ESBO (Epoxidized Soybean Oil): Properties, Uses in Plastics and Regulatory Status

ESBO (epoxidized soybean oil, also abbreviated ESO; CAS 8013-07-8) is an epoxidized vegetable oil used in PVC in two roles at once: as a heat co-stabilizer that scavenges hydrogen chloride, and as a secondary plasticizer. Because the two roles need very different levels, the first question a formulator asks is which one ESBO is doing in the recipe.

The answer moves the dosage by more than a factor of 20. ESBO sits at 1 to 2 wt% when it works as a co-stabilizer beside a primary plasticizer, and at 25 to 45 wt% when it carries the plasticizing job alone, according to Czogała and co-workers (Materials, 2021). ESBO is one of 437 substance profiles in our directory of plastic additives, each with the same identity, dosage and regulatory fields.

This page carries the identity and specification of ESBO, the ring-opening mechanism behind its stabilizing role, the dosage split by role, the 4 plastics applications, the EU and US food-contact limits with their instruments and dates, the alternatives for each role, and what a buyer specifies when sourcing a grade.

Table T1. ESBO identity card.

Footnote: identity data from the ECHA substance record 100.029.444; EU limits from the consolidated text of Regulation (EU) No 10/2011 of 14 July 2026; US status from 21 CFR 181.27. Status as of 23 September 2026.

What Is ESBO (Epoxidized Soybean Oil)?#

ESBO is soybean oil in which the carbon-carbon double bonds of the fatty-acid chains have been converted into oxirane (epoxide) rings, which turns a food oil into a reactive PVC additive. What is left of the soybean oil after epoxidation, and what is new? The triglyceride body is left: three fatty-acid chains esterified to one glycerol backbone, the architecture that makes the substance an oil. New is the oxirane ring, a three-membered ring of two carbon atoms and one oxygen atom that opens under acid attack, and that ring carries the chemical function of ESBO in PVC.

Both roles follow from that pairing. ASTM D883 defines a plasticizer as a substance incorporated into a plastic or elastomer to increase its flexibility, workability or distensibility, which is what the fatty-acid chains of ESBO do, and the hub on plasticizers for plastics compares every class in the family, from phthalates and terephthalates to adipates, citrates and the epoxidized esters. ESBO is classed there as a secondary plasticizer, a plasticizer whose compatibility with PVC is limited on its own and which is used together with a primary plasticizer, a group that also holds chlorinated paraffins, some benzoates and TXIB.

ESBO heads the group of epoxidized plasticizers, which also contains epoxidized linseed oil and the epoxidized fatty-acid esters. One further identity fact governs the data sheet: ESBO is a UVCB, a substance of unknown or variable composition, so its identity is fixed by CAS number, EC number and specification parameters rather than by a structural formula.

What does ESBO stand for?#

ESBO stands for epoxidized soybean oil, written ESO in North American trade and "epoxidised soya bean oil" in EU legal texts. Chemical inventories and certificates of analysis also use the inverted form "soybean oil, epoxidized", which is the same substance under CAS 8013-07-8. Outside chemistry, "Esbo" is the Swedish name of the Finnish city Espoo, which is why a search for the bare acronym returns cities, software products and companies rather than plastics.

What is the difference between epoxidized soybean oil and regular soybean oil?#

The difference is the double bonds: in food-grade soybean oil they are intact, and in ESBO almost all of them have been converted into oxirane rings, which is why an ESBO specification caps the iodine number at 6 while ordinary soybean oil sits far above it. That single change is what makes ESBO useful in PVC and unsuitable as a food oil. The iodine number counts the residual double bonds, so a low iodine number is direct evidence that the conversion ran to completion, and the oxirane figure counts what the conversion produced. Both oils keep the same triglyceride backbone and the same fatty-acid chain lengths, so epoxidation changes the reactivity of the molecule rather than its size: the average molecular weight of ESBO stays at about 1,000 g/mol (Czogała and co-workers, Materials, 2021).

What do oxirane oxygen content and iodine number mean for ESBO grades?#

Two numbers define a commercial ESBO grade: the oxirane oxygen content, which measures how many epoxide rings are available to capture hydrogen chloride, and the iodine number, which measures how many double bonds were left unconverted. The two are read together, because the EU sets an upper bound on oxirane content and the FDA a lower bound on oxirane oxygen. A grade with too little oxirane scavenges too little HCl per part added, and a grade with a high iodine number carries unreacted double bonds that do no stabilizing work.

