Polymer Processing Aids: 7 Types, Mechanisms, Dosage and Selection

Polymer processing aids (PPA) are additives that make melt processing run faster and cleaner: the 7 types range from fluoropolymers that coat the die wall at a few hundred ppm and remove sharkskin melt fracture, to acrylic copolymers that speed PVC fusion at around 1 phr. Because a die-wall PPA only works once it has built up its coating, the two questions every extrusion line asks are which chemistry to use and how long the conditioning takes.

Processing aids are one of the 43 families of plastic additives and sit in the processing-modifier group with lubricants, mold release agents and slip additives. The abbreviation is ambiguous: in Article 3(8) of Regulation (EU) No 10/2011 the letters PPA mean polymer production aid, a manufacturing medium that is not an additive, and outside plastics a processing aid is a food-manufacturing substance. This page uses the melt-processing sense throughout.

The sections below separate the processing aid from the lubricant, name the 4 extrusion problems it solves, explain the die-wall coating and the interfacial slip, set out the 7 types, weigh the fluoropolymer against the PFAS-free routes, match an aid to 8 polymers and processes, give dosage in ppm, wt% and phr with the source of every figure, list the interactions and the test methods, track the FDA, EU and PFAS instruments to the PPWR limits of 12 August 2026, and close with the producers and the 4 substance pages.

The 7 types of polymer processing aids differ in where they act, which polymer they suit, how much is needed and whether they are PFAS.

FDA maxima are the limits of 21 CFR 177.1520 for food-contact polymers; study ranges are the levels published in the cited papers, not supplier recommendations.

What Is a Polymer Processing Aid (PPA)?#

A polymer processing aid is an additive that delays the onset of flow instabilities and increases output in melt processing, and the term covers 2 different chemistries: die-wall aids for polyolefin extrusion and acrylic fusion aids for rigid PVC. Barry Morris (2024), in the Journal of Vinyl and Additive Technology, defines the role as the use of "polymer process aides (PPAs) to delay the onset of flow instabilities and increase output". The die-wall aid never changes bulk viscosity; the acrylic aid never touches the die.

Synonyms multiply around the same entity: polymer processing additive, process aid, extrusion aid, PPA, FPPA for the fluorinated grades and ACR for the acrylic grades. United States food-contact law adds a third vocabulary, since 21 CFR 177.1520 calls these substances "extrusion aids" and "processing aids in the production of olefin polymers". Why does one abbreviation cover two additive families, and a third thing in food regulation?

Polymer processing aid vs polymer production aid: what does PPA mean?#

In plastics processing, PPA means polymer processing aid, an additive under Article 3(7) of Regulation (EU) No 10/2011, while Article 3(8) of the same regulation uses it for polymer production aid, a manufacturing medium such as a catalyst or chain-transfer agent that is not an additive. The 3 meanings in circulation are set out below.

• Polymer processing aid: an additive intentionally added to achieve a physical or chemical effect during processing and intended to be present in the final article, which is the meaning this page covers.
• Polymer production aid: under Article 3(8), a substance that provides a suitable medium for polymer manufacture, such as a catalyst, an emulsifier or a chain-transfer agent. Production aids are not additives.
• Food processing aid: a substance used during food and beverage manufacture, covered by food law and treated only in the border section below. It is out of scope here.

Both plastics definitions sit in the same instrument, which is set out on EU 10/2011. A declaration written against Article 3(8) therefore says nothing about the additive status of the substance metered into the extruder.

Processing aid vs lubricant: what is the difference?#

A polymer processing aid works at the die wall or on melt elasticity at a few hundred ppm, while a lubricant works either between polymer chains, lowering melt viscosity, or between the melt and hot metal, and is dosed in phr. The lubricant definitions used across this site follow the Baerlocher convention: internal lubricants reduce the frictional forces between polymer chains and lower melt viscosity, external lubricants reduce adhesion between the polymer and metal surfaces. A die-wall processing aid does neither; it forms a coating that produces interfacial slip.

The naming is not stable in the trade literature. Handbook chapters and supplier catalogues use "processing aid" as an umbrella for lubricants and flow promoters, and one ranking manufacturer page calls polymer processing aids internal lubricants. Internal and external lubricant systems, the metal soaps and the waxes are covered on processing lubricants for plastics.

