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TL;DR&nbsp;— REACH regulation continues to tighten in 2026 across multiple fronts simultaneously. The SVHC Candidate List reached 253 entries in February 2026 with the addition of n-hexane and Bisphenol AF. The CMR Annex XVII update adds 22 new carcinogenic, mutagenic or reprotoxic substances with compliance obligations expected later in 2026. The PFAS broad restriction is advancing through ECHA's scientific committees with a European Commission decision anticipated post-2026. And the microplastic SPM restriction is already in force, with rinse-off cosmetics facing a 2027 deadline. For manufacturers and importers supplying the EU market, 2026 is not a year to wait for final texts — it is a year to act on what is already confirmed.&nbsp;&nbsp;&nbsp;





What is REACH and why does the 2026 update matter?&nbsp;&nbsp;&nbsp;



REACH — Registration, Evaluation, Authorisation and Restriction of Chemicals,&nbsp;Regulation (EC) No 1907/2006&nbsp;— is the foundational EU chemicals regulation governing the safe use of substances on the European market. Its scope is broad: it applies to chemical substances on their own, in mixtures, and in articles, and it affects manufacturers, importers, distributors, and downstream users across virtually every industrial sector.&nbsp;&nbsp;&nbsp;



The regulation is not static.&nbsp;ECHA&nbsp;— the European Chemicals Agency, the Helsinki-based body responsible for implementing REACH — continuously updates its restricted substances lists, candidate lists, and authorisation requirements based on new scientific assessments, risk evaluations, and proposals from EU Member States and the European Commission. 2026 is particularly dense: several restriction proposals are converging simultaneously, with deadlines falling across cosmetics, coatings, specialty chemicals, electronics, and consumer goods manufacturing.&nbsp;&nbsp;&nbsp;



Understanding where each restriction sits in the regulatory process — and what it means practically — is the starting point for any supply chain compliance strategy.&nbsp;&nbsp;&nbsp;



The REACH regulatory architecture: three lists that matter&nbsp;&nbsp;&nbsp;



Before reviewing the 2026 updates, it is useful to map the three core instruments under REACH that trigger direct obligations for companies.&nbsp;&nbsp;&nbsp;



Annex XVII — the Restricted Substances List.&nbsp;This is the most operationally consequential list. Substances on Annex XVII&nbsp;cannot be manufactured, placed on the market, or used&nbsp;in the EU except under the conditions specified in the restriction entry. Some entries impose concentration limits; others impose outright bans; others restrict use to professional or industrial contexts. Compliance is mandatory and enforced at national level by Member State authorities.&nbsp;&nbsp;&nbsp;



The SVHC Candidate List.&nbsp;Substances of Very High Concern are chemicals identified by ECHA as posing serious risks to&nbsp;human health and the environment&nbsp;— due to carcinogenicity, mutagenicity, reproductive toxicity, persistence and bioaccumulation, or equivalent concern. Inclusion on the Candidate List triggers immediate information obligations (Article 33 REACH) but does not constitute a ban. It is, however, the precursor to inclusion on Annex XIV.&nbsp;&nbsp;&nbsp;



Annex XIV — the Authorisation List.&nbsp;Substances on this list cannot be used after a sunset date unless the specific use has been granted authorisation by the European Commission. Authorisation is time-limited, use-specific, and increasingly difficult to obtain as ECHA's committee workload grows. The&nbsp;13th recommendation round&nbsp;was published in February 2026, adding further substances under evaluation for Annex XIV inclusion.&nbsp;&nbsp;&nbsp;



REACH 2026 update: the SVHC Candidate List reaches 253 entries&nbsp;&nbsp;&nbsp;



The first significant REACH update of 2026 came on 4 February, when&nbsp;ECHA officially added two new substances&nbsp;to the SVHC Candidate List, bringing the total to 253 entries.&nbsp;&nbsp;&nbsp;



n-Hexane (CAS 110-54-3)&nbsp;was added due to specific target organ toxicity after repeated exposure — the neurotoxicity pathway under Article 57(f). This is a landmark inclusion: it is&nbsp;the first SVHC identified based on neurotoxicity&nbsp;as an equivalent level of concern, rather than the traditional CMR criteria. n-Hexane is a widely used solvent in formulation processes, polymer processing, coatings, adhesives, and cleaning agents. Companies using it as a cleaning or extraction solvent in chemical manufacturing will need to screen their products urgently.&nbsp;&nbsp;&nbsp;



4,4'-[2,2,2-trifluoro-1-(trifluoromethyl)ethylidene]diphenol and its salts (Bisphenol AF / BPAF)&nbsp;— a group of 9 substances — was added due to reproductive toxicity under Article 57(c). BPAF is used as a&nbsp;process regulator and crosslinking agent&nbsp;in high-performance fluoroelastomers, specialty coatings, and adhesive applications.&nbsp;&nbsp;&nbsp;



Immediate obligations triggered by the February 2026 addition:&nbsp;&nbsp;&nbsp;



For any article containing either substance above 0.1% w/w, suppliers must inform customers and provide safe use information. Producers and importers of affected articles must notify ECHA via SCIP within six months — the notification deadline is&nbsp;4 August 2026. Safety data sheets for substances and mixtures containing these SVHCs must be updated immediately.&nbsp;&nbsp;&nbsp;



REACH 2026 update: Annex XVII CMR expansion&nbsp;&nbsp;&nbsp;



Beyond the Candidate List, a significant&nbsp;Annex XVII amendment&nbsp;is advancing through the European Commission's processes in 2026. A draft proposal published in January 2026 adds 22 substances to Entries 28, 29, and 30 of Annex XVII — the entries covering carcinogenic, mutagenic, and reprotoxic (CMR) substances in consumer products.&nbsp;&nbsp;&nbsp;



This periodic update aligns REACH restrictions with the latest CLP Regulation hazard classifications. Concentration limits for the newly added substances range from 1,000 to 3,000 ppm depending on the CMR classification category. Final adoption and publication in the EU Official Journal are expected later in 2026, with a transition period for affected companies.&nbsp;&nbsp;&nbsp;



The sectors most directly impacted include chemical manufacturers and formulators, cosmetics and personal care, textiles, consumer goods, and specialty industrial chemicals. Companies manufacturing articles or mixtures containing any of the 22 newly listed substances sold to general consumers will face direct compliance requirements. Among the notable substances in the proposal, trimethyl phosphate — used in flame retardant formulations and as a plasticizer intermediate — appears across multiple appendix entries and will require supply chain tracing.&nbsp;&nbsp;&nbsp;



REACH 2026 update: the PFAS broad restriction — where it stands&nbsp;&nbsp;&nbsp;



The most sweeping restriction proposal currently advancing through REACH is the&nbsp;universal PFAS restriction&nbsp;— a proposal to restrict per- and polyfluoroalkyl substances across the entire REACH scope. The proposal was jointly submitted in January 2023 by Denmark, Germany, the Netherlands, Norway, and Sweden, and covers 231 identified major use sectors including cosmetics, coatings, food contact materials, textiles, electronics, and medical devices.&nbsp;&nbsp;&nbsp;



Where the process stands in 2026:&nbsp;&nbsp;&nbsp;



ECHA's Risk Assessment Committee (RAC) adopted its opinion on the restriction proposal on 3 March 2026, completing a comprehensive evaluation of PFAS hazards, emissions, and risks. ECHA's Socio-Economic Analysis Committee (SEAC) agreed its draft opinion on 11 March 2026, with a 60-day public consultation running from 26 March to 25 May 2026. Once SEAC finalises its opinion, the European Commission will prepare a draft restriction decision in consultation with EU Member States — a process that is unlikely to produce a final Annex XVII entry before 2027 at the earliest. 







PFAS restriction: what the March 2026 ECHA opinions say



On 26 March 2026, ECHA announced that its two scientific committees support an EU-wide restriction of PFAS, with targeted derogations. The Risk Assessment Committee (RAC) adopted its final opinion on 2 March 2026. The Committee for Socio-Economic Analysis (SEAC) agreed its draft opinion on 10 March 2026.



SEAC supports derogations only where alternatives are not yet available and the cost-benefit balance justifies it. RAC recommends that any derogation comes with emission controls: site PFAS management plans, supply-chain communication, labelling and reporting.



The consultation on the SEAC draft opinion closed on 25 May 2026. SEAC is expected to adopt its final opinion by the end of 2026. The Commission will then propose the restriction text for a vote by Member States in the REACH Committee.



What to do now: map where PFAS are intentionally used in your products, ask suppliers for written PFAS declarations, and start qualifying alternatives for uses unlikely to get a derogation.  



What this means for industries using PFAS in 2026



The broad PFAS restriction is not yet law, but the scientific opinions are now largely complete. Industries relying on PFAS for functional coatings, surfactants, processing aids, or specialty chemical applications should be treating this as a confirmed regulatory direction — not a possibility. The window for orderly reformulation and supply chain transition is open now; it will close rapidly once the Commission decision is published.&nbsp;&nbsp;&nbsp;



Specific PFAS sub-groups are already restricted or imminently restricted under REACH independently of the broad proposal. Undecafluorohexanoic acid (PFHxA) and its related substances&nbsp;face restrictions starting April 2026. Long-chain perfluorinated carboxylic acids (C9-21 PFCAs) are being incorporated into the EU's POPs Regulation with a global ban applying from December 2026.&nbsp;&nbsp;&nbsp;



REACH 2026 update: the microplastic SPM restriction — enforcement deadlines approaching&nbsp;&nbsp;&nbsp;



Commission Regulation (EU) 2023/2055&nbsp;— restricting synthetic polymer microparticles intentionally added to products — entered into force on 17 October 2023, but its most commercially significant deadlines fall in 2026–2029. On&nbsp;17 October 2025, the first information and reporting obligations came into force: suppliers must now provide use and disposal instructions, compliance statements, and polymer identity information in SDSs and labelling.&nbsp;&nbsp;&nbsp;



The upcoming enforcement deadlines for cosmetics are:&nbsp;&nbsp;&nbsp;




17 October 2027&nbsp;— rinse-off cosmetics (shampoos, shower gels, body washes, cleansers)&nbsp;&nbsp;&nbsp;





17 October 2029&nbsp;— leave-on cosmetics (moisturisers, serums, creams, hair gels, sunscreens)&nbsp;&nbsp;&nbsp;





17 October 2035&nbsp;— colour cosmetics, lip and nail products (with mandatory labelling from 2031)&nbsp;&nbsp;&nbsp;




The key practical consequence for formulators:&nbsp;carbomers are classified as restricted SPMs&nbsp;under this regulation. The&nbsp;solubility test&nbsp;must be conducted at pH 7 on the material in its commercialised form. Carbomers are supplied as dry acidic powders and only become soluble after in-situ neutralisation — they therefore fail the solubility exclusion in their supplied state. Pre-neutralised synthetic polymers, supplied in a form that passes the pH 7 solubility test, are outside the SPM classification.&nbsp;&nbsp;&nbsp;



What to switch to: alternatives across the key restriction areas&nbsp;&nbsp;&nbsp;



Replacing carbomers (SPM restriction)&nbsp;&nbsp;&nbsp;



The most viable alternatives depend on the formulation context:&nbsp;&nbsp;&nbsp;



Pre-neutralised acrylate polymers&nbsp;supplied as aqueous dispersions or sodium salts pass the pH 7 solubility test as supplied and are outside the SPM classification. They can replicate many of the rheological and textural properties of conventional carbomers with modifications to the formulation process.&nbsp;&nbsp;&nbsp;



HASE and HEUR associative thickeners&nbsp;are outside the SPM scope for most grades and offer&nbsp;precise rheological control&nbsp;in emulsion systems. They require more formulation work to match carbomer texture but are technically fully capable substitutes in cream and lotion formats.&nbsp;&nbsp;&nbsp;



Natural polysaccharide combinations&nbsp;— xanthan-sclerotium gum,&nbsp;xanthan-guar blends&nbsp;— are COSMOS-compliant, SPM-free, and technically mature alternatives for most leave-on and rinse-off formats, with the sensory and concentration trade-offs detailed in our&nbsp;natural vs synthetic thickeners guide.&nbsp;&nbsp;&nbsp;



Replacing PFAS-containing substances&nbsp;&nbsp;&nbsp;



