DEP (Diethyl Phthalate): Properties, Uses in Plastics and Regulatory Status

DEP (diethyl phthalate, CAS 84-66-2) is a low-molecular-weight ortho-phthalate used as a plasticizer and solvent for cellulose acetate, not as a general-purpose plasticizer for flexible PVC. That distinction matters, because the restrictions that apply to the better-known phthalates were written for the esters used in PVC, which raises the question of where DEP itself stands.

The answer sits in five instruments. DEP is registered under REACH, is not on the REACH Candidate List, carries no harmonised classification under the CLP Regulation, is not listed in Annex I of Regulation (EU) No 10/2011, and is one of the 8 ortho-phthalates the US FDA still authorises as food-contact plasticizers after its final rule of 20 May 2022 (status 23 September 2026). DEP is one of 56 plasticizer pages in our directory of plastic additives, each with the same identity, dosage and regulatory fields.

This page holds the data-sheet view and the compliance view together: the identity that separates DEP from DMP, DBP and DEHP, the solvation mechanism behind a C2 ester in cellulose acetate, the physical constants and the conflicting values inside PubChem's record, the one polymer family the substance record names, the test methods that apply where no measured DEP value exists, a dated regulatory matrix across the EU, the United States and Canada, the comparison with triacetin, triethyl citrate, DMP and DBP, and the trade names under which DEP is sold.

Table T1. DEP identity card.

Footnote: identity and physical data from PubChem CID 6781; regulatory entries from ECHA registration dossiers 14869, 16604 and 1950 and the EU, US and Canadian legal texts cited in each section. Status as of 23 September 2026.

What Is DEP (Diethyl Phthalate)?#

DEP is the diethyl ester of benzene-1,2-dicarboxylic acid (ortho-phthalic acid), the shortest-chain ortho-phthalate in commercial use after DMP. Both carboxyl groups of the acid carry an ethyl group supplied by ethanol, which gives the molecule the formula C12H14O4, a molecular weight of 222.24 g/mol and the systematic name diethyl benzene-1,2-dicarboxylate. Which substance does the abbreviation DEP actually name? In the chemical trade DEP means diethyl phthalate, while outside chemistry the same three letters usually stand for a state department of environmental protection, so the CAS number 84-66-2 is the only unambiguous identifier on a purchase order.

Function separates DEP from the esters that made phthalates a regulatory subject. ASTM D883 defines a plasticizer as a substance incorporated into a plastic or elastomer to increase its flexibility, workability or distensibility, and DEP performs that role in cellulose acetate while also acting as a solvent-type plasticizer that dissolves the polymer during compounding. DEP belongs to the largest additive family by weight; the hub on plasticizers for plastics compares every class from phthalates and terephthalates to citrates, adipates and epoxidised esters. Its larger market lies outside plastics, as a fragrance carrier, and that use is treated below the contextual border of this page.

What is another name for diethyl phthalate?#

The systematic synonym for diethyl phthalate is ethyl phthalate, and the abbreviation used in technical literature is DEP. The same molecule appears in catalogues as diethyl benzene-1,2-dicarboxylate and as phthalic acid diethyl ester, and it is sold under three trade names recorded in this directory, Palatinol A, Unimoll DA and Kodaflex DEP, all of them describing CAS 84-66-2.

Is DEP a phthalate, and which type?#

Yes, DEP is a phthalate in the strict regulatory sense: it is an ester of ortho-phthalic acid, and with two ethyl groups it sits at the bottom of the low-molecular-weight range. Being an ortho-phthalate does not by itself mean being restricted. Among the phthalate plasticizers, the low-molecular-weight esters DEHP, DBP, BBP and DIBP carry REACH Annex XVII entry 51, while DEP carries no REACH restriction at all as of 23 September 2026.

The commercial split runs between molecular-weight classes, not between restricted and unrestricted names. European Plasticisers records that the high-molecular-weight ortho-phthalates DINP, DIDP and DPHP account for about 85 % of Western European ortho-phthalate production, while the low-molecular-weight group containing DEP stays under 11 %. Where each ester sits inside that split is set out on phthalate plasticizers.

DOTP belongs in the third row for a structural reason: it is an ester of terephthalic acid, a para isomer, and therefore not an ortho-phthalate, whereas DEP is one.

