Frontiers in Chemical Engineering), and it is the main reason a formulator moves from paraffin wax to Fischer-Tropsch wax or PE wax when die build-up becomes the limiting defect rather than metal release. Fischer-Tropsch wax sits between the other two: it occupies the same molecular-mass band as paraffin wax, so it processes at a similar dosage, but its narrow distribution and higher melting point behave more like PE wax at the die. The trade-off is cost and availability against consistency, since paraffin wax is a broadly traded petroleum commodity while Fischer-Tropsch wax comes from a narrower synthetic supply base led by Sasol.

Which Wax Does Each Polymer and Process Need?#

The wax a compound needs follows the polymer, the process and the filler load: paraffin wax plus a trace of oxidized PE wax for rigid PVC extrusion, PE wax or Fischer-Tropsch wax at whole-percent levels for filled masterbatch, and montan esters where the part must release from hot steel without losing surface quality. Table 5 collects the levels by polymer and process before the four sections below examine each in turn.

Table 5. Wax dosage by polymer and process

Supplier TDS ranges and one published formulation set these levels; trials decide the final level for a specific compound, and phr applies to PVC while wt% applies to polyolefins and masterbatch. The whole package, not just the lubricant, is on additives for PVC, which sets stabilizer and filler levels alongside the lubricant system above.

Rigid PVC pipe, profile and siding#

Rigid PVC pipe runs on the oldest lubricant package in the industry: 0.6-1.5 phr paraffin wax, 0.6-1.5 phr calcium stearate and 0.1-0.2 phr oxidized PE wax. Profile and siding compounds scale the same three components down slightly, to 0.8-1.2 phr paraffin wax, 0.8-1.2 phr calcium stearate and the same 0.1-0.2 phr OPE. Calcium stearate is not a wax; it is named here as the co-lubricant and heat-stabilizer component that is dosed against paraffin wax, never substituted for it.

The pairing is not arbitrary: Krzewki and Collins (1981) showed that calcium stearate can accelerate or delay fusion depending on temperature and on whether wax is present, and that with wax present, more calcium stearate accelerates fusion. That fusion synergy is why formulators retrial both components together whenever either level changes, rather than adjusting one in isolation. Struktol's guidance is to reduce calcium stearate as much as possible for improved flow. Stabilizer and drinking-water requirements for this application are on additives for PVC pipe, the page covering the full pipe formulation.

PVC injection moulding and calendering#

In PVC injection moulding and calendering the wax shrinks to a trace: 0.07-0.15 phr of oxidized PE wax inside an ester-based package, because paraffin wax at pipe levels would haze the surface and foul the rolls. Opaque injection moulding runs an ester lubricant at 0.7-1.5 phr, a complex ester at 0.3-0.75 phr, OPE at 0.07-0.15 phr and calcium stearate at 0.3-1.0 phr, alongside 0.5 phr of paraffin wax. Opaque calendering swaps the complex ester for a secondary ester at 0.5-0.75 phr and keeps calcium stearate at 0.3-0.75 phr with the same OPE range. Clear injection moulding drops paraffin wax and runs on the ester system alone, and clear extrusion widens the OPE range to 0.1-0.3 phr, since external lubricants at pipe-level dosage can haze a clear compound.

Masterbatch and filled compounds#

In filler masterbatch the wax is no longer a trace additive: Radebe and co-workers at the University of Pretoria showed that 3 wt% wax with 1.0 wt% zinc stearate brought the melt viscosity of a 60 wt% calcium carbonate LLDPE masterbatch back to just above that of the neat polymer, from three times higher without them. Their 2022 study in the Journal of Polymer Engineering tested Fischer-Tropsch wax as a direct drop-in for PE wax at the same 3 wt% level, and both waxes performed the carrier and viscosity-reduction role in the filled system. Wax is the universal carrier across masterbatch formulations generally, not only in calcium carbonate systems.

Clariant's Licocene wax line is built around that role: positioned as a dispersion aid and carrier that allows higher filler loadings at lower processing temperature and shear than an unmodified wax achieves. Where a wax ends and a dispersing agent for plastics and masterbatch begins is a formulation choice, since both wet filler and pigment surfaces.

