Trixylyl phosphate

Trixylyl phosphate (TXP) is an aromatic phosphate ester. It was historically used as a flame retardant for acetate plastics (cellulose nitrate and cellulose acetate) and PVC. It also saw significant use as a fire-resistant hydraulic fluid.

Trixylyl phosphate is now banned or restricted in several jurisdictions, due to its poor safety profile. Short term exposure can cause organophosphate-induced delayed neuropathy, but it is also regarded as a reproductive toxin. In the EU is classified as a substance of very high concern, requiring authorisation to be used.

Synthesis
Trixylyl phosphate is prepared industrially by the reaction of phosphoryl chloride with mixed xylenols. In practise this produces a range of products.