The two instruments state their parameters differently and are therefore tabulated separately rather than merged into one range.

Table T2. ESBO specification parameters, EU and US instruments side by side.

Footnote: the EU wording ("oxirane") and the FDA wording ("oxirane oxygen") are reproduced as each instrument states them. This page does not combine them into a single range. EU values from the consolidated text of 14 July 2026.

Why does ESBO have no single molecular formula?#

ESBO has no single molecular formula because it is a UVCB substance, a substance of unknown or variable composition: a mixture of epoxidized triglycerides whose fatty-acid chains vary with the soybean crop. Its molecular weight is therefore given as an average of about 1,000 g/mol (Czogała and co-workers, Materials, 2021), not as an exact value, and the schema and database records on this page carry that average with its qualifier rather than a formula.

What Does ESBO Do in PVC? Dual Function as Co-Stabilizer and Plasticizer#

ESBO does two jobs in one molecule: its oxirane rings capture the hydrogen chloride that PVC releases when it is heated, and its long triglyceride body sits between the polymer chains as a plasticizer. No other plasticizer class carries a reactive group that neutralises a degradation product of the polymer it softens. The two functions run in parallel, which is why a recipe that names ESBO has to state its level before the role is clear.

The stabilizing job is the one that earns ESBO its place in a PVC one-pack. That second job puts ESBO in the list of PVC co-stabilizers beside the polyols, phosphites, beta-diketones and hydrotalcite, each of which covers a different part of the degradation problem. The plasticizing job is secondary in the technical sense: real, but not efficient enough to carry a flexible compound at normal addition levels.

How does ESBO scavenge hydrogen chloride?#

ESBO scavenges hydrogen chloride by opening its oxirane rings: the ring reacts with HCl to form a chlorohydrin, and zinc and calcium soaps in the stabilizer package catalyse that reaction. The chlorine ends up bound in the additive rather than free in the melt, and the epoxide is consumed in the process, which is why the oxirane content of a grade sets how much hydrogen chloride a given addition level can absorb.

Removing that hydrogen chloride matters because the reaction it feeds is autocatalytic. Unstabilized PVC begins to lose HCl above about 70 °C and its thermal degradation sets in at about 250 °C, and the liberated HCl accelerates further dehydrochlorination, which leaves conjugated polyene sequences in the chain and turns the compound yellow, then brown. Only 0.1 % dehydrochlorination is enough to cause unacceptable discoloration, so the scavenger works long before any mechanical property is measurably affected. The reaction ESBO interrupts is explained in full on PVC thermal degradation and dehydrochlorination.

How does ESBO plasticize PVC?#

ESBO plasticizes PVC the way any ester plasticizer does, by placing its long fatty-acid chains between the polymer chains, but it is classed as a secondary plasticizer because its compatibility with PVC is limited on its own. Compatibility is a solubility question: a polymer and a plasticizer stay compatible when their solubility parameters lie within about 1.5 (cal/cm3)^0.5 of each other, and a plasticizer that sits outside that window separates or exudes instead of softening.

The consequence is a dosage rule rather than a yes or no. As a partner to a primary plasticizer ESBO stays at a low level and contributes softening as a side effect of its stabilizing job, while as the main plasticizer it needs 25 to 45 wt% to reach the same hardness a primary ester reaches at a lower level. The same classification covers chlorinated paraffins, benzoates and TXIB, and the distinction is set out on primary vs secondary plasticizers together with the other secondary esters.

Why is ESBO synergistic with calcium-zinc stabilizers?#

ESBO and calcium-zinc systems reinforce each other: the zinc and calcium soaps catalyse the opening of ESBO's oxirane rings, and the epoxide in turn removes hydrogen chloride before it can feed the zinc-burning cycle. Zinc soaps regenerate zinc chloride as they work, and zinc chloride is itself a strong catalyst for dehydrochlorination, the failure mode called zinc burning. Polyols, phosphites, beta-diketones and hydrotalcite are the other components that counter it. ESBO is a standard component of calcium-zinc stabilizers packages for flexible PVC, where it is dosed as part of the stabilizer side of the recipe rather than the plasticizer side.