What Problems Do Processing Aids Solve? Melt Fracture, Pressure and Die Build-Up#

Polymer processing aids address 4 extrusion problems: surface melt fracture (sharkskin), gross melt fracture and stick-slip, the extrusion pressure that caps output, and die build-up on the die faces. Each of the 4 has a different origin inside the die, which is why one chemistry rarely answers all of them.

• Surface melt fracture, known as sharkskin: a fine periodic roughness that makes polyethylene film hazy.
• Gross melt fracture and stick-slip: volume distortion, with pressure and output oscillation in linear polyethylene.
• Extrusion pressure and output: the critical flow rate at which distortion appears caps line speed.
• Die build-up, known as die drool: a deposit on the open faces of the die that has to be wiped off.

Extrusion is where almost every processing aid earns its keep, and the extrusion package as a whole is treated on additives for plastic extrusion. A die-wall aid attacks the first 3 problems through one change, a lower wall shear stress and a higher critical flow rate. The full defect taxonomy is on melt fracture and sharkskin.

What is sharkskin melt fracture?#

Sharkskin is surface melt fracture: a fine, periodic roughness that appears above a critical output and makes polyethylene film hazy, and it originates at the die exit rather than inside the die. Muliawan, Hatzikiriakos and Sentmanat (2005) tied the onset of sharkskin to the high-rate extensional behaviour of the melt, which is why an additive that changes the melt at the exit boundary removes it at a few hundred ppm.

The 3 instability types have 3 different birthplaces. Gross melt fracture originates in the contraction region at the die entrance and produces the helical distortion typical of polystyrene. Stick-slip, also called oscillating flow or spurt, is a slip along a fracture surface near the wall, and Hatzikiriakos and Dealy (1992) showed that it requires melt compressibility and a two-branch flow curve, which is why it belongs to linear polyethylene.

What is die drool (die build-up)?#

Die drool is the unwanted, spontaneous accumulation of extruded polymer melt on the open faces of an extrusion die, and Musil and Zatloukal at Tomas Bata University in Zlín trace its driving force to the negative pressure at the die exit edge. Their 2013 definition separates an external type from an internal type, and the first published remark on the phenomenon dates from 1946.

Composition, not only geometry, decides how fast the deposit grows. The contributors documented in the same review are the low-molecular-weight fraction of multimodal polyethylene, hexane extractables, volatile stabilizers, metallic stearates in Ziegler-Natta polyolefins, and the interaction between a processing aid and an inorganic pigment.

The defect travels under 8 shop-floor names: drooling, die lip build-up, die bleed, die plate-out, die deposit, die drip, die moustache and gummy crust, with die bearding used in polyamide compounding. The remedy catalogue is on die build-up (die drool).

How Do Polymer Processing Aids Work? Die-Wall Coating and Interfacial Slip#

Die-wall processing aids work in 3 steps: they disperse as immiscible droplets in the melt, migrate to and coat the metal die wall under flow, and then let the polymer slip along that low-energy coating, which lowers wall shear stress and raises the output at which melt fracture starts. The fluoropolymer is immiscible with the polyolefin melt, so it survives compounding as a dispersed phase, and that immiscibility is the precondition for the mechanism.

Kharchenko, McGuiggan and Migler at the National Institute of Standards and Technology (2003) developed a frustrated total internal reflection method that made the flow-induced coating directly visible in the Journal of Rheology, and Yang, Arefi, Gritsichine and Tzoganakis at the University of Waterloo (2025) modelled how its thickness builds up and linked that build-up to the slip velocity. Once the polymer no longer sticks to the metal, the wall shear stress at a given output falls below the critical value for surface melt fracture.

How long does a PPA take to work? Conditioning and time-to-clear#

A die-wall processing aid works only once its coating has built up on the die, and the time until melt fracture disappears on a running line is called the time-to-clear (TTC). Yang and colleagues at the University of Waterloo (2025) measured slip velocity and time-to-clear as the two quantities that compare one chemistry against another, because the layer thickness build-up governs both.

Conditioning time is a commercial number, not only a physical one. A blown-film line with a long conditioning period produces off-specification film at every changeover and after every die clean, so the time-to-clear enters the cost calculation next to the additive price. PFAS-free chemistries are generally reported to need longer conditioning, a higher level, or both; the magnitudes are not confirmed here, so no figure for the difference is published.

