Barrier Additives for Plastic Packaging: 6 Types, Nanoclay, MXD6 and How to Select Them

A barrier additive is a solid or polymeric component compounded into a plastic that slows the diffusion of gas, water vapour or aroma through the wall without consuming anything, which is what separates it from an oxygen scavenger that removes the permeant by chemical reaction. Six routes do this work in plastics, from organically modified montmorillonite whose platelets are about 1 nanometre thick to a nylon phase blended into a PET preform, so which route belongs in which package, and what does European food-contact law actually authorise? A 10 % nylon-MXD6 blend takes the oxygen ingress of a PET bottle from 0.027 to 0.011 cubic centimetres per bottle per day at 0.21 atmospheres, and the European Union caps organoclay at 12 % w/w in polyolefins for dry foods.

The 6 types, in the order used throughout this page, are organoclay nanocomposites based on montmorillonite, halloysite nanotubes, platy mineral fillers such as talc, mica and kaolin, nylon-MXD6 blended into the wall, EVOH and PVDC barrier layers, and graphene and carbon nanotube nanoplatelets. Shape decides most of the outcome, because a barrier additive works by geometry rather than by chemistry, and the same clay gives a different result as an agglomerate, an intercalated stack or an exfoliated platelet.

This reference separates the passive barrier from the active scavenger, explains the tortuous-path mechanism and why dispersion decides it, sets out the 6 types with the aspect ratios and the food-contact entries that constrain each, publishes every level in the public record with the basis of the number, gives 7 selection steps, describes how permeation is measured, sets out the European and United States regulatory position including the nanoform rule, covers the EPBP, APR and PPWR recyclability conditions, names the suppliers, and closes with the substance pages in the plastic additives database.

The table below compares the 6 types on what is added, the shape that does the work, the host polymers in which each is used, the clarity cost and whether the type holds a European food-contact entry.

Types 4 and 5 are barrier polymers rather than additives in the strict sense. They appear here because a formulator buys and doses them the same way, and because the recycling guidelines treat them as additives to the host stream.

What Are Barrier Additives in Plastic Packaging?#

A barrier additive is a component compounded into a plastic wall to reduce the rate at which oxygen, water vapour, carbon dioxide or an aroma molecule passes through it, and it achieves that by obstructing the diffusion path rather than by reacting with the permeant. The trade uses four names for the same job: passive barrier, barrier filler, barrier nanofiller and, where the added phase is itself a polymer, barrier resin. None of these removes anything from the package. A barrier additive changes a rate, so a filled bottle keeps gaining oxygen for as long as it stands on the shelf, only more slowly than an unfilled one would.

Why does a rate matter more than a total in packaging? Shelf life is a race between the oxidation of the product and the arrival of the oxidant, and slowing the arrival buys months without changing the recipe of the food. Barrier additives are one of the functional families among the plastic additives covered on this site, and one of the few whose performance is set by particle geometry rather than by chemical reactivity.

Passive barrier or active scavenger? The distinction that decides the material#

A passive barrier slows the permeant down and an active scavenger consumes it, which means the passive route controls how fast oxygen arrives while the active route controls how much oxygen is present. The two are not interchangeable and they are frequently sold together, because the passive construction fixes the ingress rate and the active system deals with the headspace oxygen present at filling and with whatever still gets through. Mitsubishi Gas Chemical's data for its MX-Nylon grades shows the size of the passive contribution in whole bottles: 0.027 cubic centimetres of oxygen per bottle per day at 0.21 atmospheres for plain PET, 0.016 for a 5 % MXD6 blend, 0.011 for a 10 % blend and 0.0075 for a three-layer bottle with 10 % MXD6.

The best passive construction in that data set therefore still admits about a quarter of the oxygen a plain bottle admits. Removing the remainder is a different job with a different chemistry and a different legal route, and the chemistries that consume oxygen instead of obstructing it are covered on oxygen scavengers for plastic packaging.

Nylon-MXD6 appears in both columns. On its own it is a passive barrier polymer, and once a cobalt carboxylate is present in the same wall it becomes the oxidisable substrate of an active system.

Which permeant? Oxygen, water vapour and carbon dioxide behave differently#

A barrier is always a barrier to something specific, because oxygen, water vapour and carbon dioxide differ in molecular size, in solubility in the polymer and in how strongly humidity changes the result. Humidity is the variable that catches formulators out. The same Mitsubishi Gas Chemical data set reports oriented MXD6 film at 23 °C and 20 micrometres transmitting 2.8 cubic centimetres per square metre per day per atmosphere at 60 % relative humidity, 3.5 at 80 % and 5.5 at 90 %, while non-oriented film of the same polymer transmits 4.3, 7.5 and 20 under the same three conditions. An EVOH-32 grade in the same comparison ranges from 0.5 to 50 depending on humidity, a factor of 100 between the best and worst case for one material.

