Candidate List Duty Triggers in Component Level Imports
Candidate List duties trigger when any discrete component article exceeds 0.1 percent SVHC by weight, regardless of aggregate assembly mass.
Diisooctyl Phthalate
Meaning
Ester additives impart flexibility and cold-temperature impact resistance to rigid polyvinyl chloride resin matrices. The high-molecular-weight plasticiser diisooctyl phthalate modifies intermolecular forces within vinyl polymer chains to produce flexible sheet products and synthetic elastomeric gaskets. Its functional scope stops in rigid structural application where plasticisation reduces tensile strength and heat deflection temperature below design limits, rendering the resin unsuitable for load-bearing components.
Plasticiser Performance
Branched isomeric ester structures lower the glass transition temperature of vinyl compounds during extrusion processing. Incorporating diisooctyl phthalate provides melt viscosity reduction, allowing lower processing temperatures and preventing thermal degradation of heat-sensitive polyvinyl chloride resins. Tooling design must accommodate increased material shrinkage when processing highly plasticized vinyl grades.
Regulatory Classification
Substance hazard assessments restrict specific ortho-phthalate ester plasticisers in consumer products and medical tubing applications. Regulatory restrictions surrounding diisooctyl phthalate force compounders toward alternative plasticisers such as trimellitates or polymeric esters. Manufacturers must certify plasticiser identity on safety data sheets to maintain product compliance across international jurisdictions.
Extraction Resistance
Volatilization and chemical extraction migrate plasticiser molecules out of flexible vinyl parts during long-term exposure to heat or organic solvents. Formulations using diisooctyl phthalate exhibit moderate migration resistance compared to lower-molecular-weight phthalates. Part failure occurs when plasticiser loss causes embrittlement or dimensional shrinkage in field service.