How do acrylic processing aids work in PVC?#

Acrylic processing aids work inside the melt rather than at the die: the high-molecular-weight acrylic chains increase entanglement in the PVC melt, which brings fusion forward, raises melt strength and extrudate swell, and moderates sharkskin. Sombatsompop and Phromchirasuk (2004) at King Mongkut's University of Technology Thonburi measured the effect on mixing torque, wall shear stress and extrudate swell, and found the methyl methacrylate / butyl acrylate copolymer more effective than the methyl methacrylate / ethyl acrylate grades.

What changes in the compound is the fusion curve. Faster and more uniform fusion means that the primary particle structure of the PVC breaks down earlier in the extruder, which raises melt elasticity and improves surface quality in rigid PVC and PVC-wood composites. Acrylic aids also prevent plate-out, the PVC deposit on rolls, dies and screws, a different phenomenon from die drool.

7 Types of Polymer Processing Aids#

The 7 types of polymer processing aids are fluoropolymer PPAs, silicone and polyether-siloxane PPAs, boron nitride and particulate PPAs, polyolefin, ester and polyurethane PPA masterbatches, acrylic processing aids for PVC, flow enhancers for filled compounds and melt-strength enhancers. The first 4 work at the die wall in polyolefin extrusion and are dosed in ppm; the last 3 change the bulk melt, are dosed in phr or whole per cent, and are mainly a PVC and compounding story.

1. Fluoropolymer processing aids (VDF-HFP and PVDF)#

Fluoropolymer processing aids are fluoroelastomers and fluorothermoplastics, mainly vinylidene fluoride / hexafluoropropylene copolymers (CAS 9011-17-0, EC 618-470-6) and PVDF, that coat the die wall of a polyolefin extrusion line at a few hundred ppm and remove sharkskin. The family also includes the VDF-HFP-TFE terpolymer (CAS 25190-89-0), and all of them are delivered as a 2 to 5 % masterbatch.

Their regulatory position is more complex than their chemistry. 21 CFR 177.1520 lists the 65 to 71 % fluorine grade as an extrusion aid at up to 0.2 wt% of the olefin polymer, and the grade with at least 87 % vinylidene fluoride, together with PVDF homopolymer, as a processing aid at up to 1.0 wt%. These are polymeric PFAS, which is why 3M announced on 20 December 2022 that it would exit PFAS manufacturing, including PFAS-based additive products, by the end of 2025.

2. Silicone and polyether-siloxane processing aids#

Silicone processing aids are polydimethylsiloxane-based systems, above all polyoxyethylene-grafted PDMS (CAS 68937-54-2), which the FDA lists as an extrusion aid for olefin polymers at up to 0.3 wt%. They reach the die wall by the same route as a fluoropolymer, and the review literature on PFAS alternatives, including Donahue-Boyle and colleagues (2026), treats siloxanes as an established non-fluorinated option.

Their European position rests on 2 separate instruments. The parent polydimethylsiloxane is FCM 575 in the Union list of Regulation (EU) No 10/2011 for grades above 6,800 Da with a viscosity of at least 100 cSt at 25 degrees Celsius. Residual cyclosiloxanes D4, D5 and D6 at 0.1 wt% or more in mixtures are separately restricted after 6 June 2026 under entry 70 of REACH Annex XVII, a purity requirement rather than a ban.

3. Boron nitride and particulate processing aids#

Boron nitride processing aids are hexagonal boron nitride particles used at 0.005 to 0.5 %, which remove surface melt fracture and postpone gross melt fracture through a surface-energy effect rather than a liquid coating. Rosenbaum, Randa, Hatzikiriakos, Stewart and Henry (2000) established that range, Rathod and Hatzikiriakos (2004) tied the mechanism to surface energy, and Muliawan (2005) described boron nitride as an "energy dissipater" against gross melt fracture.

Combination beats either component alone: Seth (2011) at the University of British Columbia showed that boron nitride with a small amount of fluoroelastomer outperforms both single additives. Boron nitride is FCM 583 in the EU Union list under group restriction 16, with a total specific migration limit of 6 mg/kg expressed as boron, and holds FDA food contact notification FCN 970 at 1 wt%, granted as a nucleating agent in polyhydroxyalkanoates rather than as a general processing-aid clearance.