PFAS perform multiple distinct functions — surface tension reduction, hydrophobic and oleophobic coatings, thermal stability, lubrication — and no single alternative chemistry covers all uses.&nbsp;&nbsp;&nbsp;



In&nbsp;surface coatings, fluorine-free water-repellent chemistries based on wax emulsions, dendrimers, silicone, and bio-based C6 chemistry are advancing as alternatives, though performance at extreme conditions (high temperature, prolonged moisture exposure) remains a gap for some industrial applications.&nbsp;&nbsp;&nbsp;



In&nbsp;cosmetics, PFAS are used primarily for film-forming, texture enhancement, and water-resistance in colour cosmetics and sunscreens. Alternatives include silicone-based film formers, polyacrylate crosspolymers, and bio-derived esters — with each requiring careful stability and performance testing in the target formulation.&nbsp;&nbsp;&nbsp;



In&nbsp;specialty industrial applications, the alternatives are highly use-specific and often still in development. ECHA's SEAC consultation running until May 2026 is specifically gathering&nbsp;socioeconomic impact data&nbsp;on the availability of alternatives across all 231 identified sectors.&nbsp;&nbsp;&nbsp;



Replacing n-hexane in formulation and cleaning processes&nbsp;&nbsp;&nbsp;



The addition of n-hexane to the&nbsp;SVHC Candidate List&nbsp;in February 2026 does not constitute an immediate ban, but triggers information and notification obligations that signal regulatory direction. Alternative solvents — heptane, isoparaffins, ethyl acetate, bio-based alcohols — are available for most cleaning and extraction applications, with solvent selection depending on the polarity of the substrate and the required evaporation profile.&nbsp;&nbsp;&nbsp;



How companies should manage REACH compliance in 2026&nbsp;&nbsp;&nbsp;



Map your substances against the current lists.&nbsp;The SVHC Candidate List, Annex XVII, and the authorisation list are all live documents.&nbsp;ECHA CHEM, ECHA's new chemicals database live since September 2025, is now the authoritative single source. Any substance present in your products, mixtures, or articles at above 0.1% w/w needs to be screened against all three instruments.&nbsp;&nbsp;&nbsp;



Update safety data sheets proactively.&nbsp;The February 2026 SVHC additions require SDS updates for all substances and mixtures containing n-hexane or BPAF. Waiting for enforcement is not a defensible compliance posture — EU and EEA&nbsp;suppliers of substances and mixtures&nbsp;must update SDSs immediately upon Candidate List inclusion.&nbsp;&nbsp;&nbsp;



Submit SCIP notifications on time.&nbsp;The notification deadline for the February 2026 SVHC additions is 4 August 2026. SCIP submissions must be made through ECHA's REACH-IT and IUCLID systems. Companies producing or importing articles containing SVHCs above 0.1% w/w in quantities exceeding one tonne per year are legally required to notify.&nbsp;&nbsp;&nbsp;



Engage your supply chain.&nbsp;REACH compliance cannot be managed in isolation. Under&nbsp;Article 33 REACH, the information obligation flows downstream through the supply chain. If your suppliers have not updated their substance disclosures to reflect the February 2026 additions, their silence is your compliance gap.&nbsp;&nbsp;&nbsp;



Begin reformulation planning now for SPM-restricted substances.&nbsp;The 2027 deadline for rinse-off cosmetics is within a standard product development cycle for formulations beginning now. Teams developing new rinse-off products for the EU market should be treating carbomers as unavailable from the design stage — not as an existing ingredient to be replaced later.&nbsp;&nbsp;&nbsp;



For a detailed breakdown of how the microplastic regulation specifically affects&nbsp;cosmetic thickener selection, including which synthetic polymers fall inside and outside the SPM classification, see our dedicated article on rheology modifiers and emulsion stabilisation.&nbsp;&nbsp;&nbsp;



FAQ



How many substances are on the SVHC Candidate List in 2026?



253 entries after the 4 February 2026 update, which added n-hexane and bisphenol AF and its salts.



Is the EU PFAS restriction adopted?



Not yet. ECHA's committees support it with targeted derogations. SEAC's final opinion is expected by the end of 2026, then the Commission proposes the text and Member States vote.



What are the obligations when a substance joins the SVHC list?



Suppliers must update SDS, inform customers when an article contains more than 0.1% w/w, and notify ECHA within six months if above 1 tonne per year.



What can replace n-hexane?



See our alternatives section. Solvent substitution depends on the process: check solvency, evaporation rate and flash point with our technical team.


Search alternatives in our online catalogue.

Replacing a restricted substance? 

Adhesive &amp; Sealants Coatings, Inks &amp; Construction Industrial specialties Plastics

REACH 2026: Restricted Substances, Key Updates and What to Switch To


TL;DR — Vulcanisation transforms a plastic rubber compound into a highly elastic product by building a three-dimensional cross-linked network. Sulphur systems form sulphidic cross-links that deliver superior tensile strength, tear resistance, and dynamic fatigue performance, making them the go-to choice for natural rubber, SBR, and dynamic applications. Peroxide systems form carbon–carbon cross-links with significantly higher bond energy, delivering better thermal stability, lower compression set, and superior resistance to thermo-oxidative ageing — making them the preferred curing system for EPDM, silicone rubber, and applications requiring high-temperature or hot-steam resistance. For EPDM rubber compounds specifically, combined sulphur and peroxide vulcanisation systems offer a way to balance the trade-offs of both, yielding higher tensile strength and elongation at break than either system alone.





What is vulcanisation and why does the curing system choice matter?



Vulcanisation is the process of transforming a plastic rubber compound into a highly deformable and elastic material by forming a three-dimensional cross-linked network structure within the rubber matrix. During this process, curing agents react with functional groups on the elastomer chains, creating chemical bridges between polymer segments that define the mechanical, thermal, and ageing behaviour of the final rubber product.&nbsp;



The choice of vulcanisation system is one of the most consequential formulation decisions in rubber compounding. It determines not just the type of cross-link formed — and therefore the fundamental property profile of the vulcanizate — but also the processing temperatures, cure kinetics, filler compatibility, and end-use performance window of the rubber compound. As reviewed in Chemical Papers, sulphur systems and organic peroxides remain the two most widely used vulcanisation approaches across the rubber industry, and the choice between them is driven primarily by the elastomer type and the requirements of the final product.&nbsp;



How&nbsp;does&nbsp;sulphur&nbsp;vulcanisation&nbsp;work?&nbsp;



Sulphur&nbsp;vulcanisation&nbsp;has been known for over 160&nbsp;years&nbsp;but the underlying mechanism&nbsp;remains&nbsp;an active area of research. In practice, elemental&nbsp;sulphur&nbsp;is always used in combination with accelerators — most commonly thiazole,&nbsp;sulfenamide, or thiuram derivatives — and activators such as zinc oxide and stearic acid. The role of&nbsp;zinc oxide in sulphur cure&nbsp;is to activate the accelerator, forming zinc-accelerator complexes that&nbsp;initiate&nbsp;the&nbsp;sulphidation&nbsp;of rubber chain segments.&nbsp;&nbsp;



The result is the formation of sulphidic cross-links connecting polymer chains. These cross-links exist in three forms — monosulphidic (C–S–C), disulphidic (C–S₂–C), and polysulphidic (C–Sₓ–C, where x = 3–6) — and the ratio between them is controlled by the sulphur-to-accelerator ratio in the formulation. Conventional sulphur systems (high sulphur, low accelerator) produce predominantly polysulphidic networks; efficient vulcanisation (EV) systems (low sulphur, high accelerator) produce predominantly monosulphidic cross-links; semi-EV systems fall between the two.



Polysulphidic&nbsp;cross-links are longer and more flexible than mono- or&nbsp;disulphidic&nbsp;bonds. This gives conventionally&nbsp;sulphur-cured rubber its characteristic advantages: high tensile strength, high tear resistance, and good dynamic fatigue performance. The longer cross-links can redistribute stress under load, dissipating energy before chain failure occurs. The trade-off is inferior&nbsp;heat&nbsp;ageing resistance:&nbsp;polysulphidic&nbsp;bonds break down more readily at elevated temperatures, leading to reversion — a softening and loss of mechanical properties — on prolonged exposure to heat.&nbsp;&nbsp;



How does peroxide&nbsp;vulcanisation&nbsp;work?&nbsp;&nbsp;



Organic peroxides — the most widely used being&nbsp;dicumyl peroxide (DCP)&nbsp;— cure rubber through a free-radical mechanism. At processing temperatures, the peroxide decomposes thermally into radicals, which react with the rubber polymer chains either by hydrogen abstraction or by addition to double bonds in unsaturated rubbers. Both mechanisms generate macromolecular radicals on the rubber chains, which then recombine to form&nbsp;carbon–carbon cross-links&nbsp;directly between polymer chain segments.&nbsp;&nbsp;



These C–C bonds have significantly higher dissociation energy than&nbsp;sulphidic&nbsp;cross-links — approximately 348 kJ/mol for C–C versus 273 kJ/mol for C–Sₓ–C bonds. This is the chemical basis for the main advantages of&nbsp;peroxide-cured vulcanizates: higher resistance to thermo-oxidative ageing, superior thermal stability, better performance in hot steam environments, and lower compression set — a critical property in sealing applications.&nbsp;&nbsp;



The limitation of peroxide systems is the risk of chain scission reactions occurring alongside cross-link formation. When a macroradical undergoes beta-scission rather than recombination, it fragments the polymer chain instead of bridging it — leading to degradation of mechanical properties rather than network formation. The extent of this side reaction depends on the polymer structure, peroxide concentration, and processing temperature. Some polymers — notably polypropylene and certain halogenated rubbers — are highly prone to chain scission and are therefore not suitable for peroxide&nbsp;vulcanisation.&nbsp;&nbsp;



Sulphur vs peroxide: the key property trade-offs&nbsp;&nbsp;



The following trade-offs are consistently reported across the&nbsp;peer-reviewed literature&nbsp;on rubber&nbsp;vulcanisation&nbsp;systems:&nbsp;&nbsp;




Tensile and tear strength&nbsp;— Sulphur-cured vulcanizates consistently outperform peroxide-cured ones in tensile strength and tear resistance, particularly in natural rubber and SBR. The longer, more flexible&nbsp;sulphidic&nbsp;cross-links distribute stress more effectively under tensile loading. In a comparative study of nitrile rubber composites,&nbsp;sulphur-cured NBR filled with carbon black&nbsp;showed tensile strength values&nbsp;rising&nbsp;from 13.1 to 21.2 MPa with increasing filler concentration.&nbsp;&nbsp;



Thermal stability and ageing resistance&nbsp;— Peroxide-cured vulcanizates maintain their mechanical properties significantly better after prolonged heat exposure. The higher bond energy of C–C cross-links&nbsp;resists&nbsp;thermal degradation more effectively than&nbsp;polysulphidic&nbsp;bridges. This is the decisive advantage in applications requiring extended service at elevated temperatures.&nbsp;&nbsp;



Compression set&nbsp;— Peroxide systems deliver lower compression set — meaning the rubber recovers more completely after prolonged compressive loading. This is critical in sealing applications such as gaskets, O-rings, and weather-stripping, where permanent deformation under load directly compromises sealing function.&nbsp;&nbsp;



Dynamic properties&nbsp;— Both curing systems produce vulcanizates with similar dynamic mechanical properties (storage modulus G', loss modulus&nbsp;G'', and loss factor tan δ), as confirmed by&nbsp;comparative DMTA testing&nbsp;on EPDM rubber compounds. The curing system has less influence on dynamic stiffness than on static mechanical properties.&nbsp;&nbsp;



Processing and cost&nbsp;— Sulphur systems are&nbsp;generally lower-cost&nbsp;and easier to process.&nbsp;Peroxide curing typically requires higher processing temperatures and more precise control to avoid premature decomposition.&nbsp;The by-products of peroxide decomposition — notably acetophenone and cumyl alcohol from&nbsp;dicumyl&nbsp;peroxide — can also affect&nbsp;odour, which is relevant in food contact and potable water applications.&nbsp;&nbsp;