What Are the Physical and Chemical Properties of ESBO?#

ESBO is a UVCB substance rather than a single compound, so it is specified by property ranges rather than by fixed constants: an average molecular weight of about 1,000 g/mol, an oxirane content and an iodine number. For appearance, density, viscosity and flash point, read the supplier's technical data sheet for the exact grade, because those values are grade-specific and are not set by any regulation.

Our source library holds no density, viscosity, boiling point, flash point, refractive index, acid value or colour number for ESBO, and this page prints none rather than copying a typical value from one supplier's product page, because a producer's typical value describes that grade and not the substance. The three quantities that carry legal weight are already in Table T2: oxirane, oxirane oxygen and iodine number. Those are the figures a certificate of analysis has to match.

How Much ESBO Is Used in PVC? Dosage by Role#

ESBO is used at two very different levels: 1 to 2 wt% when it works as a co-stabilizer beside a primary plasticizer, and 25 to 45 wt% when it is the main plasticizer, according to Czogała and co-workers (Materials, 2021). Which level applies is decided by the job the formulator has given the additive, not by the polymer, because both levels are PVC levels. A compound whose hardness target is met by DOTP, DINP or DEHA needs ESBO only for its oxirane rings, while a compound with no other ester has to reach its Shore A target on ESBO alone.

Table T3. ESBO dosage by role.

The full range of plasticizers for PVC and their levels is tabulated on the PVC page, where ESBO sits beside the primary esters that usually carry the hardness target.

ESBO as a co-stabilizer: 1 to 2 wt%#

At 1 to 2 wt% ESBO is a co-stabilizer, not a plasticizer: the level is set by how much hydrogen chloride the compound has to absorb during processing and service, not by the hardness target. Two variables drive that demand: the thermal history of the compound, from extrusion, calendering or plastisol fusion, and the service temperature the article sees afterwards.

At this level ESBO works with the rest of the stabilizer package rather than replacing any part of it. The 4 other co-stabilizer classes named in our source library are the polyols, the organophosphites, the beta-diketones and hydrotalcite, and each addresses a different failure route: zinc chloride, early colour or long-term HCl uptake. The wt% figures on this page are ESBO figures; the overall stabilizer content of a PVC formulation is a separate quantity that belongs to the heat-stabilizer hub.

ESBO as a main plasticizer: 25 to 45 wt%#

When ESBO carries the plasticizing job alone it has to be dosed at 25 to 45 wt%, an order of magnitude above its co-stabilizer level, because its compatibility with PVC is lower than that of a primary ester plasticizer. PVC plastisol closure gaskets sit in exactly that band, at 25 to 45 % total plasticizer, most often ESBO together with phthalates.

The upper end of that band is a high loading by any standard: flexible PVC as a class runs at 5 to 65 wt% total plasticizer for a Shore A hardness of about 50 to 90, so a gasket formulated on ESBO uses a large share of the available plasticizer budget for a single secondary ester. That is the trade the gasket application accepts in exchange for having the HCl scavenger and the softener in one raw material.

How do phr values convert to weight percent?#

Compound recipes give ESBO in parts per hundred resin, and the conversion is arithmetic: divide the parts of ESBO by the total parts of the whole formulation and multiply by 100. A compound of 100 phr PVC, 40 phr ESBO and 5 phr stabilizer totals 145 parts, so 40 phr of ESBO is 40 / 145 x 100 = 27.6 wt%. Real compounds also carry fillers, lubricants and pigments, so the total includes every component. The conversion in both directions sits on PHR (parts per hundred resin), with the let-down ratios that masterbatch dosing uses.

What Is ESBO Used For? 4 Applications in Plastics#

ESBO is used in 4 main plastics applications: PVC gaskets for glass jar lids, cling film and other food-contact film, toys and childcare articles, and flexible PVC flooring and plastisols. Three of the four are food-contact or child-contact applications, which is why the regulatory section of this page carries more detail than the property section.

• PVC plastisol gaskets in metal lids for glass jars, the application that defines ESBO's food-contact profile.
• Cling film and other flexible food-contact film, where ESBO works beside the main film plasticizer.
• Toys and childcare articles made from flexible PVC.
• Flooring, plastisols and flexible PVC compounds, where ESBO belongs to the stabilizer side of the recipe.