4. Polyolefin, ester and polyurethane PPA masterbatches#

The fourth group is a set of proprietary PFAS-free masterbatches built on modified polyolefins, esters and thermoplastic polyurethane, which deposit on the die in the same way a fluoropolymer does but without fluorine. The chemistries of the commercial grades are not disclosed, so this reference records launches rather than formulations: Ampacet and Techmer PM in 2023, Baerlocher USA with Baerolub AID on 29 November 2023, and Clariant with AddWorks PPA on 23 April 2024.

Two research routes show the same physics without fluorine. Kulikov (2005) found that thermoplastic polyurethane deposits on the die and can postpone sharkskin to a 12 to 20 times higher extrusion rate. Hong, Cooper-White, Mackay, Hawker and Malmström (1999) tested hyperbranched polymers with C16 or C20/22 alkane end groups at up to 10 % in LLDPE and eliminated melt fracture with minimal preconditioning. Both are research levels, not commercial dosages.

5. Acrylic processing aids for PVC#

Acrylic processing aids are high-molecular-weight methyl methacrylate copolymers with ethyl or butyl acrylate, used in rigid PVC to bring fusion forward, raise melt strength and prevent plate-out. The grades named in the published comparison are PA20, a methyl methacrylate / butyl acrylate copolymer, and K120 and K130, both methyl methacrylate / ethyl acrylate copolymers. Suppliers divide the class into standard, lubricating and foam-regulating families.

The acrylic processing aid is not the acrylic impact modifier, although both are acrylic copolymers for rigid PVC: the processing aid is high-molecular-weight and changes fusion and melt strength, while the impact modifier is a core-shell particle that changes toughness. The distinction from core-shell toughening grades is set out on impact modifiers for PVC. In EU food contact, the Union list carries a (MMA, BA, styrene, GMA) copolymer with CAS 37953-21-2 as FCM 857, authorised as an additive only in rigid PVC at up to 2 % at room temperature or below, without using the term processing aid.

6. Flow enhancers for filled and reinforced compounds#

Flow enhancers are wax and metal-soap combinations that restore the melt viscosity of a highly filled or reinforced compound, so that a masterbatch at 60 wt% filler can still be extruded near the viscosity of the unfilled polymer. Radebe, Wesley-Smith, Focke and Ramjee (2022) at the University of Pretoria showed the effect quantitatively: in a 60 wt% calcium carbonate LLDPE masterbatch, 3 wt% wax plus 1 wt% zinc stearate brought the melt viscosity back to just above that of the neat polymer, against roughly 3 times higher for the untreated filled compound.

Wax molar mass distinguishes the 2 chemistries compared: a Fischer-Tropsch wax at 776 number-average and 786 weight-average Da against a polyethylene wax at 4,715 and 14,960 Da. No separate commercial product class is established for flow enhancers beyond this study and the wax and metal-soap literature, and the page on flow enhancers carries the detail.

7. Melt-strength enhancers for foam, thermoforming and blow molding#

Melt-strength enhancers raise the elasticity of the melt so that it can carry its own weight in foaming, thermoforming and blow molding, and in PVC that job is done by the high-molecular-weight acrylic grades. The same acrylic chemistry that brings fusion forward raises melt strength and extrudate swell, and supplier guidance credits the high-molecular-weight grades with regulating cell structure in PVC foam board and wood-plastic composite.

Outside PVC the ground is thinner. No data on chain extenders or other melt-strength routes for polyolefin foam, PET or thermoforming is established here, so those routes are treated on the page for melt strength enhancers. Foam formulations across EPS, XPS, PU and PE foam are on additives for plastic foams.

Fluoropolymer or PFAS-Free Processing Aid: Which to Choose?#

Choose a PFAS-free processing aid for anything that becomes EU food-contact packaging, because the PPWR has set a 50 ppm total-PFAS limit including polymeric PFAS since 12 August 2026, and keep the fluoropolymer where it is still permitted and where conditioning time is critical. The decision is regulatory before it is technical, and the table below separates the two routes criterion by criterion.

This is not a performance verdict. The evidence supports the regulatory contrast and the qualitative statement on conditioning, not a number for the performance gap, so no multiple, percentage or time ratio appears on this page. The chemistry-by-chemistry comparison, with the launch timeline, sits on the PFAS-free page linked from the type table above.

