DIBP (Diisobutyl Phthalate): Properties, Uses in Plastics and Regulatory Status

DIBP (diisobutyl phthalate, also written DiBP; CAS 84-69-5) is a low-molecular-weight ortho-phthalate used as a gelling aid and plasticizer for nitrocellulose, adhesives and polymer dispersions, and it is one of the 4 ortho-phthalate plastic additives that the European Union has capped at 0.1 % in the plasticised material of all articles since 7 July 2020. Because DIBP carries a harmonised reproductive-toxicity classification and sits on the REACH Authorisation List, what a formulator may still do with it is decided by regulation rather than by performance.

ECHA placed DIBP on the REACH Candidate List on 13 January 2010, Regulation (EU) No 125/2012 moved it into Annex XIV as entry 7 with a sunset date of 21 February 2015, Regulation (EU) 2018/2005 extended the 0.1 % limit of Annex XVII entry 51 to every article from 7 July 2020, and Regulation (EU) No 10/2011 gives the substance the number FCM 1085 without authorising it as an additive in food-contact plastics. DIBP is one of 56 plasticizer pages in our directory of plastic additives, each with the same identity, dosage and regulatory fields.

Gelation speed, a typical substitution factor of 0.92 against DEHP and a single sourced dosage of up to 15 % in water-based adhesives are the whole technical case for the substance. Everything else about DIBP is regulatory, from the straight-chain isomer DBP it was once swapped for to the terephthalate and benzoate esters that now replace it.

Table T1: DIBP identity card. Sources: PubChem CID 6782, ECHA Candidate List, Regulation (EU) No 10/2011.

What Is DIBP (Diisobutyl Phthalate)?#

DIBP is the bis(2-methylpropyl) ester of ortho-phthalic acid (benzene-1,2-dicarboxylic acid), a low-molecular-weight plasticizer whose two short branched C4 chains make it a strong solvent for polymers rather than a general-purpose softener. The substance forms when ortho-phthalic acid reacts with isobutanol, so both ester arms carry the branched 2-methylpropyl group instead of a linear chain, and both sit in the ortho position, adjacent to each other on the benzene ring. That combination of a short chain, a branch point and ortho substitution is what separates DIBP from the C8 and C9 esters that carry the volume of the plasticizer market.

What is diisobutyl phthalate in formulation terms? It is a solvating ester that answers the ASTM D883 definition of a plasticizer, a substance incorporated into a plastic or elastomer to increase its flexibility, workability or distensibility, while working mainly through solvent power rather than through lubrication. DIBP belongs to the largest additive family by weight, and the hub on plasticizers for plastics compares every class from ortho-phthalates to terephthalates, citrates and benzoates. Our source library records no production-process data for DIBP, so no esterification conditions, catalysts or yields are stated on this page.

What is another name for diisobutyl phthalate?#

Diisobutyl phthalate is also written di-isobutyl phthalate and abbreviated DiBP, and its systematic name is bis(2-methylpropyl) benzene-1,2-dicarboxylate. The same substance appears in catalogues as bis(2-methylpropyl) phthalate and under 3 trade names, Palatinol IC, Kodaflex DIBP and Hatcol DIBP, of which only Palatinol is attributable: Palatinol is a BASF plasticizer brand. The brand owners of Kodaflex DIBP and Hatcol DIBP are not recorded in our source library and are therefore not stated here.

Is DIBP the same as DBP?#

No: DIBP (CAS 84-69-5) carries two branched isobutyl chains while DBP (CAS 84-74-2) carries two straight-chain n-butyl chains, and the two substances have separate CAS numbers, separate Candidate List dates, separate Annex XIV entries and different Proposition 65 status. Both are isomers of the same molecular formula C16H22O4 with the same molecular weight of 278.34 g/mol, which is why laboratory reports and supplier literature confuse them so often. The straight-chain isomer, DBP (dibutyl phthalate), joined the REACH Candidate List on 28 October 2008, fifteen months before DIBP, and it holds Annex XIV entry 6 against DIBP's entry 7.

The two esters are treated identically in exactly 2 places. REACH Annex XVII entry 51 covers DEHP, DBP, BBP and DIBP at the same limit of 0.1 % by weight in the plasticised material of articles, individually or in any combination, and Delegated Directive (EU) 2015/863 restricts the same 4 phthalates at 0.1 % in the homogeneous material of electrical and electronic equipment.

Table T2: DIBP against DBP. Substitution-factor values are typical figures from one secondary source, not supplier data.