How does DEP differ from DEHP and DBP?#

DEP, DBP and DEHP are the same ortho-phthalate backbone with different alcohols: ethyl (C2, 222.24 g/mol), butyl (C4, 278.34 g/mol) and 2-ethylhexyl (C8, 390.6 g/mol). Same acid, different alkyl chain length, and a different regulatory consequence: DEP has the formula C12H14O4 and CAS 84-66-2, DBP has C16H22O4 and CAS 84-74-2, and DEHP has C24H38O4 and CAS 117-81-7. Table T6 in the alternatives section places all three beside the two non-phthalate options used in the same polymer.

The regulatory record, not a structure-activity rule, separates them. DEHP and DBP carry harmonised classifications for reproductive toxicity in category 1B, with hazard statements H360FD for DEHP and H360Df plus H400 for DBP, and both fall under REACH Annex XVII entry 51. The C8 ester, DEHP (DOP, dioctyl phthalate), carries a harmonised Repr. 1B classification and Annex XVII entry 51; DEP carries neither.

How Does DEP Plasticize Cellulose Acetate?#

DEP plasticizes cellulose acetate by placing its ester molecules between the cellulose chains, weakening the hydrogen bonding and dipole forces that hold them together and lowering the glass transition temperature. The same ester also dissolves the resin during compounding, which is why the substance record lists DEP as plasticizer and solvent rather than as plasticizer alone. Why does a short-chain ester work on cellulose acetate when longer esters do not? Compatibility decides it: a plasticizer stays in a polymer when polymer and plasticizer solubility parameters differ by no more than about 1.5 (cal/cm3)^0.5, and cellulose acetate is more polar than PVC, so short-chain polar esters fall inside its window.

No Tg-depression figure, solubility parameter or hydrogen-bonding study for DEP is recorded in our source library, so this page describes the mechanism without quantifying it. The 4 classic plasticization theories are listed below.

• Lubricity theory, which treats the plasticizer as a lubricant between polymer chains.
• Gel theory, which treats the polymer as a gel whose contact points the plasticizer breaks.
• Free-volume theory, which treats plasticization as an increase in the free volume available for chain motion.
• Mechanistic theory, also called solvation-desolvation, which treats plasticizer and polymer as being in dynamic equilibrium.

The four theories and the solubility-parameter window are explained on how plasticizers work, and a solvating plasticizer such as DEP is the case the mechanistic theory describes best.

What Are the Physical and Chemical Properties of DEP?#

DEP is a clear, colourless liquid that is denser than water and insoluble in it, with a boiling point of 295 °C (563 °F) and a molecular weight of 222.24 g/mol. The record adds a relative density of 1.120 at 25/25 °C (1.12 at 68 °F, USCG 1999) and no significant odour.

Table T2. DEP physical and chemical properties.

PubChem records two melting points for DEP, -3 °C (27 °F) and -40.5 °C, and two flash points, 161 °C and 140 °C (284 °F), because the record merges data from the National Toxicology Program (1992), the United States Coast Guard (1999) and later submissions, and the Fahrenheit and Celsius flash-point values do not convert into each other. Check the supplier's data sheet before using either value for a safety calculation. The diethyl phthalate boiling point of 295 °C, the diethyl phthalate molecular weight of 222.24 g/mol and the insolubility in water are consistent across the sources in the record and can be quoted without that caveat.

Which Polymers Use DEP, and at What Dosage?#

DEP is recorded for one polymer family, cellulose acetate and the related cellulose esters, where it acts as both plasticizer and solvent. The substance record carries a polymer entry and a function, and it carries no dosage value at all. How much DEP goes into a cellulose acetate compound? No DEP-specific plasticizer content is recorded here, so this page states none; the comparable cellulose-acetate plasticizers in the same data set sit at a typical 10 wt% for triacetin and at 10 to 35 wt% for triethyl citrate, and a supplier data sheet is the only reliable source for a DEP level.

Table T3. Polymers recorded for DEP and the levels the record does and does not contain.

Footnote: the two reference rows are printed so that a formulator has an order of magnitude for the polymer, not a substitute figure for DEP. Status as of 23 September 2026.

Cellulose ester recipes are quoted in wt% rather than in PHR (parts per hundred resin), and the conversion needs the full formulation total, because wt% for any component equals its phr divided by the total phr of the recipe multiplied by 100. A compound quoted at 20 phr of plasticizer on 100 parts of resin therefore carries 16.7 wt%.