Two consequences follow for specification writing. A permeability value without its temperature, thickness and relative humidity is not a number at all, and a hydrophilic barrier polymer that performs best in a dry laboratory can lose most of its advantage in a humid supply chain. Water vapour is the second target, and the additive that removes water inside a package is a different product entirely, covered under desiccant masterbatch.

How Do Barrier Additives Work? The Tortuous Path#

Every passive barrier additive works by geometry: impermeable platelets dispersed in the polymer block the straight line through the wall, so a diffusing molecule has to travel around each obstacle and the effective path length rises well above the wall thickness. Nothing is consumed and no reaction occurs. The polymer between the platelets keeps the permeability it always had, and the improvement comes from the detour, from the volume that the filler occupies and, in a nanocomposite, from the reduced mobility of the polymer close to the platelet surface. Kojima, Usuki, Kawasumi and Okada at Toyota Central R&D described that constrained interphase in Journal of Materials Research in 1993 as the reason the nylon 6 clay hybrid gains stiffness and heat distortion temperature at loadings of a few per cent.

Aspect ratio: why an exfoliated platelet beats a mineral plate#

Aspect ratio, the width of a particle divided by its thickness, is the single property that separates a barrier filler from an ordinary one, and exfoliated montmorillonite reaches 100 to 1,000 against 5 to 40 for talc. A high aspect ratio produces a long detour at a low volume fraction, which is why a nanocomposite can change a transport property at loadings where a conventional filler changes almost nothing. The ranges below are typical filler-table values rather than supplier data, and they are the reason the 6 types on this page rank in the order they do.

Aspect-ratio ranges are typical values compiled from filler reference tables, not measurements on a specific grade. Our source library holds no quantified permeability-reduction factor for any of these fillers in a named polymer, so no barrier improvement percentage is stated on this page.

Intercalated, exfoliated or agglomerated: the 3 dispersion states#

The same organoclay gives three completely different results depending on how far the compounding process separates its silicate layers, and only the fully separated state delivers the aspect ratio the mechanism needs. The 3 states and what each one means for barrier are listed below.

• Agglomerated. The clay stays as micrometre-scale stacks of layers. Aspect ratio stays low, the detour is short, and the clay behaves like an ordinary mineral filler with a haze penalty.
• Intercalated. Polymer chains enter between the silicate layers and push them apart while the stack stays ordered. Aspect ratio rises, part of the surface becomes available, and the result sits between the other two states.
• Exfoliated. The individual layers, about 1 nanometre thick, separate and disperse through the matrix. This is the state that reaches an aspect ratio of 100 to 1,000 and the state every nanocomposite datasheet assumes.

Dispersion is therefore a process variable rather than a purchasing decision, and the same statement holds for carbon nanofillers: Bauhofer and Kovacs showed in Composites Science and Technology in 2009 that percolation in carbon nanotube composites depends strongly on dispersion and aspect ratio rather than on loading alone. A barrier trial that reports no improvement has usually failed at the extruder rather than at the material.

Why a barrier nanofiller needs a compatibilizer#

A silicate platelet is hydrophilic and a polyolefin is not, so an untreated clay agglomerates in polyethylene or polypropylene and delivers none of its aspect ratio, which is why barrier nanocomposites use an organic surface modifier on the clay and a functionalised polymer in the matrix. Two separate interventions are therefore needed, one on the particle and one on the polymer, and the polymer-side intervention is almost always a maleic anhydride graft. The matrix side of the problem is solved by that grafted polyolefin, because the same chemistry that anchors a glass fibre or a mineral filler to a polyolefin matrix anchors a clay platelet, through maleic anhydride grafted polymers such as PE-g-MAH and PP-g-MAH.

The clay side of the problem is solved before the clay reaches the extruder. The surface modifier is what turns montmorillonite into an organoclay, and the European Union entry for the food-contact grade names dimethyldialkyl(C16-C18)ammonium-modified montmorillonite specifically, not the natural mineral, which means the legal identity of the filler and its dispersion behaviour are fixed by the same quaternary ammonium treatment.

The Association of Plastic Recyclers takes the same view from the recycling side, listing EVOH at 10 wt% or less with a PE-g-MAH tie layer as Preferred in polyethylene film. Where a mineral rather than a clay carries the barrier, the surface treatment route runs through silanes and titanates instead, which are covered on coupling agents for filled and reinforced plastics.