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

DIBP, DBP 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 benzene ring. DIBP carries branched isobutyl chains in the ortho position, DBP (CAS 84-74-2) carries linear n-butyl chains in the same ortho position, and dibutyl terephthalate (CAS 1962-75-0) carries linear butyl chains in the para position, on opposite corners of the ring. Branching changes solvating power and volatility; ring position changes how the molecule is metabolised, because a para-substituted diester does not form the stable monoester that the ortho-phthalate toxicity pathway runs through.

The consequence is the sharpest illustration of why formula is not status. DIBP and DBP both carry the harmonised classification Repr. 1B with hazard statement H360Df, both sit on the REACH Candidate List and both occupy Annex XIV entries, while dibutyl terephthalate (DBT) carries the same formula and the same molecular weight but none of the three listings.

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

DIBP 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. European Plasticisers defines the low-molecular-weight class by that 3 to 6 carbon backbone and groups DEHP with it for regulatory purposes even though DEHP's alcohol chain is C8. Where the cut-off sits between low vs high molecular weight ortho-phthalates decides which restrictions apply, because the high-molecular-weight esters DINP, DIDP and DPHP are not covered by entry 51 at all.

The 4 substances named in REACH Annex XVII entry 51 are listed below.

• DEHP, bis(2-ethylhexyl) phthalate, CAS 117-81-7
• DBP, dibutyl phthalate, CAS 84-74-2
• BBP, benzyl butyl phthalate, CAS 85-68-7
• DIBP, diisobutyl phthalate, CAS 84-69-5

How Does DIBP Plasticize and Gel a Polymer?#

DIBP plasticizes a polymer by pushing its short branched ester molecules between the 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 sites on the polymer backbone, the branched alkyl tails occupy space between chains, and the result is a compound whose chain segments move at a lower temperature than the unplasticized resin. Compatibility decides whether that happens at all: a plasticizer stays in a polymer when the solubility-parameter difference between the two sits within roughly plus or minus 1.5 (cal/cm3)^0.5.

Why does a branched C4 chain make DIBP a solvent rather than a general-purpose softener? Shorter alcohol chains raise solvating power and lower the fusion temperature, while longer and more branched chains lower volatility, so a C4 ester sits at the solvating end of the scale and pays for it with higher volatility than a C9 or C10 ester. The 4 classic plasticization theories that describe this behaviour are listed below.

• Lubricity theory, which treats the plasticizer as an internal lubricant between chains
• Gel theory, which treats plasticization as the breaking of gel structure at polymer-polymer contact points
• Free volume theory, which treats plasticization as an increase in the space available for segmental motion
• Mechanistic theory, the solvation-desolvation equilibrium that explains reversible plasticizer action

The four theories are explained with solubility parameters and compatibility windows on how plasticizers work. Our source library records no solubility parameter, gelation temperature or glass transition value for DIBP itself, so none is given here.

Why is DIBP called a gelling aid and a fast fuser?#

DIBP is called a gelling aid because it swells and dissolves polymer particles at a lower temperature than a general-purpose ester, which is the property that decides how fast a paste or a dispersion gels. In a PVC plastisol the dispersed resin particles gel and fuse between 140 and 220 °C (284 and 428 °F), and a solvating plasticizer moves that window downward, which shortens oven time and lowers line energy. The 5 fast fusers recorded in our source library are listed below.

• DBP, dibutyl phthalate
• DIBP, diisobutyl phthalate
• BBP, benzyl butyl phthalate
• DIHP, diisoheptyl phthalate
• Dipropylene glycol dibenzoate

Fast fusion carries one recurring penalty: this group can cause a strong paste viscosity rise over storage time, which is why formulators dose fast fusers as a fraction of the total plasticizer rather than as the whole. Patent literature reports that monobenzoates such as isononyl benzoate and isodecyl benzoate combine fast fusion with viscosity depression, which is the trade-off that fast-fuser blends and their shelf-life behaviour are compared on in plasticizers for PVC plastisol.

What Are the Physical and Chemical Properties of DIBP?#

DIBP is an oily, colourless liquid with a slight ester odour that is denser than water and insoluble in it, with a melting point of -64 °C (-83 °F), a boiling point of 296.5 °C (565.7 °F) and a flash point of 185 °C (365 °F, open cup). The values below are taken from the PubChem record for CID 6782, with each row carrying the handbook that PubChem prints beside it.

Table T3: physical and chemical properties of DIBP, with the handbook source named per row.