DEP in cellulose acetate and cellulose esters#

Cellulose acetate is the polymer family where DEP is a working plasticizer rather than a solvent carrier, alongside triacetin, triethyl citrate and triphenyl phosphate. Those four esters form the cellulosic set recorded in this directory for cellulose acetate, cellulose acetate butyrate (CAB) and nitrocellulose, and each covers a different balance of solvating power, permanence and regulatory position. DEP and triacetin are the two short-chain solvating members, triethyl citrate is the citrate ester with an EU food-contact authorisation, and triphenyl phosphate adds flame retardancy.

The full set of plasticizers for cellulose acetate and CAB compares triacetin, DEP, TEC and TPP side by side, and the choice turns on whether the article needs an EU food-contact status or a flame-retardant contribution.

Why DEP is not a flexible-PVC plasticizer#

Our source library records no PVC use for DEP, and the reason is permanence: flexible PVC carries 5 to 65 wt% of a plasticizer that has to stay in the article, and volatility is driven by molecular weight and vapour pressure. Hallstar's ester-selection literature records the trend: a higher carbon number in the ester alcohol lowers volatility and improves low-temperature flexibility while reducing compatibility. The 3 recorded reasons are listed below.

• Molecular weight of 222.24 g/mol for DEP against 390.6 g/mol for DEHP.
• Boiling point of 295 °C (563 °F) for DEP against 383 °C (721 °F) for DOTP.
• No recorded PVC dosage for DEP in any primary source held here.

The esters that do carry flexible PVC are listed on plasticizers for PVC, and all of them sit above 390 g/mol. One divergence belongs on the record: public-health summaries such as the ATSDR Public Health Statement describe DEP in consumer plastics more broadly, while the substance record used here lists cellulose acetate only.

What Is DEP Used For in Plastics?#

In plastics, DEP has two jobs: it plasticizes cellulose acetate and cellulose esters, and it acts as a solvent that carries other components into those same compounds. Both jobs follow from the same property, a short C2 chain that keeps the ester polar enough to dissolve a polar resin. The 3 uses recorded for the substance in and around plastics are listed below.

• Cellulose acetate and cellulose ester compounds, where DEP lowers the glass transition temperature and makes a brittle resin formable.
• Solvent and carrier function inside those compounds, where DEP dissolves the polymer during compounding and disperses the other additives in the recipe.
• Laboratory and analytical supply as a reference material, offered by vendors such as Sigma-Aldrich and AccuStandard, which is trade evidence rather than a plastics application.

The list stops there on purpose. Cellulose acetate reaches the market as film, sheet, moulded articles, spectacle frames and filter tow, and DEP works in that polymer wherever a solvating plasticizer is wanted, but no application-specific grade or loading is recorded here. The other applications named in the substance record, fragrances and cosmetics, are covered below the contextual border.

How Does DEP Perform? Volatility, Migration and Test Methods#

No measured volatility, migration or extraction value for DEP is recorded in our source library, so the honest starting point is its two governing properties: a molecular weight of 222.24 g/mol and a boiling point of 295 °C (563 °F). Volatility is loss to air, driven by molecular weight and vapour pressure, with higher molecular weight lowering volatility. A C2 ester therefore sits at the volatile end of the plasticizer range, which is consistent with the solvent function the record assigns to DEP.

Four standards define how those indicators are measured, and all four are method references rather than DEP values. ASTM D1203 Methods A and B and ISO 176 measure plasticizer loss by activated-carbon and air-oven exposure, ISO 177 measures migration into a contacting material, and ASTM D1239 measures resistance to extraction by chemical reagents. ASTM D1203, ISO 176, ISO 177 and ASTM D1239 are explained on plasticizer migration, with the sample geometries and exposure times behind each result.

Detection in a finished article follows a different route. Solvent extraction followed by gas chromatography with mass spectrometry separates DEP from DMP, DBP and DEHP by retention time and mass spectrum rather than by molecular weight. A finished article is screened for DEP with the methods described under phthalate testing in plastics, and a report stating only a total phthalate content has not identified which ester is present.

Table T4. DEP performance indicators and the methods that measure them.

How Does DEP Interact with Other Plasticizers and Additives?#

In cellulose ester compounds DEP is combined rather than used alone: triacetin and triethyl citrate cover the same solvating role, and triphenyl phosphate adds flame retardancy to the same polymer. The rule governing any such combination is the solubility-parameter window, a difference of no more than about 1.5 (cal/cm3)^0.5 between polymer and plasticizer. The 3 partners recorded for DEP in that polymer are listed below.

• Triacetin (glycerol triacetate), used at a typical 10 wt% in cellulose acetate.
• Triethyl citrate, used at 10 to 35 wt% in cellulose acetate, poly(vinyl acetate) and PLA.
• Triphenyl phosphate, a flame-retardant plasticizer used in PVC and in cellulosics.

