N-[3-(methoxydimethylsilyl)propyl]ethylenediamine

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Persistence Assessment

N-[3-(methoxydimethylsilyl)propyl]ethylenediamine (CAS 3069-33-8) is expected to hydrolyse rapidly in contact with water to N-[3(hydroxydimethylsilyl)propyl]ethylenediamine and methanol (half-life of 0.7 h at 20-25°C and pH 7). Therefore, the substance is not persistent.

There are reliable ready biodegradation data available for N-[3-(methoxydimethylsilyl)propyl]ethylenediamine (CAS 3069-33-8). The substance is expected to hydrolyse within the timescale of a ready biodegradation test.

The percentage biodegradation of N-[3-(methoxydimethylsilyl)propyl]ethylenediamine (CAS 3069-33-8) was reported to be 11.1% after 28 days. The test substance is therefore not considered to be readily biodegradable and indicates that no significant biodegradation is expected for the silanol hydrolysis product. Therefore, this hydrolysis product meets the criteria for persistence (P). The other hydrolysis product methanol is readily biodegradable and therefore not persistent.

Therefore, the substance itself is not persistent, but the silanol hydrolysis product may meet the criteria for persistence (P).

Bioaccumulation Assessment

N-[3-(methoxydimethylsilyl)propyl]ethylenediamine (CAS 3069-33-8) is expected to hydrolyse rapidly in contact with water to N-[3(hydroxydimethylsilyl)propyl]ethylenediamine and methanol (half-life of 0.7 h at 20-25°C and pH 7). Therefore, the parent substance will not bioaccumulate, it is not B and not vB.

Furthermore, a log Kow value of 0.8 was predicted for the parent substance and a log Kow value of 0.1 was predicted for the hydrolysis product N-[3(hydroxydimethylsilyl)propyl]ethylenediamine using an appropriate calculation method.

Therefore, N-[3-(methoxydimethylsilyl)propyl]ethylenediamine (CAS 3069-33-8) and its hydrolysis products do not meet the criteria for bioaccumulation; they are not B and not vB.

Toxicity Assessment

N-[3-(methoxydimethylsilyl)propyl]ethylenediamine (CAS 3069-33-8) is expected to hydrolyse rapidly in contact with water to N-[3(hydroxydimethylsilyl)propyl]ethylenediamine and methanol (half-life of 0.7 h at 20-25°C and pH 7).

There are no long-term data available to assess N-[3-(methoxydimethylsilyl)propyl]ethylenediamine (CAS 3069-33-8) according to the definitive criteria for T for the environment.

A 48-hour EC50 value of >100 mg/L has been determined for the effects of the test substance on mobility of Daphnia magna.

The algae study is covered by read-across to the analogoue substance N-(3-(trimethoxysilyl)propyl)ethylenediamine (CAS 1760-24-3) (EC50 (72h) of 8.8 mg/L). Both, the registered substance and the read across substance N-(3-(trimethoxysilyl)propyl)ethylenediamine (CAS 1760-24-3) hydrolyse rapidly and have similar hydrolysis products. The substance is not considered as T for the environment as the available data do not meet the screening criteria for T for the environment (E/LC50 <0.1 mg/L).

The substance is not classified for specific target organ toxicity, carcinogenicity, mutagenicity or reproductive and developmental toxicity in mammals. The criteria for “T” based on mammalian effects are therefore not met.

Summary and overall Conclusions on PBT or vPvB Properties

The substance is expected to hydrolyse very rapidly in the presence of water and therefore the substance does not meet the criteria for PBT or vPvB. The hydrolysis product may persist in the environment but does not meet the criteria for B and T and therefore the hydrolysis product should not be concluded as PBT or vPvB.