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

Toxicity to soil macroorganisms except arthropods

Description of key information

The long-term effect of the substance on earthworms was examined in a study according to OECD TG 222 and in compliance with GLP. In this study, groups of adult earthworms (4 replicates of 10 animals) were exposed to nominal test concentrations of 0 (control), 1.0, 3.0, 9.0, 27, 90, 270, and 520 mg/kg artificial soil dw for 28 days. As there was no indication of significant loss of test substance during the test, nominal test concentrations were not analytically verified. After the 28 -day exposure period, the adult earthworms were counted, removed, and weighed. The remaining soil (without the adult earthworms) was returned to the respective test containers and left standing for an additional 28 days. Adult worms were scored for mortality, behavioural and morphological abnormalities feeding activity, body weights. The number of juveniles after 56 days were counted to determine reproduction. All validity criteria were met.

A significant effect on adult mortality was observed only at the highest tested concentration of 520 mg/kg soil dw. Body weights and feeding activity were significantly reduced at test concentrations of 270 and 520 mg/kg soil dw. With respect to behaviour, at test concentrations of 270 and 520 mg/kg soil dw the earthworms did not burrow into the soil within 15 minutes after introducing. On day 28 no further behavioural abnormalities were observed. Finally, based on the number of juveniles after 56 days exposure, reproduction was significantly affected at test concentrations of 27 mg/kg soil dw and higher. Based on these findings, the critical effect value was a 56 -d EC10 value for reproduction of 47.7 mg/kg soil dw (95% C.L.: 27.1 - 83.9 mg/kg), based on nominal concentration.

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for soil macroorganisms:

47.7 mg/kg soil dw