The spread between those numbers is a sourcing problem rather than a measurement problem. PubChem carries NTP (1992) and USCG (1999) values side by side, so the density appears as 1.047 at 68 °F and as 1.0490 g/cm3 at 15 °C and the flash point as 365 °F and 385 °F; the Wikipedia entry prints a third set (density 1.038 g/cm3, melting point -37 °C), so a specification must name the source it follows. No vapour pressure, viscosity or refractive index for DIBP is recorded in our source library, and none is stated here.

Which Polymers Use DIBP, and at What Dosage?#

DIBP is used in 3 polymer systems, polyvinyl acetate and acrylic dispersions, nitrocellulose, and historically PVC, and the only dosage figure with a primary source behind it is up to 15 % in water-based adhesives. That figure comes from the HSDB record carried by PubChem CID 6782 and covers adhesive formulations, not plastic compounds. No sourced DIBP dosage exists for PVC, for nitrocellulose or for any other plastic, and every line of the table below that lacks a figure says so rather than offering a plausible range.

Table T4: recorded DIBP levels by system. Four of the five rows carry no DIBP-specific dosage figure.

How does a weight-percent figure convert to the phr a compound recipe uses? Weight percent equals the parts of one ingredient divided by the total parts of the whole formulation, multiplied by 100, so 15 phr of DIBP in a system of 100 phr resin plus 15 phr plasticizer gives 15 / 115 x 100 = 13.0 wt%. A real compound also contains fillers, stabilizers and lubricants, so the divisor is the full formulation total rather than resin plus plasticizer alone. Formulation recipes give levels in PHR (parts per hundred resin), which converts to weight percent only with that full total in hand.

DIBP in PVAc and acrylic dispersions#

DIBP works in polyvinyl acetate and acrylic dispersions as a solvating plasticizer that softens the polymer particles as the water leaves, which is why the reported level in water-based adhesives reaches 15 %. In a dispersion the polymer arrives as discrete particles rather than as a continuous melt, and film formation depends on those particles deforming and fusing as the aqueous phase evaporates. A short branched ester with high solvating power lowers the temperature at which the particles soften enough to coalesce, so the adhesive forms a continuous film at ambient conditions instead of needing heat.

That coalescing and gelling role is the reason DIBP appears at high percentages in adhesive formulations and at no recorded percentage in plastic compounds. Our source library records the polymer systems for DIBP without a dosage for either PVAc or acrylic dispersions, so the 15 % figure stays attached to water-based adhesives, where the HSDB record places it, and is not generalised to dispersions as a class.

DIBP in nitrocellulose and in legacy PVC#

DIBP plasticizes nitrocellulose and once served as an efficient co-plasticizer in PVC compounds, where its typical substitution factor of 0.92 meant about 8 % less material than DEHP for the same hardness. Nitrocellulose is a cellulose ester with strong intermolecular hydrogen bonding, and a solvating plasticizer is what makes the resulting film flexible rather than brittle. In legacy PVC compounds DIBP sat alongside a general-purpose ester, and it has also been recorded as a legacy plasticizer in polyurethane systems and sealants.

The PVC use is now closed inside the EU. Annex XVII entry 51 limits DIBP to 0.1 % by weight in the plasticised material of every article placed on the market since 7 July 2020, a level no plasticizer function survives, so the compound recipes that once carried it have been reformulated. The esters that replaced DIBP in that role are compared on plasticizers for PVC. The 0.92 substitution factor is a typical value from a single secondary source and is never supplier data.

What Is DIBP Used For?#

DIBP has 3 recorded uses, adhesives, lacquers, and service as a gelling aid alongside other plasticizers, which means most of its volume has always sat next to plastics rather than inside them. The AI-generated summaries that dominate these search results describe DIBP as "primarily used as a plasticizer to soften and add flexibility to plastics", and the application record does not support the word "primarily". The 3 recorded uses are listed below.

• Adhesives, in particular water-based polyvinyl acetate and acrylic systems
• Lacquers, in particular nitrocellulose lacquers
• Gelling aid used together with other plasticizers in a blend

Adhesives and sealants#

Adhesives are DIBP's largest recorded use, at up to 15 % of a water-based formulation according to the HSDB record behind PubChem CID 6782. The polymer being plasticized in those systems is polyvinyl acetate or an acrylic copolymer, and the function is film formation rather than the permanent flexibility a plasticizer delivers in flexible PVC. Sealants and polyurethane systems carry DIBP as a legacy plasticizer in the same solvating role.

Adhesives and sealants sit on the edge of the plastics border of this reference, so the chemistry is recorded here and the market is not. Inside the EU, any adhesive that ends up as part of an article is caught by the same 0.1 % limit as the article itself, because entry 51 applies to the plasticised material rather than to the ingredient that put the phthalate there.