Polyolefin film, WPC and engineering plastics#

Wood-plastic composites need far more lubricant than unfilled compounds: 2-8 parts of a blended package in wood-filled PVC and 1-6% of compound in wood-filled polyolefins. Amide and metal-soap blends sit at 1.0-3.0% of compound in the same filled-system category. Montan esters and natural refined waxes are also marketed for polyamide, where the surface defect they address is called die bearding rather than die drool, though our source library holds no dosage figure for that use. Package design for filled systems is on lubricants for wood-plastic composites, the sibling page for this dosage tier.

Our source library gives no wax dosage specific to unfilled PE or PP film. In that application the wax role is carried mainly by the masterbatch carrier and the dispersant rather than by a standalone lubricant addition, and melt-fracture control at the die belongs to the processing-aid family rather than to wax dosage. The film and pipe packages for the base resin are on additives for polyethylene.

How Much Wax Does a Compound Need?#

A compound needs between 0.07 phr and 3 wt% of wax, and the span is that wide because the job changes: 0.07-0.3 phr of oxidized PE wax is a release film, while 3 wt% of PE wax in a 60% filler masterbatch is a viscosity reducer. Levels are given in PHR (parts per hundred resin) for PVC, not in weight percent, which is why the two ends of that range look so different even though both describe a working wax dosage.

Four factors drive the level a given compound needs.

• Polymer and process, since PVC extrusion runs a lower wax level than PVC injection moulding needs around it.
• Filler and pigment load, since a higher filler load raises the wax demand needed to wet and disperse it.
• Metal release the tool geometry needs, since a complex die or deep mould cavity needs more release than a simple profile die.
• Whether the part will be printed, welded or must stay clear, since paraffin wax at pipe-level dosage is not recommended for any of the three.

The PPI TR-2 Appendix C range composition for US PVC pressure pipe gives a worked example: 100 phr PVC, 0.70 phr heat stabilizer, 1.20 phr paraffin wax, 0.15 phr PE wax, 5.00 phr calcium carbonate, 0.50 phr titanium dioxide, 0.03 phr pigment and 0.45 phr calcium stearate, totalling 108.03 phr, with PVC at 92.57 wt% of the finished compound. Converting the paraffin wax line to weight percent: 1.20 phr in a compound totalling 108.03 phr is 1.20 divided by 108.03, or 1.11 wt% of the finished compound. That conversion is a unit calculation on a published range composition, not a recommended formulation in itself, and it can be checked in the PHR to weight percent calculator.

How Do Waxes Interact with Other Lubricants and Additives?#

A wax never works alone: in PVC it is dosed against a metal soap, in masterbatch against a zinc stearate, and in extrusion it is balanced against the tendency of low-molecular-mass waxes to build up on the die. Table 6 lists the main interactions and what to do about each.

Table 6. Wax interactions with co-additives and phenomena

Ethylene bis stearamide, an amide wax classed by Baerlocher as an external PVC lubricant, melts at 138-144 °C and carries EU FCM 250 with no SML; it is a co-lubricant reached for when a higher melting point is needed than a hydrocarbon wax provides. Die build-up is defined by Musil and Zatloukal (Tomas Bata University, 2013 and 2014) as "unwanted spontaneous accumulation of extruded polymer melt on open faces of extrusion die," and their work is the basis for treating lower-molecular-mass waxes as a contributing cause rather than a cure. Synergy and antagonism across all additive families are mapped under additive interactions, which extends this same logic to stabilizer and filler interactions.

Over-lubrication, plate-out and exudation#

Too much external wax shows up in four ways: fusion takes longer, the surface goes hazy, the lubricant exudes to the surface, and formulation residues plate out on calender rolls, dies and screws.

• Fusion time lengthens as the excess wax delays resin particle breakdown.
• Surface clarity drops, turning a compound that should be clear or glossy hazy.
• The lubricant exudes, or blooms, to the surface once the compound is saturated.
• Plate-out deposits build on calender rolls, dies and screws from the excess formulation components.

Plate-out is the PVC-specific deposit of formulation components on calender rolls, dies and screws, and it is driven by over-lubrication and by incompatible external lubricants rather than by any single ingredient acting alone. Our source library gives no numeric over-lubrication threshold for any wax class, and none is published here; the practical ceiling is set by the compound as a whole and is found by trial, not by a fixed phr limit. Causes and cures are collected under plate-out in PVC processing, and the solubility limit behind blooming and exudation in plastics applies to lubricants as much as it applies to plasticizers.

