DBP (Dibutyl Phthalate): Properties, Uses in Plastics and Regulatory Status

DBP (dibutyl phthalate, also written di-n-butyl phthalate or DnBP; CAS 84-74-2) is a low-molecular-weight ortho-phthalate used as a fast-fusing plasticizer and solvent for PVC, polyvinyl acetate and nitrocellulose, and it is one of the 4 phthalates the European Union has restricted in all articles since 7 July 2020. Because DBP has carried a harmonised reproductive-toxicity classification for years, its remaining plastics uses are defined by what regulators still allow rather than by what formulators would like to do.

DBP entered the REACH Candidate List on 28 October 2008, has needed authorisation for EU use since the Annex XIV sunset date of 21 February 2015 under entry 6, is capped at 0.1 % by weight of the plasticised material of all articles under Annex XVII entry 51, and carries a specific migration limit of 0.12 mg/kg into food under Regulation (EU) 2023/1442. Among plastic additives, DBP belongs to the small group whose plastics market closed by regulation rather than by competition. DBP is one of 56 plasticizer pages in our directory of plastic additives, each carrying the same identity, dosage and regulatory fields.

This page carries the plastics data sheet and the compliance record in one place: the identity and isomer distinctions that separate DBP from DIBP and from dibutyl terephthalate, the solvation mechanism that makes it a fast fuser, the measured physical constants, the reported 10 to 35 wt% use range in PVC, polyvinyl acetate and nitrocellulose, the performance trade-off behind its typical substitution factor of 0.86, the dated restriction matrix across REACH, EU 10/2011, RoHS, FDA, TSCA, Proposition 65, CPSIA, Canada and Japan, and the 4 replacement routes that formulators actually use.

Table T1. DBP identity card.

Footnote: identity and physical data from PubChem CID 3026; regulatory entries from the ECHA obligation lists and the EU legal texts cited in each section. Status as of 22 September 2026.

What Is DBP (Dibutyl Phthalate)?#

DBP is the di-n-butyl ester of ortho-phthalic acid (benzene-1,2-dicarboxylic acid), a strongly solvating plasticizer whose two short, straight C4 chains make it dissolve PVC faster than any general-purpose phthalate. Both carboxyl groups of the aromatic diacid carry an n-butanol-derived ester group, and both sit in the ortho position, on adjacent ring carbons, which is the arrangement that defines an ortho-phthalate. Which substances does the name DBP actually cover, given that the same three letters also stand for diastolic blood pressure and for peroxides such as DBPO? In a plastics context DBP means dibutyl phthalate, CAS 84-74-2, and this reference uses it in no other sense.

As a solvating plasticizer DBP meets the ASTM D883 definition of a plasticizer, a substance incorporated into a plastic or elastomer to increase its flexibility, workability or distensibility. That definition is functional rather than structural, which is why DBP counts as a plasticizer in PVC and as a solvent in nitrocellulose and polyvinyl acetate, where the same molecule dissolves the polymer instead of merely spacing its chains. As a solvating ester, DBP belongs to the plasticizer family, which Ceresana put above 8 Mt of a 36.7 Mt plastic-additive market in 2023; the hub on plasticizers for plastics compares all classes and their host polymers.

What is another name for dibutyl phthalate?#

Dibutyl phthalate is also called di-n-butyl phthalate, DnBP and dibutyl benzene-1,2-dicarboxylate, and it is sold under the trade names Palatinol C, Vestinol C, Kodaflex DBP and Unimoll DB. The "n" marks the straight-chain butyl group, which is the single letter that separates DBP from its branched isomer DIBP in a specification, a customs declaration or a restriction entry.

Is DBP the same as DIBP?#

No: DBP (CAS 84-74-2) carries two straight n-butyl chains while DIBP (CAS 84-69-5) carries two branched isobutyl chains, and the two substances have separate CAS numbers, separate Annex XIV entries and different Proposition 65 status. Both are low-molecular-weight ortho-phthalates, both are classified Repr. 1B with hazard statement H360Df, and both fall inside REACH Annex XVII entry 51, so the difference never works as a compliance route. The branched isomer, DIBP (diisobutyl phthalate), entered the Candidate List two years later, on 13 January 2010, and sits at Annex XIV entry 7 against DBP's entry 6.

The food-contact treatment differs more sharply than the hazard profile does. DBP is FCM substance 157 with an individual specific migration limit of 0.12 mg/kg, while DIBP holds FCM number 1085 without being authorised as an additive at all, a number assigned only so that the substance can be counted into group restrictions 32 and 36 when it co-occurs from use as a polymerisation aid.

Table T1b. DBP and DIBP compared.

Why do DBP, DIBP and dibutyl terephthalate share the formula C16H22O4?#

DBP, DIBP and dibutyl terephthalate are isomers: all three share the formula C16H22O4 and a molecular weight of 278.34 g/mol, but they differ in how the butyl chains branch and in where the ester groups sit on the ring. DBP carries two linear n-butyl chains on adjacent ring positions, DIBP carries two branched isobutyl chains on the same adjacent positions, and dibutyl terephthalate (CAS 1962-75-0) carries two linear n-butyl chains on opposite positions, the para arrangement that takes it out of the ortho-phthalate class entirely.

Identical formulas therefore carry different regulatory status. DBP and DIBP are both classified Repr. 1B and both sit on the REACH Candidate List and in Annex XVII entry 51, while dibutyl terephthalate (DBT) is on neither list and is not restricted under Annex XVII, and it carries the same formula and the same fast fusion without the ortho-phthalate classification.

