Registration Dossier

Diss Factsheets

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Two studies are available for the acute toxicity to fish endpoint with both using read-across substances (two different substances). In a 96-h acute toxicity study, Leuciscus idus were exposed to oleic acid-based IQAC, DMS quaternised at nominal concentrations of 0 (control), 0.32; 1.0; 1.8; 3.2; 5.6 mg/l under semi-static conditions. The 96-h LC50 was 1.8 mg a.i./l (2.4 mg/l, nominal). This study has been selected as the key study as this provides the most conservative assessment for fish toxicity from both of the read-across substance studies.

For invertebrates, the key study is a reliable (Klimisch 1) guideline study measuring the immobilisation of Daphnia magna to the test substance 9-Octadecenoic acid (Z)-, reaction products with diethylenetriamine, di-Me sulfate-quaternized. Under the conditions of the test, the 48 hour EL50 (immobility) was determined to be 0.89 mg/l based on nominal loading rates. The NOELR was determined to be 0.63 mg/l.

There are also two long-term invertebrate studies which were both carried out on read across substances and the data is presented as a Weight of Evidence. For the read across substance 931 -745 -8, the effects on reproduction were studied over a 21 day period.The effects on reproduction were evaluated based on the reproduction per introduced animal, since the most ecologically relevant response variable is the total number of living offspring produced per parent animal which does not die accidentally or inadvertently during the test.The overall effect threshold for effects of the test item under the test conditions was >145 µg/L NOEC and LC50 for reproductive output. The endpoint of adult mortality was also measured over the course of the experiment, with a NOEC of 46 µg/L calculated for parent mortality after 21 days, shown to be statistically significant compared to controls when tested with the step-down Cochran-Armitage test procedure (α = 0.05). For the read across substance 937 -237 -2, the authors present a NOEC of >100 μg/l for Daphnia magna based on a three generation assessment. Some effects were observed in the F2 generation (growth rate decreased and the size and colour of the control animals were not reached. The reproduction rate was significantly lower than in the parental generation and the F1 generation. The mortality of the parental animals increased. The authors consider the effects observed to be due to the test substance.

For algae and cyanobacteria, four studies were available on the test substance and two differerent read-across substances. The key study uses the test substance, which provided the most conservative assessment of the toxicity for algae and cyanobacteria. The EL50 (growth rate) was determined to be 0.29 mg/l based on nominal loading rate WAF concentrations. The NOEC was calculated to be 0.10 mg/l. The supporting studies (on read-across substances) presented a range of EC50's from >0.4 to 4.8 mg/l and NOEC's from 0.178 to 0.32 mg/l.

For microorganisms, a reliable study (Klimisch 2) was carried out on the read-across substance, imidazolium compounds, 2-C17-unsatd.-alkyl-1-(2-C18-unsatd. amidoethyl)-4,5-dihydro-N-methyl, Me sul...; oleic-acid based IQAC, DMS quaternised (2 constituents). The toxicity to microorganisms from an activated sludge unit was assessed. The 3-hour EC50 was 564 mg/l with a 95% confidence limit of 364 -887 mg/l and the NOEC 308.6 mg/l.

Additional information

The EC50's and NOEC's for the acute studies are expressed based on nominal concentrations, irrelevant of whether an attempt has been made analytically to measure the exposure concentrations. This is due to the nature of the test substance (various constituents), which have largely been prepared as water accommodated fractions (WAF) making it difficult to determine which of the constituents (one or several) are dissolved in the solution and whether potential toxicity is attributed to one or a mix of the components. Therefore, the results are expressed based on nominal loading rates for the test substance in all of the studies.