Which Processing Aid Suits Each Polymer and Process?#

The processing aid follows the polymer and the defect: a die-wall PPA at ppm level for polyethylene film, pipe and cable, an acrylic processing aid at about 1 phr for rigid PVC, an ester-based drool reducer for polyamide compounding, and a wax plus metal-soap system for highly filled compounds. The table below pairs 8 polymers and processes with the preferred aid and the one number that governs it.

Pipe formulations for PE and PVC are compared on additives for plastic pipes; the lubricant figures in the PVC row are the Struktol pipe package reused unchanged across this site.

Processing aids for polyethylene film, pipe and cable#

Polyethylene film, pipe and cable are the main market for die-wall processing aids, dosed at a few hundred ppm and limited by the FDA to 0.2 wt% for the 65 to 71 % fluorine grade in food-contact polymers. Grades, line trials and time-to-clear targets are set out on processing aids for polyethylene.

Blown and cast film for packaging carry the densest additive package on this site, set out on additives for packaging film, and film is where the defect is most visible, because sharkskin shows up as haze across the whole web.

High-density polyethylene is the harder case: Adesina, Nasser and Hussein (2015) found that 0.05 wt% of a fluoropolymer did not eliminate stick-slip in HDPE and that gross melt fracture reappeared at 141 reciprocal seconds.

Cable compounds add their own flame-retardant and stabiliser constraints, set out on additives for wire and cable compounds.

Die drool rather than surface quality is the driver in cable and pipe extrusion, where the metallic stearates used as acid scavengers in Ziegler-Natta polyolefins are among the documented contributors to the deposit.

A processing aid never travels alone. The polyethylene film package also carries processing stabilisers, a phenolic antioxidant with a phosphite, plus slip, antiblock, antistatic and antifog additives, all set out on additives for polyethylene.

Processing aids for rigid PVC pipe, profile and foam#

Rigid PVC pipe, profile and foam use an acrylic processing aid together with the lubricant package, because the acrylic brings fusion forward while the external lubricants hold it back. Rigid PVC has a high melt viscosity and a narrow thermal window, so it needs a balanced lubricant system before any processing aid is added.

That balance answers which processing aid suits PVC pipe: an acrylic aid at the low end of the range, roughly 0.5 to 1.0 phr, against a pipe lubricant package of paraffin at 0.6 to 1.5 phr, calcium stearate at 0.6 to 1.5 phr and oxidised polyethylene wax at 0.1 to 0.2 phr. The lubricant balance the acrylic works against is set out on lubricants for PVC compounding.

Supplier literature reports that acrylic aids counteract the fusion delay caused by external lubricants, and that too much external lubricant limits fusion even at a higher processing-aid level. Both statements rest on a secondary source.

Foam and wood-plastic composite take the high-molecular-weight grades, where melt strength is the limiting property. Complete rigid formulations by application are on rigid PVC formulations.

Processing aids for PMMA, polyamide and filled compounds#

Three processing problems need a different answer from the polyolefin die-wall aid: PMMA, where conventional PPAs do not work, polyamide compounding, where the issue is die bearding, and highly filled compounds, where the melt is too viscous. The 3 cases are set out below.

• PMMA extrusion: Stamboulides and Hatzikiriakos (2006) measured a critical shear stress of 0.35 plus or minus 0.03 MPa for spiral and helical distortion and found conventional polyolefin processing aids ineffective, while fatty glyceride blends reduce extrusion pressure.
• Polyamide compounding: an ester-based additive at 0.2 to 2.0 % reduces the die bearding and drool on the die faces, according to the supplier technical data sheet for that additive class.
• Filled and reinforced compounds: 3 wt% wax plus 1 wt% zinc stearate in a 60 wt% calcium carbonate LLDPE masterbatch restores melt viscosity to near the neat polymer, a flow problem rather than a wall one.

Additive packages for compounds outside the commodity polyolefins are on additives for nylon (polyamide).

How to select a polymer processing aid in 6 steps#

Select a polymer processing aid in 6 steps: name the defect, match the polymer and process, settle the PFAS position, screen the food-contact route, set the level and delivery form, and confirm it on a line trial. The sequence puts the commercial constraints first, because a grade that fails the end-market specification is not worth trialling.