How Is a Wax Specified and Tested?#

A wax is specified by dropping point, viscosity, specific gravity and hardness, and it is checked in the finished compound by melt flow rate and fusion behaviour. A wax data sheet carries four numbers that matter: dropping point, viscosity at 150 °C, specific gravity and hardness, while the two properties that actually decide how it behaves, molecular mass and its distribution, usually appear on neither the data sheet nor the label. Table 7 lists each property with its typical unit and method.

Table 7. Wax specification properties

Molecular mass and its distribution are the real discriminators between wax classes, yet they rarely appear on a commercial data sheet, which is why a paraffin wax and a Fischer-Tropsch wax with the same dropping point can still behave differently at the die. The compound itself is checked by melt flow rate, not the wax alone, using ISO 1133 or ASTM D1238. PVC fusion is checked by torque-rheometer fusion testing (Brabender), tracking fusion time and torque; the specific ASTM standard number for this method is not established in our source library, so none is published here. Fusion time and torque come from PVC fusion testing, the dedicated method page for that test.

Which Waxes Are Allowed in Food-Contact Plastics?#

Every wax class in this family has an EU food-contact entry, but they are not equivalent: PE wax (FCM 549) and montan wax (FCM 529) carry no specific migration limit, oxidized PE wax (FCM 811) is capped at 60 mg/kg, and refined low-viscosity paraffin wax (FCM 93) is capped at 0.05 mg/kg and excluded from fatty foods. In the US, clearance follows the wax's chemical origin rather than a single functional category, so petroleum wax, synthetic petroleum wax, oxidized polyethylene and montan wax esters each sit under a separate 21 CFR section. None of these clearances is written here as "FDA approved"; each is a listing under a specific 21 CFR section with its own conditions of use.

EU 10/2011: FCM numbers and SMLs for waxes#

Refined paraffin wax is the strictest case: EU Regulation (EU) No 10/2011 lists low-viscosity refined paraffinic waxes as FCM 93 with a specific migration limit of 0.05 mg/kg, excludes them from fatty foods, and adds three composition specifications that a candle-grade paraffin wax will not meet. Table 8 sets out the food-contact matrix for the whole family.

Table 8. Food-contact matrix for waxes

EU entries are verified against the consolidated text of Regulation (EU) No 10/2011 of 16 March 2025. The overall migration limit of 10 mg/dm² applies in addition to every specific migration limit in the table, and it applies to the whole compound, not to the wax alone. FDA sections listed here are clearances with their own conditions of use, not recommended dosages. How FCM numbers, SMLs and the overall migration limit work together is explained on EU 10/2011.

FDA 21 CFR clearances for waxes in plastics#

The US system splits waxes by origin rather than by function: petroleum wax sits in 21 CFR 178.3710, synthetic petroleum wax in 178.3720, oxidized polyethylene in 177.1620 and montan acid partial esters in 178.3770, each with its own conditions of use. Petroleum wax under 178.3710 carries UV absorbance limits in addition to its identity requirements. Oxidized polyethylene is cleared twice: once under 177.1620 for its use as a component at a number-average molecular mass of at least 1,200, and again under 172.260 as a direct food additive at the same molecular-mass specification. Montan acid partial esters, refined by the Gersthofen process and optionally calcium-neutralised, are cleared under 178.3770 specifically as PVC lubricants, with a required dropping point of 76-105 °C.

One further section, 178.3860, clears rice bran wax as a release agent at up to 1.0% by weight, but only for dry foods, and it has no role in plastics lubrication; it is mentioned here only to keep it separate from the polymer waxes above (eCFR version 2026-09-01). The structure of the 21 CFR parts is decoded on FDA food contact rules for plastic additives.

REACH registration and the polymer exemption#

Polymers are exempt from REACH registration under Article 2(9), so polyethylene wax and oxidized polyethylene wax have no registration dossier at all, while paraffin waxes carry 100 active registrations under EC 232-315-6. Microcrystalline wax carries 30 active registrations, and montan wax carries 3, all filed as Article 18 intermediates (ECHA CHEM, queried 2026-09-22). None of the wax classes on this page appears on the REACH Candidate List.

Fischer-Tropsch wax's REACH status is not established: the CAS or EC identifier used by its producers could not be verified, and this page states no exemption or registration count for it until that identifier is confirmed. The polymer exemption and what it means for additive buyers is on REACH and plastic additives.

