DIETHYL PHTHALATE

Diethyl phthalate (DEP), also called phthalic acid diethyl ester, is an aromatic diester with CAS 84-66-2 and formula C12H14O4, used as a plasticizer, fragrance solvent and formulation carrier. Its low volatility and compatibility with selected cellulose derivatives and organic ingredients make it useful where flexibility or a persistent liquid carrier is required. The ester molecules interact with compatible polymers or dissolved ingredients without becoming covalently incorporated into the polymer chain, which also makes migration and extraction important considerations.

CAS No: 84-66-2
EC No: 201-550-6
Molecular formula: C12H14O4
Molecular weight: 222.24 g/mol
Appearance: Clear, colorless, oily liquid
Odor: Practically odorless to faintly aromatic
Boiling point: Approximately 296-299 °C at atmospheric pressure
Density: Approximately 1.12 g/cm³ at 20-25 °C
Water solubility: Approximately 1.0-1.1 g/L at 25 °C
Refractive index: Approximately 1.50 near room temperature

WHAT IS DIETHYL PHTHALATE?

Diethyl phthalate (DEP) is a low-volatility ortho-phthalate ester used to plasticize compatible polymers and dissolve or carry selected fragrance and formulation ingredients. Identified by CAS 84-66-2, this liquid combines limited water solubility with compatibility with many organic solvents and selected resins.

For a film producer, ethyl phthalate can reduce brittleness when the polymer and dosage are suitable. In fragrance work, the same ester can provide dilution and influence evaporation behavior. Neither role establishes compatibility with every resin or guarantees that a particular finished product is legally marketable.

Manufacture involves esterification of phthalic anhydride with ethanol, followed by purification to remove residual alcohol, acidity and other unwanted components. Commercial DEP is supplied as a liquid. Additional impurity control and documentation distinguish materials intended for sensitive fragrance, analytical or pharmaceutical work.

Assay alone is insufficient to describe the offered material. Color, odor, water, acidity, residual starting materials and contamination by other phthalates can affect suitability. Compliance with an excipient specification also requires more than the presence of the correct CAS number.

Dimethyl phthalate, dibutyl phthalate and bis(2-ethylhexyl) phthalate are different substances with different alkyl groups and regulatory profiles. Diethyl terephthalate is a positional isomer, not another name for the ortho compound. A general statement about all phthalates should not replace substance-specific assessment.

COMMON PRODUCT & CHEMICAL NAMES OF DIETHYL PHTHALATE:

Diethyl phthalate
DEP
Phthalic acid diethyl ester
Diethyl benzene-1,2-dicarboxylate
Diethyl 1,2-benzenedicarboxylate
1,2-Benzenedicarboxylic acid, diethyl ester
Diethyl o-phthalate
Ethyl phthalate
Diethyl phthalate NF

The systematic names identify the two ethyl ester groups on adjacent positions of the aromatic ring. DEP is the abbreviation, and the final entry is a pharmacopoeial quality description rather than a different chemical. Ethyl phthalate is a conventional shortened name that should be accompanied by the CAS number in purchase documents.

Monoethyl phthalate is a different compound and an important metabolite of DEP. Database identifiers, reference-standard codes and waste codes are not useful substitutes for the chemical name and do not define the quality of bulk supply.

CAS NO, EC / EINECS NO AND CHEMICAL IDENTIFICATION OF DIETHYL PHTHALATE

Product name: Diethyl phthalate
Common abbreviation: DEP
Chemical name: Diethyl benzene-1,2-dicarboxylate
INCI name: DIETHYL PHTHALATE
CAS No: 84-66-2
EC / EINECS No: 201-550-6
Molecular formula: C12H14O4
Molecular weight: 222.24 g/mol
Chemical class: Aromatic dicarboxylic acid diester, ortho-phthalate
Main functions: Plasticizer, solvent, carrier and fragrance fixative

These identifiers describe one substance, while its purity, contaminants and intended-use documentation determine whether a batch fits an application. REACH registration information exists for DEP, but the relevant supply-chain coverage and uses must be established for the offered product. An INCI name is an identification tool, not a universal permission to use the ingredient.