Cross-link density&nbsp;— Both systems can achieve comparable cross-link density levels, but the network architecture differs. Sulphur systems form heterogeneous networks mixing mono-, di-, and&nbsp;polysulphidic&nbsp;links; peroxide systems produce more uniform C–C networks. The&nbsp;equilibrium swelling test&nbsp;in solvents is the standard method for measuring cross-link density and assessing network structure in vulcanizates.&nbsp;&nbsp;




Which curing system for which rubber?&nbsp;&nbsp;



Peroxide vs Sulphur Curing for EPDM: Temperature, Steam and Chemical Resistance







Natural rubber (NR) —&nbsp;sulphur&nbsp;preferred&nbsp;&nbsp;



Natural rubber&nbsp;contains&nbsp;a high proportion of cis-1,4-polyisoprene with abundant double bonds along the backbone — the ideal substrate for accelerated&nbsp;sulphur&nbsp;vulcanisation. Sulphur curing of natural rubber delivers the high tensile strength, resilience, and dynamic performance that make NR the material of choice for&nbsp;tyres, conveyor belts, and anti-vibration mounts. Peroxide curing of NR is technically possible but less common, as chain scission side reactions can degrade mechanical properties in highly unsaturated systems at the temperatures&nbsp;required&nbsp;for DCP decomposition.&nbsp;&nbsp;



SBR (styrene-butadiene rubber) —&nbsp;sulphur&nbsp;preferred, peroxide&nbsp;viable&nbsp;&nbsp;



SBR is a copolymer of styrene and butadiene with sufficient unsaturation to support&nbsp;effective sulphur vulcanisation. Sulphur-cured SBR offers good tensile and dynamic properties for&nbsp;tyre&nbsp;treads, footwear, and general rubber goods. Peroxide&nbsp;vulcanisation&nbsp;of SBR is also&nbsp;viable&nbsp;and produces C–C cross-links with better heat ageing resistance, though at some cost to tensile performance. The choice between systems in SBR is typically driven by the end-use temperature requirement.&nbsp;&nbsp;



EPDM rubber — both systems&nbsp;viable; peroxide preferred for high-temperature applications&nbsp;&nbsp;



EPDM is unusual in being efficiently curable with both&nbsp;sulphur&nbsp;and peroxide systems, which is why it is the most extensively studied rubber in comparative&nbsp;vulcanisation&nbsp;research. EPDM is an ethylene-propylene terpolymer where the third diene monomer — most commonly ethylidene norbornene (ENB), dicyclopentadiene (DCPD), or 1,4-hexadiene — provides the pendant unsaturation sites&nbsp;required&nbsp;for&nbsp;sulphur&nbsp;vulcanisation, while the saturated ethylene-propylene backbone enables peroxide cross-linking.&nbsp;&nbsp;



For&nbsp;EPDM rubber compounds&nbsp;used in hot steam seals, automotive cooling system hoses, and heat-resistant profiles, peroxide curing is the standard choice: peroxide-cured EPDM can withstand continuous service up to approximately 150°C and intermittent steam exposure up to 200°C. For dynamic sealing applications, weatherstripping, and membranes where tensile and tear properties take priority over heat ageing,&nbsp;sulphur&nbsp;curing delivers better mechanical performance. Research on carbon-black-filled EPDM compounds has also found that&nbsp;sulphur systems outperform peroxide&nbsp;in cross-link density and mechanical performance in filled formulations, while peroxide systems are more suitable for unfilled EPDM compounds.&nbsp;&nbsp;



Nitrile rubber (NBR) — both&nbsp;viable; peroxide for sealing applications&nbsp;&nbsp;



Nitrile rubber — acrylonitrile butadiene rubber (NBR) — is widely used in petroleum-resistant seals, fuel hoses, and aerospace gaskets. Both&nbsp;sulphur&nbsp;and peroxide curing systems are used commercially. Sulphur-cured NBR with carbon black reinforcement delivers&nbsp;high tensile strength&nbsp;suitable for dynamic applications. Peroxide-cured NBR delivers better compression set and heat ageing resistance, making it the preferred choice for precision seals in automotive and industrial fluid systems. Hydrogenated NBR (HNBR), with its saturated backbone, is&nbsp;almost exclusively&nbsp;peroxide-cured.&nbsp;&nbsp;



Silicone rubber — peroxide only (conventional grades)&nbsp;&nbsp;



Conventional silicone rubber lacks carbon–carbon unsaturation and cannot be&nbsp;sulphur-cured. Peroxide&nbsp;vulcanisation&nbsp;— commonly with DCP, bis-2,4-dichlorobenzoyl peroxide, or di-tert-butyl peroxide — is the standard cross-linking method for heat-cured silicone rubber, producing C–C and C–O–C cross-links via hydrogen abstraction from the silicone methyl groups. Addition-cure silicone systems (platinum-catalysed&nbsp;hydrosilylation) are also widely used but fall outside the&nbsp;sulphur-peroxide comparison.&nbsp;&nbsp;



Butyl rubber (IIR) and&nbsp;halobutyl&nbsp;rubber — limited unsaturation requires specific approaches&nbsp;&nbsp;



Butyl rubber has&nbsp;very low&nbsp;unsaturation, which makes conventional accelerated&nbsp;sulphur&nbsp;systems slow and inefficient.&nbsp;Specialised&nbsp;sulphur&nbsp;systems using high accelerator loadings, or&nbsp;resol&nbsp;resin curing, are typically used. Peroxide curing of standard butyl rubber is problematic due to its tendency toward chain scission rather than cross-link formation. Halogenated butyl rubbers (CIIR, BIIR) allow&nbsp;somewhat more&nbsp;latitude in curing system&nbsp;selection.&nbsp;&nbsp;



The combined&nbsp;sulphur&nbsp;and peroxide&nbsp;vulcanisation&nbsp;approach&nbsp;&nbsp;



For EPDM rubber specifically, research has&nbsp;established&nbsp;that&nbsp;combined sulphur-peroxide vulcanisation&nbsp;systems offer a way to engineer properties beyond the range of either system alone. When both curing agents are used simultaneously, the rubber network&nbsp;contains&nbsp;a mixture of&nbsp;sulphidic&nbsp;cross-links, C–C cross-links, and — when coagents are present — multifunctional coagent-mediated cross-links.&nbsp;&nbsp;



The result is a lower overall cross-link density than pure&nbsp;sulphur&nbsp;or pure peroxide systems individually, but a higher tensile strength and elongation at break than either alone. The mutually compatible cross-link types&nbsp;appear to balance&nbsp;each other's weaknesses: the more flexible&nbsp;sulphidic&nbsp;bridges contribute to elongation and tensile performance, while the C–C bonds contribute to thermal stability and compression set resistance.&nbsp;&nbsp;



The role of&nbsp;peroxide co-agents&nbsp;— low molecular weight organic compounds with reactive double bonds, such as zinc diacrylate (ZDA), zinc&nbsp;dimethacrylate&nbsp;(ZDMA), or ethylene glycol&nbsp;dimethacrylate&nbsp;(EGDMA) — is to increase cross-linking efficiency in peroxide systems by participating directly in additional cross-link formation, increasing cross-link density and improving the mechanical properties of the peroxide-cured vulcanizate.&nbsp;&nbsp;



The selection of&nbsp;vulcanisation&nbsp;system is&nbsp;ultimately a&nbsp;product specification exercise: what temperature range must the rubber survive, what mechanical loads will it carry, is compression&nbsp;set&nbsp;a failure mode, and what processing constraints apply? Understanding the relationship between cross-link type, cross-link density, and the resulting physical properties of rubber compounds is the foundation of that decision.&nbsp;







&nbsp;


Peroxide vs Sulphur Vulcanisation — Which Curing System for Which Rubber? 


TL;DR&nbsp;— Natural thickeners (xanthan gum, guar, carrageenan, cellulose derivatives) offer biodegradability, clean-label appeal, and broad regulatory compliance but come with batch variability, higher use levels, and sensory compromises. Synthetic thickeners (carbomers, acrylate&nbsp;crosspolymers) deliver precision, efficiency, and predictable performance but face growing regulatory pressure — most notably&nbsp;EU Regulation 2023/2055, which classifies carbomers as synthetic polymer microparticles. The right answer is rarely one or the other: it is a system decision driven by pH, electrolyte load, sensory target, sustainability positioning, and the regulatory timeline of your market.&nbsp;





Why the natural vs synthetic debate matters more than ever&nbsp;



The cosmetic thickener market was&nbsp;valued at $2.7 billion in 2023&nbsp;and is projected to reach $5.5 billion by 2030. The growth is not evenly distributed: natural polysaccharide thickeners held approximately 42.5% of the market in 2025, marking the first time naturally derived options have drawn level with synthetic types in volume share.&nbsp;



This shift is not purely&nbsp;marketing-driven. Three structural forces are reshaping thickener selection logic across the industry: tightening regulation on synthetic polymers in Europe and increasingly globally, consumer pressure for clean-label and biodegradable formulations, and a genuine improvement in the performance ceiling of natural and bio-fermented alternatives. Formulators who understand the real trade-offs — rather than the simplified "natural good, synthetic bad" narrative — are better positioned to make durable formulation decisions.&nbsp;



What do natural thickeners actually offer?&nbsp;



Natural thickeners are derived from plant, algal, or microbial sources. The main classes in cosmetic formulation are&nbsp;polysaccharide gums&nbsp;(xanthan, guar, carrageenan, sclerotium, locust bean), cellulose derivatives (HEC, HPMC, CMC), and starches. Their shared advantages are well documented.&nbsp;




Biodegradability.&nbsp;Natural polysaccharides are broken down by environmental microorganisms, which means they do not accumulate in aquatic environments the way persistent synthetic polymers do. This is a genuine environmental benefit, not just a marketing claim, and it becomes increasingly material as microplastic regulations tighten globally.&nbsp;



Regulatory positioning.&nbsp;Under&nbsp;EU Regulation 2023/2055&nbsp;restricting synthetic polymer microparticles, natural polymers are explicitly excluded from the definition of restricted SPMs.&nbsp;Formulators building European product lines for 2027 onwards — the first enforcement deadline for rinse-off cosmetics — face no equivalent regulatory risk with xanthan gum, guar, or carrageenan that they do with carbomers.&nbsp;



Consumer and certification appeal.&nbsp;COSMOS,&nbsp;Ecocert, and NATRUE certification frameworks require a high proportion of natural-origin ingredients. Natural thickeners are straightforwardly compliant; synthetic thickeners require case-by-case assessment and are&nbsp;frequently&nbsp;excluded. As over&nbsp;62% of US consumers&nbsp;in 2024 reported actively checking ingredient lists before&nbsp;purchase, the INCI legibility of "xanthan gum" versus "carbomer" carries real commercial weight.&nbsp;



Functional breadth.&nbsp;Several natural thickeners bring secondary benefits beyond viscosity. Hyaluronic acid is a humectant and active ingredient simultaneously. Carrageenan contributes&nbsp;film-forming properties. Guar gum provides conditioning in hair care. These multifunctional profiles can simplify formulations and reduce ingredient count.&nbsp;



Synergistic combinations.&nbsp;The&nbsp;guar-xanthan synergy&nbsp;is one of the best-documented examples in cosmetic science: combining the double-helix structure of xanthan with the mannan backbone of guar produces synergistically enhanced viscosity and a more balanced texture profile than either alone. Similar synergies exist between xanthan and locust bean gum, and between sclerotium gum and xanthan.&nbsp;




Where natural thickeners fall short&nbsp;



The limitations are real and should not be glossed over. Formulators who have switched from synthetic to natural systems under commercial pressure — without adequate&nbsp;reformulation&nbsp;time — have learned these trade-offs the hard way.&nbsp;




Higher use concentrations.&nbsp;Carbomers typically achieve target viscosity at 0.1–0.5%. Xanthan gum&nbsp;generally requires&nbsp;0.5–1.5%, and higher&nbsp;concentrations&nbsp;risk introducing the characteristic stringy, ropy texture that consumers associate with poor-quality gels. This has direct cost implications when natural raw material prices are already higher than synthetic equivalents.&nbsp;