6 Types of Barrier Additives for Plastics#

The 6 barrier routes available to a plastics formulator are organoclay nanocomposites, halloysite nanotubes, platy mineral fillers, nylon-MXD6 blends, EVOH and PVDC layers, and graphene and carbon nanotube nanoplatelets. The order below combines commercial weight in packaging with the depth of primary evidence available for each, and it runs through every table, list and image on this page. Two of the six, halloysite and the carbon nanofillers, have no established food-contact route in Europe, and this page says so rather than describing them as if authorisation existed.

1. Organoclay (montmorillonite) nanocomposites#

Organoclay is montmorillonite, CAS 1318-93-0 and EC 215-288-5, whose roughly 1 nanometre thick silicate layers are separated by an organic surface modifier so that they disperse in a polymer and reach an aspect ratio of 100 to 1,000 when fully exfoliated. The mineral is a smectite clay, sold under trade names including Cloisite from BYK and Nanomer, and the same material is called bentonite when the clay is montmorillonite-rich, nanoclay when the target is the exfoliated state and organically modified montmorillonite in the regulatory texts. Its recorded functions in plastics are stiffness, heat distortion temperature, gas barrier and char formation, and all four depend on the same exfoliation.

The landmark result for the family is not a barrier measurement. In the Toyota nylon 6 clay hybrid described by Kojima, Usuki, Kawasumi and Okada in Journal of Materials Research volume 8 in 1993, 4.7 wt% of montmorillonite raised the heat distortion temperature to 152 °C, 87 °C above neat nylon 6. That figure is quoted here because it fixes the loading scale at which a nanocomposite changes bulk properties, and it should not be read as a permeability result. The European food-contact position is covered in the regulatory section below, and the family page for this filler is nanoclay (organoclay) in plastics.

2. Halloysite nanotubes#

Halloysite is a clay whose particles roll into hollow tubes rather than flat platelets, with an aspect ratio of 5 to 20, a particle size of 1 to 20 micrometres and a specific surface area of up to 117 square metres per gram. Its identity carries two numbers that have to be kept apart: the European Chemicals Agency entry is CAS 12068-50-7 with EC 686-506-8, while PubChem holds a separate record under CAS 12298-43-0. Physically it sits between a mineral filler and a nanofiller, with a density of 2.54 grams per cubic centimetre and a Mohs hardness of 2.5.

The evidence base is thinner than for montmorillonite in exactly the way the geometry predicts, because a tube of aspect ratio 5 to 20 obstructs a diffusion path far less effectively than a platelet of aspect ratio 100 to 1,000. Our source library records no European Union food-contact entry and no United States food-contact entry for halloysite, and no barrier dosage in a named polymer, so this page names the material and its dimensions and states that its packaging position is not established.

3. Platy mineral fillers: talc, mica and kaolin#

Three conventional platy minerals raise the barrier of a filled compound at loadings measured in tens of per cent rather than single figures: mica at an aspect ratio of 20 to 100, talc at 5 to 40 and kaolin at 10 to 30. All three are long-established fillers rather than barrier specialities, and all three hold European food-contact entries: talc is FCM No 615, reference 92080, with no specific migration limit, mica is FCM No 597, reference 67120, also with no specific migration limit, and kaolin is FCM No 410, reference 62720, with an Annex II aluminium migration limit of 1 milligram per kilogram. Each also appears in 21 CFR 178.3297 in the United States, mica as aluminium potassium silicate and talc as magnesium silicate.

The trade-offs are the ones that apply to any mineral at high loading rather than anything specific to barrier. Opacity arrives with the filler, which rules these minerals out of a clear bottle; density rises, which matters in a film that has to float in a recycling wash; and talc carries a processing caution of its own, because its Lewis-acid surface sites can catalyse polymer oxidation and depolymerisation at elevated temperature, so a talc-filled barrier compound needs its antioxidant package checked rather than copied. The full loading and selection picture for mineral fillers is on fillers for plastics, with grade-level detail on talc in plastics and on mica in plastics.

4. Nylon-MXD6 as a blended barrier phase#

Nylon-MXD6, poly(m-xylylene adipamide) with CAS 25718-70-1, is a semi-aromatic polyamide made from m-xylylenediamine and adipic acid whose low intrinsic oxygen permeability lets it act as a barrier phase when it is blended into or layered inside a PET wall. Mitsubishi Gas Chemical produces it as MX-Nylon and publishes the permeability data quoted throughout this page. The measured effect on a whole bottle is the clearest evidence any type on this page offers: oxygen ingress falls from 0.027 cubic centimetres per bottle per day at 0.21 atmospheres for plain PET to 0.016 at 5 % MXD6, 0.011 at 10 % and 0.0075 for a three-layer bottle with a 10 % MXD6 layer.

