Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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.

Diss Factsheets

Administrative data

basic toxicokinetics
Type of information:
not specified
Adequacy of study:
key study
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Assessment of Q1 GLP compliant data

Data source

Reference Type:
other: written assessment

Materials and methods

Principles of method if other than guideline:
No test method followed. Written assessment based on available Q1 GLP compliant data.
GLP compliance:

Test material

Constituent 1
Chemical structure
Reference substance name:
EC Number:
EC Name:
Cas Number:
Molecular formula:
C38 H40 O8 P2
3-{[bis(2,6-dimethylphenoxy)phosphoryl]oxy}phenyl bis(2,6-dimethylphenyl) phosphate
Constituent 2
Reference substance name:
Tetrakis (2,6-dimethylphenyl)-m-phenylene biphosphate
Tetrakis (2,6-dimethylphenyl)-m-phenylene biphosphate

Results and discussion

Any other information on results incl. tables

The substance is an aromatic organo-phosphorus ester of molecular weight that does not preclude absorption. No specific predictions about toxicokinetic behaviour can be made from the chemical structure. The structure suggests potential for cholinesterase inhibition, but this was specifically investigated in a repeated dose oral toxicity study with no effect identified. The substance is a non-volatile powder of non-respirable particle size, so inhalation exposure is not anticipated. Non-enzymatic hydrolysis is unlikely so exposure to degradants is not applicable.



Acute oral and dermal toxicity studies showed no treatment related effects and therefore provide no evidence of absorption by either route. In a repeated dose oral toxicity study also there is no significant evidence of adsorption. The substance has very high log Pow value, which would suggest ready diffusion across membranes and hence absorption. In view of the extremely low water solubility, however, this may not be a true representation of lipophilicity. Exposure in a screening reproductive toxicity test indicates no effects to parent or F1 animals and no adverse effects were indicated by mutagenicity testing.



There is no experimental evidence to indicate distribution except, perhaps, to the liver in the repeated dose oral toxicity study. The extremely high Pow values obtained by testing and QSAR may be suggestive of potential for accumulation, but bioaccumulation potential tends to decrease as Pow becomes increasingly high, becoming more an effect of low water solubility rather than accumulation. This observation is further borne out by the data available from fish bioaccumulation and QSAR estimations of BCF. 



The studies conducted provide no information about potential metabolism, but from the chemical structure, biotransformation of any absorbed substance would be expected. Ester hydrolysis by hydrolase enzymes could occur together with oxidative metabolism by the microsomal mixed function oxidase system and subsequent conjugation reactions.



There is no experimental evidence to indicate a route of excretion but the parent substance is not sufficiently water-soluble for elimination in its unchanged form in urine or bile, but may be eliminated in faecal matter. Biotransformation of any absorbed substance is, however, anticipated and the resulting metabolites could be eliminated either in urine, bile or faeces. As the parent substance non-volatile and could not be eliminated via the lungs in expired air.

Applicant's summary and conclusion