Batch-to-batch variability.&nbsp;Natural polymers are agricultural or&nbsp;fermentation&nbsp;products. Molecular weight distribution, degree of acetylation, and viscosity-building capacity can vary between harvests, suppliers, and even production batches. Synthetic polymers are polymerized to specification — their batch consistency is reliably tighter. For industrial scale manufacturing, this variability translates into more frequent in-process viscosity adjustment and tighter incoming QC requirements.&nbsp;



Electrolyte sensitivity in&nbsp;some grades.&nbsp;Standard xanthan gum is&nbsp;relatively electrolyte-tolerant, but not all natural thickeners share this property. Carrageenan performance can be significantly&nbsp;affected by the cation type and concentration in the formula. This limits direct substitution in high-salt systems without&nbsp;reformulation&nbsp;work.&nbsp;



Microbial susceptibility.&nbsp;Natural polysaccharides are substrates for microbial growth. Formulations thickened with natural gums typically require a more robust preservation system, which can conflict with clean-beauty positioning goals and add cost and complexity.&nbsp;



Sensory compromises.&nbsp;Research on eco-reformulated emulsions&nbsp;confirms&nbsp;that while natural polysaccharide combinations can replicate the structural and stability properties of synthetic acrylics, the sensory profile is not always identical. Consumers accustomed to the clean, cushioned feel of a carbomer gel may perceive natural alternatives as slightly heavier, stickier, or less elegant — particularly in lightweight serums and fluid emulsions.&nbsp;




What do synthetic thickeners actually offer?&nbsp;



Synthetic thickeners — primarily carbomers, acrylate&nbsp;crosspolymers, HASE polymers, and HEUR polymers — have dominated professional cosmetic formulation for decades for reasons that&nbsp;remain&nbsp;technically valid.&nbsp;




Efficiency.&nbsp;Carbomers build extremely high viscosity at low concentrations. A 0.2–0.5% carbomer gel can achieve viscosities equivalent to 1.5% or more of a natural polysaccharide, which matters for both cost-in-use and sensory lightness.&nbsp;



Formulation clarity.&nbsp;Carbomers produce&nbsp;exceptionally clear gels&nbsp;that are difficult to replicate with natural alternatives. For transparent vitamin C serums, clear eye gels, or hyaluronic acid ampoules, carbomers have long been the default because the optical clarity is part of the premium aesthetic.&nbsp;



Batch consistency.&nbsp;Synthetic polymers are manufactured to precise molecular weight specifications. Viscosity, gel strength, and rheological profile are highly reproducible between production runs — a significant operational advantage at manufacturing scale.&nbsp;



Rheological precision.&nbsp;HASE and HEUR associative thickeners offer a level of&nbsp;rheological tunability&nbsp;not available in natural systems.&nbsp;Hydrophobe&nbsp;size, acid content, and molecular weight can be adjusted to dial in specific shear-thinning profiles, yield stress values, and levelling&nbsp;behaviour&nbsp;— which is why they&nbsp;remain&nbsp;the dominant choice in sophisticated waterborne coatings and complex cosmetic emulsions.&nbsp;



Processing&nbsp;ease.&nbsp;Synthetic thickeners are&nbsp;generally less&nbsp;prone to microbial contamination and do not require the same preservation burden as natural alternatives. They are also typically more straightforward to disperse and hydrate in standard manufacturing equipment.&nbsp;




The regulatory inflection point: carbomers and the microplastic classification&nbsp;



The most consequential recent development in thickener&nbsp;selection&nbsp;is the classification of carbomers as synthetic polymer microparticles under&nbsp;EU Regulation 2023/2055, which entered into force on 17 October 2023.&nbsp;



The technical reasoning is precise: the regulation's solubility test must be conducted at pH 7 on the material in its&nbsp;commercialised&nbsp;form. Carbomers are supplied as&nbsp;a dry&nbsp;acidic powder and only become soluble after the formulator&nbsp;neutralises&nbsp;them. In their supplied state at pH 7, they fail the&nbsp;solubility&nbsp;exclusion — and are therefore classified as restricted SPMs. Pre-neutralised&nbsp;solid polymers, supplied in a form that passes the pH 7 solubility test as-is, are excluded from this classification.&nbsp;



The enforcement timelines are&nbsp;phased by product category: rinse-off cosmetics must comply by October 2027, leave-on products (moisturisers, serums, creams) by October 2029, and&nbsp;colour&nbsp;cosmetics by October 2035 — though from 2031,&nbsp;colour&nbsp;products must already carry a label&nbsp;stating&nbsp;they&nbsp;contain&nbsp;microplastics. For R&amp;D teams developing products with a 2–4 year&nbsp;launch window, the compliance deadline for leave-on products is already within the development horizon for formulations beginning now.&nbsp;



This does not make synthetic thickeners obsolete. Pre-neutralised&nbsp;acrylate polymers, HASE and HEUR systems, and acrylate&nbsp;crosspolymers&nbsp;supplied in soluble form may be outside the SPM classification depending on their specific chemistry and supplied form. But it does make carbomer in its conventional form a time-limited ingredient in the European market — and formulators who have not yet started their reformulation work are behind the curve.&nbsp;



The middle ground: hybrid and blended approaches&nbsp;



The most&nbsp;practically effective&nbsp;response to the natural-vs-synthetic dilemma is not a binary choice — it is a blended strategy. Combining a small amount of synthetic associative thickener with a natural polysaccharide base can deliver the stability and consistency of the synthetic&nbsp;component&nbsp;while achieving certification compliance at a natural ingredient ratio that meets COSMOS thresholds.&nbsp;



Carbomer-xanthan gum combinations have long been used to&nbsp;balance gel strength and electrolyte tolerance&nbsp;— carbomer contributes texture precision and&nbsp;clarity,&nbsp;xanthan gum contributes salt resistance and natural-origin credentials. As carbomer regulatory pressure increases, the pragmatic replacement is often not pure natural but rather a combination of a pre-neutralised&nbsp;synthetic (outside SPM classification) with a polysaccharide co-thickener.&nbsp;



Research on&nbsp;surfactant-free emulsion systems&nbsp;has confirmed strongly synergistic action when agarose-stearate is combined with carbomer, producing gel-like&nbsp;behaviour&nbsp;comparable to commercial cosmetic creams. The principle&nbsp;generalises: the most stable and sensorially elegant formulations often come from synergistic combinations, not from single-ingredient substitution.&nbsp;



A practical decision framework&nbsp;



The choice between natural and synthetic thickeners — or a blend — comes down to six variables that should be evaluated before bench work begins:&nbsp;




System polarity and&nbsp;pH.&nbsp;Carbomers and HASE require&nbsp;neutralisation&nbsp;and&nbsp;underperform&nbsp;below pH 5. If you are formulating an AHA toner, vitamin C serum, or&nbsp;low-pH&nbsp;exfoliant, natural thickeners or pre-neutralised&nbsp;acrylates are the only&nbsp;viable&nbsp;options.&nbsp;



Electrolyte load.&nbsp;High ionic strength systems — mineral sunscreens, formulations with electrolytic preservatives, salt-based toners —&nbsp;favour&nbsp;xanthan gum, HEUR thickeners, or modified cellulose over standard carbomers.&nbsp;



Regulatory market and timeline.&nbsp;If your primary market is the EU and your product is a leave-on, you have until October 2029 to reformulate away from carbomer. That timeline should already be driving your pipeline decisions. If your market is the US,&nbsp;MoCRA&nbsp;does not currently include a carbomer SPM restriction, though&nbsp;REACH-driven reformulations&nbsp;from European operations are increasingly being applied globally for simplicity.&nbsp;



Sustainability certification.&nbsp;COSMOS-certified formulations require&nbsp;a minimum&nbsp;natural-origin content. The certification pathway is straightforward with polysaccharide thickeners and impossible with conventional carbomers.&nbsp;



Sensory target.&nbsp;For ultra-light transparent serums and clear gel formats, the carbomer aesthetic is still unmatched by natural alternatives. For cream emulsions, lotions, and rinse-off products, the performance gap between natural and synthetic has narrowed significantly — especially with well-designed polysaccharide blends.&nbsp;



Manufacturing capability.&nbsp;Natural thickeners require careful hydration protocols, adequate shear equipment, and tighter batch-to-batch QC. If your manufacturing partner is not set up for this, switching from synthetic to natural without process adjustment will create quality problems.&nbsp;




Xanthan Gum vs Sclerotium Gum vs HEC: Which Natural Thickener for Cosmetics?



Choosing between natural thickeners is rarely a question of which is "best" — it is a question of which fits the system. Xanthan gum, sclerotium gum, and HEC cover different ground in terms of texture, pH range, and application context. The table below maps the key criteria.







A few practical points worth noting. Sclerotium gum, produced by fungal fermentation of Sclerotium rolfsii, is the closest natural alternative to carbomer in terms of sensory profile — its smooth, non-stringy texture makes it the preferred option in premium leave-on formats where the ropy feel of xanthan at higher concentrations is not acceptable. HEC's exceptional pH range (2.0–12.0) and electrolyte tolerance make it the default choice in rinse-off and ophthalmic systems where other natural thickeners would destabilize. Xanthan remains the workhorse for aqueous gels and acidic serums, particularly where cost and availability are constraints.



Summary&nbsp;



Natural and synthetic thickeners are not competing on an even playing field anymore. Regulatory pressure in Europe has put a hard expiry date on conventional carbomers in the EU market. Consumer demand for transparent labelling and biodegradable formulas is tilting commercial preference toward natural alternatives across all price tiers. And the performance gap between best-in-class natural blends and synthetic systems has narrowed&nbsp;substantially over&nbsp;the past decade.&nbsp;



But "natural" is not a performance guarantee, and "synthetic" is not an environmental death sentence. The formulator's job is to match the right chemistry to the&nbsp;system,&nbsp;the sensory brief, the regulatory context, and the sustainability ambition — and to start that work early enough that the EU's phased deadlines do not become a crisis. For a deeper dive into how thickener choice affects emulsion stability specifically, see our articles on&nbsp;rheology modifiers in cosmetics&nbsp;and&nbsp;emulsion&nbsp;stabilisation.&nbsp;










Natural vs Synthetic Thickeners for Cosmetics: Performance Trade-offs and How to Choose

Formulations Industry Insights Market Trends


Emulsions are at the heart of countless formulated products — from skin creams and sunscreens to paint, mayonnaise, and pharmaceutical topicals. Yet an emulsion is never truly stable: it is a thermodynamically unfavourable system that will always tend to revert to its separated oil and water phases. The role of the formulator is to slow this process down — ideally for the full commercial shelf life of the product.



Rheology modifiers are among the most powerful tools available for doing so. They work by altering the flow behaviour of the continuous phase, building network structures that physically inhibit droplet movement and coalescence. But choosing and using them correctly requires a clear understanding of what makes emulsions fail in the first place, and what each modifier chemistry actually does at a molecular level.



This article walks through the science — from instability mechanisms to modifier selection — and is intended as a practical guide for formulators across cosmetics, pharmaceuticals, coatings, and food.





1. Why Emulsions Fail: The Four Instability Mechanisms



Before selecting a rheology modifier, it is essential to identify the dominant destabilisation route in your system. The scientific literature identifies four primary mechanisms:




Creaming and sedimentation arise from density differences between the dispersed and continuous phases. In oil-in-water (O/W) emulsions, the lighter oil droplets rise to the surface; in water-in-oil (W/O) emulsions, denser water droplets settle to the bottom. The process is governed by Stokes' law: droplet size and the viscosity of the continuous phase are the two levers a formulator can pull.



Flocculation involves droplets aggregating into clusters without merging. While reversible, flocculation accelerates subsequent coalescence and creaming if left unchecked.



Coalescence is the irreversible merging of droplets into progressively larger ones, ultimately leading to complete phase separation. It is often the consequence of inadequate interfacial stabilisation by surfactants or polymers



Ostwald ripening occurs when differences in Laplace pressure between droplets of unequal size drive the diffusion of material from smaller to larger droplets, causing a gradual coarsening of the droplet size distribution.




In practice, these mechanisms act in concert and can reinforce one another. A rheology modifier primarily addresses gravitational separation and flocculation and can indirectly slow coalescence by restricting droplet mobility.