Orientation changes the result as much as loading does. Oriented film transmits 2.8, 3.5 and 5.5 cubic centimetres per square metre per day per atmosphere at 60, 80 and 90 % relative humidity, while non-oriented film of the same polymer transmits 4.3, 7.5 and 20, so a stretch-blow-moulded bottle wall and an unoriented sheet of the same recipe are different barriers. The polymer carries a second identity as the oxidisable substrate of a cobalt-catalysed scavenging system, which is why a bottle specification has to state whether the nylon phase is present to slow oxygen or to consume it, and the substance page is nylon-MXD6.

5. EVOH and PVDC barrier layers#

EVOH and PVDC are barrier polymers used as a continuous coextruded layer rather than as a dispersed additive, and their performance is set by the layer rather than by a particle geometry. EVOH is strongly humidity-dependent, with an EVOH-32 grade ranging from 0.5 to 50 cubic centimetres per square metre per day per atmosphere across the humidity range in the Mitsubishi Gas Chemical comparison, which is why EVOH normally sits between two moisture-resistant layers instead of on a surface. Polyvinylidene chloride is named in the same passive-barrier group in our sources, and no permeability, dosage or food-contact figure for PVDC in plastics packaging is recorded in our source library, so none is stated here.

Recycling guidance treats both as contaminants of the host stream rather than as neutral layers. The European PET Bottle Platform allows EVOH up to 3 wt% in coloured PET bottles and treats it as incompatible in clear ones, while the Association of Plastic Recyclers lists EVOH at 10 wt% or less with a PE-g-MAH tie layer as Preferred in polyethylene film. Those two thresholds, 3 wt% and 10 wt%, are the practical ceiling on a coextruded barrier in packaging that has to be recycled, and the general rules are on design for recycling.

6. Graphene and carbon nanotube nanoplatelets#

Graphene, CAS 1034343-98-0 and EC 801-282-5, is recorded in our source library as a conductive, barrier and reinforcing nanofiller, and it is registered under REACH with 9 active dossiers as checked on the ECHA CHEM database on 22 September 2026. Its geometry is the most favourable of any material on this page, since a graphene nanoplatelet is a two-dimensional sheet, and the same applies to the very high aspect ratio of a carbon nanotube. Neither reaches food packaging in Europe today, because neither is on the Union list of Regulation (EU) No 10/2011 and nanoforms may be used only where they are explicitly authorised under Article 9(2).

Multi-walled carbon nanotubes carry a second constraint that has nothing to do with food contact. Commission Delegated Regulation (EU) 2024/2564, the 22nd adaptation to technical progress of the CLP Regulation, gives multi-walled carbon tubes the harmonised classification Carc. 1B H350i and STOT RE 1 H372 for the lung by inhalation under index number 006-104-00-2, applying from 1 May 2026, for tubes of 30 nanometres to less than 3 micrometres in diameter, at least 5 micrometres long and with an aspect ratio above 3:1. The substance pages are graphene in plastics and carbon nanotubes (CNT) in plastics.

Which Polymers and Packages Use Barrier Additives?#

Barrier additives go where the product loses value to a permeant faster than the plain polymer can keep it out: PET bottles for beer, wine and juice, polyolefin and coextruded film for meat, fish and cheese, and nylon and PLA structures where a clay nanocomposite carries both stiffness and barrier. The host polymer follows the package rather than the chemistry. PET takes a blended or layered nylon phase, polyolefins take an organoclay with a grafted compatibilizer or a coextruded EVOH layer, and engineering compounds take mineral plates that were specified for stiffness in the first place. The full food-contact stack for these packages is on additives for food packaging.

PET bottles: the barrier phase next to reheat and acetaldehyde additives#

A PET preform wall of perhaps 0.3 millimetres rarely carries a barrier phase alone, because the same wall usually holds a reheat additive that shortens oven time before stretch-blow moulding and, in water and beverage bottles, an acetaldehyde scavenger that protects taste. The barrier phase is by far the largest of the three by mass, at several per cent of the wall against a few hundred parts per million for the other two, and it is the one that decides both the haze of the finished bottle and the non-PET fraction that the recycler measures. Grade-level selection for this polymer is covered on additives for PET resin.