PVC gaskets for glass jar lids#

The PVC plastisol gasket inside a metal jar lid is the application ESBO is best known for, and the one that put it on the food-contact agenda: these gaskets contain 25 to 45 % plasticizer, most often ESBO together with phthalates. The gasket stays soft enough to seal against glass after pasteurisation and to release cleanly on opening, and a plastisol that gels and fuses on the lid gives that seal in one coating step. Gasket recipes pair ESBO with phthalate plasticizers, which is why gasket migration studies measure both.

A survey of baby food packed in glass jars found ESBO at below 1.5 to 50.8 mg/kg with a mean of 11.9 mg/kg, migrated from the lid gaskets, and the EU sets a separate 30 mg/kg limit for gaskets sealing glass jars of infant formula, follow-on formula, processed cereal-based foods and baby foods against a general 60 mg/kg. How the gasket case compares with the other food-contact plasticizers is set out on plasticizers in food contact materials.

Cling film and food-contact film#

ESBO also appears in PVC cling film, where it works beside the main film plasticizer rather than replacing it: in that market the primary plasticizer is normally DEHA, with DINCH as the other common choice. DEHA carries an EU specific migration limit of 18 mg/kg as FCM substance 207, which is three times tighter than the 60 mg/kg that applies to ESBO, so the film's compliance case is usually decided by the primary ester rather than by the co-stabilizer. Our source library records no ESBO dosage for cling film, so this page states the role and no number. The full additive package for food-contact film is on additives for food packaging.

Toys and childcare articles#

ESBO is one of 5 plasticizers that have replaced restricted phthalates in PVC toys, together with ATBC, DEHT, TXIB and DINCH, according to Helene Wiesinger and colleagues (Environmental Science & Technology, 2024). The regulatory direction of travel in this application is set by the EU Toy Safety Regulation (EU) 2025/2509, which bans CMR substances and endocrine disruptors in toys and applies from 1 August 2030. Which plasticizers each jurisdiction allows in toys is tabulated on plasticizers for toys, with the restriction entries that apply to each.

Flooring, plastisols and flexible PVC compounds#

In PVC flooring ESBO belongs to the stabilizer side of the recipe: the compounds use liquid calcium-zinc, barium-zinc or potassium-zinc stabilizers, an organophosphite booster and ESBO, with a kicker added for foamed layers, according to Baerlocher's flooring formulations. PVC plastisols as a class gel and fuse at 140 to 220 °C, a window that belongs to the process rather than to ESBO, and the stabilizer package has to hold colour across it. Gelation and fusion behaviour is covered on plasticizers for PVC plastisol.

How Does ESBO Perform in PVC? Efficiency, Migration and Limits#

ESBO is efficient in its stabilizing role and inefficient in its plasticizing one: 1 to 2 wt% is enough to scavenge hydrogen chloride, while 25 to 45 wt% is needed before it can carry the plasticizing job alone. That contrast, measured by Czogała and co-workers (Materials, 2021), tells a formulator which role to buy the material for.

The stabilizing performance is worth its cost: 0.1 % dehydrochlorination already causes unacceptable discoloration, so a compound that loses its scavenger loses its appearance before it loses its mechanical properties. Three limits govern where ESBO is used and at what level.

• Limited compatibility with PVC on its own, the property that makes ESBO a secondary plasticizer and caps the level at which it replaces a primary ester.
• Migration into fatty foods from jar gaskets, measured at below 1.5 to 50.8 mg/kg with a mean of 11.9 mg/kg in baby food from glass jars, the reason the EU wrote a separate 30 mg/kg limit for that article. Why esters leave a compound at all is explained on plasticizer migration.
• Grade variability, because ESBO is a UVCB whose oxirane content and iodine number differ between suppliers within the ranges the specifications allow.

Our source library holds no volatility, extraction, Shore A, thermal-stability-time or Congo red value for ESBO, so this page names those test concepts without printing a figure.

How Does ESBO Interact with Other Plasticizers and Stabilizers?#

ESBO is almost never used alone: it is combined with a primary plasticizer that carries the softening, with metal soaps that catalyse its HCl capture, and with other co-stabilizers that cover the parts of the stabilizer job it cannot do. The 3 groups it is formulated with are listed below.