1. Name the defect: sharkskin, gross melt fracture, stick-slip, die drool, long fusion or low melt strength.
2. Identify the polymer and the process, since a die-wall aid only works in polyolefin extrusion and an acrylic aid only in PVC.
3. Decide the PFAS position first, from the end market: EU food-contact packaging, US state rules and customer specifications.
4. Screen the food-contact route against 21 CFR 177.1520 and the status of the substance under Regulation (EU) No 10/2011.
5. Set the level and the delivery form, which for a die-wall aid should be a masterbatch dosed to a target in ppm.
6. Run a line trial and measure the time-to-clear, the extrusion pressure and the output at which melt fracture returns.

The same logic for every family is laid out in how to select plastic additives.

How Much Processing Aid Is Needed? Dosage in ppm, wt% and phr#

Polyethylene extrusion needs a die-wall processing aid at a few hundred ppm, and the FDA caps the common fluoroelastomer grade at 0.2 wt% of the polymer in food-contact use, while rigid PVC uses an acrylic processing aid at roughly 0.5 to 2.0 phr according to supplier guidance. Every figure below carries its source type, because legal maxima, study levels and supplier ranges are 3 different things.

The FDA maxima are legal ceilings for food-contact use, not recommended dosages, and no line runs at 0.2 wt% of a fluoroelastomer.

Units are the commonest source of error here. 1,000 ppm equals 0.1 wt%, and PVC formulations are written in phr, parts per hundred parts of resin, so a level in phr is not directly comparable with a level in wt% of the compound. The conversion between phr, wt% and ppm is set out on PHR (parts per hundred resin).

Two qualifiers apply to the acrylic row: the range of 0.5 to 2.0 phr rests on a single secondary supplier source, not on a manufacturer data sheet, and the foam grades sit above it without a published figure.

Masterbatch dosing adds a second conversion, from the active content of the concentrate to the level in the finished compound. Check any masterbatch dose against the target ppm with the let-down ratio calculator.

Why is a PPA supplied as a masterbatch?#

A processing aid is almost always supplied as a 2 to 5 % masterbatch, because a few hundred ppm cannot be weighed accurately at the extruder and because the mechanism depends on a fine, even dispersion of droplets. How additives are fed and dispersed in the first place is covered on plastic compounding.

Dispersion quality is not a convenience here, it is the mechanism. A die-wall aid has to reach the metal surface as immiscible droplets, so an agglomerated additive lengthens the time-to-clear and wastes the fluoropolymer that never arrives at the wall.

Carrier resins, let-down ratios and the difference between a single-additive and a combination concentrate are on additive masterbatch.

How Do Processing Aids Interact with Other Additives?#

Processing aids interact with 5 things in a formulation: other processing aids, acid scavengers, pigments, external lubricants and antioxidants, and in polyolefin extrusion most of those interactions show up as die build-up. Deposits on calender rolls, dies and screws in PVC have their own name and their own causes, set out on plate-out in PVC processing.

Antioxidant choice belongs in the same list. In a white-filled polyolefin, zinc 2-mercaptotolylimidazole produced about half the drool of the hindered phenol Irganox 1010, which makes the stabiliser package a lever on die build-up. Every documented pair on the site is listed in the additive interactions matrix.

How Is Processing-Aid Performance Tested?#

Processing-aid performance is tested with 3 kinds of method: rheometry on the additive and the compound, a line trial that records extrusion pressure, output and time-to-clear, and, for PVC, a torque-rheometer fusion test. Every method on this site is indexed under testing plastic additives.

A die-wall processing aid cannot be judged from a melt flow rate, because it does not change bulk viscosity: the meaningful numbers come from a running line, where the extrusion pressure drop and the time-to-clear are recorded together with the slip velocity that Yang and colleagues (2025) used to compare chemistries. Bulk flow itself is measured as melt flow rate (MFR), and a processing aid that moves it has done something other than coat the die.

One test now sits outside the rheology suite. Under the PPWR, where total fluorine in food-contact packaging exceeds 50 mg/kg, the manufacturer must on request show how much of it is PFAS, which makes total-fluorine screening a compliance test for film carrying a fluoropolymer processing aid.

How Are Polymer Processing Aids Regulated?#

Polymer processing aids are regulated through 3 routes: the US food-contact rules of 21 CFR 177.1520, which set explicit weight limits, the EU food-contact regime of Regulation (EU) No 10/2011, where the fluoroelastomer itself is not an individually listed additive, and the PFAS instruments, which since 12 August 2026 reach into food-contact packaging through the PPWR. The three routes answer different questions: what may be used in food contact, at what level, and what the fluorine content of the finished packaging may be.