Where does DBP sit among low-molecular-weight phthalates?#

DBP is one of the 4 low-molecular-weight ortho-phthalates that the EU restricts as a group: DEHP, DBP, BBP and DIBP, the esters whose alcohol chains carry 3 to 6 carbon atoms in the backbone, in the definition European Plasticisers uses. DEHP is grouped with them for regulatory purposes even though its 2-ethylhexyl chain counts 8 carbon atoms in total, because the backbone of that branched chain is 6 carbons long. The 4 substances named in REACH Annex XVII entry 51 are listed below.

• DEHP (CAS 117-81-7): the C8 branched general-purpose ester, the historical benchmark at substitution factor 1.00.
• DBP (CAS 84-74-2): the C4 linear fast fuser, the subject of this page.
• BBP (CAS 85-68-7): the mixed benzyl and butyl ester used in vinyl flooring and foams.
• DIBP (CAS 84-69-5): the C4 branched isomer of DBP, a gelling aid for nitrocellulose and dispersions.

High-molecular-weight ortho-phthalates such as DINP, DIDP and DPHP carry longer alcohol chains and are not in entry 51, which is why "phthalate" on its own says nothing about a substance's legal status. Where the split runs, and why DEHP is grouped with the short-chain esters, is set out on low vs high molecular weight ortho-phthalates.

How Does DBP Plasticize PVC and Cellulose Plastics?#

DBP plasticizes PVC by pushing its short butyl ester molecules between the polymer chains, weakening the dipole forces that hold them together and lowering the glass transition temperature of the compound. The ester carbonyl groups solvate the polar carbon-chlorine dipoles of poly(vinyl chloride), which breaks the dipole-dipole network that makes unplasticized PVC rigid at room temperature, and the butyl chains add free volume between the separated chain segments. Why does a short C4 chain make DBP so much more aggressive than a C8 phthalate? Shorter alcohol chains raise solvating power and lower the fusion temperature, while longer and more branched chains buy lower volatility and better permanence at the cost of gelation speed.

Compatibility sets the outer limit of that effect. A plasticizer stays in a polymer only while the difference between the two solubility parameters remains within about ±1.5 (cal/cm3)^0.5, and DBP sits well inside that window for PVC, polyvinyl acetate and cellulose esters, which is why it acts as a true solvent for the last two rather than as a spacer alone. The 4 classic plasticization theories are listed below.

• Lubricity theory: the plasticizer works as an internal lubricant so polymer chains slide past one another under stress.
• Gel theory: the polymer is a three-dimensional gel held by intermittent attachment points, and the plasticizer breaks a fraction of them.
• Free-volume theory: the plasticizer adds free volume between chains, raising segmental mobility and lowering the glass transition temperature.
• Mechanistic theory (solvation-desolvation): plasticizer molecules exchange continuously between solvated and desolvated states at the polar sites of the polymer.

The four theories are explained with solubility parameters on how plasticizers work. No solubility parameter, gelation temperature or glass transition value is recorded for DBP itself in this reference, so the relationship above is described without a number attached to it.

Why is DBP called a fast fuser?#

DBP is called a fast fuser because it swells and dissolves PVC particles at a lower temperature than general-purpose plasticizers, which is the property that decides how a plastisol gels. Fusion, also called gelation or solvating power, measures how fast and at what temperature a plasticizer penetrates a PVC particle and turns a liquid paste into a continuous solid, and it is the single most important plasticizer property in plastisol processing. The 5 fast fusers named in this reference are listed below.

• DBP (dibutyl phthalate): the C4 linear ortho-phthalate, restricted in the EU.
• DIBP (diisobutyl phthalate): the C4 branched isomer, restricted alongside it.
• BBP (butyl benzyl phthalate): the benzyl-butyl ester used in flooring and foam.
• DIHP (diisoheptyl phthalate): the branched C7 ester.
• Dipropylene glycol dibenzoate: the non-phthalate dibenzoate fast fuser.

Fast fusion comes with a cost. Fast fusers lower the processing temperature, and they can also drive a strong rise in paste viscosity over storage time, which shortens the usable shelf life of a plastisol and forces either a viscosity depressant or a shorter production window. Monobenzoates such as isononyl benzoate and isodecyl benzoate combine fast fusion with viscosity depression, according to the patent literature, which is the reason benzoates rather than phthalates now carry this role.

What Are the Physical and Chemical Properties of DBP?#

DBP is a colourless, oily liquid that is insoluble in water, with a melting point of -35 °C (-31 °F), a boiling point of 340 °C (644 °F) at 760 mmHg and a flash point of 157 °C (315 °F). Its relative density places it above 1, so it sinks in water rather than floating, unlike DEHP.

Table T2. Physical and chemical properties of DBP.

Footnote: the flash point is recorded in °F in the primary record and converted arithmetically to °C here. Status as of 22 September 2026.

Two density figures circulate for the same substance, and a specification has to say which one it follows. Density is reported as 1.0459 to 1.0465 at 20 °C by PubChem and as 1.049 at 20 °C (68 °F) by the US Coast Guard handbook of 1999, a spread of roughly 0.3 % that matters when a plastisol recipe is converted between volume and weight. The flash point is recorded in the primary source in degrees Fahrenheit, at 315 °F, so the 157 °C stated here is the arithmetic conversion of that figure and not a second measurement.