No blend ratio, combined loading or synergy study for DEP is recorded here, so this page names the partners and gives no proportions. Whether an ester can carry a compound alone is the distinction drawn on primary vs secondary plasticizers: a primary plasticizer solvates the polymer by itself, a secondary plasticizer only in combination.

What Is the Regulatory Status of DEP?#

DEP is registered under REACH, is not a Substance of Very High Concern, is not restricted under REACH Annex XVII, is not listed in Annex I of Regulation (EU) No 10/2011, and is one of the 8 ortho-phthalates the US FDA still authorises as food-contact plasticizers (status 23 September 2026). Two cells below are open rather than negative: the US TSCA status and the California Proposition 65 entry are not confirmed in our source library and are marked as being verified.

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

List mechanics, not a difference in assessment, separate the EU and US positions. DEP holds no EU food-contact authorisation because Annex I is a positive list and DEP is absent from it, while in the United States it holds a prior sanction under 21 CFR 181.27. Entries 51 and 52 name four and three phthalates; both are explained on REACH Annex XVII restrictions, and neither names DEP.

Is DEP an SVHC or restricted under REACH?#

No: DEP is registered under REACH (Regulation (EC) No 1907/2006) but it is not on the Candidate List of Substances of Very High Concern, and it carries no entry in Annex XIV or Annex XVII as of 23 September 2026. Three dossiers are recorded, numbers 14869, 16604 and 1950, with statuses Active, No longer Valid and Active, and the tonnage band is not captured here, so this page states none. Registration is only the first obligation under REACH and plastic additives; restriction and authorisation are separate steps.

The contrast with the four restricted low-molecular-weight esters is exact and dated. DEHP, DBP and BBP have been on the SVHC Candidate List since 28 October 2008 and DIBP since 13 January 2010, all four under Article 57(c) for reproductive toxicity and later under Article 57(f), and all four are named in Annex XVII entry 51. DEP has never been added.

Does DEP have a harmonised CLP classification?#

No: DEP has no harmonised classification in Annex VI of the CLP Regulation (EC) No 1272/2008, and 1,710 of the 1,769 companies that notified it to ECHA report that it does not meet the GHS hazard criteria. A notification status is a statement by registrants, not a conclusion by an EU authority, and the ECHA record adds that only 3.3 % of those companies provided full GHS information.

Harmonised entries exist for the four restricted esters: DEHP is classified Repr. 1B with H360FD, DBP with H360Df and H400, BBP with H360Df, H400 and H410, and DIBP with H360Df. The difference between a harmonised entry and a company notification is set out under CLP classification of plastic additives, and the absence of both for DEP is a statement about the record rather than a safety verdict.

Is DEP allowed in food-contact plastics?#

No in the EU and yes with limits in the US: DEP is not listed in Annex I of Regulation (EU) No 10/2011 in the consolidated text of 14 July 2026, and it is one of the 8 ortho-phthalates the US FDA still authorises as a food-contact plasticizer. The Union list in Annex I of EU 10/2011 is a positive list, so an absent substance is not authorised as an additive in EU plastic food-contact materials, and DEP consequently carries no FCM number and no specific migration limit.

The US route runs through a different instrument. The FDA final rule of 20 May 2022 (87 FR 31080) revoked 23 ortho-phthalates plus 2 other substances and left 9 authorised, 8 of them as plasticizers, namely DINP, DIDP, DEHP, DCHP, BPBG, DEP, EPEG and DIOP, plus diallyl phthalate as a monomer, and the agency notes that some DEP uses were removed while others remain. Prior sanctions under 21 CFR 181.27 sit alongside food-additive regulations and food-contact notifications in FDA food contact rules for plastic additives.

Is DEP allowed in toys and childcare articles?#

DEP is not restricted in toys under EU REACH Annex XVII, US 16 CFR 1307 or Canada's SOR/2016-188, because none of these closed lists names it. In the United States, 16 CFR 1307.3 restricts DEHP, DBP and BBP permanently and DINP, DIBP, DPENP, DHEXP and DCHP from 25 April 2018, each above 0.1 %, and those 8 restricted phthalates are listed on CPSIA phthalate limits. Canada's SOR/2016-188 lists DEHP, DBP, BBP, DINP, DIDP and DNOP at up to 1,000 mg/kg in the vinyl of toys and child care articles, and the EU Toy Safety Regulation (EU) 2025/2509 bans CMR substances and endocrine disruptors in toys from 1 August 2030, which reaches a substance only once it carries such a classification.