2. How Rheology Modifiers Stabilise Emulsions



Rheology modifiers stabilise emulsions through two complementary mechanisms:



2.1 Viscosity Enhancement of the Continuous Phase



A higher viscosity in the continuous phase directly slows the creaming or sedimentation rate of dispersed droplets, as Stokes' law predicts. The increased resistance to droplet movement reduces the frequency of inter-droplet collisions, limiting flocculation and coalescence. Hydroxyethyl cellulose (HEC), for instance, is well documented for providing both colloidal protection and thickening effects that stabilise emulsions through the formation of three-dimensional network structures with strong elastic properties.



2.2 Three-Dimensional Network Formation



Beyond simple viscosity, many rheology modifiers form physical or chemical gel networks that provide a yield stress — a threshold force below which the system behaves as a solid, physically "locking" droplets in place. This is particularly effective against gravitational separation. Acrylic polymers such as carbomers, for example, act through swelling or chemical cross-linking to form a polymeric three-dimensional network that heavily modifies the rheology of the system while offering increased resistance to destabilisation mechanisms.



2.3 Steric and Electrostatic Barrier Effects



Unadsorbed macromolecules within the emulsion create steric hindrance, acting as physical barriers that reduce direct contact between droplets. In the case of charged polymers, electrostatic repulsion between droplets of the same charge further prevents aggregation. Hydrophilic macromolecules adsorbed at the droplet interface form a stabilising layer that creates a stable spatial structure.



3. Classes of Rheology Modifiers and Their Mechanisms



3.1 Acrylic Polymers (Carbomers / Carbopol)



Carbomers — cross-linked polyacrylic acid polymers — are among the most widely used rheology modifiers in cosmetics and pharmaceuticals. They build viscosity and form gels upon neutralisation with a base (typically sodium hydroxide or triethanolamine), becoming anionic and swelling considerably in water to create a dense, entangled network).



Their mechanism of emulsion stabilisation is primarily through gel network formation: the resulting structure physically immobilises oil droplets and provides a yield stress that resists gravitational separation. Carbomers are highly efficient — low concentrations (typically 0.1–1%) achieve high viscosity — and are particularly favoured for their ability to create clear gels.



Formulation considerations: Carbomers require neutralisation to develop viscosity. They are sensitive to electrolytes (salts reduce viscosity) and perform best at pH 6–10. High-electrolyte or salt-tolerant formulations may require specialised grades or alternative modifiers



Why the industry is actively moving away from carbomer



What was once a no-brainer choice has become, in 2026, a strategic liability. Three converging pressures are driving brands and contract manufacturers to seek alternatives — and the substitution window is narrower than many realise.



The regulatory clock is ticking — and it's non-negotiable. Under Commission Regulation (EU) 2023/2055, in force since 17 October 2023, carbomers are officially classified as microplastics (Synthetic Polymer Microparticles, SPM). The technical reasoning is subtle but decisive: the solubility test set out by the regulation must be conducted on the material in its commercialised form at pH 7. Carbomers are supplied in their solid acidic form and only become soluble after in-situ neutralisation by the formulator — so they fail the solubility test as defined, unlike pre-neutralised solid synthetic polymers that remain unchanged at pH 7.



3.2 Polysaccharides: Xanthan Gum



Xanthan gum is a high-molecular-weight microbial polysaccharide produced by fermentation of Xanthomonas campestris. It is notable for its pseudoplastic (shear-thinning) behaviour: at rest, it forms a rigid structured network with high viscosity; under shear (pumping, spreading), viscosity drops dramatically, then recovers when shear is removed.



This shear-thinning behaviour is ideal for emulsion stabilisation: the product remains structured during storage (resisting gravitational separation) but flows easily on application. Xanthan gum is stable across a broad pH range (4–10), tolerant of heat, freeze-thaw cycles, and compatible with electrolytes — making it suitable for formulations where carbomers would underperform.



Xanthan gum also acts synergistically with other polysaccharides such as guar gum, locust bean gum, and konjac mannan, with the result typically being an increased viscosity or gel formation, depending on concentration and the ionic environment.



Formulation considerations: At concentrations above 1%, xanthan gum may impart a "stringy" texture. It is anionic and incompatible with cationic surfactants. For natural and Ecocert-certified formulations, it is frequently the first-choice modifier



Beyond xanthan gum, several other polysaccharides contribute significantly to emulsion stability through viscosity enhancement, gel formation, or interfacial interactions. Gellan gum is particularly effective at low concentrations, forming fluid gels that can suspend droplets and improve physical stability without excessively increasing viscosity. Carrageenans (especially κ- and ι-types) interact with proteins and form structured networks that help prevent phase separation in emulsified systems. Alginates, derived from brown algae, create ionically crosslinked gels in the presence of divalent cations (e.g., calcium), enhancing droplet immobilization. Konjac glucomannan is known for its high water-binding capacity and synergistic gel formation with xanthan gum, contributing to improved texture and stability. Additionally, pullulan, although less commonly used as a primary stabilizer, can contribute to film-forming properties and viscosity modulation in certain formulations. These polysaccharides, alone or in combination, provide formulators with versatile tools to tailor rheology and stability, particularly in systems where natural or biodegradable ingredients are preferred.



3.3 Cellulose Derivatives: HEC and HPMC



Hydroxyethyl cellulose (HEC) and hydroxypropyl methylcellulose (HPMC) are water-soluble polymers that increase the viscosity of aqueous solutions through chain entanglement. HEC in particular provides both colloidal protection and thickening via three-dimensional network structures with strong elastic properties.



Hydrophobically modified HEC (HMHEC) is also used as an associative thickener in waterborne coatings (ScienceDirect, Associative thickeners for waterborne paints).



Cellulose derivatives are generally easier to incorporate than carbomers (no neutralisation required) but may not deliver the same level of formulation clarity or gel strength.



3.4 Inorganic Rheology Modifiers: Clays and Fumed Silica



Clays such as bentonite, hectorite (Laponite), and attapulgite form structured suspensions in water through electrostatic interactions between clay platelets, creating a "house-of-cards" network that exhibits a yield stress. Fumed silica operates similarly via hydrogen bonding between silanol groups. Both categories are widely used in waterborne coatings and cosmetics for precise rheological control, and are derived from mineral sources.



4. Selecting the Right Modifier: Key Formulation Variables



An important practical consideration highlighted in research: a modifier that works in a waterborne paint may be incompatible with a high-electrolyte cosmetic formula, or may lose performance in a system with a free surfactant concentration that disrupts its network structure.



For cosmetic emulsions specifically, the ideal rheological profile during the product's lifecycle is shear-thinning: high viscosity at rest during storage (10,000–100,000 mPa·s) to prevent phase separation, and low viscosity under shear during application (50–100 mPa·s) for easy spreadability.



5. The Role of Modifier Combinations



Single-modifier systems are often not enough. The scientific literature consistently shows that combining rheology modifiers with other stabilising ingredients — or combining two modifiers — can yield synergistic effects.



The cellulose formation by modified HEC, when combined with polysaccharides or cross-linked polymers, produces formulations with enhanced stability profiles. Carbomer–xanthan gum combinations are used to balance the gel strength of carbomer with the electrolyte tolerance of xanthan. Similarly, work on AS–Carbomer940 systems showed a strongly synergistic action, with the combined network providing gel-like behaviour comparable to commercial cosmetic creams.



6. Characterising Emulsion Stability: What to Measure



Selecting a modifier is only the first step; verifying its performance requires appropriate characterisation methods. The key tools are:




Oscillatory rheology (G', G''): measures the viscoelastic properties of the formulation, including whether it behaves more like a solid (elastic, G' dominant) or a liquid (viscous, G'' dominant) at rest.



Flow curves (shear stress vs. shear rate): quantifies shear-thinning behaviour and yield stress.



Thixotropy loop tests: measure structural recovery after shear — critical for products that must recover viscosity after application or pumping.



Turbiscan / backscattering methods: track droplet migration (creaming, sedimentation) in real time without dilution.



Dynamic light scattering (DLS): monitors droplet size distribution over time to detect Ostwald ripening or flocculation.




7. Practical Guidance: Key Points for Formulators




Identify your dominant instability mechanism first. Gravitational separation calls for yield stress and viscosity modification; Ostwald ripening requires a different approach (e.g., ripening inhibitors, narrower droplet size distribution).



Match modifier chemistry to your system's pH and electrolyte profile. Carbomers are excellent in low-salt, neutral-to-alkaline systems; xanthan gum is the workhorse for electrolyte-tolerant, natural formulations.



Consider the full lifecycle of the product. Viscosity needs differ between manufacturing (pumping), storage (anti-settling), and application (spreadability). Shear-thinning modifiers address all three stages simultaneously.



Explore synergistic combinations. Single-modifier systems may fall short; co-formulation with a complementary modifier often improves both stability and sensory profile.



Always test in your specific matrix. Modifier performance is highly system-dependent: surfactant interactions, temperature, pH, and ionic strength all affect the final rheological outcome.



Why your emulsions fail: here's how to Stabilise Emulsions with Rheology Modifiers


TL;DR&nbsp;— Fumed silica (pyrogenic silica) is a synthetic, amorphous nano-SiO₂ produced by flame hydrolysis. Its defining feature is a dense surface of reactive silanol groups that build reversible hydrogen-bond networks, delivering thixotropy, anti-settling, reinforcement, and flow improvement across formulations. It comes in hydrophilic (untreated) and hydrophobic (silane-treated) grades, differentiated by surface area and polarity compatibility. In coatings it controls rheology, prevents sag, and hardens dried films. In&nbsp;cosmetics&nbsp;it improves texture, absorbs oils, and stabilizes emulsions. In&nbsp;pharma&nbsp;it functions as a glidant, moisture adsorbent, and semisolid thickener. Grade&nbsp;selection&nbsp;— surface treatment + surface area +&nbsp;pharmacopoeial&nbsp;compliance where needed — drives performance more than loadings do.&nbsp;&nbsp;





What is fumed silica?&nbsp;&nbsp;



Fumed silica, also called pyrogenic silica, is a synthetic, amorphous form of silicon dioxide (SiO₂) produced by&nbsp;flame hydrolysis&nbsp;— typically the combustion of silicon tetrachloride in an oxygen-hydrogen flame at&nbsp;very high&nbsp;temperature. It is used as a thickener, anti-settling agent, reinforcing filler and flow aid across coatings, cosmetics and pharmaceutical formulations. It is produced by flame hydrolysis of silicon tetrachloride (SiCl₄) at temperatures above 1,000°C.The process generates ultra-fine primary particles that fuse into branched, chain-like aggregates, which in turn agglomerate into larger, three-dimensional tertiary structures. The result is an extremely light, white powder with no internal porosity and a specific surface area that can range from 50 to over 600 m²/g depending on the grade.&nbsp;&nbsp;



Fumed silica consists of finely dispersed amorphous silicon dioxide whose surface is covered by highly reactive silanol groups available for chemical reactions. It shows a space-filling particle structure related to a high surface area and lacking micropores. These characteristics enable fumed silica to act as a free-flow additive in powder-like solids, as a thickener in various liquids, and as a powerful reinforcing filler in elastomers.&nbsp;&nbsp;&nbsp;



This combination — nanoscale particle size, extreme surface reactivity, and structural versatility — is the basis for fumed silica's role across coatings, personal care, and pharmaceutical manufacturing.&nbsp;&nbsp;



For more information on precipitated silica and how it compares to fumed silica, you can refer to our dedicated article on precipitated silica.



Fumed Silica vs Pyrogenic Silica: Same Product, Different Names



Fumed silica and pyrogenic silica are identical — two names for the same material. "Fumed" refers to the production process (flame hydrolysis), while "pyrogenic" (from the Greek pyr, fire) describes the same thermal origin. Suppliers use both terms interchangeably: Evonik markets its range under the Aerosil® brand for example.  In technical datasheets and procurement, you may encounter either. For regulatory filings under REACH, the registered substance is silicon dioxide (CAS 7631-86-9), covering both designations.



