Registration Dossier
Registration Dossier
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.
The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 202-908-4 | CAS number: 101-02-0
Endpoint summary
Administrative data
Link to relevant study record(s)
Description of key information
The absorption efficiencies used in the assessment are:
Dermal - 50%
Oral - 100%
Inhalation - 100%
Key value for chemical safety assessment
- Bioaccumulation potential:
- low bioaccumulation potential
- Absorption rate - oral (%):
- 100
- Absorption rate - dermal (%):
- 50
Additional information
The metabolism of TPP has been described as involving step-wise hydrolysis of the parent phosphite with release of phenol, or oxidation of the parent compound to triphenyl phosphate with subsequent step-wise hydrolysis to release phenol (Abou-Dania, 1992). This is supported by the hydrolysis data in the dossier, which shows rapid hydrolysis from TPP to phenol with little accumulation of intermediate products. Complete metabolism would result in the release of three molecules of phenol, and phosphoric acid. The hydrolysis rate of TPP is pH-dependent. Oxidation of TPP to the more stable phosphate form is the basis for its successful commercial use as an antioxidant. The relative bioavailability of the phosphite vs phosphate forms and their comparative hydrolysis kinetics have not been fully described.
While there are no specific toxicokinetic studies of TPP, toxicology testing appears to indicate that it is readily absorbed via the oral route. Due to its rapid hydrolysis in water, with a half-life of 0.5 hours at neutral pH (see hydrolysis section), it may be appropriate to consider the toxicokinetics of phenol for oral and inhalation routes since there would be a high likelihood of hydrolysis via these routes. The Phenol RAR (ECB 2006) concludes 100% absorption via the oral and inhalation routes and rapid elimination with low potential for bioaccumulation. These conclusions are also being applied to TPP.
The basis for the dermal absorption recommendation is discussed in Section 7.1.2.
Reference: Abou-Donia MB. (1992) Triphenyl Phosphite: A Type II Organophosphorus Compound-Induced Delayed Neurotoxic Agent. In J. Chambers and P. Levi (Eds), Organophosphates: Chemistry, Fate and Effects (pp 327 – 351). San Diego, CA: Academic Press.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