• Primary plasticizers such as DOTP, DINP and DEHA, which carry the hardness target. In a DOTP / DEHT (dioctyl terephthalate) compound ESBO sits at 1 to 2 wt% as the co-stabilizer while DOTP carries the hardness.
• Calcium-zinc and barium-zinc soaps, which catalyse the oxirane-HCl reaction and are protected by it from the zinc chloride they generate.
• Other co-stabilizers, namely polyols, organophosphites, beta-diketones and hydrotalcite, which handle zinc chloride, early colour and long-term HCl uptake.

Compatibility decides which combinations hold together: a plasticizer and a polymer stay compatible when their solubility parameters lie within about 1.5 (cal/cm3)^0.5 of each other. Suppliers sell these combinations as one-pack additive systems, so that the metal soaps, the epoxide and the secondary co-stabilizers arrive pre-blended. The complete recipe around ESBO is on additives for PVC, from resin and plasticizer to stabilizer, filler and lubricant.

What Is the Regulatory Status of ESBO?#

ESBO is authorised for EU food-contact plastics as FCM substance 532 with a specific migration limit of 60 mg/kg, is not a Substance of Very High Concern, is not restricted under REACH Annex XVII and is not a persistent organic pollutant (status 23 September 2026). The matrix below states each instrument, the status under it and the date of that status.

Table T5. ESBO regulatory matrix, as of 23 September 2026.

Four fields are open rather than negative, and the distinction matters to a compliance officer: "status being verified" means our sources do not confirm the entry, not that the substance is absent from the list. Every additive's specific migration limits (SML) are listed in one table, with the group restrictions beside the individual values.

Is ESBO allowed in food-contact plastics in the EU?#

Yes: ESBO is listed in Annex I of Regulation (EU) No 10/2011 as FCM substance 532, with a specific migration limit of 60 mg/kg and a stricter 30 mg/kg limit for the PVC gaskets that seal glass jars of infant formula, follow-on formula, processed cereal-based foods and baby foods. The listing carries a specification as well as a limit: the oxirane content stays below 8 % and the iodine number below 6, so a grade outside those bounds is outside the authorisation even if its migration is compliant.

The 60 mg/kg is also a group total. Group restriction 32 applies the same 60 mg/kg as an SML(T) to the sum of 22 listed plasticizer FCM substances, among them ATBC (FCM 138), DEHA (FCM 207), ESBO (FCM 532), DINP (FCM 728), DINCH (FCM 775) and DEHT (FCM 798), so a compound carrying more than one of them meets the sum rather than each value separately. Group restriction 32 and the overall migration limit of 10 mg/dm2 are explained on EU 10/2011.

Why do infant-food jar gaskets carry a lower 30 mg/kg limit?#

Because the measurements showed that the limit was being approached: a survey of baby food in glass jars found ESBO between below 1.5 and 50.8 mg/kg, with a mean of 11.9 mg/kg, and infants eat much more jar food per kilogram of body weight than adults do. Koni Grob and Anja Fankhauser-Noti at the Kantonales Labor Zürich carried out the gasket-migration work behind those figures, and the EU Scientific Committee on Food set a tolerable daily intake for ESBO of 1 mg per kilogram of body weight. How a gasket is tested against these limits is described on migration testing of plastics for food contact, with the simulants and contact conditions each article category requires.

Is ESBO allowed in food contact in the United States?#

In the United States ESBO is a prior-sanctioned substance under 21 CFR 181.27, which lists it as a plasticizer in food-packaging materials with a specification of iodine number no higher than 6 and oxirane oxygen no lower than 6.0 %. A prior sanction is not a food-additive regulation and not an approval: it records an acceptance issued before the 1958 food-additive amendments, and it stands on its own terms.

The same section covers 12 other prior-sanctioned plasticizers, among them ATBC, ATEC, DBS, DEP, DIBA, DIOP, EHDPP, triacetin and TEC, so a US compliance file often cites 181.27 for more than one component. What a prior sanction means, and how it differs from a food-additive listing, is on FDA food contact rules for plastic additives.

Is ESBO an SVHC or restricted under REACH?#

No: ESBO is not on the REACH Candidate List of Substances of Very High Concern, is not on Annex XIV, is not restricted under Annex XVII and is not listed under the EU POPs Regulation (EU) 2019/1021 (status 23 September 2026). The registration status and tonnage band are not confirmed in our sources, so this page does not state them. Every plastic additive that is on the SVHC Candidate List is tracked there; ESBO has never been added.