What makes fumed silica functionally unique?&nbsp;&nbsp;



The silanol surface and hydrogen-bond network&nbsp;&nbsp;



The functional core of fumed silica is its surface silanol density. Fumed silica has&nbsp;a relatively&nbsp;high density of surface silanol groups&nbsp;(1.5–4.51/nm²), and the properties of fumed silica can be chemically&nbsp;modified&nbsp;by reacting with these silanol groups. In untreated, hydrophilic grades, these&nbsp;silanols&nbsp;form reversible hydrogen bonds with each other and with polar molecules in the surrounding medium, building a three-dimensional network that thickens the system at rest and breaks down under shear — a behavior known as&nbsp;thixotropy.&nbsp;&nbsp;



This is a critical distinction from other thickeners: fumed silica's network is physical, not chemical. It rebuilds rapidly after shear is removed, which is why it prevents&nbsp;sag&nbsp;and settling during storage but allows smooth application under brush, roller, or spray conditions.&nbsp;&nbsp;



Reinforcement in cured systems



Beyond rheology, once a formulation cures or dries, the silica network becomes a nano-reinforcer within the polymer matrix. Pyrogenic silica chemically after-treated has a positive influence on&nbsp;the mar resistance&nbsp;of both UV-curing and solvent-based coating systems.&nbsp;&nbsp;Studies on nanoparticle-filled coatings have found that including fumed silica can increase the scratch hardness of a UV-cured polymer coating by 10–35% and significantly raise its resistance to wear.&nbsp;&nbsp;In clear coatings, properly dispersed fumed silica can deliver these benefits without compromising optical transparency, since the primary particles sit well below visible-light wavelengths.&nbsp;&nbsp;



Thermal and chemical inertness&nbsp;&nbsp;



Fumed silica is chemically inert across a wide pH range and temperature window. It is non-combustible, non-reactive with most organic binders and active ingredients, and contributes no color or odor to formulations. These qualities make it suitable for applications demanding high purity and long shelf-life stability — particularly in pharmaceutical and cosmetic contexts.&nbsp;&nbsp;



Hydrophilic vs. hydrophobic grades: the key distinction&nbsp;&nbsp;



The most important grade-selection decision for fumed silica is the choice between hydrophilic and hydrophobic forms — a distinction driven by surface chemistry and the polarity of the target system.&nbsp;&nbsp;



Hydrophilic fumed silica&nbsp;&nbsp;



Untreated fumed silica&nbsp;is inherently&nbsp;hydrophilic. Its surface silanol groups make it water-wettable and readily dispersible in aqueous and polar media. It is the default choice for water-based paints, aqueous pharmaceutical suspensions, and hydrophilic cosmetic gels. Its thickening and anti-settling performance in polar systems is strong, but it can absorb atmospheric moisture and may show less stable rheology in systems exposed to humidity over time.&nbsp;&nbsp;



Hydrophobic fumed silica&nbsp;&nbsp;



Converting hydrophilic silica to hydrophobic is possible by placing some silane in a fluid bed reactor. Due to the reduced density of the silanol group,&nbsp;better dispersion behaviour&nbsp;is&nbsp;indicated&nbsp;in contrast with hydrophilic types. Common treating agents include&nbsp;hexamethyldisilazane&nbsp;(HMDS),&nbsp;dimethyldichlorosilane&nbsp;(DDS), and polydimethylsiloxane (PDMS), which cap the surface&nbsp;silanols&nbsp;with hydrophobic organic groups. The result is a material that under the joint action of hydrophobic functional groups and hydrogen bonds, forms a three-dimensional network structure in highly polar systems, providing better&nbsp;rheological and thixotropic properties&nbsp;for waterborne coatings and adhesives compared to&nbsp;other&nbsp;fumed silica.&nbsp;&nbsp;&nbsp;



Hydrophobic grades are preferred in solvent-borne coatings, silicone sealants, non-aqueous cosmetic formulations (anhydrous creams, lipsticks, pressed powders), and oil-based pharmaceutical systems. They also deliver improved moisture resistance and long-term rheological stability.&nbsp;&nbsp;



Surface area as a grade parameter&nbsp;&nbsp;



Within each category,&nbsp;surface&nbsp;area is the primary variable for controlling intensity of effect. Higher surface area grades (e.g., ~200–300 m²/g) deliver stronger thickening and anti-settling performance but require more careful dispersion to avoid agglomerate-driven haze or texture defects. Lower surface area grades are easier to disperse and exert a milder rheological effect — useful where subtle stabilization is needed without significant viscosity&nbsp;build.&nbsp;&nbsp;



Selecting the right grade therefore comes down to three questions: What is the polarity of the system? What level of rheological effect is needed? And what are the processing and dispersion capabilities available?&nbsp;&nbsp;



Applications in coatings&nbsp;&nbsp;



Fumed silica is one of the most widely used functional additives in the&nbsp;coatings industry, performing across multiple roles simultaneously: rheology modifier, anti-settling agent, anti-sag agent, matting agent, and film reinforcer.&nbsp;&nbsp;



Rheology control and anti-sag&nbsp;&nbsp;



In liquid paints and varnishes, fumed silica prevents the formulation from sagging on vertical surfaces after application, while&nbsp;maintaining&nbsp;flow under application shear. Fumed silica is one of the&nbsp;most commonly used&nbsp;flow additives in the powder coating industry, produced by hydrogen-oxygen flame hydrolysis of&nbsp;halosilane&nbsp;with a high specific surface area. The particle size of fumed silica is usually between 10 and 40 nanometers, and&nbsp;numerous&nbsp;grades are specially designed for use in&nbsp;powder paint applications&nbsp;due to differences in specific surface area and hydrophobicity.&nbsp;&nbsp;&nbsp;



In powder coatings specifically, fumed silica acts as a&nbsp;flow additive&nbsp;that reduces interparticle friction, improving the flowability of the powder through equipment — a function that directly affects coating uniformity and surface quality.&nbsp;&nbsp;



Film hardness and scratch resistance&nbsp;&nbsp;



Once the coating has&nbsp;cured, the silica network provides mechanical reinforcement. It has been shown that such modified silica has a surprisingly low influence on the rheological properties of liquid coatings: it is possible to incorporate up to 15% fumed, structurally modified silica into a UV-binder system without pseudoplastic behavior of the resulting liquid, while the viscosity increase&nbsp;remains&nbsp;acceptable. This makes it possible to push silica loading high enough to deliver meaningful hardness gains without sacrificing application behavior.&nbsp;&nbsp;



Matting&nbsp;&nbsp;



In certain coating systems — furniture lacquers, leather finishes, industrial topcoats — a matte rather than glossy surface is&nbsp;required. Fumed silica at controlled concentrations scatters light at the surface of the dried film, reducing gloss. Grade&nbsp;selection&nbsp;here is critical: too coarse an agglomerate introduces visible texture; too fine a primary particle may not provide sufficient matting effect.&nbsp;&nbsp;



Waterborne systems&nbsp;&nbsp;



Hydrophobic fumed silica is a commonly used rheology additive in waterborne coatings.&nbsp;Its dispersion in aqueous systems typically requires careful&nbsp;selection&nbsp;of dispersing technology, as the hydrophobic surface is inherently resistant to wetting in water. Non-ionic dispersants are generally&nbsp;the most effective&nbsp;at achieving stable aqueous dispersions of hydrophobic grades, enabling their use in waterborne architectural and industrial coatings where low-VOC requirements increasingly drive formulation choices.&nbsp;&nbsp;



Applications in cosmetics and personal care&nbsp;&nbsp;



Fumed silica is commonly used in pharmaceuticals and cosmetics as an anti-tacking agent, adsorbent, emulsion stabilizer, or glidant, or to increase viscosity. In personal care specifically, it serves several distinct functions depending on the formulation type.&nbsp;&nbsp;



Texture and skin feel&nbsp;&nbsp;



In makeup powders, fumed silica acts as a light, "invisible" filler that improves texture and flow. It provides a silky feel, prevents caking in pressed powders, and can scatter light to give a soft-focus effect on the skin. In foundation, skincare creams, and BB products, it smooths the application profile and absorbs surface sebum without leaving a chalky residue.&nbsp;&nbsp;



Oil absorption and sebum control&nbsp;&nbsp;



Hydrophilic grades, with their high surface silanol density, are effective at adsorbing oils. In sunscreens, primers, and mattifying products, fumed silica reduces the greasy feel that comes from high concentrations of emollient actives and oils.&nbsp;&nbsp;



Emulsion stability&nbsp;&nbsp;



In emulsified formulations — lotions, serums, face creams — fumed silica contributes to the structural network of the continuous phase, slowing the sedimentation of dispersed particles and inhibiting phase separation. It works synergistically with polymeric thickeners and is a well-established&nbsp;component&nbsp;of the&nbsp;mineral-origin rheology modifier&nbsp;toolkit alongside clays and Laponite.&nbsp;&nbsp;



Regulatory status&nbsp;&nbsp;



In regulations governing cosmetic products, silica and hydrated silica are not restricted from use in any way in the European Union. According to Australia's National Industrial Chemicals Notification and Assessment Scheme, amorphous synthetic silica is a Tier I chemical, not considered to pose an unreasonable risk to the health of workers and public health. The Cosmetic Ingredient Review (CIR) Expert Panel has also concluded that synthetically manufactured amorphous silica is safe in current practices of use and concentration when formulated to be non-irritating.&nbsp;&nbsp;



Handling considerations for formulators: inhalation of fumed silica dust should be avoided. Standard occupational safety controls — enclosed mixing,&nbsp;appropriate extraction, and personal protective equipment — apply.&nbsp;&nbsp;



Texture and skin feel&nbsp;&nbsp;



In makeup powders, fumed silica acts as a light, "invisible" filler that improves texture and flow. It provides a silky feel, prevents caking in pressed powders, and can scatter light to give a soft-focus effect on the skin. In foundation, skincare creams, and BB products, it smooths the application profile and absorbs surface sebum without leaving a chalky residue.&nbsp;&nbsp;



Oil absorption and sebum control&nbsp;&nbsp;



Hydrophilic grades, with their high surface silanol density, are effective at adsorbing oils. In sunscreens, primers, and mattifying products, fumed silica reduces the greasy feel that comes from high concentrations of emollient actives and oils.&nbsp;&nbsp;



Emulsion stability&nbsp;&nbsp;



In emulsified formulations — lotions, serums, face creams — fumed silica contributes to the structural network of the continuous phase, slowing the sedimentation of dispersed particles and inhibiting phase separation. It works synergistically with polymeric thickeners and is a well-established&nbsp;component&nbsp;of the&nbsp;mineral-origin rheology modifier&nbsp;toolkit alongside clays and Laponite.&nbsp;&nbsp;



Regulatory status&nbsp;&nbsp;



In regulations governing cosmetic products, silica and hydrated silica are not restricted from use in any way in the European Union. According to Australia's National Industrial Chemicals Notification and Assessment Scheme, amorphous synthetic silica is a Tier I chemical, not considered to pose an unreasonable risk to the health of workers and public health. The Cosmetic Ingredient Review (CIR) Expert Panel has also concluded that synthetically manufactured amorphous silica is safe in current practices of use and concentration when formulated to be non-irritating.&nbsp;&nbsp;



Handling considerations for formulators: inhalation of fumed silica dust should be avoided. Standard occupational safety controls — enclosed mixing,&nbsp;appropriate extraction, and personal protective equipment — apply.&nbsp;&nbsp;



Applications in pharmaceuticals&nbsp;&nbsp;



In pharmaceutical manufacturing, fumed silica appears under the monograph name&nbsp;Colloidal Silicon Dioxide&nbsp;in the major pharmacopoeias (USP/NF, European Pharmacopoeia, Japanese Pharmacopoeia) and is considered an established, well-characterised&nbsp;excipient.&nbsp;&nbsp;



Glidant in solid dosage forms&nbsp;&nbsp;



The primary pharmaceutical use is as a&nbsp;glidant in tablet and capsule manufacturing. Small quantities of glidant substances added to the formulation and&nbsp;blended together&nbsp;can improve the flow of the powder substantially and&nbsp;facilitate&nbsp;capsule or tablet die filling.&nbsp;&nbsp;Fumed silica works by coating the surface of larger API and excipient particles, reducing interparticle friction and cohesive forces. This allows powder blends to flow uniformly through hoppers and into press dies — a direct factor in weight uniformity, content uniformity, and tablet hardness consistency.&nbsp;&nbsp;



