Dioctyl phthalate

Dioctyl phthalate (CAS 117-81-7), abbreviated DEHP, is a high-molecular-weight phthalate ester used primarily as a plasticizer to increase flexibility and processability in PVC and other polymer systems.

Where is Dioctyl phthalate used?

• PVC compounding: plasticizer in flexible films, cables, hoses and flooring for sustained flexibility under mechanical stress
• Printing and packaging: plasticizer in inks and coatings to prevent cracking and improve adhesion on flexible substrates
• Adhesives and sealants: aids dispersion and controls viscosity during processing
• Industrial formulations: solvent and carrier
• In legacy nail products it served as a film-forming aid and solvent.
• Dielectric fluids for electrical capacitors.
• Production of synthetic rubber as a softener to facilitate rebound and make it harder to deform under pressure.
• Manufacture of medical and sanitary products such as blood bags and dialysis equipment.
• Common ingredient in nitrocellulose lacquers, a type of fast-drying, durable and resistant paint.

Good to know: Regulatory restrictions have significantly reduced its use in the cosmetic sector; DEHP is subject to restriction under REACH and other frameworks in certain end-use categories. Buyers should confirm regional regulatory compliance requirements before sourcing.

Formulation notes

• Plastics can contain 1 to 40% dioctyl phthalate.
• Not chemically bound to plastic material but only present in dissolved state, so it can be easily extracted on contact with liquids or fats.
• Reacts with strong oxidants, acids, alkalis and nitrates.
• In the past dioctyl phthalate was the most used phthalate, but due to sterility risk industry partially replaced it with DiNP and DiDP.

Typical specification

• Clear, colorless, viscous liquid with a slight characteristic odor.
• Industrial grade and food and/or medical grade are available on the market.
• Good heat and ultraviolet light stability.

Regulatory status

• Subject to restriction no. 51 of Annex XVII of REACH together with DBP and BBP.
• Carries the hazard statement H360Fd: may damage fertility and may damage the unborn child.
• Among the 8 phthalates included in substances subject to authorization under Annex XIV of REACH.

Storage, packaging and handling

• Should be stored separated from strong oxidants, acids, alkalis and nitrates, in a cool, dry, well-closed place.

Frequently asked questions about Dioctyl phthalate

What purity can be expected for dioctyl phthalate?

Dioctyl phthalate achieves a purity of ≥99.5% through advanced distillation and purification processes.

How does dioctyl phthalate perform in insulation applications?

It provides constant volume resistivity performance for critical insulation applications in power transmission and telecommunications.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.