Lacquers, nitrocellulose and inks#

DIBP plasticizes nitrocellulose lacquers, the coating chemistry that also made DBP a standard fast fuser for decades. Printing inks carry the same solvating ester for the same reason, to keep a cellulose or acrylic binder film flexible after the solvent leaves. Coatings and printing inks are outside the plastics border of this reference and are treated in one supplementary paragraph at the end of this page rather than developed here.

What products still contain DIBP?#

Inside the EU, DIBP survives only where Annex XVII entry 51 does not reach: articles for exclusively industrial or agricultural use, outdoor articles without prolonged skin contact, vehicles and aircraft placed on the market before 7 January 2024 and their spare parts, laboratory measuring devices, and imported articles that were never compliant. Entry 51 also carves out food-contact materials under Regulation (EU) No 10/2011, medical devices, electrical and electronic equipment under RoHS and the immediate packaging of medicinal products, each of which is governed by its own instrument instead. Tan and colleagues, writing in Food Chem X in 2026, measured DIBP at 2.5 to 5.0 µg/L migrating from take-out containers and bags with an SPME-GC method. What a supplier means by phthalate-free plastics decides whether DIBP is covered by the claim, and no market share or tonnage for non-compliant articles is recorded in our source library.

How Does DIBP Perform as a Plasticizer?#

DIBP is more efficient than DEHP on a weight basis: its typical substitution factor is 0.92, meaning about 8 % less DIBP gives the same hardness as DEHP at the reference value of 1.00, and only DBP at 0.86 is more efficient among the four restricted ortho-phthalates. Efficiency of this kind is a weight economy, not a performance verdict, because the same short branched chain that delivers it also raises volatility. A C4 ester at 278.34 g/mol loses more material at processing temperature and over service life than a C9 or C10 ester, and lower molecular weight is the direct cause.

Fast fusion is the second half of the trade-off. Short chains raise solvating power and lower the fusion temperature, which shortens gelation time, and this group can produce a strong paste viscosity rise over storage. Neither behaviour has a measured value for DIBP in our source library, and no volatility, migration, extraction, low-temperature or Shore A figure is stated here for that reason.

Table T5: performance indicators for DIBP. Substitution factors are typical values from one secondary source, not supplier data.

Substitution factors for 15 plasticizers are listed on plasticizer efficiency and substitution factors, where the same reference basis of DEHP at 1.00 applies.

How Does DIBP Interact with Other Plasticizers and Additives?#

DIBP is normally a minority partner rather than the main plasticizer: our source library records its function as a gelling aid used with other plasticizers, which means it is dosed to set gelation speed while a general-purpose ester carries the softening. The 3 interaction rules that govern that partnership are listed below.

• Compatibility first: the polymer-to-plasticizer solubility-parameter difference stays within roughly plus or minus 1.5 (cal/cm3)^0.5 for both partners, or the blend exudes
• Division of labour: the solvating partner sets fusion and gelation temperature, the general-purpose partner sets final hardness and permanence
• Viscosity budget: fast fusers including DBP, DIBP, BBP, DIHP and dipropylene glycol dibenzoate can raise paste viscosity strongly over storage, so their share of the total plasticizer is capped

Patent literature reports that monobenzoates deliver the same fast fusion with viscosity depression instead of viscosity rise, which is why benzoate and terephthalate esters have taken over the partner role that DIBP once held. Modern gelling partners come from the non-phthalate plasticizers group instead, and a blend built from them carries no Annex XIV or entry 51 exposure at all.

What Is the Regulatory Status of DIBP?#

DIBP is registered under REACH, has been on the Candidate List since 13 January 2010, sits in Annex XIV as entry 7 with a sunset date of 21 February 2015, is limited to 0.1 % in the plasticised material of all articles under Annex XVII entry 51, is not authorised as an additive in EU food-contact plastics, and is restricted in electrical equipment, in US children's products and, since the final 2026 risk evaluation, faces US risk management. The matrix below records each instrument separately, as of 23 September 2026.

Table T6: DIBP regulatory matrix across 13 instruments, status as of 23 September 2026.

Entry 51 and its exemptions are set out in full on REACH Annex XVII restrictions, which lists the article categories that stay outside the 0.1 % limit.

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

Yes on both counts: DIBP has been on the REACH Candidate List since 13 January 2010 as toxic for reproduction under Article 57(c), and it moved to Annex XIV as entry 7, so using it in the EU after the sunset date of 21 February 2015 requires an authorisation. Endocrine-disrupting properties under Article 57(f) were added to the grounds later, and Regulation (EU) 2021/2045, adopted on 23 November 2021, wrote those properties into the Annex XIV entries of DEHP, BBP, DBP and DIBP. DIBP joined the SVHC Candidate List on 13 January 2010, fifteen months after DEHP, DBP and BBP.

