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 aquatic invertebrates

Description of key information

SIKA Hardener LI was assessed in a short-term toxicity to aquatic invertebrates study according to EU-method C.2 and OECD guideline 202. Young Daphnia (Daphnia magna) were exposed in a semi-static test to water accomodated fractions (WAF) at nominal concentrations of 100 mg/L. The 48 h EC50 was determined at greater than 100 mg/L and the 48 h NOEC at 100 mg/L. 

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 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, its two primary hydrolysis products and from an analogous substance were assessed:

In the study with the parent compound SIKA Hardener LI, young Daphnia were exposed in a semi-static test to the test item for 48 hours. A supersaturated test item solution was prepared by dispersing the test item amount (nominal load of 100 mg/L) into the test medium two days before the start of the renewal periods (on day -2 and -1). 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 nominal concentration tested was 100.0 mg/L. In this 48-hour semi-static acute toxicity test with Daphnia magna the 48 h EC50 value was > 100 mg/L, and the 48 h NOEC was determined to be 100 mg/L. The results were based on the nominal concentrations. Due to the fast hydrolysis and the very low water solubility of the test item this approach was done. Analytical measurements were not possible due to fast hydrolysis. For details please refer to the IUCLID5 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) towards freshwater shrimp, using the species Daphnia magna. Six 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. The resulting solution was filtrated through 0.45μm filters. The daphnia were immobilized on the surface already after 24 hours caused by an oily phase of the test item. The second experiment was performed likewise but with stirring instead of shaking. The resulting solution was left to stand for about 30 minutes. The lower phase was used for the test which was performed as a semi-static test. After 24 hours, the daphnia were immobilized on the surface. The oily film was visible again. All following experiments were performed under semi-static conditions with medium renewal after 24 hours. For the third and fourth experiment, a stock solution in acetone was prepared. The treatments 0.1 and 1 mg/L were prepared by spiking the corresponding amount of dilution water with this stock solution. The treatment 1 mg/L was used as lying well above maximal water solubility of 0.227 mg/L. No daphnia were immobilized after 48 hours. In the control, the same concentration of acetone didn’t show any effect. Based on these experiments, the fifth experiment was performed as a limit-test using the treatment 1 mg/L with a acetone-spiked test solution. After 48 hours 30 % of the daphnia were immobilized on the surface. Therefore the last experiment was performed using five concentrations between 0.1 and 1 mg/L. Twenty daphnia were exposed to the test item for 48 hours in a semi-static test system. After 24 and 48 hours, the immobilized daphnia were counted. As no daphnia were dead after 24 hours, but immobilized on the surface, some of them were able to remobilize during the test. This was potentially due to the test item’s physicochemical properties causing film-formation at the top of the water phase (as noted at higher concentrations). None of the animals were immobilized in the control. The 48 h EC50 was determined about 1 mg/L (exact value after liner extrapolation: 1.02 mg/L) and the 48 h NOEC was 0.18 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 acute toxicity of the second hydrolysis product 3 -aminomethyl-3,5,5 -trimethylcyclohexylamine to Daphnia magna was studied under static conditions over a period of 48 hours according to OECD TGD 201 and EU-method C.2. Six concentrations ranging from 2.1 to 66.4 mg/L were tested. Immobilisation was observed. The following endpoint was derived: EC50 (48 h): 23 mg/L; Conf. limit: 17-31 mg/L (see ECHA dissemination homepage).

In addition data from the analogues substance SIKA Hardener LG (3-(2-(2-Hydroxyethoxy)ethylimino)-2,2-dimethylpropyldodecanoate, CAS 931419-77-1) is reported. SIKA Hardener LI and SIKA Hardener LG both have the same aldehyde component (2,2 -Dimethyl-3 -lauroyloxy-propanal), but different amine components. Data from the OECD toolbox support the use of data from SIKA Hardener LG also as read across fro SIKA Hardener LI (see attachment in section 13). In this study, young Daphnia were exposed in a semi-static test to the test item for 48 hours, added to test water at concentrations of 6.25; 12.5; 25.0; 50.0 and 100.0 mg/L. The 48h-NOEC (EC0) was determined to be 50.0 mg/L, the 48h-EC50 was calculated to be 125.5 mg/mL and the 48h-EC100 was determined to be >100.0 mg/mL.

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 100 mg/L was derived. The data presented for the supporting substance SIKA Hardener LG with a LC50 of 125 mg/L well supports the results obtained for SIKA Hardener LI. Results from the two hydrolysis products further support the results and lead to 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 daphnia. 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 1.02 mg/L does not lead to a classification. The data with -aminomethyl-3,5,5 -trimethylcyclohexylamine with an LC50 of 23 mg/L fully confirm the overall classification and labelling of the substance with R52/53. 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.