Dodecanoic acid, 3-[[3-[[[2,2-dimethyl-3-[(1-oxododecyl)oxy]propylidene]amino]methyl]-3,5,5-trimethylcyclohexyl]imino]-2,2-dimethylpropyl ester

Short-term toxicity to fish

Description of key information

SIKA Hardener LI was assessed in a short-term toxicity to fish study, according to EU method C.1 and OECD guideline 203. Young Rainbow trout (Oncorhynchus mykiss) were exposed in a semi-static test to the test item for 96 hours to water accomodated fractions (WAF) with nominal concentrations of 6.25; 12.5; 25.0; 50.0 and 100.0 mg/L. The 96 h LC50 was determined to be 87.2 mg/L and the 96 h NOEC was determined to be 25.0 mg/L. 

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

87.2 mg/L

Additional information

Due to the high reactivity of the substance in water, a weight of evidence approach using data form the parent molecule and its two primary hydrolysis products were assessed:

In the study with the parent compound SIKA Hardener LI, young fish were exposed in a semi-static test to the test item for 96 hours, added to test water at a range of concentrations. A supersaturated test item solution (Stock solution = S.S.) was prepared by dispersing the low water soluble test item amount (nominal load of 100 mg/L) into the Test Medium two days before the start of the renewal periods. This solution was shaken for 24 hours at app. 30 ºC, then was left settling for 24 hours at app. 20 ºC and thereafter filtrated through a 0.45 μm filter. The following nominal concentrations were used in the main study: 6.25; 12.5; 25.0; 50.0 and 100.0 mg/L. In this 96-hour semi-static acute toxicity test with Rainbow trout (Oncorhynchus mykiss) the 96 h LC50 value was 87.2 mg/L, and the 96 h NOEC was determined to be 25.0 mg/L. The results are based on the nominal concentrations (for details see study record).

The second study was performed in order to evaluate the toxic potential of the hydrolysis product 2,2 -Dimethyl-3 -lauroyloxy-propanal (aldehyde component) the toxic potential of test item towards freshwater fish, using the species Danio rerio. Three experiments were performed. As the test item is poorly water soluble, the “water-accommodated fraction” was tested in the first experiment. This was done by weighing the nominal load 100 mg/L, adding the corresponding amount of dilution water and shaking vigorously for 24 hours. As it was not possible to filtrate or centrifuge the resulting emulsion, the test was performed with the unfiltered emulsion. Seven fish were exposed to the test item for 96 hours in a static test. After 48 hours, 100 % mortality was observed in the treatment, probably caused by the undissolved test item. In the control, none of the fish showed signs of morbidity at the end of the test. The pH and the oxygen values were normal. Experiments two and three were performed under semi-static conditions with medium renewal after 24 hours. For the second experiment a stock solution in acetone was prepared. The treatments 0.1 mg/L and 1 mg/L were prepared by spiking the corresponding amount of dilution water with this stock solution. The treatment concentration of 1 mg/L was above maximal water solubility of 0.227 mg/L. Three fish were exposed to the test item for 96 hours. No mortality was observed in both treatment groups and the control. Based on these experiments, the third experiment was performed as a limit-test under semistatic conditions, using a treatment concentration of 1 mg/L with an acetone-spiked test solution. Seven fish were exposed to the test item for 96 hours in a static test. None of the fish died or showed signs of toxicity during the test. The pH and the oxygen values were normal. The 96 h LC50 was determined at greater than 1 mg/L and the 96 h NOEC was 1 mg/L. These data were already submitted in a NONS dossier under Directive 92/32/EEC (notification number 05 -04 -1922 -00 from 2005 -10 -25) and considered valid and uncritical from the German Competent Authority (BAUA).

The toxicity of the second hydrolysis product 3 -aminomethyl-3,5,5 -trimethylcyclohexylamine to Algae was evaluated according to EU Method C.1. In this 96-h acute toxicity study, Leucisus idus were exposed to Isophoronediamine at nominal concentrations of 0 (control), 70, 100, 140, 200 and 280 mg/l under semi-static conditions. The 96-h LC50 was determined as 110 mg/L. (see ECHA dissemination homepage).

Conclusion:

Due to the physical-chemical properties of SIKA Hardener LI (fast hydrolysis, low water solubility) it is not possible to perform standard ecotoxicology tests. It was decided to do the test by preparing a WAF and base the EC50 and NOEC calculations on nominal concentrations (justification see study record). A value of 87.2 mg/L was derived. Results from the two hydrolysis products support the findings and lead to the same environmental classification and labelling (R52/53 or chronic cat.3, see also biodegradation other ecotoxicological results). For 2,2 -Dimethyl-3 -lauroyloxy-propanal (aldehyde component) different tests were done to assess the ecotoxicology towards fish. In the end it was also not possible to use measured data for EC50 calculations (details see above). As the substance is readily biodegradable, the LC50 of > 1 mg/L leads to no classification. The data with -aminomethyl-3,5,5 -trimethylcyclohexylamine with an LC50 of 110 mg/L show a slightly higher LC50 as compared with the parent compound SIKA Hardener LI, but are in general in the same concentration range. These data confirm that the classification and labelling and the hazard assessment of the ecotoxicology of SIKA Hardener LI can be based on the main study with the product itself.