5H-Cyclopenta[h]quinazoline, 6,6a,7,8,9,9a-hexahydro-7,7,8,9,9-pentamethyl-

Long-term toxicity to aquatic invertebrates

Description of key information

The long-term toxicity and the reproductive toxicity to aquatic invertebrates (Daphnia magna) was examined in a study in accordance with OECD TG 211 and in compliance with GLP criteria. In this study, 10 replicates of one daphnid were exposed to a blank control and dilutions of 1:1573, 1:492, 1:154, 1:48, and 1:15 of a filtrate of 100 mg/L test substance for 21 days under semi-static conditions (weekly renewal). Test substance analysis was performed in fresh medium at the start of the test (day 0), and in fresh and aged media at each renewal period (days 7 and 16). Measured test concentrations ranged from 11-14% of nominal in freshly prepared test media, and 10-11 in aged test media. Time weighted average (TWA) measured concentrations were determined to be n.a. (control), 7.86, 22.4 71.1 235, and 734 µg/L.

Observations on mortality of adults and offspring occurrence were made daily. The number of offspring was counted at each water renewal and determined for each day. Dead offspring was counted if possible at each water renewal. Dead adults and offspring were removed at each water renewal day. The date of first eggs, of first brood and the number of offspring per adult in each treatment replicate was documented. Additionally, any signs of intoxication (e.g. pale adults, aborted eggs) were recorded. The validity criteria of the test were met.

At the control and the test item concentrations of 22.4, and 71.1 µg/L, one adult animal died during the test. In the test concentrations of 7.86 and 235 µg/L all parent animals survived until test end. At the highest test concentration of 734 µg/L, 6 parent animals died during the course of the test. The first offspring were recorded in the control and at the test item concentrations 22.4 and 71.1 µg/L in the daily observations on day 9, and at the lowest test concentration of 7.86 µg/L on day 8. At the concentration of 235 µg/L the first offspring was observed on day 12. At the highest test concentration of 734 µg/L, no offspring was produced. There was no significant toxic effect of the test item on the mean reproduction determined up to and including the test concentration of 7.86 µg/L. At the concentration of 22.4 µg/L, the mean reproduction per introduced and surviving daphnids was statistically significantly reduced by 25.2% live offspring compared to the control. Apart from the reported mortality and the reduced reproduction, in the highest test concentration most daphnids were recorded to be smaller and paler than in the control. Based on these findings, the EC10 of the reproduction per introduced and surviving adult was determined to be 16.3 and 14.6 µg/L, respectively. The 21 -d EC10 of 14.6 µg/L is used in the assessment.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.015 mg/L