Dioctyl Phthalate CAS 117-81-7

What is Dioctyl Phthalate?

Dioctyl phthalate, more precisely di(2-ethylhexyl) phthalate or DEHP, is the classic general purpose plasticiser for flexible PVC: a clear, oily, high-boiling liquid with very low volatility.

It is made by esterifying phthalic anhydride with 2-ethylhexanol, and for decades it accounted for the majority of all plasticiser consumption worldwide.

Its position has changed. DEHP is classified as toxic for reproduction and is restricted in toys, food contact and medical devices in the EU and many other markets, and it requires authorisation under REACH.

It remains widely used in cable, flooring, hose and general industrial PVC in markets where those restrictions do not apply, but buyers should check the regulatory position of their destination and end use before committing.

Why DOP specifically

• Excellent PVC compatibility. Solvates PVC efficiently and gives a well-understood balance of flexibility and permanence.
• Low volatility. Stays in the compound over long service life, unlike lower molecular weight plasticisers.
• The reference plasticiser. Decades of formulation data exist against DOP, which is why it remains the comparison standard.
• Cost position. Among the cheapest plasticisers per unit of plasticising efficiency.

How Dioctyl Phthalate is Manufactured

DOP is made by esterifying phthalic anhydride with 2-ethylhexanol, then purified by stripping and treatment.

• Phthalic anhydride feed. Molten or flake PAN with low colour, since colour carries into the ester.
• 2-Ethylhexanol feed. Excess alcohol drives the esterification to completion.
• Esterification. Reaction over an acid or titanate catalyst at about 200 °C with continuous water removal.
• Excess alcohol stripping. Unreacted 2-EH is distilled off and recycled.
• Neutralisation and washing. Residual acidity is neutralised and the ester washed.
• Treatment and filtration. Activated carbon or clay treatment and filtration deliver the final colour and clarity.

Typical Commercial Specification

Figures below are representative of commercial general purpose DOP. Tell us the application and destination market and we will confirm both specification and regulatory position.

Physical & Chemical Properties

Behaviour in the process

DOP behaves as a classic monomeric plasticiser, and its limitations are the ones the alternatives were developed to address:

• Migrates slowly. Monomeric plasticisers migrate into contacting materials over time, which is why food contact and medical uses are restricted.
• Extracted by oils and fats. Not suitable where the article contacts fatty foods or oils for long periods.
• Low volatility but not zero. Loses a little over decades at elevated temperature, causing gradual stiffening.
• Good electrical properties. When acidity and resistivity are controlled, which is why cable grades are specified separately.

DOP and Alternative Plasticisers

Plasticiser choice is now driven as much by regulation as by performance, and DOP sits at the restricted end of that spectrum.

Stated plainly: DOTP is the straightforward drop-in replacement for DOP in most applications, with very similar performance and no phthalate classification. Where DOP is still used, it is because the market permits it and the cost is lower.

Industries We Supply Dioctyl Phthalate To

DOP serves cable, flooring, hose and general flexible PVC markets.

Where Dioctyl Phthalate is Used

Flexible PVC compounding accounts for essentially all DOP consumption, with cable and flooring the largest segments.

In flexible PVC compounding

DOP is added at 20 to 80 parts per hundred resin depending on the flexibility required, and it works by inserting between PVC chains and reducing the forces that hold them rigid. Loading level, not plasticiser type, sets most of the mechanical properties, which is why substitution between DOP and DOTP is comparatively straightforward.

Regulatory position

DEHP is classified as toxic for reproduction Category 1B, is on the REACH authorisation list, and is restricted in toys, childcare articles, food contact materials and many medical devices in the EU and other jurisdictions. We will flag the position for your destination market at enquiry, because the restriction depends on the article and the market rather than on the plasticiser alone.

Quality Control & Testing

Every lot is released against a batch-specific Certificate of Analysis, with acid value and colour reported because both affect compound quality and electrical performance.

• DOP purity and ester content — by gas chromatography, the primary grade measure.
• Acid value — critical for cable, where residual acidity corrodes conductors.
• Colour — by APHA, predicting the appearance of the finished compound.
• Water content — confirming adequate drying after washing.
• Volatility — predicting permanence in the finished article.
• Specific resistance — for cable grades, confirming electrical performance.

Common Process Problems & Likely Causes

When DOP causes trouble, it is usually acid value, colour or regulatory position. This table is the shortcut our technical desk works through before anyone opens a complaint file.