Authorisation is a use-by-use permission rather than a product approval, and the latest application date of 21 August 2013 closed before the sunset date, so a company that did not apply in time lost the legal route entirely. Entry 7 and its sunset date sit in the REACH Annex XIV Authorisation List beside DEHP at entry 4, BBP at entry 5 and DBP at entry 6, all four carrying the same 21 February 2015 sunset.

Why is DIBP restricted in the EU?#

DIBP is restricted in the EU because it carries a harmonised classification as toxic for reproduction category 1B with the hazard statement H360Df, and that one classification triggered 4 separate instruments between 2010 and 2020. Article 57(c) of REACH makes a category 1B reproductive toxicant eligible for the Candidate List automatically. The 4 instruments, in date order, are listed below.

1. REACH Candidate List inclusion, 13 January 2010, on Article 57(c) grounds of toxicity for reproduction
2. REACH Annex XIV entry 7, added by Regulation (EU) No 125/2012, with a latest application date of 21 August 2013 and a sunset date of 21 February 2015
3. RoHS, 0.1 % in homogeneous material under Delegated Directive (EU) 2015/863, applying from 22 July 2019 and from 22 July 2021 for categories 8 and 9
4. REACH Annex XVII entry 51, 0.1 % in the plasticised material of all articles, extended from toys and childcare articles to every article by Regulation (EU) 2018/2005 from 7 July 2020

Each instrument does a different job: authorisation controls use inside the EU, the Annex XVII restriction controls the article regardless of where it was made, and RoHS controls the material inside electrical equipment. How other jurisdictions handle the same 4 substances is compared on phthalate restrictions worldwide.

Is DIBP allowed in food-contact plastics?#

No, in neither jurisdiction: DIBP is not an authorised additive under Regulation (EU) No 10/2011, and the US FDA revoked its food-contact authorisation in the final rule of 20 May 2022 (87 FR 31080). The FDA rule removed 23 phthalates from the food-contact clearances and left exactly 8 ortho-phthalates authorised as plasticizers, DINP, DIDP, DEHP, DCHP, BPBG, DEP, EPEG and DIOP, and DIBP is not among them. On the EU side the position is stricter still, because Table 1 of Annex I to Regulation (EU) No 10/2011 is a positive list and a substance absent from it may not be used as a plasticiser or as any other additive at all.

The EU nevertheless assigns DIBP the food-contact material number FCM 1085 and counts it in 2 group restrictions, group restriction 32 at an SML(T) of 60 mg/kg across 22 plasticizer FCM numbers and group restriction 36 at an SML(T) of 0.6 mg/kg expressed as DEHP equivalents. Both sit under the general overall migration limit of 10 mg/dm2, or 60 mg/kg for articles intended for infants. Group restrictions 32 and 36 and the overall migration limit are explained on EU 10/2011.

What does FCM 1085 mean if DIBP is not authorised?#

FCM 1085 is a bookkeeping number, not a permission: Regulation (EU) 2023/1442 gave DIBP an FCM number so that any DIBP reaching the plastic as a polymerisation aid still counts against group restriction 32 (60 mg/kg) and group restriction 36 (0.6 mg/kg in DEHP equivalents, with DIBP weighted four times). Group restriction 36 sums the four ortho-phthalates as DBP x5 plus DIBP x4 plus BBP x0.1 plus DEHP x1, so the weighting decides how much headroom a residue consumes. Arithmetic from that published weighting: 0.05 mg/kg of DIBP contributes 0.05 x 4 = 0.20 mg/kg of the 0.6 mg/kg budget, a third of the total, before any other phthalate is counted. A polymer production aid is not an additive in the legal sense, which is exactly why DIBP has a number but no authorisation.

Is DIBP allowed in toys and childcare articles?#

No: DIBP is limited to 0.1 % in toys and childcare articles in the EU under REACH Annex XVII entry 51 and is prohibited above 0.1 % in children's toys and child care articles in the United States under 16 CFR 1307.3(b), effective 25 April 2018. The US provision came in with the final rule of 27 October 2017 (82 FR 49982) and covers DINP, DIBP, DPENP, DHEXP and DCHP, alongside the permanent prohibition on DEHP, DBP and BBP in 16 CFR 1307.3(a).