Three of those constants set the handling window. A melting point of -35 °C (-31 °F) keeps DBP liquid through any storage climate, a boiling point of 340 °C (644 °F) at 760 mmHg puts its distillation range above every PVC processing temperature, and a flash point of 157 °C (315 °F) sits far above the temperature at which a plastisol is mixed. No vapour pressure, viscosity, refractive index or numerical water-solubility value for DBP is recorded in this reference, so none is stated here, and the qualitative "insoluble in water" of the primary record is the only solubility statement this page carries.

Which Polymers Use DBP, and at What Dosage?#

DBP is used in 3 polymer systems: PVC, polyvinyl acetate and nitrocellulose, at 10 to 35 wt% of the plastic material according to the ECHA use mapping behind PubChem's record. That band is a reported use range drawn from a mapping exercise, not a recommended dosage, and it describes a legacy pattern rather than current EU practice. How does a wt% range convert to the phr figures a PVC recipe uses? Weight percent equals the parts of the ingredient divided by the total parts of the whole formulation, multiplied by 100, so 30 phr of DBP in a compound of 100 phr PVC plus 30 phr DBP is 30 divided by 130, or 23.1 wt%.

The divisor matters more than the arithmetic. A real compound also carries heat stabilizers, fillers and lubricants, so the denominator is the full formulation total and not the resin-plus-plasticizer pair alone, and a recipe that reads 30 phr on the mixing sheet lands below 23.1 wt% once 20 phr of calcium carbonate and 3 phr of a stabilizer are added. Compound recipes give DBP in PHR (parts per hundred resin), which converts to weight percent against the full formulation total.

Table T3. Reported DBP levels by polymer.

Footnote: the 10 to 35 wt% band is a reported use range from the ECHA plastic additives initiative mapping, given once for all listed polymers. It is not a recommended dosage.

DBP in PVC compounds and plastisols (legacy use)#

DBP once served as a secondary plasticizer and fusion aid in flexible PVC compounds, where a typical substitution factor of 0.86 made it the most efficient ester in the plasticizer table, needing about 14 % less material than DEHP for the same hardness. Formulators used it in small additions alongside a general-purpose ester rather than as the sole softener, because its short chains bring volatility and mobility that a long-chain phthalate does not.

That market is now defined by a concentration limit. REACH Annex XVII entry 51 caps DEHP, DBP, BBP and DIBP at 0.1 % by weight of the plasticised material, individually or in any combination, in all articles since 7 July 2020 under Regulation (EU) 2018/2005, which is two orders of magnitude below the 10 to 35 wt% band the use mapping records. A legacy compound built on the old levels cannot be placed on the EU market as an article, and reformulation rather than dilution is the only route to compliance. DBP competed with DEHP and BBP across the plasticizers for PVC range before entry 51 closed the market.

DBP in PVAc and nitrocellulose#

DBP acts as both plasticizer and solvent in polyvinyl acetate and nitrocellulose, which is why the ECHA use mapping records the same 10 to 35 wt% band for all three polymer systems. In PVC the ester spaces chains that already form a solid; in polyvinyl acetate and in cellulose nitrate it dissolves the polymer outright, because the solubility parameters of those two polymers sit closer to DBP's own than PVC's does.

Cellulose plastics are the part of that picture that belongs to a plastics reference. Nitrocellulose lacquers and printing inks built on the same solvent behaviour are coatings and inks, which sit outside the plastics border of this site, so their formulation rules and their separate regulatory regimes are not covered here and appear only as a scope note below the contextual border.

What Is DBP Used For in Plastics?#

Inside plastics, DBP has 3 uses: cellulose plastics, PVC plastisols and fast-fusing PVC blends, while its larger historical markets, adhesives and printing inks, sit outside the plastics border of this reference. The 3 plastics uses are listed below.

• Cellulose plastics: cellulose nitrate and cellulose acetate compounds, where DBP acts as a solvent-type plasticizer.
• PVC plastisols: liquid pastes gelled and fused by heat, where DBP lowers the gelation temperature.
• Fast-fusing PVC blends: compounds where a small DBP addition speeds fusion alongside a general-purpose ester.

Cellulose plastics and nitrocellulose#

Cellulose plastics are the oldest market for DBP, which softens cellulose nitrate and cellulose acetate compounds that would otherwise be too brittle to form. Cellulose esters need a plasticizer to be processable at all, a requirement that goes back to camphor in celluloid, and the short-chain phthalates filled that role once synthetic esters became available. What makes a solvating ester the right tool for a cellulose ester rather than a spacing one? Cellulose nitrate and cellulose acetate carry polar nitrate and acetate groups along a rigid backbone, so an ester that dissolves those groups produces a homogeneous compound, while a poorly solvating long-chain plasticizer separates out instead.

No DBP-specific dosage for cellulosics is recorded beyond the 10 to 35 wt% mapping band, which covers PVC, polyvinyl acetate and nitrocellulose together rather than each one separately, so a cellulose acetate recipe cannot be read off this page. The full set of esters used in these compounds sits on plasticizers for cellulose acetate.