Packaging, Storage & Shipping

• Standard packing. 200 L drums, 1000 L IBCs, flexitanks, ISO tank containers and bulk parcels.
• Storage. Clean, dry, covered storage at ambient temperature; DOP is combustible rather than flammable.
• Material compatibility. Carbon steel and stainless steel are suitable; stainless preferred where colour matters.
• Contamination control. Keep tanks and lines clean; carry-over shows as colour and acidity in the compound.
• Moisture. Keep dry; water affects compounding and electrical properties.
• Segregation. Keep apart from strong oxidisers and from food materials.
• Shelf life. Typically 24 months in sealed storage; colour and acid value are the practical checks.
• Transport classification. Not classified as dangerous goods for transport.

Hazards & Safe Handling

DOP is not flammable or acutely toxic in normal handling, but it is classified as toxic for reproduction and is subject to extensive regulatory restriction in consumer, food contact and medical applications.

• Reproductive toxicity. Classified Category 1B, may damage fertility and the unborn child. Exposure should be controlled, particularly for workers of reproductive age.
• Endocrine activity. Identified as an endocrine disruptor under EU criteria, which underlies the restrictions on consumer applications.
• Low acute toxicity. Not acutely toxic by the usual routes; the concern is chronic and reproductive rather than immediate.
• Combustible liquid. Flash point about 207 °C; not a flammable-liquid hazard but it will burn in a fire.
• Skin and eye contact. Mild irritant; use gloves and eye protection for routine handling.
• Hot handling. Compounding operations run hot; thermal burns are the realistic process hazard.
• Environment. Persistent and harmful to aquatic life; prevent entry to drains and watercourses.

Regulatory & Compliance Notes

DOP is one of the most heavily restricted plasticisers, with the position varying significantly by market and application. The notes below are orientation rather than legal advice.

• GHS classification. Reproductive toxicity Category 1B; otherwise not classified for acute hazards.
• REACH authorisation. DEHP is on the REACH authorisation list in the EU, meaning specific uses require authorisation.
• Toys and childcare articles. Restricted in toys and childcare articles in the EU, US and many other jurisdictions.
• Food contact. Restricted or prohibited in food contact materials in most developed markets.
• Medical devices. Labelling requirements and substitution pressure apply to DEHP-containing medical devices in the EU.
• RoHS. DEHP is restricted in electrical and electronic equipment under RoHS in the EU.

We Supply Dioctyl Phthalate Worldwide

Chelora Chemicals is a supplier and export partner, not a single-plant trader. We ship Dioctyl Phthalate from India and from partner sources to customers across Asia, Europe, the Middle East, Africa, and North and South America, handling the export documentation, transport paperwork and freight so the material arrives ready to use.

• Incoterms. EXW, FOB, CIF, CFR and DAP quoted to suit your purchasing terms and freight arrangements.
• Ports. Regular shipments through Nhava Sheva (JNPT) and Mundra, with other ports arranged where routing and cargo rules allow.
• Documentation. Commercial invoice, packing list, certificate of origin, COA, SDS and the transport declaration issued as a complete set.
• Flexible volumes. From a pallet of drums up to repeat bulk shipments on a supply contract.
• Supply continuity. Because we are independent of any one producer, a plant turnaround or a shipping disruption at one source does not have to become your stock-out.

Buying Dioctyl Phthalate from Chelora

We are an independent sourcing and supply partner. For DOP that means settling three things at enquiry: the application and its acid value and resistivity requirements, the destination market and whether DEHP is permitted there, and whether a non-phthalate alternative would serve you better.

• Documentation on every lot. Batch-specific COA (purity, acid value, colour, volatility), plus SDS and the full transport paperwork.
• Analysis before commitment. Representative analysis shared ahead of a commercial order so your lab can qualify the material.
• Quantities. From a pallet of drums through to full bulk shipments on contract supply.
• Grade matching. General purpose or cable-grade DOP, or a DOTP or DINP alternative where the destination market restricts phthalates.
• Inspection. Independent third-party inspection available at loading when the contract requires it.
• Related products. Dioctyl Terephthalate, Phthalic Anhydride, Polyvinyl Chloride and other feedstocks alongside Dioctyl Phthalate from one supplier.

How ordering works

• Send the enquiry. Product, grade or purity, quantity, destination port and the Incoterm you buy on. If you have a spec sheet, attach it — it saves a round trip.
• We quote. Price, lead time, packing format and a sample COA, normally within one working day.
• Qualify the supply. For first orders or critical applications, we share the analysis and handling documentation so your technical and safety teams can sign off before you commit.
• Confirm the order. Proforma invoice issued; payment terms agreed against the volume and the relationship.
• Allocation and QC. Material allocated and released against a batch-specific COA, with an independent inspection where the contract calls for it.
• Ship and document. Filled, labelled and loaded with the full export document set, and tracked through to arrival.

Related Products

Buyers of DOP often source related PVC compound inputs alongside it — DOTP, PVC resin and phthalic anhydride are commonly bought on the same programme.