CHEMICAL STRUCTURE AND MOLECULAR PROPERTIES OF DIETHYL PHTHALATE

The structure C6H4(COOC2H5)2 contains a benzene ring with two adjacent ethyl carboxylate groups. Ester oxygens provide polar interaction sites, while the aromatic ring and ethyl groups contribute organic-phase affinity. The neutral molecule has no hydrogen-bond donor group.

This balance explains the solvent and plasticizer behavior of phthalic acid diethyl ester. Its water solubility is limited rather than zero, and dissolution in a polymer depends on the chemistry and structure of that polymer. The two ester groups can undergo hydrolysis under suitable conditions, so strong acid or alkali exposure is relevant to formulation stability.

HOW DOES DIETHYL PHTHALATE WORK AT THE MOLECULAR LEVEL?

In a compatible polymer, DEP associates with the chains and modifies intermolecular interactions and segmental mobility. This can lower glass-transition behavior and increase flexibility. The extent of plasticization depends on the polymer, loading, thermal history and remaining processing solvent.

As a fragrance solvent, diethyl o-phthalate dissolves suitable aroma materials and changes the liquid environment from which they evaporate. Its low volatility can contribute to a fixative effect, but this does not mean every odor note is strengthened or retained by the same amount. Evaluate the complete odor profile over time.

Because the ester is not chemically bonded to the polymer backbone, it can redistribute, migrate or be extracted. Initial flexibility is therefore not evidence of permanent plasticization or food-contact suitability.

Main functions:

Plasticization of compatible cellulose-derived materials
Dissolution and dilution of selected organic ingredients
Carrier action in fragrance intermediates
Modification of film flexibility and processing behavior

Water, temperature, acidity, polymer composition and concentration affect these outcomes. Excess addition can produce tack, loss of mechanical strength, exudation or unacceptable odor-release changes.

PHYSICAL AND CHEMICAL PROPERTIES OF DIETHYL PHTHALATE

General technical characteristics:

Physical form: Clear, colorless to almost colorless oily liquid
Chemical character: Neutral organic ester with limited water solubility
Molecular formula: C12H14O4
Molecular weight: 222.24 g/mol
Assay: A representative reagent product specifies at least 99.0 % by GC
Density: Approximately 1.12 g/cm³ near 20-25 °C
Boiling point: Approximately 296-299 °C at atmospheric pressure
Water solubility: Approximately 1.0-1.1 g/L at 25 °C
Kinematic viscosity: A published supplier value is approximately 11.53 mm²/s at 20 °C
Vapor pressure: Approximately 0.3 Pa at 25 °C in representative documentation
Refractive index: Approximately 1.50 near room temperature
Flash point: Published supplier examples are approximately 161 °C, open cup, and 170 °C, closed cup

Assay, acidity and water are separate controls. A GC purity result does not necessarily establish the absence of acidic residues, moisture or restricted contaminants. Specify analytical methods and the basis of any acidity limit, since acid value in mg KOH/g is not interchangeable with a percentage expressed as an acid.

Low color and unobtrusive odor matter especially in fragrance and clear-film work. Refractive index and density support identity checks but do not replace an impurity profile. A barely noticeable raw-material odor also does not prove sensory neutrality in every perfume.

Viscosity must retain its unit and temperature. Kinematic viscosity in mm²/s is different from dynamic viscosity in mPa·s or Pa·s, and values must not be copied between these fields.

Flash-point data depend on the test and product documentation. The listed open- and closed-cup examples are not an ordered conversion or a safe heating recommendation. For low-temperature transfer, require a defined crystallization test and acceptance limit rather than combining freezing-point values obtained under unspecified conditions.

