Dioctyl Phthalate (DOP)

About This Product

Dioctyl phthalate, more precisely di(2-ethylhexyl) phthalate or DEHP, has CAS number 117-81-7 and is a clear, oily, high-boiling liquid of low volatility. For most of the twentieth century it was the reference general-purpose plasticiser against which all others were compared. Its technical performance explains that position. Plasticisers work by inserting themselves between polymer chains, screening the attractive forces that hold rigid PVC together so the chains can slide past one another, which converts a hard resin into a flexible one. DOP does this efficiently, at low cost, with good compatibility across a wide loading range and adequate permanence. What removed it from general use was toxicology rather than performance: it is classified in the EU as toxic for reproduction category 1B and as an endocrine disruptor, it is listed in REACH Annex XIV so its use requires authorisation, and it is restricted in toys, childcare articles, food contact and medical devices. Supply is therefore conditional on the end use being permitted in the destination market. DOTP and DINP are the usual replacements. Where permitted it is used in industrial PVC compounds, cables, flooring, coated fabrics and as a reference plasticiser in testing. Bio Green Chem supplies DOP to specification on assay, acidity, water, colour, volatiles and specific gravity, subject to authorisation and end-use verification.