Is ESBO Safe? Health, Safety and Environmental Profile#

The EU Scientific Committee on Food set a tolerable daily intake for ESBO of 1 mg per kilogram of body weight, and the food-contact limits in Regulation (EU) No 10/2011 are built on that figure. A tolerable daily intake is an exposure benchmark rather than a hazard classification, and the migration limits translate it into a number a laboratory measures on an article.

The measured exposure evidence comes from the gasket case. Baby food packed in glass jars carried ESBO at below 1.5 to 50.8 mg/kg with a mean of 11.9 mg/kg, and the 30 mg/kg limit applies to the gaskets sealing those jars. A Swiss survey reported ESBO migration of up to 1,170 mg/kg in foods, a figure our source library holds from a secondary source only. The wider measurement literature is summarised on chemicals migrating from plastic food packaging.

Three statements about ESBO's safety profile are worth keeping apart.

• Regulatory status: authorised for EU food contact under FCM 532 with two migration limits, prior-sanctioned in the United States under 21 CFR 181.27, and absent from the SVHC, Annex XIV, Annex XVII and POPs lists.
• Exposure evidence: the SCF tolerable daily intake of 1 mg/kg body weight and the measured baby-food range of below 1.5 to 50.8 mg/kg.
• Open points: this page states no GHS or CLP classification, no California Proposition 65 status and no TSCA status, because none is confirmed in our sources.

ESBO is a bio-based but non-degradable additive, which under the APR design guidance raises no recyclability objection of the kind that degradable polymers, fibres and fillers raise.

What Are the Alternatives to ESBO?#

ESBO has two sets of alternatives, one per role: epoxidized linseed oil and the non-epoxide co-stabilizers replace its stabilizing function, while DEHA, DINCH and ATBC replace its plasticizing function in food-contact articles. A substitution that swaps only one function leaves the other uncovered, which is why ESBO survives in gasket and film recipes.

Table T6. ESBO and its 4 closest alternatives.

Full property data for the primary plasticizers sit on the plasticizer comparison page, where efficiency, permanence and cost drivers are set side by side.

ESBO vs epoxidized linseed oil (ELO)#

ELO carries more epoxide per kilogram than ESBO, so it scavenges more hydrogen chloride per part added, but it is not listed in Annex I of Regulation (EU) No 10/2011, which rules it out of EU food-contact plastics where ESBO is allowed. The numeric contrast sits in the US specifications: 21 CFR 178.3740 requires an oxirane oxygen of at least 9 % for ELO against the 6.0 % minimum for ESBO under 21 CFR 181.27, and an iodine number of at most 5 against at most 6.

Epoxidized linseed oil carries a higher oxirane content but is absent from Annex I, so the choice is decided by the application before the chemistry: a food-contact article in the EU takes ESBO, while a technical compound outside food contact takes either. Both are UVCBs of epoxidized triglycerides, ELO under CAS 8016-11-3 and EC 232-401-3.

ESBO vs beta-diketone, hydrotalcite and polyol co-stabilizers#

ESBO is not the only HCl scavenger in a calcium-zinc package: hydrotalcite does the same job by exchanging its interlayer carbonate for chloride, while beta-diketones and polyols address early colour and zinc chloride rather than hydrogen chloride. Hydrotalcite scavenges HCl by ion exchange rather than by ring opening, and it is the long-term component of calcium-zinc systems, where its capacity outlasts that of an epoxide.

What ESBO adds that none of the others adds is the second function. It is the only co-stabilizer class that also plasticizes, which is why it appears in flexible compounds and gaskets rather than in rigid pipe, where a softening side effect would be a defect. Beta-diketones such as dibenzoylmethane (CAS 120-46-7) handle early colour, which ESBO does not, so the two are complements rather than substitutes in one package.

ESBO vs DEHA, DINCH and ATBC as food-contact plasticizers#

Against the primary food-contact plasticizers, ESBO is the one with the most permissive individual limit and the tightest article-specific one: 60 mg/kg in general against DEHA's 18 mg/kg, but 30 mg/kg in the single article where it matters most. DINCH (FCM 775) and ATBC (FCM 138) carry no individual specific migration limit at all and are controlled through the group-32 total of 60 mg/kg, so a direct comparison of substance-specific numbers is available only for ESBO and DEHA. All 4 substances sit inside group restriction 32, which means a compound using more than one of them is assessed on the sum.