These figures describe reference properties and selected supplier examples, not contractual limits. For the offered water, acidity, color, crystallization behavior and test methods, please contact Ataman Kimya.

MIGRATION AND PLASTICIZER RETENTION OF DIETHYL PHTHALATE

The useful mobility of DEP within a polymer is also a route for loss during service. Contacting liquids, temperature, film thickness and the affinity of surrounding materials influence retention. Heat-aged softness alone cannot establish resistance to extraction.

For a cellulose-derived film, examine the glass transition, tensile response and plasticizer loss together. Surface tack, blooming, mass loss and changed odor can indicate a problem requiring compositional analysis. A low-volatility plasticizer can still migrate even when evaporation is slow.

SECTORS AND INDUSTRIAL APPLICATIONS OF DIETHYL PHTHALATE

Main areas of use:

Compatible cellulosic plastics and technical films
Selected coatings and resin formulations
Fragrance intermediates and permitted personal-care applications
Pharmaceutical film-coating development with suitable excipient controls
Analytical standards and laboratory studies

DIETHYL PHTHALATE IN CELLULOSIC FILMS

Purpose: Reduce brittleness and adjust flexibility.
Function: Increase mobility within a compatible polymer matrix.
Performance effect: Can change elongation, film handling and glass-transition behavior.
Limitations: Polymer substitution, plasticizer loading, extraction and aging must be evaluated.

DIETHYL PHTHALATE IN FRAGRANCE SYSTEMS

Purpose: Dilute and carry compatible aroma materials.
Function: Provide a persistent organic liquid phase and modify evaporation.
Performance effect: Can support homogeneous dosing and a desired release profile.
Limitations: Sensory effects, market restrictions, package compatibility and final-product safety remain decisive.

DIETHYL PHTHALATE IN COATINGS AND RESINS

Purpose: Adjust film flexibility and processing characteristics.
Function: Act as a compatible external plasticizer or solvent component.
Performance effect: Can reduce cracking in a suitable binder system.
Limitations: Excess plasticization can reduce hardness, chemical resistance or adhesion.

DIETHYL PHTHALATE IN PHARMACEUTICAL COATINGS

Purpose: Modify a selected excipient film.
Function: Plasticize a compatible coating polymer.
Performance effect: Can influence film integrity and release behavior.
Limitations: Excipient quality, exposure, dissolution, stability and product-specific authorization require separate validation.

COSMETIC, FOOD AND PHARMACEUTICAL STATUS OF DIETHYL PHTHALATE

Cosmetic regulation is substance- and market-specific. DEP should not be assigned the same status as DBP or DEHP merely because all are phthalates. Historical European scientific opinions supported the cosmetic uses evaluated at that time, but they are not substitutes for current finished-product safety assessment and legal review.

At US federal level, the FDA states that it has no safety concerns with DEP as currently used in cosmetics and fragrances. This is not blanket premarket approval of an ingredient, a concentration or every route of exposure. State rules can be stricter.

Washington restricts intentionally added ortho-phthalates in cosmetics from 1 January 2025, and separately restricts their use as fragrance solvents or fixatives in covered beauty and personal-care products. A formulation intended for this market cannot rely on the general federal statement to justify adding DEP.

No E-number direct-food-additive use is proposed. Historical references to packaging do not establish current permission for a particular food-contact material. Verify the applicable authorization, contact conditions and migration requirements before developing such a use.

A pharmacopoeial monograph exists for diethyl phthalate, and pharmaceutical applications concern excipient functions such as film plasticization. Presence in an aspirin coating is not evidence that DEP is an active painkiller or a required reagent in aspirin synthesis. Industrial material and an analytical reference standard must not be assumed suitable as production excipients.

WHICH PROBLEMS CAN DIETHYL PHTHALATE HELP SOLVE?

Brittle compatible films
The ester can improve flexibility when polymer compatibility and loading are suitable. Strength, tack and aging still need measurement.