PVC plastisols and fast-fusing blends#

PVC plastisols used DBP to pull the gelation temperature down inside the 140 to 220 °C (284 to 428 °F) gel and fuse window, at the cost of a paste viscosity that rises during storage. A plastisol is a dispersion of PVC particles in liquid plasticizer that stays fluid until heat drives solvation, so the temperature at which that solvation starts sets the line speed of a coating or rotational-moulding process. A blend rather than a single ester does that job: a general-purpose plasticizer carries the bulk of the softening and a small fast-fusing addition moves the gelation onset down the temperature scale.

The trade-off runs through the storage tank. A fast fuser that swells PVC particles readily at oven temperature also swells them slowly at room temperature, so paste viscosity climbs between mixing and use, and the same property that shortens the fusion window shortens the shelf life of the paste.

Closure gaskets show the concentration involved: plastisol lid gaskets carry 25 to 45 % plasticizer, which is why the entry 51 limit of 0.1 % in the plasticised material ended this application for DBP rather than merely reducing it. Fast-fuser blends and their viscosity trade-offs are compared on plasticizers for PVC plastisol.

What products still contain DBP?#

Inside the EU, plastic articles may still contain DBP only where REACH Annex XVII entry 51 exempts them, which covers industrial and agricultural articles without prolonged skin contact, laboratory measuring devices, medical devices, food-contact materials under separate rules, and spare parts for vehicles and aircraft placed on the market before 7 January 2024. The exemption list also names articles for outdoor use without prolonged skin or mucous-membrane contact, electrical and electronic equipment covered by RoHS instead, and the immediate packaging of medicinal products.

"Prolonged skin contact" carries a defined meaning in that entry: more than 10 minutes of continuous contact or more than 30 minutes of intermittent contact per day. Food-contact plastics form the second exempted route, where Regulation (EU) No 10/2011 governs instead of entry 51 and allows DBP only as a plasticiser in repeated-use articles contacting non-fatty foods, or as a technical support agent in polyolefins at 0.05 % maximum in the final product. Answering this question by exemption category rather than by consumer product is the only version that can be checked against a legal text.

How Does DBP Perform as a Plasticizer?#

DBP is the most efficient plasticizer in the substitution-factor table at a typical value of 0.86 against DEHP's reference of 1.00, which means about 14 % less DBP gives the same hardness, and it is also the most volatile and most mobile of the group because its C4 chains are the shortest. If DBP is the most efficient ester, why did formulators move away from it even before the restrictions arrived? Short-chain esters are more volatile and more mobile than long-chain esters, so the same small molecule that softens efficiently also leaves the article efficiently, through evaporation at the surface, migration into contacting materials and extraction by fats and solvents.

The viscosity drift compounds the problem in paste applications. Fast fusers lower the processing temperature and can drive a strong rise in plastisol viscosity over storage time, so a DBP-containing paste that meters correctly on day one may not do so a month later. Substitution factors for 15 plasticizers are listed on plasticizer efficiency and substitution factors.

No measured volatility, migration, extraction or low-temperature value for DBP is recorded in this reference, so Table T4 names the test methods without inventing results for them. ASTM D1203, ISO 177 and ASTM D1239 are explained on plasticizer migration.

Table T4. DBP performance indicators and their test methods.

Footnote: substitution factors are typical figures from one secondary source (Kanademy), not supplier data, and are published here as unverified.

How Does DBP Interact with Other Plasticizers and Additives?#

DBP is a blending partner rather than a standalone plasticizer: formulators combine it with a general-purpose ester for bulk softening, with monobenzoates where paste viscosity has to stay flat, and they now have to count it together with DIBP, BBP and DEHP against a single food-contact limit. The 3 interactions that decide a recipe are listed below.

• With general-purpose phthalates: DBP supplies gelation speed while DEHP or a terephthalate supplies bulk softening and permanence.
• With monobenzoates: isononyl and isodecyl benzoate combine fast fusion with viscosity depression, according to the patent literature, which offsets the paste viscosity rise a fast fuser causes.
• With the other entry 51 phthalates: group restriction 36 of Regulation (EU) No 10/2011 makes DBP, DIBP, BBP and DEHP share one food-contact budget, so their presence in one compound adds up in regulatory terms as well as physical ones.

Every blend also has to stay inside the compatibility window, because two plasticizers that each sit within ±1.5 (cal/cm3)^0.5 of the polymer do not automatically stay mutually compatible at high total loading, and exudation at the surface is the failure mode. DPGDB (dipropylene glycol dibenzoate) is the dibenzoate formulators pair with or substitute for DBP when gelation speed matters.

What Is the Regulatory Status of DBP?#

DBP is a Substance of Very High Concern, needs authorisation for EU use since the sunset date of 21 February 2015, is limited to 0.1 % in the plasticised material of all articles under REACH Annex XVII entry 51, carries an EU food-contact migration limit of 0.12 mg/kg, and lost its US food-contact authorisation on 20 May 2022 (status 22 September 2026).

Table T5. DBP regulatory matrix, status as of 22 September 2026.

Is DBP an SVHC, and does it need REACH authorisation?#

Yes on both counts: DBP entered the REACH Candidate List on 28 October 2008 as toxic for reproduction, and it has needed authorisation for EU use since the Annex XIV sunset date of 21 February 2015 under entry 6. The Candidate List entry rests on Article 57(c) of REACH, the reproductive-toxicity ground, and two Article 57(f) grounds were added afterwards, first for endocrine-disrupting properties affecting human health and then, on 23 January 2024, for endocrine-disrupting properties affecting the environment. DBP has been on the SVHC Candidate List since 28 October 2008, which is the same day DEHP and BBP were listed.