The other instruments that touch plastic additives are summarised in plastic additive regulations.

FDA: 21 CFR 177.1520 limits for extrusion aids and processing aids#

The FDA sets explicit weight limits for processing aids in food-contact polymers: 0.2 wt% for the 65 to 71 % fluorine VDF-HFP copolymer, 1.0 wt% for the high-VDF copolymer and PVDF, and 0.3 wt% for polyoxyethylene-grafted polydimethylsiloxane, all under 21 CFR 177.1520. The table below sets each substance beside its European position.

The wording matters as much as the number. No processing aid is "FDA approved"; a grade is listed in 21 CFR 177.1520 at up to a stated weight per cent, under stated conditions of use, and the responsibility for the finished article stays with the converter. The section itself calls these substances extrusion aids and processing aids in the production of olefin polymers, never processing aids in the food sense.

The full map of 21 CFR sections for plastic additives is on FDA food contact rules.

EU 10/2011: why a fluoroelastomer PPA is not an individually listed additive#

The EU Union list does not carry the VDF-HFP fluoroelastomer as an additive in its own right: only its monomers appear, vinylidene fluoride as FCM 132 with a specific migration limit of 5 mg/kg and hexafluoropropylene as FCM 282 with a non-detectable limit. That absence is a fact about the Union list, not a prohibition, and this reference makes no claim in either direction about the lawfulness of a fluoropolymer processing aid in EU food-contact plastics.

Which route authorises its use as a polymeric additive is not established here, so that answer comes from the supplier's declaration of compliance for the specific grade. Where no specific migration limit is set, the generic limit of 60 mg/kg and the overall migration limit of 10 mg per square decimetre apply.

Three other processing-aid substances do have entries of their own: polydimethylsiloxane as FCM 575, boron nitride as FCM 583 under group restriction 16, and the (MMA, BA, styrene, GMA) copolymer as FCM 857. Every additive migration limit on the site is listed on specific migration limits (SML).

PPWR, the EU PFAS restriction and TSCA 8(a)(7) reporting#

Since 12 August 2026, Article 5(5) of the EU Packaging and Packaging Waste Regulation (EU) 2025/40 has barred food-contact packaging containing 50 ppm or more of total PFAS, polymeric PFAS included, the limit that reaches fluoropolymer processing aids in polyethylene film. The 4 instruments that govern this family are listed below.

• PPWR, Regulation (EU) 2025/40: 25 ppb for any individual PFAS by targeted analysis, with polymeric PFAS excluded from that quantification, 250 ppb for the sum of targeted PFAS, and 50 ppm for total PFAS including polymeric PFAS. Which additives may be used in food packaging is on additives for food packaging.
• EU universal PFAS restriction: proposed in 2023 by five member states, updated in 2025 with four restriction options, and pending the opinions of the Committee for Risk Assessment and the Committee for Socio-economic Analysis.
• TSCA 8(a)(7) reporting: a fluoropolymer processing aid falls within the structural PFAS definition, and US reporting duties are explained on TSCA and plastic additives.
• US state laws: Minnesota's Amara's Law bans intentionally added PFAS in stages from 1 January 2025 to 1 January 2032.

The packaging rules in full are on EU Packaging and Packaging Waste Regulation (PPWR), including the duty to show on request how much of the measured total fluorine is PFAS wherever total fluorine exceeds 50 mg/kg.

The American reporting window is not fixed. A final rule of April 2026 superseded the 13 October 2026 deadline of the May 2025 interim rule and tied the period to 60 days after a revised scope rule that was still pending at the last check, so no date is stated here.

Silicone processing aids carry a restriction of a different kind. Entry 70 of REACH Annex XVII, as amended by Regulation (EU) 2024/1328, restricts residual D4, D5 and D6 cyclosiloxanes at 0.1 wt% or more in mixtures after 6 June 2026, and is set out on REACH Annex XVII restrictions.

The PPWR limits are in force, the EU universal restriction is pending, and the TSCA window is not fixed. No instrument bans fluoropolymer processing aids as such.