Who Supplies Polymer Waxes?#

Polymer waxes come from two kinds of company: wax producers such as Sasol, Clariant and Solstice Advanced Materials, and additive compounders such as Struktol, Baerlocher, Peter Greven and Platinum Industries, who blend wax into ready-made lubricant packages. Table 9 lists each company's wax and lubricant brand lines.

Table 9. Polymer wax producers and brand lines

Clariant's Advanced Surface Solutions unit makes the Licocene, Licowax and Ceridust wax lines, and its Adsorbents and Additives business unit reported CHF 987 million in 2025 sales. Honeywell's former Advanced Materials business, including the A-C polyethylene and OPE wax brand, was spun off in 2025 as Solstice Advanced Materials. Buyers should compare waxes by dropping point, viscosity and molecular mass, not by trade name, because the same class is sold under a dozen brands.

No verifiable public market size or price figure for polymer waxes exists in our source library, so none is published here; price drivers and grade differences are tracked separately on PE wax price. Plants, grades and certifications by company are collected in the directory of PE wax and polymer wax manufacturers.

What Other Lubricants Work Alongside Waxes?#

A wax is one of four lubricant families in a plastics formulation, next to metal soaps, esters and fatty amides, and almost every real package mixes at least two of them. The taxonomy runs: hydrocarbon waxes, fatty acids and alcohols, metal soaps, and esters and amides, including the montan esters covered above. Every dosage table on this page shows that pairing in practice: paraffin wax with calcium stearate, oxidized PE wax with an ester package, PE wax with zinc stearate. Mold-release formulations draw on the same four families: waxes, fatty esters, silicones and metallic soaps.

Metal stearates and ester lubricants compared with waxes#

Metal soaps and esters differ from waxes in one property: they carry a polar group, which is why calcium stearate wets metal and glycerol monostearate works between the polymer chains, while a paraffin wax chain does neither on its own. Calcium stearate (CAS 1592-23-0) melts at about 160 °C and is classed as internal, zinc stearate (CAS 557-05-1) melts at about 120 °C and is classed as external, glycerol monostearate melts at 56-62 °C and is classed as internal, and a complex ester plus calcium soap blend melts at 125-135 °C and is classed as combined. Calcium and zinc soaps are covered in full under metal stearates.

Ethylene bis stearamide, an amide wax, melts higher again, at 138-144 °C, and carries EU FCM 250 with no specific migration limit, sitting functionally between the hydrocarbon waxes and the metal soaps. GMS, PETS, EGDS and the montan esters are compared under ester lubricants, which extends the wax-versus-ester comparison made throughout this page to the full ester family.

Waxes outside plastics: what this page does not cover#

The same paraffin wax and polyethylene wax sold for plastics processing are also sold for candles, car-care products, cosmetics and bicycle chains, and none of those uses is covered here: this page is about waxes compounded into plastics. plasticadditives.net covers additives used in plastics only; car care, candles, cosmetics, textile finishing and chain lubricants sit outside that border even where the underlying chemistry is identical to a grade described above.

What is the difference between PE wax and OPE wax?#

Oxidized PE wax carries polar carboxyl groups that PE wax does not, which lets it anchor to metal and give the same release at 0.07-0.3 phr that plain PE wax needs several times more to reach. Both are made from the same polyethylene backbone; oxidation is the single processing step that separates the two classes' metal-release behaviour.

Is polyethylene wax the same as polyethylene?#

Chemically yes, physically no: PE wax is polyethylene with an average molecular mass of up to about 10,000 g/mol, and it is made either by polymerising ethylene directly or by breaking down high-molecular-weight polyethylene. The short chain length is what lets it melt and flow at processing temperature instead of behaving like a moulding resin.

Can a wax be used as a mould release agent?#

Yes: waxes are one of the four classes of release agent, alongside fatty esters, silicones and metallic soaps, and oxidized PE wax and montan esters are the wax chemistries used for internal release in plastics. External mould-release sprays are process chemicals applied to the tool rather than additives compounded into the resin, and they sit outside the scope of this page.

Is paraffin wax allowed in food-contact plastics?#

Only in refined grades that meet a specification: EU 10/2011 lists low-viscosity refined paraffinic waxes as FCM 93 with a specific migration limit of 0.05 mg/kg and no use in fatty foods, and the high-viscosity refined grade as FCM 94 with no SML. A candle-grade or unrefined paraffin wax meets neither specification and has no food-contact clearance under this entry.

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