Both limits are expressed as 0.1 % by weight of the plasticized component rather than of the finished toy, so a single accessible plasticized component above the threshold makes the whole article non-compliant. The eight phthalates of 16 CFR 1307 are listed on CPSIA phthalate limits. Limits in China, Japan and Mercosur are not recorded in our source library and are not stated here.

Is DIBP restricted under RoHS?#

Yes: DIBP is one of the 4 phthalates that Delegated Directive (EU) 2015/863 added to RoHS at 0.1 % in homogeneous material, applying from 22 July 2019 and from 22 July 2021 for categories 8 and 9. Categories 8 and 9 cover medical devices and monitoring and control instruments, which received the two-year extension. The four RoHS phthalates and their category dates are on RoHS and plastic additives.

Is DIBP listed under California Proposition 65?#

No, DIBP is not on the Proposition 65 list as of the OEHHA list of 31 July 2026, while DBP and BBP have been listed since 2 December 2005 and DEHP since 1 January 1988 for cancer and since 24 October 2003 for developmental and male reproductive toxicity. This is the single point where the US treatment of DIBP and DBP diverges, and a warning obligation that attaches to one does not attach to the other. Listing dates for every plasticizer are tabulated on California Proposition 65.

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

EPA released the final TSCA risk evaluation for DIBP in December 2025 and published the notice of availability on 6 January 2026 (91 FR 373), finding unreasonable risk driven by specific conditions of use, in the same notice that covered BBP, DBP, DCHP and DEHP. According to EPA's risk-evaluation page for DIBP, the unreasonable risk falls on workers from 4 conditions of use and on the environment from 7, with US production below 1 million pounds per year; the Federal Register notice itself confirms only the general finding. EPA's cumulative risk analysis for phthalates covers DEHP, DBP, BBP, DIBP, DCHP and DINP together, which is the mechanism by which the exposures from all 6 substances are assessed as one.

A risk evaluation is a finding rather than a prohibition. The next step is risk management under TSCA section 6(a), and no final risk-management rule for DIBP is recorded in our source library. Draft-stage documents from August 2025 still circulate and still rank in search results, so the 6 January 2026 notice is the reference that matters. How a TSCA risk evaluation becomes a section 6(a) rule is explained on TSCA and plastic additives.

Is DIBP Toxic? Health, Safety and Environmental Profile#

DIBP carries a harmonised classification under Annex VI of the CLP Regulation as toxic for reproduction category 1B, with the hazard statement H360Df: it may damage the unborn child and is suspected of damaging fertility. A harmonised classification binds every supplier in the EU and is not open to a company's own reinterpretation. The 3 layers of that profile are listed below.

• Classification: Repr. 1B, H360Df, harmonised under Annex VI of Regulation (EC) No 1272/2008
• Evidence base: rodent anti-androgenic effects and human epidemiology linking phthalate metabolites to reproductive endpoints
• Regulatory consequence: Candidate List entry on Article 57(c) grounds, Annex XIV entry 7, Annex XVII entry 51 and RoHS

Foster described the rodent evidence in the International Journal of Andrology in 2006 as phthalate syndrome, a cluster of anti-androgenic developmental effects produced by ortho-phthalate esters in rats. Human evidence remains correlative: Swan and colleagues at the University of Rochester reported in Environmental Health Perspectives in 2005, in 85 mother-son pairs, that four phthalate metabolites including monoisobutyl phthalate can be inversely related to the anogenital index. The rodent and human evidence behind the Repr. 1B classifications is summarised on phthalates: health effects.

Endocrine-disrupting properties under Article 57(f) were added to the Candidate List grounds for the four restricted ortho-phthalates, and Regulation (EU) 2021/2045 carried them into the Annex XIV entries in 2021. The Article 57(f) grounds are part of the wider question of endocrine disruptors in plastics. On the environmental side, DIBP is not listed under the EU POPs Regulation (EU) 2019/1021, and no LD50, NOAEL or ecotoxicity value for DIBP is recorded in our source library.

What Replaces DIBP? Alternatives and Substitutes#

Our source library names 2 direct replacements for DIBP, DOTP and dibutyl terephthalate, and both work by moving the ester groups from the ortho to the para position so the substance leaves the phthalate restrictions behind. The table below sets the two terephthalates against DIBP and the three ortho-phthalates that share its legal fate.

Table T7: DIBP against its three restricted peers and two terephthalate replacements. Substitution-factor values are typical figures from one secondary source, not supplier data.

Full property data for the replacement esters sit on the plasticizer comparison page.

