Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Hydrolysis

To assess the hydrolysis behaviour of SIKA Hardener LH a read across approach was applied using data from the structural analogue substance SIKA Hardener LI, with both substances sharing comparable hydrolytic properties.

SIKA Hardener LI was assessed in an abiotic degradation study according to EU-method C.7 and OECD guideline no. 111. Hydrolysis of SIKA Hardener LI was most rapid in acidic environment (pH 4) and high temperature compared to basic environment (pH 9) and low temperature. At pH 7 and 12 °C (285.2 K) the degradation half-life was 0.19 days and rate constant 3.56 days (85.44 h).

Biodegradation

In a biodegradation study (MITI, 2011), the test substance Sika Hardener LH was completely hydrolyzed to 2,2-dimethyl-3-oxopropyl dodecanoate and hexamethylenediamine. These converted products were biodegraded. The percentage (average) of biodegradation by BOD was 91% after 28 days. Further, the test substance is considered to be readily biodegradable.

Adsorption/Desorption

Due to the immediate hydrolysis of the test item upon contact with water, experimental determination of the adsorption coefficient was technically not feasible. Instead, experimental determination of the adsorption coefficient was replaced by a theoretical based evaluation. The log Koc value of the test item was calculated to be = 9.535 using the MCI method (KOCWIN v2.00).Based on this result, adsorption of the test item to solid soil phase is expected.

Bioaccumulation

The study does not need to be conducted as from experience in handling and use it is very unlikely that direct and indirect exposure of the aquatic compartment occurs, as the substance rapidly hydrolysis in contact with water. In addition based on the very high predicted log Pow of over 10 (14.22 as estimated by EPIWIN) the substance has a very low potential to pass biological membranes and thus will not be easily bioavailable.