Dry-coating&nbsp;of fumed silica grades on the surface of cohesive APIs lowers cohesion and therefore improves blend uniformity during batch blending.&nbsp;Dry-coating&nbsp;with fumed silica grades also positively&nbsp;impacts&nbsp;compaction, improving compaction strength and tablet dissolution rate. Even at&nbsp;very low&nbsp;loadings — often below 1% by weight — fumed silica produces measurable improvements in flow, making it one of the most dose-efficient excipients in solid oral dosage manufacturing.&nbsp;&nbsp;



Moisture control and desiccant function&nbsp;&nbsp;



Fumed silica is available in hydrophilic,&nbsp;hydrophobic&nbsp;and food grade variants. In moisture-sensitive formulations, hydrophilic fumed silica acts as a localized desiccant, adsorbing free water within the powder blend and protecting the API from hydrolytic degradation during processing and storage.&nbsp;&nbsp;



Thickening in semi-solid formulations&nbsp;&nbsp;



In ointments, gels, and topical pastes, fumed silica provides thickening and structural stability. Silica is used in pharmaceuticals as a thickener in pastes and ointments to inhibit the separation of components and&nbsp;maintain&nbsp;flow properties in powder products. It is also a general excipient for pharmaceuticals and can function as a&nbsp;carrier for fragrances.&nbsp;&nbsp;&nbsp;



Drug delivery and carrier applications&nbsp;&nbsp;



Beyond its classical excipient roles, fumed silica is being explored as a&nbsp;carrier in drug delivery systems. Its high surface area and adsorptive capacity allow it to carry and stabilize poorly soluble active compounds, with research ongoing into its potential to improve bioavailability of BCS Class II and IV drugs.&nbsp;&nbsp;



How does grade&nbsp;selection&nbsp;translate to application performance?&nbsp;&nbsp;



The table below summarizes the main selection logic:&nbsp;&nbsp;







A key practical point: in every system, dispersion quality directly&nbsp;determines&nbsp;performance. Agglomerates that are not fully&nbsp;broken down&nbsp;during mixing reduce effective surface area, creating uneven rheological response, visible texture defects, or inconsistent flow in tablet presses. Selecting the right dispersing method — high-shear mixing, rotor-stator equipment, or bead milling — is as important as the&nbsp;grade&nbsp;choice itself.&nbsp;&nbsp;



Summary&nbsp;&nbsp;



Fumed silica is one of the few inorganic additives that genuinely crosses industry boundaries at a functional level. The same material that prevents paint from sagging on a wall stabilizes a cosmetic emulsion on a shelf and ensures a pharmaceutical tablet fills its die uniformly. What changes between applications is not the fundamental chemistry but the grade — primarily the surface treatment and specific surface area — and the care taken to disperse it correctly. Understanding those parameters is the starting point for any formulation decision involving this material.&nbsp;&nbsp;


Coatings, Inks &amp; Construction Cosmetics &amp; Personal Care Pharmaceuticals

Fumed Silica — Properties, Grade Selection and Applications in Coatings, Cosmetics and Pharma 


What&nbsp;is&nbsp;PVDF?&nbsp;



PVDF (polyvinylidene fluoride) is a semi-crystalline thermoplastic fluoropolymer — meaning it is both a thermoplastic (melt-processable, recyclable) and a fluoropolymer (fluorine-containing backbone). It combines the processing advantages of thermoplastics with the chemical and thermal resistance characteristic of fluoropolymers, making it uniquely suited to demanding industrial, energy and pharmaceutical applications.



Polyvinylidene fluoride (PVDF) is a semi-crystalline thermoplastic fluoropolymer produced by the polymerization of vinylidene difluoride (VDF). It occupies a distinctive position in the fluoropolymer family.It is more processable than PTFE, denser with better mechanical strength than most commodity plastics, and uniquely capable of exhibiting piezoelectric behavior depending on its crystalline structure. &nbsp;



PVDF has a set of valuable properties :




a relatively high melting point,



high mechanical strength even at elevated temperatures,



chemical and raditation resistance.




This combination explains why PVDF has expanded far beyond its original niche in chemical handling into electronics, energy storage, filtration, biomedical devices, and architectural coatings.



Applications of PVDF — By Industry and Grade



Polyvinylidene Fluoride Properties: At a Glance







Chemical&nbsp;resistance&nbsp;



PVDF expresses inherent resistance to ozone oxidation, nuclear radiation, UV damage, and microbiological and fungal growth — a profile that is fairly distinctive among thermoplastic materials. This resistance stems from the elemental stability of its carbon–fluorine bonds. It withstands most mineral acids, halogens, and aromatic solvents, though hot concentrated sulfuric acid and hot amines represent known limits of resistance.



Thermal&nbsp;stability&nbsp;



PVDF maintains useful properties across a wide temperature range, from −30 °C to 170°C.Its thermal degradation temperature remains in the 400–450 °C range regardless of the crystalline phase or manufacturing method used. MDPI This stability underpins its suitability for high temperature industrial processing environments.



Mechanical&nbsp;performance&nbsp;



PVDF is one of the most rigid and abrasion-resistant of the melt-processable fluoropolymers, with excellent resistance to stress fatigue, abrasion, and cold flow. Compared to fully fluorinated polymers such as PTFE, PVDF offers superior mechanical strength and better dimensional stability under load.



Electrical&nbsp;properties&nbsp;



PVDF exhibits a relatively high dielectric constant and low dielectric loss across a wide frequency range, making it suitable for insulation and capacitive applications.Crucially, in its electroactive crystalline form, it also develops piezoelectric and pyroelectric behavior — the ability to generate an electric charge in response to mechanical stress or temperature change — which distinguishes it from virtually all other melt-processable engineering polymers.



UV and&nbsp;weathering&nbsp;resistance&nbsp;



As a fine powder grade, PVDF is an ingredient in high-end architectural paints for metals. These coatings have extremely good gloss and color retention and are used on many prominent buildings around the world.&nbsp; This weathering durability is a direct consequence of the strength and inertness of its carbon–fluorine backbone.



What&nbsp;crystalline phases&nbsp;does&nbsp;PVDF&nbsp;form, and&nbsp;why&nbsp;does&nbsp;it&nbsp;matter?&nbsp;



One of the most technically significant aspects of PVDF is its crystalline polymorphism. Depending on how the polymer is processed, it can adopt several distinct structural phases, each with different property profiles.



The α-phase is the form that crystallizes naturally from the melt. It is non-polar and therefore does not exhibit piezoelectric properties. It is the dominant phase in most standard industrial processing.



The β-phase is the most electroactively valuable form. In the β-phase, the electronegative fluorine and electropositive hydrogen atoms are located on opposite sides of the polymer's carbon–carbon backbone, creating a net dipole moment that renders the piezoelectric properties to PVDF. This phase does not form spontaneously and must be induced through specific processing treatments such as mechanical stretching, high-pressure crystallization, or electrical poling.



The γ-phase is an intermediate form with weaker electroactive properties than β, typically obtained by solution casting or annealing near the melting point.



The practical implication is clear: the same base polymer can behave very differently depending on processing conditions. FOrs tructural or chemical resistance applications, the α-phase is entirely adequate. For sensor, actuator, or energy harvesting applications, maximizing β-phase content is critical.



What&nbsp;grades of PVDF&nbsp;exist?&nbsp;



PVDF is available in a range of grades tailored to different processing routes and end-use requirements. The two fundamental categories are homopolymers and copolymers.



Homopolymer grades deliver the highest crystallinity, the strongest mechanical properties, and the greatest chemical resistance. They are the standard choice for piping, chemical equipment, and applications requiring maximum purity or electrochemical stability.



Copolymer grades — primarily based on VDF copolymerized with hexafluoropropylene (HFP) or chlorotrifluoroethylene (CTFE) — trade some crystallinity for improved flexibility and lower processing temperatures. Copolymers with CTFE are among the most flexible PVDF products, showing excellent low-temperature performance and low shrinkage, making them ideal for wire, cable and tubing applications requiring enhanced flexibility.



Beyond the homopolymer/copolymer distinction, grades are further differentiated by:




Melt viscosity, which determines suitability for extrusion versus injection molding



Particle size and form (pellets vs. powder vs. dispersion), which is critical for coating applications and battery slurry preparation



Purity level — industrial, semiconductor, and battery grades differ significantly in their contamination thresholds



Molecular weight, which influences mechanical performance and melt flow behavior




For a broader perspective on how resin grade selection affects formulation and processing outcomes across polymer families, see our dedicated guide.





How&nbsp;is&nbsp;PVDF&nbsp;processed?&nbsp;



PVDF can be processed using techniques applicable to standard thermoplastics. Processing temperatures range between 190 and 280 °C. Drying of the resin before processing is usually not necessary, but care must be taken to eliminate dead zones where molten resin can collect and thermally decompose if residence time is excessive.&nbsp;



Extrusion&nbsp;



Extrusion is the dominant route for producing PVDF pipes, tubes, rods, films, and sheet. Controlled screw design, temperature profiling, and the elimination of stagnation points are essential to maintain polymer stability and surface quality. PVDF is available in the form of piping products, sheet, tubing, films, plate, and as an insulator for premium wire. It can be injected, molded, or welded.&nbsp;



Injection&nbsp;molding&nbsp;



Injection molding is used to produce precision components such as fittings, connectors, valve bodies, and housings. Appropriate mold design, temperature control, and shrinkage compensation are necessary to obtain dimensionally accurate parts.



Solution&nbsp;processing&nbsp;and&nbsp;coating&nbsp;



PVDF can be dissolved in polar solvents such as N-methylpyrrolidone (NMP), dimethylformamide (DMF), or dimethyl sulfoxide (DMSO) to form solutions suitable for casting films, preparing battery electrode slurries, or applying functional coatings. Solution-based processing routes include solution casting, spin coating, and film casting.



Compression&nbsp;molding&nbsp;and&nbsp;powder&nbsp;processing&nbsp;



Powder grades of PVDF are used in compression molding, rotational lining, and spray coating. As a fine powder or aqueous dispersion, PVDF is also the basis of high-performance architectural coatings applied to metal cladding panels.



What&nbsp;are the main application areas for&nbsp;PVDF?&nbsp;



Chemical&nbsp;processing&nbsp;equipment&nbsp;



Valves, piping, and other solid and lined components are typical applications of PVDF in chemical processing equipment. It is the only fluoroplastic available in rigid pipe form.&nbsp; It is also used for pump impellers, tank linings, heat exchanger tubes, and fittings in plants handling aggressive acids, solvents, and oxidizing agents.



Electrical&nbsp;and&nbsp;electronics&nbsp;



PVDF is commonly used as insulation on electrical wires because of its combination of flexibility, low weight, low thermal conductivity, high chemical corrosion resistance, and heat resistance. It is also used in high-frequency electronic devices and as a substrate or functional layer in flexible electronics.



Sensors,&nbsp;actuators, and&nbsp;energy&nbsp;harvesting&nbsp;



The β-phase piezoelectric properties of PVDF make it the polymer of choice for flexible sensors and transducers, acoustic emission detectors, pressure sensors, and vibration-based energy harvesting devices. Unlike ceramic piezoelectric materials, PVDF is lightweight, flexible, and biocompatible, making it uniquely suited to wearable and implantable sensor applications.



Lithium-ion batteries&nbsp;



PVDF has been the dominant polymeric binder in the mass production of lithium-ion batteries for decades. It has a good binding capacity while swelling to a limited extent in the electrolyte, facilitating the transfer of lithium ions to the surface of the active material. It is used both as a cathode and anode binder and as a separator coating in gel-polymer battery architectures. Battery-grade PVDF is subject to tight purity and particle size specifications that differentiate it significantly from industrial grades.



Filtration membranes&nbsp;



PVDF is used in biotechnology as a membrane to immobilize proteins and as a binder component for electrochemical applications. More broadly, PVDF membranes are widely used in ultrafiltration and microfiltration for water treatment, pharmaceutical filtration, and semiconductor ultrapure water systems, valued for their chemical durability, controllable porosity, and resistance to fouling treatments.



Architectural&nbsp;coatings&nbsp;



PVDF-based coatings applied as liquid or powder to metal cladding offer outstanding resistance to UV radiation, color fading, chalking, and atmospheric pollutants. This application relies on powder or dispersion grades and typically uses a blend of PVDF with acrylic resins to optimize both film formation and durability. The result is a coating with a service life measurable in decades — a property profile explored in depth in our article on sustainable coating systems.