Difficult handling of a fragrance intermediate
DEP can help dissolve or dilute selected ingredients, but the result requires clarity, stability and odor evaluation.

Uncontrolled ingredient release
The carrier can change evaporation behavior, although the complete blend determines whether the change is desirable.

Inconsistent plasticizer selection
A defined assay, acidity and impurity specification can improve batch comparisons. A common CAS number alone cannot do this.

THINGS TO CONSIDER WHEN USING DIETHYL PHTHALATE

The main selection error is treating either all phthalates or all plasticizers as interchangeable. DEP requires its own chemical, performance and market assessment.

State whether dosage is on the whole mixture or dry polymer.
Distinguish a concentrate from the finished consumer product.
Test polymer compatibility and plasticizer retention.
Include odor and package compatibility in fragrance evaluations.
Avoid claiming that low water solubility means no migration.
Define restricted-phthalate testing where required by the customer.
Confirm local product restrictions before commercial development.
Use the actual supplier classification for the supplied material.

Low room-temperature volatility does not eliminate exposure during spraying or heated processing. Select ventilation, eye protection and gloves for the whole formulation, including its volatile solvents and fragrance ingredients.

INITIAL FORMULATION APPROACHES FOR DIETHYL PHTHALATE

The two compositions below are complete laboratory starting points, not validated commercial recipes. All percentages are w/w on the total mixture. Use is limited to controlled technical evaluation, and neither example establishes consumer safety, medicinal suitability or legal permission in a restricted market.

EXAMPLE 1: DIETHYL PHTHALATE IN AN AROMA-MATERIAL DILUTION STUDY

Components:

Diethyl phthalate: 50.00 %
Benzyl acetate: 50.00 %
Total: 100.00 %

This binary model examines DEP as a carrier for one liquid aroma material. It is an intermediate for comparing clarity and odor development, not a finished perfume or a skin-application instruction. A 50 % carrier level is not a recommended concentration in every finished product.

Evaluation criteria:

Clarity and phase stability
Odor development on a suitable test strip
Mass loss and release profile against a comparison carrier
Color change during defined storage
Compatibility with the selected bottle and seal

Safety note: Assess the complete mixture and prevent skin and eye contact. Do not commercialize the model in markets prohibiting the intended DEP use.

EXAMPLE 2: DIETHYL PHTHALATE IN A TECHNICAL CELLULOSE ACETATE FILM SCREEN

Components:

Acetone-soluble cellulose acetate: 18.00 %
Diethyl phthalate: 2.00 %
Acetone: 80.00 %
Total: 100.00 %

Assuming complete acetone removal and no plasticizer loss, DEP represents 10.00 % of the dry polymer-plus-plasticizer film, equivalent to approximately 11.11 parts per 100 parts polymer. Select an actually acetone-soluble cellulose acetate and adapt mixing and casting to its solution viscosity. The example is not a food-contact or medicinal coating specification.

Evaluation criteria:

Solution clarity and casting consistency
Film thickness, tensile behavior and elongation
Glass-transition response and surface tack
Residual acetone and plasticizer retention
Extraction and aging under defined conditions

Safety note: Acetone creates a flammable-solvent mixture. Use suitable closed handling, ignition control and ventilation, and do not assume the flash point of pure DEP applies to this blend.

DIETHYL PHTHALATE SIMILAR PRODUCTS AND ALTERNATIVES

An alternative must match the application as well as the desired chemical policy. Compare solubility, sensory behavior, migration, mechanical properties and regulatory requirements together.

DIETHYL PHTHALATE AND TRIETHYL CITRATE

Triethyl citrate is a non-phthalate candidate for selected carrier and plasticizer applications. It has a different ester structure, and hydrolysis, odor behavior and polymer compatibility must be tested rather than assuming an equal-mass replacement.

