Trioctyl Trimellitate (CAS 3319-31-1) is a trimellitate ester plasticizer, an ester of trimellitic anhydride and 2-ethylhexanol that appears as a clear, almost colorless viscous liquid, and it is used mainly in PVC wire and cable insulation, automotive interiors, medical tubing and rubber compounds. This Technical Grade ester offers exceptionally low volatility, a flash point above 240°C, and a boiling point near 414°C. It is a premium high-temperature plasticizer for PVC, prized for extremely low migration and extraction . These properties make it the preferred choice for medical devices, blood bags, and tubing where plasticizer leaching must be minimized. TOTM is equally valued in wire and cable insulation rated for 105°C service, automotive interiors, and sealing gaskets.
Typical Properties
| Molecular formula | C33H54O6 |
|---|---|
| Molecular weight | 546.78 g/mol |
| Appearance | viscous yellow liquid |
| Form | Oil |
| Color | Colourless |
| Odor | mild odor |
| Boiling point | 414 °C |
| Density | 0.923009 g/cm³ @ Temp: 110 °C; Press: 750 Torr |
| Water solubility | 1.8ng/L at 25°C |
| Flash point | 505 °F |
| HS code | 29173990 |
| Grades available | Technical Grade |
Typical literature values for identification; lot-specific results are stated on the certificate of analysis (COA) and the safety data sheet (SDS) that accompany every delivery.
Trioctyl Trimellitate
Applications
Primarily used as a plasticizer for PVC in wire/cable insulation, automotive interiors, medical tubing, and flooring for heat resistance and low volatility; in adhesives, coatings, and inks for flexibility; in lubricants as additive; in rubber for processing aid; in research for polymer studies; in food-contact materials as approved by FDA.
Safety & Risks
Low acute toxicity with LD50 oral >5000 mg/kg (rat); mild irritant to eyes/skin/respiratory (H315, H319, H335); not classified as hazardous by GHS but combustible—avoid ignition sources (H227). Incompatible with strong oxidizers; decomposes to COx on heating. Use PPE, ventilate; no carcinogenic effects but monitor chronic exposure.
Packaging
Typically packaged in 200kg or 1000kg iron drums/IBC totes with epoxy lining for corrosion resistance; store in cool, dry, ventilated areas away from heat/oxidizers per SDS guidelines.