Three constraints therefore act on the same number. Performance pushes the nylon fraction up, clarity pushes it down, and the European PET Bottle Platform caps PA-MXD6 at 5 wt% in clear and white three-layer bottles and 6 wt% in coloured and opaque ones, with no tie layers. The formulator chooses between shelf life and recyclability rather than searching for an optimum.

Polyolefin film, nylon and PLA: where the clay route wins#

Organoclay is the barrier route for polyolefin film, nylon and PLA because those polymers take the clay into the melt on standard equipment, while PET bottle production is built around a second polymer phase instead. In polyolefins the European ceiling is explicit and narrow, at 12 % w/w of dimethyldialkyl(C16-C18)ammonium-modified montmorillonite for dry foods at room temperature or below.

Nylon is the polymer in which the nanocomposite effect was first demonstrated, in the Toyota nylon 6 clay hybrid, and it remains the matrix in which an exfoliated clay carries stiffness, heat distortion temperature and barrier at the same loading. The formulation context for that polymer is on additives for nylon (polyamide).

PLA sits under a tighter entry than either of them. FCM 1075 authorises an HDTMA-bromide-modified montmorillonite at up to 4.0 % w/w, and the authorised use is long-term water storage rather than food contact in general, so a compostable tray or a hot-filled cup is outside the entry even at a loading a third of the polyolefin ceiling. The same nanoform condition applies, which means the platelets must lie parallel to the surface and be fully embedded in the polymer.

Food type constrains the polyolefin route more tightly than loading does. The FCM 1030 entry authorises the modified montmorillonite only for dry foods at room temperature or below, so a polyethylene film for a moist or fatty food falls outside that entry however little clay it carries, and the structure then needs a different barrier or a different legal basis. The host polymer context for those films is on additives for polyethylene.

The clay route also keeps the line simple. A dispersed platelet runs through the single extruder that already makes the film, while a coextruded barrier layer needs a second extruder, a tie layer and a die built for the structure, so the choice between them is a capital question as much as a formulation one, and the equipment is usually fixed long before the recipe is.

Film brings its own interaction, since a barrier filler shares the wall with slip, antiblock and antifog additives that are also chosen for surface behaviour, and antiblock minerals such as talc and kaolin are already present in film recipes for a different reason. The full film package is on additives for packaging film.

How Much Barrier Additive Does a Package Need?#

There is no general dosage for a barrier additive, because the level is set by the permeation target over the shelf life and then cut back by a clarity limit, a food-contact ceiling or a recycling threshold, whichever binds first. The published numbers fall into three kinds that must never be mixed: a regulatory ceiling, a recyclability condition and a research loading. No supplier barrier dosage window for a named grade in a named polymer is recorded in our source library, and none is invented here.

A Union list ceiling is a food-contact maximum, not a performance recommendation. A recyclability condition has no legal force but decides whether customers accept the package. Neither is a specification for your wall.

Levels arrive in three units on this page, since a barrier polymer is quoted in weight per cent of the article, a clay ceiling in per cent w/w of the food-contact material and a concentrate in let-down ratio. A barrier nanofiller normally reaches the machine as an additive masterbatch rather than as a powder, because a pre-dispersed carrier is the only practical way to reach an exfoliated state on production equipment, and the unit rules including conversion to wt%, ppm and let-down ratio apply as to any other concentrate.

How Do You Select a Barrier Additive? 7 Steps#

Select a barrier additive in 7 steps: name the permeant and the target, fix the package geometry, choose between a dispersed phase and a layer, check the food-contact route, check the recycling guidelines, check the clarity cost, then confirm by measuring the finished package. The steps run in that order because each one can eliminate a route, and the cheapest elimination comes first.

1. Name the permeant and the target. Oxygen, water vapour, carbon dioxide and aroma need different materials, and a target without a temperature and a relative humidity cannot be checked.
2. Fix the package geometry. Wall thickness, surface area and orientation decide how much barrier the geometry already provides, since oriented MXD6 film transmits 2.8 cubic centimetres per square metre per day per atmosphere against 4.3 for the same polymer unoriented.
3. Choose between a dispersed phase and a layer. A dispersed phase runs on existing single-layer equipment, while a coextruded layer needs a second extruder and a tie layer, and the tie layer is itself a recycling problem.
4. Screen the food-contact route in every market. The organoclay ceilings of 12 % and 4.0 % w/w apply to defined foods and conditions, and nanoforms outside the Union list are not permitted under Article 9(2).
5. Check the recyclability guidelines for the stream the package enters. EPBP limits of 5 and 6 wt% for PA-MXD6 and 3 wt% for EVOH, and the APR Preferred condition for EVOH in polyethylene film, decide acceptance before any trial.
6. Check the clarity cost. A dispersed second phase scatters light at every phase boundary, and an agglomerated clay is worse than no clay at all.
7. Confirm by measurement on the finished package. A plaque proves the mechanism works; only the converted, filled and stored package proves the barrier protects the product.