Biomedical&nbsp;and&nbsp;pharmaceutical&nbsp;



PVDF can be used as a component of implants and sutures, as an engineering plastic in aggressive biological environments, as a component of transducers and sensors in the field of process control, and in the synthesis of separation membranes for biomedical applications. Its physiological inertness and mechanical robustness make it a credible alternative to metallic implant materials in selected structural applications.



How&nbsp;does&nbsp;PVDF compare to&nbsp;other&nbsp;fluoropolymers?&nbsp;



PVDF is often evaluated alongside PTFE, PFA, and ETFE. The key differentiator is processability: unlike PTFE, which cannot be melt-processed conventionally, PVDF is fully compatible with standard extrusion and injection molding equipment. Although the insulating properties and chemical inertness of PVDF are not as good as those of fully fluorinated polymers such as PTFE and FEP, the balance of properties available in PVDF qualifies it for many engineering applications across a temperature range from −73 to 149 °C.&nbsp;



Where PTFE excels in extreme chemical inertness and continuous high-temperature performance, PVDF offers better mechanical strength, easier and less costly processing, wider grade differentiation, and the unique advantage of electroactive behavior — a capability entirely absent in PTFE.



Key&nbsp;technical&nbsp;takeaways&nbsp;for&nbsp;formulators&nbsp;and&nbsp;engineers&nbsp;



PVDF is not a monolithic material. Grade selection, crystalline phase management, and processing route together determine whether the resulting part or coating will perform as a chemical-resistant structural component, a high-purity battery binder, a flexible piezoelectric sensor, or a decades-durable architectural finish. Understanding those levers — and matching them to application requirements — is the starting point for any serious formulation or design work involving this polymer.



FAQ on PVDF



What does PVDF stand for?



PVDF stands for polyvinylidene fluoride (also written polyvinylidene difluoride), a semi-crystalline thermoplastic in the fluoropolymer family. Its repeating unit — (CH₂–CF₂)n — alternates hydrogen and fluorine atoms, which drives its core pvdf properties: chemical durability, thermal stability, and piezoelectricity. Understanding what is pvdf starts with this structural duality, which distinguishes it from fully fluorinated polymers like PTFE.



What is the difference between PVDF homopolymer and PVDF-HFP copolymer?



PVDF homopolymer offers maximum crystallinity, stiffness, and chemical resistance. PVDF-HFP introduces hexafluoropropylene co-monomers that disrupt chain packing, reducing crystallinity and lowering the glass transition temperature. The result is a softer, more flexible material with higher ionic conductivity — a key advantage in gel polymer electrolytes — at the cost of some mechanical strength relative to the homopolymer.



Is PVDF food safe or biocompatible?



PVDF is approved for food and drinking water contact under FDA regulations and the European food contact regulation (EU 10/2011). In biomedical contexts, it is used in surgical sutures, hernia meshes, and implantable sensors. Its piezoelectric β-phase also enables active biomedical devices, though implant-grade applications require full device-level validation beyond material classification alone.



Can PVDF be recycled or is it considered sustainable?



As a thermoplastic, PVDF is theoretically recyclable through melt reprocessing, and closed-loop schemes have been explored for photovoltaic backsheets. In practice, fluoropolymer recycling infrastructure remains limited, and PVDF faces tightening PFAS scrutiny in the EU. Its long service life partially offsets end-of-life challenges, but the material does not qualify as inherently sustainable under current circular economy standards.



What solvents dissolve PVDF?



PVDF dissolves in polar aprotic solvents: N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), and dimethyl sulfoxide (DMSO). Solubility is temperature-dependent, and solution concentration critically affects membrane morphology in phase inversion casting — central to polyvinylidene fluoride uses in filtration. Aliphatic hydrocarbons, water, and alcohols do not dissolve PVDF, which underpins its use in aqueous chemical environments.




Coatings, Inks &amp; Construction Industrial specialties Plastics Polyurethane

Polyvinylidene Fluoride (PVDF): Properties, Grades, Applications and Processing

Coatings, Inks &amp; Construction Plastics Rubber

UV Light Stabilizer Additives &amp; HALS: A Practical Guide for Formulators


Ten years ago, plant protein was a protein conversation.



A brand team would brief a product by grams per serving, PDCAAS or DIAAS score, and cost. Pea vs soy vs rice. That was the vocabulary. That was the pitch to the consumer: as much protein as dairy, without the dairy.



That brief is dead. Plant protein products priced and positioned as dairy-equivalent commodities are losing shelf velocity across most major European markets, because consumers who want a scoop of protein are now comparing plant products to each other — not to whey. The question isn't whether you have 25 grams per serving. The question is whether your product tastes like something a real adult wants to drink every morning for a year.



What the 2026 consumer actually rejects



Three signals will get a plant protein product sent back to R&amp;D:



Off-notes



Pea beaniness. Rice grittiness. Soy's papery aftertaste. Plant protein isolates deliver protein and sensory baggage at the same time. The consumer who pays a premium for a differentiated product will not tolerate the baggage.



Solubility and mouthfeel



Chalky suspensions, separation in shakers, poor dispersion in cold water, gritty settling. These are all solvable formulation problems that most brands don't fully solve.



Single-origin dependency



A brand built exclusively on one protein source — particularly pea — is increasingly exposed to supply, pricing, and allergen concerns. Multi-origin blends are the new baseline, both for nutritional profile and for supply resilience.



The brands winning the category in 2026 are treating plant protein as a sensory and supply-chain problem first, a protein problem second.



The portfolio question



Safic-Alcan gives formulators access to one of the broadest multi-origin plant-protein portfolios in Europe:




Pea — isolates, concentrates, textured



Soy — isolates, concentrates, textured, hydrolysates



Wheat — gluten, hydrolysed wheat proteins, textured



Rice — concentrates, isolates, organic grades



Faba bean — isolates, concentrates, textured



Chickpea — concentrates, flours



Lentil — concentrates, flours



Oat — concentrates, isolates



Potato — isolates



Sunflower — isolates, concentrates



Pumpkin seed — concentrates



Hemp — concentrates, hearts



Almond, cashew, peanut — protein powders



Mung bean — isolates



Algae and microalgae — spirulina and others




That breadth exists because sensory and supply-chain optimisation requires it. A dairy-alternative yogurt, a sports nutrition shake, a meat analogue, and a high-protein RTD all need different blends — not different marketing. Our Life Sciences team supports the formulation work.





The body-composition brief



Plant protein is no longer just a meat-alternative or dairy-alternative play. It's a weight management and longevity ingredient, which is where the category is quietly migrating.



In the GLP-1 era, consumers and clinicians are increasingly concerned about lean mass preservation during rapid weight loss. A 2024 meta-analysis of 22 GLP-1 receptor agonist trials found that approximately 25% of total weight lost on these therapies came from lean mass, with semaglutide 2.4 mg weekly among the least effective at preserving it. Protein intake sufficient to support muscle protein synthesis is one of the few non-pharmaceutical levers available — which is why adequate high-quality protein has become a standard clinical recommendation for GLP-1 patients.



High-quality plant protein — particularly from blends that cover the full amino acid profile — is a practical answer. Satiety-oriented formulations, muscle-recovery positioning, and "adequate protein in mid-life" longevity formulations are all growing faster than base sports nutrition.



Pair plant protein with AvailOm® High EPA for joint recovery and inflammation claims, or with Morosil® for body composition-focused weight management products, and the stack tells a story the dairy protein category cannot match on sustainability and consumer trust.



Energy, vitality, and the functional stack



Plant protein is the anchor of the energy and vitality category, but it's rarely the whole story. The 2026 sports nutrition brief typically includes creatine, BCAAs or EAAs, peptides, caffeine or caffeine alternatives, electrolytes, and increasingly functional botanicals and mushroom extracts for energy and cognitive support.



Safic-Alcan's Life Sciences portfolio covers the full stack. The microbiota layer — gut-performance and gut-brain axes — is the frontier most sports nutrition brands are under-formulating.



Meet us in Barcelona



The full multi-origin plant-protein portfolio, the complementary actives (creatine, peptides, AvailOm®, Morosil®), and technical and regulatory support from our Life Sciences team — all on our stand at Vitafoods Europe 2026.



Bring your brief. Come taste the difference.



→ 5–7 May 2026 · Fira Barcelona Gran Via · Booth 3B143






Register today for Vitafood and come visit ut at our booth

Vitafood is just around the corner!

Plant protein isn't about protein anymore


Every consumer knows about the gut microbiome now. Brand teams should treat that as bad news.



When a category concept is universally understood, it stops being a differentiator. "Probiotics" printed on a pack used to signal innovation. In 2026 it signals baseline — the equivalent of a shampoo bottle saying "contains water." The CFU count arms race is over; nobody on the consumer side reads the number anymore, and most of the clinically meaningful differences between products never lived in the CFU count to begin with.



The brands winning microbiota-positioned launches in 2026 are doing three things differently.



1. They've moved from probiotics to the full stack



The modern microbiota brief is not "add a probiotic." It's an architecture:




Prebiotics — substrates that selectively feed beneficial strains (inulin, FOS, GOS, resistant dextrins, specific plant polyphenols). The ISAPP consensus defines a prebiotic as "a substrate that is selectively utilized by host microorganisms conferring a health benefit".



Probiotics — live strains with documented survival through gastric transit and clinical endpoints at realistic doses.



Postbiotics — formally defined by ISAPP in 2021 as a "preparation of inanimate microorganisms and/or their components that confers a health benefit on the host". The category unlocks matrix compatibility that live-strain products cannot match.



Yeast and fungi — Saccharomyces boulardii and selected fungal components with distinct clinical profiles.



Synbiotic and postbiotic combination stacks — built for a specific claim, not a generic "gut health" label.




Safic-Alcan's Life Sciences portfolio covers all five. For formulators moving beyond single-strain probiotic products, the combination possibilities are where the differentiation lives.



2. They've moved from "gut health" to specific axes



"Gut health" is a claim category the consumer has learned to discount. The signal is in the axes — gut plus something else:




Gut-skin axis — microbiota strains and metabolites linked to skin barrier function, inflammatory markers, and visible skin outcomes. The scientific anchor for beauty-from-within claims beyond collagen alone.



Gut-brain axis — strains with clinical data on mood, stress, cognitive markers, and sleep. A mainstream mental-wellness claim route for 2026.



Gut-immune axis — the original microbiota claim, still the largest category, but now requiring specificity on strain and endpoint.



Gut-metabolic axis — strains and postbiotics linked to glucose regulation, lipid metabolism, and body composition. The natural complement to Morosil® in weight management formulations.




Each axis has different ingredient logic, different clinical literature, and different regulatory considerations. "Our probiotic supports gut health" is a 2016 claim. The 2026 version names the axis.



3. They've solved survival and format before worrying about CFU



The clinically meaningful variables are:




Strain specificity (down to the strain designation, not just genus + species)



Delivered dose at the point of action, not the point of manufacture



Gastric and bile survival under realistic formulation and storage conditions



Shelf stability across the product's commercial life



Matrix compatibility — can the strain actually live in the gummy, stick, shot, or chocolate the brand wants to build?




This is where postbiotics have quietly become the category's release valve. A bioactive metabolite or heat-inactivated cell preparation with clinical data doesn't need to survive — and opens up formats (RTDs, baked goods, non-refrigerated chains) that live strains can't realistically handle.



Format considerations



Live probiotic strains remain gold standard for many claims, but increasingly formulators are building hybrid stacks: live probiotic as the anchor, prebiotic substrate, postbiotic secondary actives, and a clean-label carrier system that supports stability.



Pair the microbiota stack with AvailOm® omega-3 for combination longevity and cognitive formulations, or with plant proteins for sports and recovery formats, and the architectural possibilities expand quickly.



Meet us in Barcelona



Safic-Alcan's microbiota portfolio covers probiotics, prebiotics, postbiotics, yeasts and fungi across all four major axes, with technical and regulatory support from our Life Sciences team.



→ 5–7 May 2026 · Fira Barcelona Gran Via · Booth 3B143




Beyond CFU counts: the 2026 microbiota stack

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