Authorisation followed from that listing. Annex XIV entry 6 set a latest application date of 21 August 2013 and a sunset date of 21 February 2015, after which DBP may be placed on the EU market or used only under an authorisation granted for a named use, or under an exemption. Regulation (EU) 2021/2045, adopted on 23 November 2021 and published in OJ L 418 of 24 November 2021, added the Article 57(f) endocrine-disruptor grounds to the Annex XIV entry and set derogation dates of 14 June 2023 for the latest application and 14 December 2024 for the sunset for the uses that had been exempt until then: the immediate packaging of medicinal products, food-contact materials and mixtures containing 0.1 to 0.3 % of the substance. Entry 6 and its derogation dates sit on the REACH Annex XIV authorisation list.

The two lists therefore no longer say the same thing about DBP. The Annex XIV entry names reproductive toxicity and endocrine-disrupting properties for human health, while the Candidate List entry also carries endocrine-disrupting properties for the environment, added on 23 January 2024, after the Annex XIV amendment of 2021.

Why is dibutyl phthalate banned?#

Dibutyl phthalate is restricted because it carries a harmonised classification as toxic for reproduction category 1B (H360Df) under the EU CLP Regulation, which triggered its REACH Candidate List entry in 2008, an authorisation requirement from 21 February 2015 and a 0.1 % limit in the plasticised material of all articles from 7 July 2020. The classification came first and every instrument that follows cites it.

The EU measure is a concentration limit with named exemptions, not a blanket ban. REACH Annex XVII entry 51, as extended by Regulation (EU) 2018/2005, prohibits placing an article on the market if DEHP, DBP, BBP or DIBP exceed 0.1 % by weight of the plasticised material, individually or in any combination, and the entry exempts articles for exclusively industrial or agricultural use, outdoor articles without prolonged skin contact, laboratory measuring devices, medical devices, food-contact materials, electrical and electronic equipment under RoHS, the immediate packaging of medicinal products, and spare parts for vehicles and aircraft placed on the market before 7 January 2024. Entry 51 and its exemptions are set out on REACH Annex XVII restrictions.

Two instruments do prohibit outright rather than restrict. US CPSC rule 16 CFR 1307.3(a) permanently prohibits more than 0.1 % DBP in children's toys and child care articles, and the FDA final rule of 20 May 2022 (87 FR 31080) revoked the food-contact authorisations for DBP altogether. The word "banned" fits those two; for the EU the accurate description is a 0.1 % restriction on all articles plus an authorisation requirement.

Is DBP allowed in food-contact plastics?#

In the EU, yes but barely: DBP is FCM substance 157 in Annex I of Regulation (EU) No 10/2011 with a specific migration limit of 0.12 mg/kg since Regulation (EU) 2023/1442, the lowest individual phthalate limit in the Union list, and it may be used only as a plasticiser in repeated-use articles for non-fatty foods or as a technical support agent in polyolefins at up to 0.05 % of the final product. The previous limit was 0.3 mg/kg, so the 2023 amendment cut it by 60 %. Group restrictions 32 and 36 and the overall migration limit are explained on EU 10/2011.

The group arithmetic is stricter than the individual limit suggests. Group restriction 36, introduced by Regulation (EU) 2023/1442, sets a total specific migration limit of 0.6 mg/kg expressed as DEHP equivalents for DBP, DIBP, BBP and DEHP together, and it weights each substance by its relative potency: DBP counts five times, DIBP four times, BBP one tenth and DEHP once. Every milligram of DBP therefore consumes the group budget five times faster than a milligram of DEHP, which makes DBP the binding constraint in any compound where the four co-occur. Group restriction 32 adds a separate 60 mg/kg ceiling that covers a wider set of substances.

The weighting comes from a toxicological assessment rather than from a chemical property. EFSA's opinion of 18 September 2019 set a group tolerable daily intake of 50 µg per kg body weight per day for DBP, BBP, DEHP and DINP expressed as DEHP equivalents, and the recitals of Regulation (EU) 2023/1442 cite that opinion as the basis for the group limit. Every additive's limit is tabulated under specific migration limits (SML).

In the United States, no: the FDA final rule of 20 May 2022 (87 FR 31080) revoked the food-contact authorisations for DBP, leaving 8 ortho-phthalates authorised as plasticizers, namely DINP, DIDP, DEHP, DCHP, BPBG, DEP, EPEG and DIOP.

Is DBP allowed in toys and childcare articles?#

No: DBP is prohibited above 0.1 % in children's toys and childcare articles in the EU (REACH Annex XVII entry 51), the United States (16 CFR 1307.3(a), permanent), Japan (MHLW Notification 336) and, at 1,000 mg/kg in vinyl, Canada (SOR/2016-188). Toys and childcare articles were the first article categories the EU restriction covered, years before Regulation (EU) 2018/2005 extended entry 51 to all articles on 7 July 2020.

The four limits are the same number in different units in three of the four cases: 0.1 % by weight and 1,000 mg/kg are identical concentrations, so Canada's figure matches the EU, US and Japanese thresholds rather than undercutting them. The scope definitions differ instead of the numbers. Under SOR/2016-188, in force since 22 June 2016, a "toy" is a product for a child under 14 years of age and a "child care article" is one for a child under 4, and the Canadian limit applies specifically to the vinyl of those products.

Table T5b. DBP limits in toys and childcare articles, by jurisdiction.