DIETHYL PHTHALATE AND TRIACETIN

Triacetin can be evaluated for compatible cellulose-derived polymers. The different polarity and interactions can change water uptake, film mechanics and retention.

DIETHYL PHTHALATE AND DIPROPYLENE GLYCOL

Dipropylene glycol is used as a fragrance carrier, but it is a glycol rather than an aromatic diester. Water compatibility, solubility and odor release differ, and it does not necessarily reproduce DEP's polymer-plasticizing effect.

DIETHYL PHTHALATE AND OTHER PHTHALATE ESTERS

Changing alkyl groups changes volatility, migration and regulatory status. Another phthalate is not automatically an acceptable alternative for a customer requiring a phthalate-free formulation.

Validate any change through application trials and an assessment of the finished product.

QUALITY CONTROL AND PURCHASING CRITERIA FOR DIETHYL PHTHALATE

Begin with the intended market and function, not the price per kilogram. Fragrance, film and excipient applications emphasize different controls.

Information to clarify before purchase:

Application and destination market
Assay, identification and analytical methods
Water content and acidity specification
Color and odor acceptance criteria
Residual ethanol, starting-material residues and relevant organic impurities
Other phthalates and customer-restricted contaminants
Density and refractive index at stated temperatures
Pharmacopoeial compliance where applicable
Current safety classification and supply-chain regulatory coverage
Packaging compatibility, quantity, origin and batch traceability

A COA provides batch results or conformity, technical information describes the product profile, and an SDS addresses classification, handling and transport. An analytical reference standard is a measurement tool, not evidence that bulk material meets excipient requirements.

Purification, odor and color control, impurity testing, documentation and logistics influence cost. Please contact Ataman Kimya for the current offered specification, availability and quotation.

STORAGE AND HANDLING OF DIETHYL PHTHALATE

Keep the ester tightly closed in compatible packaging in a cool, shaded and ventilated area. Prevent contamination and avoid excessive heat. Separate from strong oxidizers and strong acids, and evaluate alkaline contact where hydrolysis matters.

Confirm compatibility of hoses, seals and coated surfaces because a solvent-plasticizer can affect some materials. For the packaging-specific shelf life, cold-handling limits and storage range, please contact Ataman Kimya. Material held for a long time should be checked for color, clarity, water and acidity before sensitive use.

Reviewed pure-substance documents classify DEP as not regulated as dangerous goods under ADR, IMDG and IATA, with no corresponding UN number or transport class. This does not override classification of a blend containing ethanol, acetone or other hazardous ingredients.

Contain spilled liquid with suitable inert absorbent and prevent entry into drains, soil and surface water. Collect residues for authorized treatment rather than washing them away. Limited water solubility is not a reason to permit environmental release.

SAFETY INFORMATION OF DIETHYL PHTHALATE

Supplier classifications are not uniform. Reviewed EU documentation includes an unclassified product and another product labeled H315, H319, H317, H335 and H336 for skin and eye irritation, skin sensitization, respiratory irritation and drowsiness or dizziness. The offered material's current local classification must therefore be confirmed with Ataman Kimya rather than assigning one universal label.

Avoid skin and eye contact and control mist or heated-vapor exposure. Use suitable protective clothing, splash protection and gloves selected from permeation data for the actual mixture. Low acute toxicity reported in older assessments does not establish absence of effects from repeated exposure or eliminate product-specific controls.

After skin contact, remove contaminated clothing and wash thoroughly. Rinse exposed eyes with water and obtain medical advice for persistent irritation, rash or other symptoms. After inhalation, move to fresh air, and after swallowing rinse the mouth and seek medical advice.

DEP is combustible even though its flash point is well above room temperature. Use appropriate foam, dry powder, carbon dioxide or water spray according to the site emergency plan. Fire or severe heating can generate carbon oxides and hazardous smoke.