The general method behind these steps is on how to select plastic additives.

How Is Barrier Performance Measured?#

Barrier performance is reported in 3 ways: as the permeant that passes a film of stated thickness, as the permeant that enters a whole container per day, and as the concentration reached inside the filled package at the end of storage. No value means anything without its conditions, because temperature, thickness, orientation and relative humidity each change the result, and humidity changes EVOH and polyamide barriers by more than an order of magnitude. Our source library holds no standard number for oxygen or water vapour transmission rate testing, so the 3 measurements below are named by what they measure and by their units rather than by a test method.

• Film permeability, in cubic centimetres per square metre per day per atmosphere, always with temperature, thickness and relative humidity: oriented MXD6 at 23 °C and 20 micrometres gives 2.8 at 60 % relative humidity and 5.5 at 90 %.
• Container ingress, in cubic centimetres per bottle per day at 0.21 atmospheres, the only unit that reflects the real geometry: 0.027 for plain PET and 0.0075 for a three-layer wall with 10 % MXD6.
• Optical cost alongside the barrier, measured as haze on the finished wall rather than estimated from the recipe, since a dispersed second phase is a light-scattering phase.

A fourth measurement decides market access rather than performance. A barrier additive in a PET bottle is assessed by the recycling protocols described below, so a wall that meets every permeation target can still fail the stream it was designed for. Optical testing is covered on haze and clarity measurement, and the full method index is on testing plastic additives.

How Are Barrier Additives Regulated?#

A barrier additive in food packaging is regulated as an ordinary plastic component under Regulation (EU) No 10/2011 rather than under the active-materials regime, because it does not act on the food and releases nothing by design. That single sentence is the practical difference from an oxygen scavenger. The general limits of Regulation (EU) No 10/2011 apply throughout: a generic specific migration limit of 60 milligrams per kilogram, an overall migration limit of 10 milligrams per square decimetre or 60 milligrams per kilogram for infant food, and 0.01 milligrams per kilogram for non-authorised substances behind a functional barrier. Every instrument named here is summarised in plastic additive regulations.

EU: the Union list entries and the nanoform rule of Article 9(2)#

Every barrier filler on this page needs its own Union list entry, and the nanoforms need a second permission, because Article 9(2) of Regulation (EU) No 10/2011 allows a substance in nanoform only where that form is explicitly authorised. Two organoclay entries exist and both are narrow. FCM 1030 covers dimethyldialkyl(C16-C18)ammonium-modified montmorillonite at up to 12 % w/w in polyolefins for dry foods at room temperature or below, with a specific migration limit of 0.05 milligrams per kilogram for the sum of 1-chlorohexadecane and 1-chlorooctadecane, and it permits the nanoform platelets on the condition that they are oriented parallel to the surface and fully embedded in the polymer. FCM 1075 covers an HDTMA-bromide-modified montmorillonite at up to 4.0 % w/w in PLA for long-term water storage under the same nanoform conditions.

The orientation condition is worth reading twice, because it turns a dispersion quality into a legal requirement rather than a performance preference. Where a nano-scale barrier filler is used outside those entries, the route closes: graphene and carbon nanotubes are not on the Union list, and no general nanoform permission exists.

Values verified against the consolidated text of Regulation (EU) No 10/2011 of 16 March 2025. Montmorillonite itself has no dossier under EC 215-288-5, because a natural clay falls under REACH Annex V; the organically modified grades are chemically modified substances whose registrations are verified case by case.

How the Union list works, including the difference between an authorised substance and a substance behind a functional barrier, is explained on EU 10/2011.

Functional barrier: the concept that the kaolin entry depends on#

A functional barrier is a layer inside a multilayer material that prevents substances behind it from migrating into the food above 0.01 milligrams per kilogram, and that limit does not apply to substances classified as carcinogenic, mutagenic or toxic to reproduction. The kaolin entry is the clearest case of the concept doing real work in this family, because nano-scale kaolin is permitted only in an EVOH inner layer sitting behind such a barrier. The concept therefore decides not only whether a substance migrates but where in the structure it may be placed at all, and the definition is set out on functional barrier.

Migration behaviour differs for this family in a way that favours it. A mineral platelet or a dispersed polymer phase is not a small mobile molecule, so the migration question moves to the surface modifier and to the monomers rather than to the barrier material itself, which is exactly what FCM 1030 and FCM 421 regulate. The general mechanism is covered on additive migration in plastics.