The 8 restricted phthalates and the exempt resins are listed on CPSIA phthalate limits.

Is DBP restricted in electrical and electronic equipment under RoHS?#

Yes: Delegated Directive (EU) 2015/863 limits DBP to 0.1 % per homogeneous material in electrical and electronic equipment, applying from 22 July 2019 and from 22 July 2021 for category 8 medical devices and category 9 monitoring and control instruments. The same directive restricts DEHP, BBP and DIBP at the same level, which is why RoHS compliance for a flexible PVC part inside an appliance and REACH entry 51 compliance for the same part answer to the same 0.1 % threshold against different denominators: a homogeneous material under RoHS, the plasticised material under Annex XVII. The RoHS restriction excludes cables and spare parts for equipment placed on the market before those dates, and it leaves phthalates in toys to REACH entry 51. The four restricted phthalates and their category deadlines are on RoHS and plastic additives.

Is DBP listed under California Proposition 65?#

Yes: DBP has been on the California Proposition 65 list since 2 December 2005 for developmental toxicity and for female and male reproductive toxicity, while its isomer DIBP is not listed. No Maximum Allowable Dose Level for DBP is recorded in this reference, so no safe-harbour figure is stated here. Listing dates for every plasticizer are on California Proposition 65.

What did the 2026 TSCA risk evaluation find on DBP?#

EPA's final TSCA risk evaluation for DBP, announced in the Federal Register on 6 January 2026 (91 FR 373), finds unreasonable risk driven by specific conditions of use, not by the substance as a whole. EPA released the final evaluations in December 2025 and the notice of availability covers five phthalates together: BBP, DBP, DCHP, DEHP and DIBP.

The finding identifies risk to workers by inhalation and, for four of the five substances, to aquatic organisms, with no unreasonable risk found to consumers or to fenceline communities. The evaluation package also includes a cumulative risk analysis covering DEHP, DBP, BBP, DIBP, DCHP and DINP together, which is the first time EPA has assessed this group's combined exposure under TSCA.

A finding of unreasonable risk is not itself a restriction. Risk management under TSCA section 6(a) has not yet been issued for DBP, so no US federal limit on its industrial use follows from the 2026 notice, and the operative US restrictions on DBP remain the CPSC toy rule and the revoked FDA food-contact authorisation. The five phthalate risk evaluations and the pending section 6(a) rules are tracked on TSCA and plastic additives.

Is DBP Toxic? Health, Safety and Environmental Profile#

DBP carries a harmonised classification under the EU CLP Regulation as toxic for reproduction category 1B (H360Df) and as very toxic to aquatic life (H400), which is the legal basis for every restriction on this page. H360Df combines two statements, "may damage the unborn child" and "suspected of damaging fertility", and a category 1B classification means the evidence comes from animal studies rather than from human data. The 3 strands of evidence behind that status are listed below.

• Regulatory classification: harmonised Repr. 1B with H360Df and H400 under CLP Annex VI, plus endocrine-disrupting properties recognised under REACH Article 57(f) for human health and, since 23 January 2024, for the environment.
• Animal evidence: phthalate syndrome, the cluster of effects that rodents exposed in utero to DEHP, DBP, BBP or DIBP show, described by Paul Foster in the International Journal of Andrology in 2006 as reduced fetal testosterone, hypospadias, cryptorchidism, shortened anogenital distance and nipple retention.
• Human association: Shanna Swan and colleagues at the University of Rochester reported in Environmental Health Perspectives in 2005, across 85 mother-son pairs, an odds ratio of 10.2 (95 % confidence interval 2.5 to 42.2) for a short anogenital index in the top versus the bottom quartile of monobutyl phthalate, the DBP metabolite.

The human finding is an association and not a demonstration of cause. An odds ratio measured across 85 pairs in one cohort can support a hypothesis without establishing that DBP exposure produced the outcome, and the confidence interval of 2.5 to 42.2 is wide enough to show how imprecise the estimate is. EFSA's opinion of 18 September 2019 handled the group rather than the substance, setting a tolerable daily intake of 50 µg per kg body weight per day for DBP, BBP, DEHP and DINP together as DEHP equivalents. Exposure routes, biomonitoring and the wider evidence base sit on phthalates: health effects.

The environmental side of the classification is separate from the health side. H400 marks DBP as very toxic to aquatic life, and the Article 57(f) grounds added on 23 January 2024 extend the endocrine-disruptor finding from human health to the environment. The Article 57(f) grounds are explained under endocrine disruptors in plastics.

Is DBP a carcinogen?#

No: DBP carries no carcinogenicity classification under the EU CLP Regulation, and its California Proposition 65 listing of 2 December 2005 is for developmental and reproductive toxicity, not for cancer. The contrast with DEHP is instructive: DEHP has been on the Proposition 65 list for cancer since 1 January 1988 and carries an IARC Group 2B classification, while DBP's regulatory record names reproductive and aquatic toxicity only. No IARC evaluation for DBP is recorded in this reference, so none is stated, and the absence of a classification is not itself evidence of absence of hazard.

What Replaces DBP? Alternatives and Substitutes#

Four routes replace DBP: the isomeric terephthalate DBT and the branched DiPT for fast fusion without an ortho-phthalate, acetyl tributyl citrate for sensitive applications, dibenzoates such as DPGDB for plastisol speed, and DOTP where a general-purpose plasticizer is enough. Switching DBP for DIBP is not one of them, because DIBP sits in the same Annex XVII entry 51, the neighbouring Annex XIV entry and the same food-contact group restriction.

