Reaction products of 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl)-5-hydroxyphenol with ((C10-16, rich in C12-13 alkyloxy)methyl)oxyrane

Endpoint summary

Description of key information

Short description of key information on bioaccumulation potential result: 
The substance is expected to be stable under the conditions of stomach and duodenum and to pass the intestines unchanged and to be excreted directly via faeces. A slight, reversible increase in liver weight at the highest dose level of the 28d study indicates that either the substance or a by-product is bioavailable. This is also an indirect evidence that metabolism and excretion takes place. Thus, bioaccumulation of the test item is considered unlikely. Most of the assumptions on metabolism and the kinetics of resorption and elimination of the substance can only be derived from considerations using Structure Activity- Relationship.

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Additional information

Functional groups relevant for hydrolysis

The substance contains ether and ester bonds. Both are generally stable with regard to pH-dependent hydrolysis at pH values present in the gastrointestinal tract. Ester bonds may undergo enzymatic cleavage, provided that the substance is taken up into cells.

Functional groups relevant for elimination

The route of excretion is assumed to be via the biles using the glucuronic acid-conjugate pathway. Glucuronic acid conjugates are most likely formed either with the phenolic -OH groups, or with secondary carboxylic acids formed in the course of the metabolism along the aliphatic side chain. It is considered rather unlikely, that water-soluble metabolites would be formed by oxidation along the sidechain and sulfation on the phenolic -OH. Glucuronidated metabolites are generally known to be rapidly excreted.

Indication of uptake

In the intestines, due to its very low solubility in water and the large molecular weight only a small amount of the article is expected to be absorbed. Almost the entire ingested test item is expected to pass the intestines unchanged and to be excreted directly via faeces. With respect to the very small part of the substance resorbed, most is expected to become directly glucuronidated in the liver and excreted via the bile. This is likely as the substance has free phenolic hydroxy groups.

In the subacute toxicity study, a slight, transient liver enlargement and an increase of blood platelets in the treated rats at the highest dose level has been observed. This indicates that the substance is bioavailable.

Evaluation of the bioaccumulation potential

A bioaccumulation of the test substance is considered unlikely, due to the fact that at high doses, slight reversible liver induction in the 28d study was shown, which is indirect evidence that metabolism and excretion takes place.