DIBP vs DBP: why swapping one for the other no longer works#

DIBP was once the cheaper stand-in for DBP, and that is no longer a compliance route: both are on the REACH Candidate List, both are in Annex XIV with the same sunset date of 21 February 2015, both fall under Annex XVII entry 51 at 0.1 %, and both are restricted under RoHS. Search summaries still repeat the historical description of DIBP as "a cost-effective substitute for dibutyl phthalate", and that description has been regulatorily false in the EU since 2015 at the latest. Efficiency does not change the answer either, since the two substitution factors, 0.92 and 0.86, sit within 7 % of each other.

One divergence survives, and it is a US one. Dibutyl phthalate carries the only listing that separates the two, Proposition 65 since 2 December 2005, while DIBP remains absent from the OEHHA list of 31 July 2026. A product sold into California therefore carries a warning obligation for DBP that it does not carry for DIBP, which is the one and only sense in which the swap still changes anything.

DIBP vs DEHP and BBP#

DEHP and BBP share DIBP's legal fate and not its chemistry: all three sit in Annex XVII entry 51 and in Annex XIV, but DEHP is a C8 general-purpose softener at 390.6 g/mol and BBP carries one butyl and one benzyl arm at 312.4 g/mol, while DIBP is the short branched C4 gelling aid at 278.34 g/mol. DEHP (DOP, dioctyl phthalate) is the C8 general-purpose ester that entry 51 restricts alongside DIBP, and it is the 1.00 reference for every substitution factor on this page. DEHP also keeps one legal route that DIBP never had, an authorisation for medical devices with a latest application date of 1 January 2029 and a sunset date of 1 July 2030 under Regulation (EU) 2023/2482.

BBP occupies the middle ground between the two on solvating power, since its benzyl arm makes it a strong solvator for PVC flooring and foams. BBP (butyl benzyl phthalate) keeps an SML of 6 mg/kg under FCM 159 that DIBP never had, because BBP appears on the positive list of Regulation (EU) No 10/2011 and DIBP does not. All three carry harmonised Repr. 1B classifications, and BBP and DEHP add aquatic hazard statements that DIBP's entry does not include.

DOTP and dibutyl terephthalate as non-ortho-phthalate replacements#

Dibutyl terephthalate is the closest chemical replacement for DIBP: same formula C16H22O4, same molecular weight of 278.34 g/mol, same fast-fusing behaviour, but the ester groups sit in the para position, so it is not on the Candidate List and not in Annex XVII entry 51. Dibutyl terephthalate is the fast-fusing member of the terephthalate class, registered under REACH at 1,000 to 10,000 tonnes per year, and it is not listed in Annex I to Regulation (EU) No 10/2011, so it carries no EU food-contact authorisation either.

DOTP takes the volume rather than the function. DOTP / DEHT (dioctyl terephthalate) took the general-purpose share that the restricted phthalates left behind, and its food-contact position is the mirror image of DIBP's: FCM 798 with a specific migration limit of 60 mg/kg, against DIBP's FCM number with no authorisation at all. Its typical substitution factor of 1.03 puts it close to DEHP on weight efficiency, which is what made the swap practical at compound scale.

Which replacement keeps the fast-fusing behaviour?#

Only 3 of DIBP's fast-fusing peers survive the phthalate restrictions: dipropylene glycol dibenzoate, the monobenzoates, and dibutyl terephthalate, because DBP, BBP and DIHP are all restricted alongside DIBP. The 3 surviving routes are listed below.

• Dipropylene glycol dibenzoate (CAS 27138-31-4), a high-solvating benzoate that replaces BBP and DIBP in plastisols, adhesives and latex sealants
• Monobenzoates such as isononyl benzoate and isodecyl benzoate, which patent literature reports combine fast fusion with viscosity depression rather than viscosity rise
• Dibutyl terephthalate (CAS 1962-75-0), the para isomer that keeps the C4 chain length and the fusion behaviour without the ortho-phthalate listings

Of those three, DPGDB (dipropylene glycol dibenzoate) is the benzoate fast fuser that survived entry 51, and it carries no SVHC status, no Annex XIV entry and no Annex XVII restriction. One supplier product, Evonik's Elatur DPT, is recorded in our our sources as a DBP and DIBP replacement, with no CAS number, no dosage and no regulatory record attached, so it is named here as a supplier product and nothing more.

Who Supplies DIBP? Trade Names, Grades and Sourcing#

Our source library records no current manufacturer for DIBP: it lists 3 trade names, Palatinol IC, Kodaflex DIBP and Hatcol DIBP, and a REACH dossier set in which one of the three registrations is marked "cease manufacture", which is what a phase-out substance looks like in the registers. The REACH tonnage band is not captured in the dossiers we hold, and US production is recorded below 1 million pounds per year on EPA's risk-evaluation page, against a 2006 Inventory Update Reporting band of 0.5 to below 1 million pounds. In current search results DIBP appears mainly as an analytical standard and as a safety data sheet rather than as a bulk plasticizer.