Do not describe the ester as environmentally harmless because degradation may occur. Prevent discharge, manage contaminated packaging and use a suitable authorized waste route. REACH registration and historical hazard reviews do not constitute blanket approval of every exposure or end use.

SUPPLY OF DIETHYL PHTHALATE FROM ATAMAN KIMYA

Ataman Kimya can be contacted to evaluate DEP supply for compatible technical formulations, fragrance intermediates and applications requiring specific quality documentation. Confirm the proposed material's composition, intended-use suitability and destination-market requirements before ordering.

Useful information in a quotation request:

Application, product category and destination market
Required assay, water, acidity, color and odor limits
Relevant impurity and other-phthalate limits
Required quality and regulatory documents
Estimated quantity and packaging preference
Existing specification or comparison sample requirements

FREQUENTLY ASKED QUESTIONS ABOUT DIETHYL PHTHALATE

What is diethyl phthalate?
An aromatic diester used as a plasticizer and solvent-carrier in suitable formulations.

What is its CAS number?
84-66-2.

What is its EC number?
201-550-6.

What are its formula and molecular weight?
C12H14O4 and approximately 222.24 g/mol.

What is its INCI name?
DIETHYL PHTHALATE, which identifies the ingredient without granting universal permission for use.

Is DEP the same as DEHP or DBP?
No. Their ester groups, chemical identities and regulatory profiles differ.

Is the ester completely insoluble in water?
No. Representative data indicate limited solubility around 1.0-1.1 g/L at 25 °C.

Does a plasticizer remain permanently in the film?
Not necessarily. DEP is not covalently bonded to the polymer and can migrate or be extracted.

Does it always improve perfume performance?
No. The full composition determines odor release, clarity and acceptability.

Are all phthalates equally restricted in cosmetics?
No. Substance-specific and class-based rules coexist, and the destination market matters.

Can DEP be intentionally added to cosmetics for Washington?
Washington's restrictions on intentionally added ortho-phthalates apply, so the general federal position does not authorize this use.

Is DEP an aspirin active ingredient?
No. References to aspirin-related applications concern functions such as coating plasticization.

Does a pharmacopoeial monograph make every batch suitable for medicine?
No. The actual quality, manufacturing controls and finished product must satisfy the intended application.

What does 2 % DEP mean in the film example?
It is 2 % of the wet mixture and, assuming only acetone is removed, 10 % of the dry polymer-plus-plasticizer mass.

Can triethyl citrate replace DEP directly?
It is a candidate, but compatibility, retention and performance require validation.

Does pure DEP have a transport UN number in the reviewed documents?
No UN number is assigned for ADR, IMDG or IATA in those documents. Mixtures require separate assessment.

Which documents should be requested?
A batch COA, current technical and safety information, and application-specific regulatory evidence.

How should the price be compared?
Against the required specification, documentation, packaging and delivery terms, not the product name alone.

DIETHYL PHTHALATE - TECHNICAL SUMMARY

Diethyl phthalate is a defined ortho-phthalate diester identified by CAS 84-66-2 and EC 201-550-6. Its relatively persistent liquid character supports compatible plasticizer and carrier functions.

Assay, water, acidity, color, odor and trace contaminants distinguish commercial supply. Identity data and a high purity value do not establish suitability for every sensitive application.

The ester can modify cellulosic film flexibility and dissolve or carry selected fragrance ingredients. Polymer compatibility, dry-film dosage, migration and sensory effects must be assessed in the actual formulation.

Cosmetic, pharmaceutical and food-contact requirements are separate. Historical evaluations are informative, but current restrictions, including applicable US state rules, must be considered before commercial development.

Supplier safety classifications differ, while combustibility, handling exposure and environmental release still require control. Please contact Ataman Kimya for the offered specification, current documents and supply conditions.

Diethyl phthalate can be sourced from ATAMAN KİMYA. For further information and supply inquiries about Diethyl phthalate, please contact ATAMAN KİMYA.