Table T6. DBP and its alternatives compared.

Footnote: substitution factors are typical figures from one secondary source (Kanademy), not supplier data. Status as of 22 September 2026.

The full replacement landscape is mapped on non-phthalate plasticizers.

DBP vs DIBP#

DIBP is not a compliance route away from DBP: the two isomers share REACH Annex XVII entry 51, sit in consecutive Annex XIV entries (6 and 7) and are both weighted into the same food-contact budget, DBP at five times and DIBP at four times the DEHP equivalent. Both carry the harmonised classification Repr. 1B with H360Df, and both lost their US food-contact authorisation in the FDA final rule of 20 May 2022.

Two differences are real but run in opposite directions. DIBP is not listed under California Proposition 65 on the OEHHA list of 31 July 2026, while DBP has been listed since 2 December 2005, so a Proposition 65 warning obligation can turn on which isomer a compound contains. Against that, DIBP is not authorised as a food-contact additive at all, holding FCM number 1085 only for the purposes of group restrictions 32 and 36, while DBP holds an individual SML of 0.12 mg/kg. Switching to diisobutyl phthalate does not leave entry 51.

Neither difference produces a compliance gain in a plastics application. A compound reformulated from DBP to DIBP still exceeds the 0.1 % article limit at any functional loading, still needs an authorisation for the EU market after the sunset dates of 21 February 2015 that both entries share, and still counts into group restriction 36 when the article contacts food.

DBP vs BBP and DEHP#

BBP is DBP's closest functional match and DEHP its closest commercial one: BBP is the other fast-fusing low-molecular-weight phthalate, used in vinyl flooring and foams, while DEHP is the general-purpose ester that carried the bulk volume. BBP (butyl benzyl phthalate) is the other fast-fusing low-molecular-weight phthalate, with an SML of 6 mg/kg since Regulation (EU) 2023/1442, and it carries H410 in addition to the H360Df and H400 that DBP also carries.

All three sit in REACH Annex XVII entry 51 and in group restriction 36, so none of them is an escape route from the others, and all three entered the Candidate List on the same day, 28 October 2008. DEHP is the commercial reference of the group, the C8 branched ester at substitution factor 1.00 and Annex XIV entry 4, against DBP's entry 6 and BBP's entry 5.

Their food-contact limits differ by a factor of 50 across the group: DBP 0.12 mg/kg, DEHP 0.6 mg/kg and BBP 6 mg/kg, a spread that mirrors the potency weighting inside group restriction 36. A compound that swaps DBP for BBP therefore gains headroom under both the individual and the group limit while keeping the fast-fusion behaviour, but it stays inside entry 51 and inside the 0.1 % article limit. DEHP (DOP, dioctyl phthalate) is the reference ester at substitution factor 1.00 and the only one of the four still authorised for US food contact.

Dibutyl terephthalate (DBT) and DiPT as direct replacements#

Dibutyl terephthalate is the like-for-like replacement for DBP: the same formula C16H22O4, the same molecular weight of 278.34 g/mol and the same fast fusion, with the ester groups moved to the para position so it is not an ortho-phthalate. Moving the second ester group from the adjacent ring carbon to the opposite one takes the substance out of the ortho-phthalate class and out of the restrictions written for it: DBT is not on the REACH Candidate List, is not in Annex XVII and is not listed in Annex I of Regulation (EU) No 10/2011.

Its industrial position is established rather than experimental. DBT is registered under REACH at 1,000 to 10,000 tonnes per year, and the ECHA use mapping records it at 10 to 35 wt% in soft PVC and polyurethane, the same band recorded for DBP. DiPT, sold as Elatur DPT, is recorded as a replacement for DBP and DIBP under that trade name alone, with no CAS number, dosage or regulatory record available here, so nothing further is stated about it.

ATBC, benzoates and TXIB as fast-fusing replacements#

ATBC matches DBP's 10 to 35 wt% use range in PVC without a hazard classification, which is why it is the standard replacement in toys, medical devices and food-contact film. ATBC (acetyl tributyl citrate) covers the same 10 to 35 wt% band in PVC without a hazard classification: it has no harmonised CLP classification, 2,150 of 2,180 notifiers report that it does not meet GHS hazard criteria, it is not an SVHC, and it holds FCM 138 under group restriction 32 with no individual SML. In the United States it is covered by the prior sanction at 21 CFR 181.27 and by 21 CFR 178.3910 for surface lubricants.

Dibenzoates cover the plastisol side of the gap. Dipropylene glycol dibenzoate is a fast fuser in its own right, and the monobenzoates add viscosity depression to fast fusion according to the patent literature, which is the combination a DBP-containing paste needed an additive package to achieve. TXIB is one of the five plasticizers Wiesinger and colleagues found replacing restricted phthalates in PVC toys.

The replacement pattern is documented rather than assumed. Helene Wiesinger and colleagues at ETH Zurich reported in Environmental Science & Technology in 2024 that ATBC, DEHT, TXIB, DINCH and epoxidized soybean oil are the substances now found in place of the restricted phthalates in toy PVC, which identifies the commercial answer to the entry 51 restriction from the article side rather than from supplier literature.