Table T8: recorded DIBP trade names. No manufacturer is recorded, and no distributor is listed as a source.

Buyers should ask any supplier for the REACH registration number, the authorisation basis for the intended EU use and a current safety data sheet before ordering, because an Annex XIV substance without an authorisation covering the specific use cannot lawfully be used in the EU. Producers of the replacement esters are listed in the directory of plasticizer manufacturers, and price levels for the substitutes are tracked on plasticizer prices.

How Does DIBP Fit into the Wider Phthalate Story?#

DIBP is the smallest-volume member of the 4 low-molecular-weight ortho-phthalates that the EU restricts as a group, and its history is the clearest illustration of how one harmonised classification removes a substance from a market of 8.4 million tonnes a year. European Plasticisers puts global plasticizer consumption at 8.4 Mt per year, and the low-molecular-weight ortho-phthalates, DEHP, DBP, BBP and DIBP, have moved from the centre of that market to its legal margins in under two decades. All 4 gained endocrine-disrupting grounds on top of their reproductive-toxicity classifications, and all 4 now sit behind the same 0.1 % article limit. The class story, from the ortho-phthalate chemistry to the high-molecular-weight esters that were never caught by entry 51, is told on phthalate plasticizers.

DIBP as a polymerisation aid and as an impurity#

DIBP does not always arrive as an ingredient: Regulation (EU) 2023/1442 assigned it an FCM number precisely because it can co-occur in a plastic as a residue of a polymerisation aid, and EU toy assessments treat DBP and DIBP impurities the same way. A residue of that kind never appears on a formulation sheet, which is why a compliance check that reads only the recipe misses it, and why group restriction 36 counts DIBP whether or not anybody dosed it. A residue that nobody added on purpose is handled as NIAS: non-intentionally added substances, the category that covers reaction products, breakdown products and process residues alike.

DIBP in recycled plastics and legacy articles#

Recycled feedstock is where DIBP still turns up: the 0.1 % limit of Annex XVII entry 51 applies to the finished article regardless of whether the phthalate was added on purpose or arrived with a recycled fraction. Articles placed on the market before the relevant dates stay in service for years, and vehicles and aircraft placed on the market before 7 January 2024 keep their exemption along with their spare parts, so legacy material re-enters the stream long after the restriction date. No DIBP concentration figure for recyclate is recorded in our source library, and none is stated here. Feedstock rules and the decontamination requirements that go with them are set out under recycled plastics regulations.

Non-plastics uses of DIBP (outside this reference)#

DIBP also appears in printing inks, lacquers and, historically, nail polish, which are coatings and cosmetics rather than plastics and therefore sit outside this reference. Those markets follow their own instruments, and the cosmetic and coating literature is not assessed here. Our source library records 3 application entries for DIBP, adhesives, lacquers and service as a gelling aid with other plasticizers, and nail polish is not one of them, so the claim is reported as it circulates rather than stated as a recorded use.

Is DIBP banned?#

Not as a substance: DIBP is subject to authorisation in the EU after the sunset date of 21 February 2015, limited to 0.1 % in the plasticised material of all articles since 7 July 2020, limited to 0.1 % in the homogeneous material of electrical equipment under RoHS, not authorised in EU or US food-contact plastics, and prohibited above 0.1 % in US children's toys and child care articles. Those are 5 distinct legal facts with 5 distinct scopes, and none is a market ban: manufacture, import and use outside those scopes remain lawful, which is why DIBP still holds active REACH registrations.

How is DIBP detected in a plastic sample?#

Phthalate content in a plastic is measured by solvent extraction followed by GC-MS, with CPSC-CH-C1001-09.4 used for US children's products, EN 14372 for childcare articles and IEC 62321-8 for RoHS compliance. Migration rather than content calls for a different setup: Tan and colleagues used an SPME-GC method in Food Chem X in 2026 to quantify DIBP migrating into liquid at 2.5 to 5.0 µg/L. The three methods and their scopes are compared on phthalate testing in plastics.

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

Yes: DIBP carries a harmonised CLP classification as toxic for reproduction category 1B, so its safety data sheet and label must show the hazard statement H360Df, the health-hazard pictogram and the signal word "Danger". What a compliant sheet must contain, section by section, is set out on safety data sheets and GHS labels.