2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl)-5-(3-((2-ethylhexyl)oxy)-2-hydroxypropoxy)phenol

Endpoint summary

Description of key information

Based on the physico-chemical characteristics of the test substance (high molecular weight > 500 g/mol, poor water solubility < 1 mg/L, log Pow > 4, large particle sizes of 446 µm, low vapor pressure < 25 kPa)

dermal, oral and respiratory absorption is considered to be low. Due to this assumption, distribution of the substance is not assessed and its bioaccumulation is considered to be negligible. In the unlikely case of uptake the substance is assumed to undergo conjugation with glucuronic acid and to be excreted after phase II metabolism via the bile based on the high lipophilicity and the large molecular weight of the substance.

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Additional information

Absorption

 

Generally, oral absorption is favored for molecular weights below 500 g/mol and log Pow values between -1 and 4. As the substance is characterized by a high lipophilicity (log P_ow > 4), high molecular weight (> 500 g/mol) and poor water solubility (< 0.1 mg/Lat 20 °C, pH ≈ 6), an absorption after oral uptake may be limited by the inability of the substance to dissolve in the fluids of the gastrointestinal tract and hence make contact with the mucosal surface unlikely. However, the absorption will be enhanced if the substance undergoes micellular solubilization by bile salts.

 

As the substance comprises of particles by far exceeding the boarder of the aerodynamic diameter for inhalable particles of 100 µm in human (85 % > 100 µm; 92 % > 40 µm), respiratory absorption via inhalation cannot be assumed. Moreover, the substance has a very low volatility. In the unlikely case of inhalation, absorption is regarded as low, but may be enhanced by micellular solubilization.

 

Skin penetration can be assumed to be negligible because the molecule may be too large for dermal uptake. As the molecular mass is above 500 g/mol and the value for the log P_ow is outside the range between

-1 and 4, a value of 10 % skin absorption can be assumed (i). Also, in an animal study no signs of toxicity after dermal application of the substance occurred.

 

Metabolism

 

Almost the entire ingested test item is expected to pass the intestines unchanged and to be excreted directly via feces. In the unlikely case of uptake, the substance is assumed to undergo conjugation with glucuronic acid. Glucoronic acid conjugates are most likely formed with the present phenolic - OH groups. It is considered rather unlikely, that water-soluble metabolites would be formed by oxidation along the side chain and sulfation on the phenolic -OH groups. The substance contains ether bonds which are generally stable with regard to pH-dependent hydrolysis at pH values present in the gastrointestinal tract.

 

Excretion

 

As mentioned above, the substance is expected to be excreted unchanged via the feces. In the unlikely case of absorption, excretion is expected to take place after phase II metabolism via the bile based on the high lipophilicity and the large molecular weight of the substance.

 

Overall, no bioaccumulation of the test substance is expected, and no distribution is assessed as substance uptake is considered to be low.

(i) European Chemicals Agency, ECHA guidance on information requirements and chemical safety assessment. Chapter R.7c: Endpoint specific guidance. DOI:10.2823/43472.Version 3.0. June 2017