Who Supplies DBP? Trade Names, Grades and Sourcing#

DBP is sold under 4 recorded trade names, Palatinol C, Vestinol C, Kodaflex DBP and Unimoll DB, and its EU supply is a phase-out picture: the REACH registration statuses include a cease-of-manufacture entry, and the substance has needed authorisation since 21 February 2015. No current manufacturer of DBP is recorded in this reference, so Table T7 names the brand family behind each trade name and states current availability as not recorded rather than guessing at it. Producers and their brand lines are listed in the directory of plasticizer manufacturers.

Table T7. DBP trade names and brand families.

Footnote: the brand family identifies the trade-name line, not a current DBP offer. No company is named here as a DBP producer because none is recorded in this reference's supplier data.

No DBP price is recorded in this reference, and the price driver is qualitative rather than quoted: a restricted substance with an authorisation requirement, a shrinking EU registrant base and no volume growth prices on availability rather than on feedstock. Buyers should ask any supplier for the REACH registration number, the authorisation route for the intended EU use and a current safety data sheet before ordering. Price drivers across the ester range are tracked on plasticizer prices.

How Does DBP Fit into the Wider Phthalate Story?#

DBP is the short-chain end of the phthalate family, the group that still accounts for the majority of plasticizer volume even after the low-molecular-weight members lost their markets. Phthalates reached about 5.5 Mt in 2015, with 90 to 95 % of that volume used as PVC plasticizers, and more than 85 % of European plasticizer consumption goes into PVC, according to European Plasticisers.

The class outlived its restricted members. The measures of the past two decades act on 4 of those esters, DEHP, DBP, BBP and DIBP, while the high-molecular-weight members such as DINP, DIDP and DPHP stay outside REACH Annex XVII entry 51, so a phthalate on a specification sheet says nothing about that substance's legal status until the CAS number is read. Country-by-country rules are compared on phthalate restrictions worldwide.

Non-plastics uses of DBP: adhesives, printing inks and lacquers#

Outside plastics, DBP is used in adhesives, printing inks and nitrocellulose lacquers, which are the markets that made it a high-volume chemical and the reason it appears in consumer-exposure studies. Those three applications rest on the same solvent behaviour that makes DBP a plasticizer for polyvinyl acetate and cellulose nitrate, so the chemistry is continuous even though the product categories are not. A lacquer, an ink vehicle and a cellulose plastic all rely on the same solvating C4 ester, which is why exposure studies and plastics restrictions have been reading the same substance from two different directions for decades.

Adhesives, coatings, inks and cosmetics sit outside this reference's plastics scope, and their rules, which run through different instruments and different annexes, are not covered here. That border is why the applications section above names only cellulose plastics, PVC plastisols and fast-fusing PVC blends, while the larger historical volumes appear only in this one supplementary paragraph. What the phthalate-free label actually covers is explained on phthalate-free plastics.

DBP in recycled PVC and legacy articles#

Legacy phthalates re-enter new articles through recycled PVC, a route Helene Wiesinger and colleagues at ETH Zurich documented in Environmental Science & Technology in 2024 when 16 % of 151 new Swiss PVC floorings exceeded 0.1 wt% of regulated substances. The substances they measured were mainly lead and DEHP rather than DBP, so the transferable point is the mechanism and not the number: a restricted additive that was legal when an article was made returns to the market inside the recyclate stream. Restabilization and legacy-substance screening are covered under additives for recycled plastics.

The timescale is long. Klotz and colleagues reported in Environmental Science & Technology in 2024 that without an active phthalate-removal step, DEHP stays above 0.1 wt% in recycled flooring for decades, which sets the horizon for any closed-loop PVC system built on legacy material.

A recyclate stream therefore has to be screened rather than assumed. Entry 51 applies to the article that reaches the market, not to the history of the material inside it, so a compounder using post-consumer flexible PVC carries the same 0.1 % obligation for DBP as one buying virgin resin and has to establish the content by analysis. How additive choice decides recyclability is set out on design for recycling.

DBP in the history of plasticized PVC#

DBP was one of the first plasticizers of the PVC era: Waldo Semon plasticized PVC at B.F. Goodrich in 1926, and dibutyl phthalate was in use by 1933, according to the historical record this reference cites. Both dates come from a secondary historical source rather than from a primary document, so they mark the sequence rather than fixing it precisely.

The sequence itself explains the regulatory position. DBP entered plastics almost a century before the hazard data that now governs it, which is why the substance appears in legacy articles, in recyclate and in biomonitoring long after its plastics market closed. The full timeline from camphor to HALS is on the history of plastic additives.

How is DBP detected in a plastic sample?#

DBP is measured in a plastic sample by solvent extraction followed by gas chromatography with mass spectrometry, the same route used for the other three phthalates of REACH Annex XVII entry 51. Extraction releases the unbound ester from the polymer matrix, and the mass spectrometer separates DBP from its isomer DIBP, which chromatography alone does not always resolve. No DBP-specific standard number is recorded here, only the technique. Sample preparation and instrument choice are covered on additive analysis and deformulation of plastics.

Does DBP need a safety data sheet and a GHS label?#

Yes: because DBP carries a harmonised CLP classification as Repr. 1B (H360Df) and as very toxic to aquatic life (H400), every supplier must provide a safety data sheet and a GHS label with the signal word Danger. The label carries the health-hazard pictogram for the reproductive-toxicity classification and the environment pictogram for the aquatic classification, together with both hazard statements. What each section must contain is set out on safety data sheets and GHS labels.