1,3,5-tris[3-(trimethoxysilyl)propyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione

Endpoint summary

Additional information

The substance undergoes rapid hydrolysis under neutral conditions, therefore the aquatic toxicity of the hydrolysis products have been considered.

Reliable short-term toxicity tests results are available for freshwater invertebrates (Daphnia magna) and algae (Pseudokirchneriella subcapitata) for

1,3,5-tris[3-(trimethoxysilyl)propyl]-1,3,5-triazinane-2,4,6-trione (CAS 26115-70-8). Exposure will have been to the hydrolysis products.

The relevant short-term values are:

Daphnia: EC₅₀ (48 h): >100 mg/L at loading rate of parent substance or >80 mg/L when expressed in terms of concentration of the hydrolysis product, tris[3-(trihydroxysilyl)propyl]-1,3,5-triazinane-2,4,6-trione.

Algae: EL₅₀ (72 h): >100 mg/L; NOELR: 100 mg/L and EL₁₀ >100 mg/L at loading rate of parent substance, or >80 mg/L, 80 mg/L and >80 mg/L respectively, when expressed in terms of concentration of the hydrolysis product, tris[3-(trihydroxysilyl)propyl]-1,3,5-triazinane-2,4,6-trione.

There are no reliable short-term toxicity to fish data available for 1,3,5-tris[3-(trimethoxysilyl)propyl]-1,3,5-triazinane-2,4,6-trione (CAS 26115-70-8).

For the silanol hydrolysis product, 1,3,5-tris[3-(trihydroxysilyl)propyl]-1,3,5-triazinane-2,4,6-trione, aquatic effects have been predicted using reliable, freely-available QSAR software (ECOSAR v2.0).

1,3,5-Tris[3-(trihydroxysilyl)propyl]-1,3,5-triazinane-2,4,6-trione is predicted to be highly soluble in water but subject to condensation reactions above approximately 100 mg/l, which will limit the effective or functional solubility in water. The effective limit of solubility is therefore expected to be up to approximately 100 mg/L, if prepared with care.

The predicted E(L)C₅₀ values are interpreted in this context.

The relevant estimated short-term values for the hydrolysis product are:

Fish: LC₅₀ (96 h): > effective limit of solubility (ECOSAR v2.0, aromatic triazines algorithm)

Daphnia: EC₅₀ (48 h): > effective limit of solubility (ECOSAR v2.0, aromatic triazines algorithm)

Algae: EC₅₀ (96 h): > effective limit of solubility (ECOSAR v2.0, aromatic triazines algorithm).

The other hydrolysis product, methanol, is not significantly toxic to aquatic organisms in published studies and is not considered further.

Effects on aquatic microorganisms relevant for WWTP are assessed based on an OECD 209 study. A 3 h NOEC value of 180 mg/L for inhibition of total respiration was determined for the substance. The substance hydrolyses rapidly and the results may be expressed in terms of concentration of the hydrolysis product, 1,3,5-tris[3-(trihydroxysilyl)propyl]-1,3,5-triazinane-2,4,6-trione, by applying a molecular weight correction: (MW of silanol=489.62/ MW of parent=615.86) * 180 mg/L = 0.795*180 mg/L = 143 mg/L.