Who Supplies ESBO? Grades, Specification and Sourcing#

Our supplier records name two producers of epoxidized natural oils for plastics, Valtris and Galata Chemicals, alongside a long tail of regional producers that our directory does not yet cover; the ESBO market is more fragmented than the phthalate and terephthalate markets. Valtris produces plasticizers, epoxidized natural oils, heat stabilizers and lubricants, and opened an office in Midland, Michigan on 17 August 2026. Galata Chemicals, based in Jersey City, New Jersey, produces organotin stabilizers, mixed-metal stabilizers, phosphites and plasticizers. More producers and their locations are in the directory of plasticizer manufacturers and suppliers. This page names no ESBO trade name, because our source library records none.

What distinguishes one grade from another is the specification rather than the brand: the oxirane oxygen content, the iodine number, and whether the supplier declares compliance with the EU 10/2011 FCM 532 specification and with 21 CFR 181.27. Published ESBO price series are not in our data set, so this page prints no figure, and price drivers are tracked on plasticizer prices. Buyers should ask for the TDS, the SDS and a written food-contact declaration naming FCM 532 and 21 CFR 181.27.

Table T7. What to specify when buying ESBO.

Footnote: density, viscosity and colour are grade-specific and are not set by either instrument; take them from the supplier's technical data sheet.

How Do Epoxidized Oils Fit into the Plasticizer and Stabilizer Families?#

ESBO is the main member of the epoxidized-oil class, the one additive class that belongs to two families at once: it is listed among the plasticizers and among the PVC co-stabilizers, and formulators pick it for either reason. The plasticizer family is the largest additive family by weight, at 8.4 million tonnes consumed each year worldwide according to European Plasticisers, and the epoxidized oils are a small, specialised part of it. The second family ESBO belongs to is covered on PVC heat stabilizers, where the epoxides sit beside the metal soaps, the organotins and the co-stabilizer classes.

Epoxidized natural oils and epoxidized fatty-acid esters#

Beside ESBO and ELO the class contains the epoxidized fatty-acid esters: epoxidized butyl esters of linseed oil fatty acids are listed in 21 CFR 178.3740 with an iodine number of at most 5 and an oxirane oxygen of at least 7.8 %. Two further members our source library names are the epoxidized fatty-acid methyl esters (EFAME) and epoxidized 2-ethylhexyl tallate, both liquid esters rather than triglycerides, which gives them lower viscosity and lower oxirane content per kilogram than the oils. ELO is the higher-oxirane member of the same class, and the ester members trade part of that capacity for handling.

Is ESBO a bio-based plasticizer?#

Yes: ESBO is made from a crop oil, which puts it among the bio-based plastic additives alongside epoxidized linseed oil, the citrates and the acetylated castor-oil monoglycerides. ESBO is one of the volume products among bio-based plasticizers, and its bio-based origin is a fact about the feedstock rather than a claim about performance or about end-of-life behaviour.

Being bio-based is not the same as being degradable. A non-degradable bio-based additive such as ESBO does not trigger the recyclability objections that degradable additives raise under the APR design guidance, where degradable polymers, fibres and fillers are the categories flagged. What the bio-based label does and does not mean is set out on bio-based plastic additives.

Uses of epoxidized soybean oil outside plastics#

Epoxidized soybean oil is also used outside plastics, for example as the raw material for acrylated epoxidized soybean oil (AESO) in UV-curable resins, and those uses are outside the scope of this reference, which covers additives used in plastics. This page carries no data on AESO, on coatings, inks, adhesives or lubricant additives.

Is ESBO banned anywhere?#

No: ESBO is not banned under any of the EU or US rules covered on this page, and the strictest measure against it is the 30 mg/kg migration limit for gaskets on infant-food jars, which restricts how much may migrate, not whether it may be used (status 23 September 2026). ESBO is absent from the REACH Candidate List, from Annex XIV, from Annex XVII and from the EU POPs Regulation (EU) 2019/1021.

Does ESBO need an SDS?#

Yes: suppliers provide a safety data sheet for ESBO as for any traded chemical, and the sheet is also where the grade-specific physical data sit. What an SDS must contain is on safety data sheets and GHS labels for plastic additives, and this page states no hazard classification for ESBO, because none is confirmed in our sources.