US: 21 CFR entries for barrier fillers and MXD6#

In the United States the food-contact route runs through 21 CFR: bentonite and dimethyldioctadecylammonium-modified bentonite are listed in 21 CFR 178.3297, as are magnesium silicate talc, aluminium potassium silicate mica and aluminium silicate China clay, while nylon MXD-6 has its own listing at 21 CFR 177.1500(a)(10)(ii). The MXD6 entry carries two conditions that constrain packaging design directly: item 10.1 limits film to 40 micrometres for food types V and IX, item 10.3 covers non-food-contact layers in polypropylene multilayers, and the cyclic monomer extraction limit is 0.5 micrograms per square inch.

Nothing in this family is FDA approved in the sense the phrase is usually used. Food-contact substances clear through listings, threshold-of-regulation exemptions or effective food contact notifications, our source library records no 21 CFR entry for halloysite, graphene or carbon nanotubes in food contact, and whether the 178.3297 aluminium silicate entry covers calcined kaolin grades is an open question rather than a settled one.

Are Barrier Additives Recyclable? EPBP, APR and the PPWR#

A barrier additive is recyclable only up to a written fraction of the host polymer, and the two published thresholds that matter are 5 to 6 wt% for PA-MXD6 in a PET bottle and 3 wt% for EVOH in a coloured PET bottle, with EVOH treated as incompatible in a clear one. The reason is arithmetic rather than chemistry: a barrier phase is by definition a second polymer or a mineral in a stream sorted for one material, and every per cent of it is a per cent of contamination in the recyclate. The general rules are on design for recycling.

EPBP and APR guidelines are industry design guidance rather than law, but under the PPWR they are the working proxies for the design-for-recycling criteria that the Commission must set by delegated act by 1 January 2028.

Density is the constraint that catches mineral barrier fillers in film, because polyethylene recycling separates by flotation. The APR guidance for polyethylene film asks for testing once density approaches 0.996 and treats film above 1.00 as non-recyclable, which caps a heavy platy mineral long before its barrier contribution runs out. That is a different failure mode from the PET case and it is the reason a clay at a few per cent is a more survivable choice than a mineral at twenty.

Law is closing the gap between guidance and obligation. The packaging and packaging waste regulation (PPWR), Regulation (EU) 2025/40, applies from 12 August 2026 and requires 30 % recycled content in contact-sensitive PET packaging and in single-use plastic beverage bottles from 1 January 2030, rising to 50 % for contact-sensitive PET in 2040, with design-for-recycling criteria due by delegated act by 1 January 2028. The consequence for this family is direct, because a barrier construction that contaminates the bottle stream reduces the recyclate a producer needs for its own target, and the behaviour of these systems in recyclate is covered on additives for recycled plastics.

Who Makes Barrier Additives? Suppliers and Trade Names#

The barrier additive business splits into two groups: the mineral and additive houses that sell clays and platy fillers, and the resin producers that sell the barrier polymer itself. BYK supplies organically modified montmorillonite under the Cloisite name, Mitsubishi Gas Chemical produces nylon-MXD6 as MX-Nylon and publishes the permeability data used throughout this page, and the platy minerals come from the established filler producers. Company profiles are collected in the directory of plastic additive manufacturers and suppliers.

This table lists only companies and names recorded in our source library. Nanomer is recorded as an organoclay trade name without a manufacturer in our sources. No ranking, no market share and no endorsement is implied.

Market figures for barrier additives as a segment are not recorded in our source library, and no segment size, growth rate or share is stated on this page. What is recorded is the mineral side of the raw material base, including world kaolin mine production of 44 million tonnes in 2024 as estimated by the United States Geological Survey, at an average United States unit value of 160 dollars per tonne.

Complete List of Barrier Additive Substances#

Five substances carry the barrier function in plastics packaging in our source library, and they divide into three clays and minerals, one barrier polyamide and one carbon nanomaterial. The table lists each with its CAS number, the shape that produces the barrier and its European food-contact position, which is the field that differs most between them and the field that decides which one a given package allows.

Halloysite, kaolin and PVDC are named on this page but have no separate substance page in the current inventory. Halloysite is covered by the nanoclay family page, kaolin by the fillers family, and PVDC is a packaging polymer rather than a plastic additive.

Every other substance used in plastics, with its CAS number, function and regulatory status, is in the plastic additives database.