Is DEP Safe? Health, Safety and Environmental Profile#

DEP has no harmonised hazard classification under the EU CLP Regulation, and 1,710 of the 1,769 companies that notified it to ECHA report that it does not meet the GHS hazard criteria. That is a classification status, not a safety finding. The 3 points the record supports are listed below.

• Classification status: no harmonised entry in Annex VI of Regulation (EC) No 1272/2008, no Candidate List entry, no Annex XVII restriction, and not classified in the ECHA C&L inventory.
• Biomonitoring status: the urinary metabolite measured for DEP in the CDC NHANES programme is monoethyl phthalate (MEP), and phthalate half-lives are under 24 hours, so a spot urine sample reflects recent exposure.
• Out of scope here: dose-response values, exposure limits and cosmetic safety assessments, none of which our source library holds for DEP.

Exposure route matters for reading those numbers. In the published biomonitoring literature the dominant DEP exposure route is personal care products rather than plastics, and this page covers the plastics use. The exposure routes and the study evidence for the group are summarised on phthalates: health effects.

One gap is stated rather than filled. No ATSDR minimal risk level, EPA IRIS reference dose, NOAEL or LD50 for DEP sits in our source library, so this page publishes classification status and biomonitoring only, and it does not translate an absence of classification into the word safe. Which additives carry an Article 57(f) endocrine-disruptor designation is tracked on endocrine disruptors in plastics; DEP does not carry one.

What Are the Alternatives to DEP?#

The 2 direct alternatives to DEP in cellulose acetate are triacetin and triethyl citrate, and the 2 phthalates closest to it in the same role are DMP and DBP. The four differ from DEP less in what they do to the polymer than in the regulatory position they bring with them, which Table T6 sets out field by field.

Table T6. DEP compared with triacetin, TEC, DMP and DBP.

Footnote: status as of 23 September 2026. An absence from a positive list (Annex I of Regulation (EU) No 10/2011) means the substance is not authorised, not that it is unregulated.

DEP vs triacetin#

Triacetin is the non-phthalate that occupies the same slot as DEP in cellulose acetate: glycerol triacetate, CAS 102-76-1, 218.20 g/mol, used at a typical 10 wt% and covered by FCM 40 in the EU Union list. Its formula is C9H14O6 and its EC number 203-051-9, it carries no harmonised CLP classification and no Candidate List entry, it holds a 21 CFR 181.27 prior sanction in the United States, and it is approved as food additive E1518.

Triacetin (glycerol triacetate) is the non-phthalate used at about 10 wt% in cellulose acetate filter tow, and the practical difference from DEP is the food-contact position: triacetin holds an Annex I entry with no specific migration limit, while DEP is absent from that annex. A compound that needs an EU food-contact declaration therefore reaches for triacetin or TEC.

DEP vs triethyl citrate (TEC)#

Triethyl citrate (TEC, CAS 77-93-0) is the citrate ester that replaces DEP where an EU food-contact authorisation is needed: it is FCM 140 in the Union list, while DEP is not listed at all. TEC has the formula C12H20O7, a molecular weight of 276.28 g/mol and EC number 201-070-7, it plasticizes cellulose acetate, poly(vinyl acetate) and PLA at 10 to 35 wt%, and its entry Ref 44640 carries no individual specific migration limit but falls under group restriction 32 at 60 mg/kg.

Triethyl citrate (TEC) holds FCM 140 in the EU Union list, which DEP does not, and it adds a US prior sanction under 21 CFR 181.27 and food-additive status E1505. Its classification record resembles DEP's: no harmonised CLP entry, with 1,942 of 2,014 notifying companies reporting that it does not meet the GHS criteria.

DEP vs DMP and DBP#

DMP is the one-carbon-shorter neighbour of DEP: dimethyl phthalate, CAS 131-11-3, 194.18 g/mol, used in cellulose esters and as the carrier solvent in which MEKP peroxide is supplied at 40 to 60 %. DMP (dimethyl phthalate) is the C1 ester, with formula C10H10O4 and EC number 205-011-6, and it shares DEP's absence from Annex I of Regulation (EU) No 10/2011. The two diverge in the United States: the FDA final rule of 20 May 2022 revoked the food-contact authorisation of DMP while leaving DEP among the 8 remaining plasticizers.