Restriction work on PFAS reaches far beyond processing aids, and the wider landscape is on PFAS restrictions and plastic additives.

Who Makes Polymer Processing Aids? Suppliers and Trade Names#

Polymer processing aids come from 3 kinds of producer: the fluoropolymer makers, the masterbatch and additive houses that launched PFAS-free lines from 2023 onwards, and the acrylic producers that serve rigid PVC. The table lists only the producers and lines with primary source support, and does not rank them.

The fluoropolymer grades in the 3M series are sold at 25 to 35 % or 88 to 93 % active as concentrates and at 100 % active as the terpolymer, which is why a let-down ratio is checked against the grade rather than the family. Company-by-company portfolios are indexed in the plastic additive manufacturers and suppliers directory.

No market size, growth rate or price appears on this page, because none is established here, and the annual PFAS sales figure 3M published in 2022 covers its whole PFAS portfolio, not processing aids.

Complete List of Processing-Aid Substances (4 Pages)#

The complete list below gives the 4 substance pages on this site that carry a processing-aid function; none of them is filed under the processing-aid family, because the commercial acrylic and PFAS-free processing aids are proprietary polymer grades rather than single named substances.

The acrylic processing aids for PVC have no substance page of their own and are covered on their page instead. Every other additive, from antioxidants to pigments, is searchable in the plastic additives database.

Are Processing Aids Safe and Recyclable? PFAS, Migration and Recycling#

Processing aids are used at some of the lowest levels of any additive family, a few hundred ppm in polyolefin extrusion, but the fluoropolymer type is a polymeric PFAS, and that single fact now drives the regulation of the whole family. Wiesinger, Wang and Hellweg at ETH Zurich (2021), in Environmental Science and Technology, identified more than 10,000 substances relevant to plastics across monomers, additives and processing aids, over 2,400 of them of potential concern and 901 approved for food-contact plastics in at least one jurisdiction. Diffusion behaviour for every additive class is on additive migration in plastics.

Are fluoropolymer processing aids PFAS?#

Yes: a fluoropolymer processing aid is a polymeric PFAS under both the EU PPWR and the structural definition used for TSCA 8(a)(7) reporting, although the industry argues that fluoropolymers are polymers of low concern. That position was set out by Korzeniowski and colleagues (2022) in Integrated Environmental Assessment and Management, and is recorded here as an argument rather than a settled finding.

The 2 instruments treat the same material differently. The PPWR counts polymeric PFAS in the 50 ppm total-PFAS limit while excluding it from the 25 ppb targeted quantification, so a film can pass a targeted screen and still fail on total fluorine. What PFAS means for plastics as a whole, including anti-drip PTFE and fluorinated containers, is on PFAS in plastics.

Do processing aids migrate into food?#

A die-wall processing aid stays largely where it is put, on the die and in the skin of the extrudate, and the food-contact limits that apply to it are weight limits on the polymer rather than migration limits, with the EU monomer limits of 5 mg/kg for vinylidene fluoride and non-detectable for hexafluoropropylene. No migration study for a polymer processing aid is established here, so no measured migration value is stated.

The PPWR limits are content limits, measured on the packaging as PFAS or as total fluorine, not migration limits. A material can comply with every specific migration limit that applies to it and still exceed the packaging content threshold.

Do processing aids help or hinder plastic recycling?#

Processing aids do not block film recycling: the Association of Plastic Recyclers lists them among the preferred additives for polyethylene flexible film, with the qualification that all additives should be minimised. That qualification is the operative part for a formulator, because the preferred rating applies to the function, not to an unlimited level.

Claims that go further are not supported here. One ranking manufacturer page states that processing aids improve recycling efficiency, and no primary source establishes that effect. How every additive family affects sorting, reprocessing and recyclate quality is on design for recycling.

Is a food processing aid the same thing?#

No: a food processing aid is a substance used during food manufacture that is not intended to remain in the finished food, while a polymer processing aid is a plastics additive that is intentionally added to the polymer and stays in it. The 2 share a name and nothing else, and the third meaning, the polymer production aid of Article 3(8), is a manufacturing medium that is not an additive either.

Is a rubber processing aid the same thing?#

No: rubber processing aids are compounding chemicals for elastomer mixing and are outside this site's scope, which covers additives used in plastics. Where plastic additives are used in elastomers, they are covered on plastic additives in rubber and elastomers.