What Else Is Called a Barrier Additive, and What Do People Ask About It?#

The phrase barrier additive covers at least three different things in the trade: a dispersed filler that lengthens the diffusion path, a barrier polymer bought as a resin, and a surface coating or metallisation that is not an additive at all. Only the first two are plastic additives in the sense this reference uses, and the third is a converting process applied to a finished film. The sections below answer the questions that arrive on the neighbouring meanings, once each, and then return to the additive.

Barrier additives, barrier coatings and metallisation#

A barrier coating or a metallised layer is applied to the surface of a finished film rather than compounded into the melt, which puts it outside the scope of a plastic additives reference even though it competes for the same specification. Silicon oxide coatings and aluminium metallisation are named in our sources as passive barrier constructions alongside EVOH, MXD6 and PVDC, and no coating thickness, permeability or food-contact figure for them is recorded in our source library. The practical difference for a formulator is where the cost and the risk sit: a compounded barrier is a resin purchase and a dispersion problem, while a coating is a separate converting step with its own line, its own yield and its own effect on recyclability.

Nanoclay outside packaging: the flame-retardant nanocomposite route#

The same organoclay that raises barrier is used as a flame-retardant synergist, because the mechanism is the same surface barrier acting on volatiles and heat instead of on oxygen. Organoclay, layered double hydroxides, carbon nanotubes and silica all reduce the peak heat release rate through a condensed-phase barrier, and they rarely pass a UL 94 rating on their own, which is why they appear as synergists next to a main flame retardant rather than as replacements for one. No reliable synergist loading window is established in our sources, so none is stated here, and the family is covered separately on nanocomposite flame retardants.

Common questions about barrier additives#

Three questions account for most of what specifiers ask about this family: how a barrier differs from a scavenger, whether nanoclays are allowed in European food contact, and which of the two jobs nylon-MXD6 is doing in a given wall. Each is answered once below, with the instrument or the data set the answer rests on.

What is the difference between a barrier additive and an oxygen scavenger?#

A barrier additive slows oxygen down and an oxygen scavenger consumes it, so a barrier changes the rate of ingress while a scavenger changes the quantity present. The clearest practical consequence is what happens at filling: a barrier does nothing about the oxygen already inside the sealed package, and a scavenger removes it. The two are combined in demanding packages precisely because neither does the other's job, and nylon-MXD6 sits in both families, acting as a passive barrier alone and as the oxidisable substrate of an active system once a cobalt carboxylate is present in the same wall.

Are nanoclays allowed in food contact plastics in the EU?#

Two modified montmorillonite entries are authorised in European food-contact plastics with narrow conditions, FCM 1030 at up to 12 % w/w in polyolefins for dry foods at room temperature or below and FCM 1075 at up to 4.0 % w/w in PLA for long-term water storage, and both permit the nanoform only where the platelets are oriented parallel to the surface and fully embedded. Outside those two entries and the kaolin condition of FCM 410, a nanoform is not permitted, because Article 9(2) of Regulation (EU) No 10/2011 requires explicit authorisation of the nano form of a substance. Graphene and carbon nanotubes hold no such authorisation.

Is MXD6 a barrier additive or an oxygen scavenger?#

Nylon-MXD6 is a passive barrier polymer on its own and becomes the oxidisable substrate of an active oxygen-scavenging system only when a cobalt catalyst is present in the same wall, so the answer is set by the rest of the formulation rather than by the polyamide. Mitsubishi Gas Chemical's own bottle data describes the passive case, with oxygen ingress falling from 0.027 cubic centimetres per bottle per day at 0.21 atmospheres for plain PET to 0.011 for a 10 % MXD6 blend. The legal consequence is larger than the technical one, because a passive MXD6 wall is regulated as an ordinary plastic under Regulation (EU) No 10/2011 while a cobalt-catalysed one is an active material under Regulation (EC) No 450/2009, and the recyclability position changes with it.

Nanomaterials in packaging: what the rules ask and what is still open#

The regulatory question about nanomaterials in food packaging is not whether the particle is safe in the abstract but whether it stays where it was put, which is why the European entries attach orientation and embedding conditions to the platelets rather than a migration limit alone. That construction tells a formulator what the legislator is worried about: a platelet lying parallel to the surface inside the polymer behaves as part of the material, while a poorly dispersed agglomerate at the surface is a different object. The conditions are therefore process requirements, and compounding quality becomes a compliance question rather than only a performance one.

Two open points belong in any honest summary of this family. No quantified permeability-reduction factor for any of these fillers in a named polymer is established in our source library, so this page describes the mechanism and publishes the ceilings rather than promising a multiple. No barrier-specific supplier dosage window is recorded either, which means the loading in a real formulation is set by trial against the ceilings above rather than read off a datasheet.