DBP shows what happens when the same chemistry reaches the C4 chain length that PVC compounds used. DBP (dibutyl phthalate) has been on the Candidate List since 28 October 2008, falls under Annex XVII entry 51, sits on Annex XIV with a sunset date of 21 February 2015, is limited to 0.12 mg/kg as FCM 157 under Regulation (EU) 2023/1442, and carries the harmonised classification Repr. 1B with H360Df and H400. As a fast-fusing plasticizer and solvent for poly(vinyl acetate) and cellulosics it is used at 10 to 35 wt%, the functional twin of DEP and its regulatory opposite.

Who Supplies DEP? Trade Names and Manufacturers#

DEP is sold under three trade names recorded in this directory, Palatinol A, Unimoll DA and Kodaflex DEP, from the Palatinol (BASF) and UNIMOLL (Lanxess) plasticizer brand lines. No manufacturer is recorded for DEP in the substance record, so this page names brand lines and owners only and claims no current production. Brand lines and their owners are mapped in the directory of plasticizer manufacturers and suppliers, which carries the company records the table below leaves open.

Table T7. DEP trade names and brand-line owners.

Footnote: a company is listed only where our source library records it, and a brand line is not evidence of a current product listing. Status as of 23 September 2026.

No DEP price figure sits in our source library, so this page publishes none, and price drivers across the ester range are tracked on plasticizer prices. Buyers should ask each supplier for the current technical data sheet and safety data sheet, the grade purity and a written statement of the intended use, because several DEP grades on the market are sold for fragrance rather than for polymer compounding.

Where Does DEP Sit Among the Low-Molecular-Weight Phthalates?#

DEP is the unrestricted end of the low-molecular-weight ortho-phthalate group, a class that also contains DBP, DIBP, BBP, DEHP and DMP and that accounts for under 11 % of Western European ortho-phthalate production. European Plasticisers puts the high-molecular-weight esters DINP, DIDP and DPHP at about 85 % of that production, which makes the low-molecular-weight group a minority of the market and a majority of the regulatory attention. Inside the group, DMP and DEP are the two members used for cellulosics and fragrance rather than for PVC, while DCHP, DnHP, DMEP and DPP appear in this directory as SVHC entries without a plastics use. Where each ester sits is set out under low vs high molecular weight ortho-phthalates.

Is diethyl phthalate banned or restricted?#

No: DEP is not banned or restricted under any of the EU, US or Canadian instruments covered on this page as of 23 September 2026, although it is not authorised as an additive in EU plastic food-contact materials. It carries no Candidate List entry, no Annex XIV listing, no Annex XVII restriction and no POPs listing, and it is absent from the 8 phthalates of 16 CFR 1307 and the 6 of SOR/2016-188. Country-by-country rules are compared on phthalate restrictions worldwide, and an absence from a positive list is a limit on one use, not a ban.

Marketing language follows a different boundary than regulation. A product sold as phthalate-free excludes DEP as well, because DEP is an ortho-phthalate by definition, even though it appears on no restriction list in this matrix.

DEP outside plastics: fragrance, personal care and coatings#

Outside plastics, DEP is a fragrance carrier and solvent in perfumery and personal care, which is where most public interest in the substance comes from. The substance record lists fragrances and cosmetics as its non-plastic applications, and biomonitoring studies identify personal care products as the dominant DEP exposure route. Those uses explain why consumer questions about DEP outnumber formulation questions by a wide margin on every search result page for the term. PlasticAdditives.net covers additives used in plastics, so cosmetic and fragrance formulation is out of scope here; the plastics question is which plasticizer a cellulose acetate compound should carry.

Why is DEP not restricted when DBP and DEHP are?#

The EU restrictions on DBP and DEHP follow from their harmonised Repr. 1B classifications: Annex XVII entry 51 lists DEHP, DBP, BBP and DIBP because each was first classified as toxic for reproduction and then added to the Candidate List. DEHP was classified first and restricted afterwards; the order matters, because a restriction under Annex XVII ends a chain that starts with a harmonised classification under Annex VI and passes through Article 57(c) of REACH. Endocrine-disrupting properties were added to the same four entries later, under Article 57(f). DEP has no harmonised classification and no Candidate List entry, so no restriction follows; that is a statement about the regulatory record, not a finding that DEP has been assessed and cleared.

Does DEP need an SDS?#

Yes: suppliers provide a safety data sheet for DEP as for any traded chemical, even though it carries no harmonised CLP classification. A data sheet that records no hazard classification in section 2 is still the document that carries identity, purity, handling, storage and the supplier's own assessment, and it is the correct source for the grade-specific values this page does not hold.